2024-03-29T04:38:32Zhttp://repository.helmholtz-hzi.de/oai/requestoai:repository.helmholtz-hzi.de:10033/86862019-08-30T11:25:06Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Bode, Helge Björn
author
Müller, Rolf
author
2003-07
Plant Physiology 2003 132(3):1153-1161
0032-0889
1532-2548
12857798
10.1104/pp.102.019760
http://hdl.handle.net/10033/8686
526270
Possibility of Bacterial Recruitment of Plant Genes Associated with the Biosynthesis of Secondary Metabolites1
oai:repository.helmholtz-hzi.de:10033/1220862019-08-30T11:27:09Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Weissman, Kira J
author
Müller, Rolf
author
2010-09-18
Myxobacterial secondary metabolites: bioactivities and modes-of-action. 2010, 27 (9):1276-95 Nat Prod Rep
1460-4752
20520915
10.1039/c001260m
http://hdl.handle.net/10033/122086
Natural product reports
Myxobacterial secondary metabolites: bioactivities and modes-of-action.
oai:repository.helmholtz-hzi.de:10033/1463762019-08-30T11:37:00Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Kopp, Maren
author
Irschik, Herbert
author
Gemperlein, Katja
author
Buntin, Kathrin
author
Meiser, Peter
author
Weissman, Kira J
author
Bode, Helge B
author
Müller, Rolf
author
2011-05
The anti-fungal leupyrrins are secondary metabolites produced by several strains of the myxobacterium Sorangium cellulosum. These intriguing compounds incorporate an atypically substituted γ-butyrolactone ring, as well as pyrrole and oxazolinone functionalities, which are located within an unusual asymmetrical macrodiolide. Previous feeding studies revealed that this novel structure arises from the homologation of four distinct structural units, nonribosomally-derived peptide, polyketide, isoprenoid and a dicarboxylic acid, coupled with modification of the various building blocks. Here we have attempted to reconcile the biosynthetic pathway proposed on the basis of the feeding studies with the underlying enzymatic machinery in the S. cellulosum strain So ce690. Gene products can be assigned to many of the suggested steps, but inspection of the gene set provokes the reconsideration of several key transformations. We support our analysis by the reconstitution in vitro of the biosynthesis of the pyrrole carboxylic starter unit along with gene inactivation. In addition, this study reveals that a significant proportion of the genes for leupyrrin biosynthesis are located outside the core cluster, a 'split' organization which is increasingly characteristic of the myxobacteria. Finally, we report the generation of four novel deshydroxy leupyrrin analogues by genetic engineering of the pathway.
Insights into the complex biosynthesis of the leupyrrins in Sorangium cellulosum So ce690. 2011, 7 (5):1549-63 Mol Biosyst
1742-2051
21365089
10.1039/c0mb00240b
http://hdl.handle.net/10033/146376
Molecular bioSystems
Insights into the complex biosynthesis of the leupyrrins in Sorangium cellulosum So ce690.
oai:repository.helmholtz-hzi.de:10033/2669122019-08-30T11:28:24Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Wiedmann, Romina M
author
von Schwarzenberg, Karin
author
Palamidessi, Andrea
author
Schreiner, Laura
author
Kubisch, Rebekka
author
Liebl, Johanna
author
Schempp, Christina
author
Trauner, Dirk
author
Vereb, Gyorgy
author
Zahler, Stefan
author
Wagner, Ernst
author
Müller, Rolf
author
Scita, Giorgio
author
Vollmar, Angelika M
author
2012-11-15
The abundance of the multimeric vacuolar ATP-dependent proton pump, V-ATPase, on the plasma membrane of tumor cells correlates with the invasiveness of the tumor cell, suggesting the involvement of V-ATPase in tumor metastasis. V-ATPase is hypothesized to create a proton efflux leading to an acidic pericellular microenvironment that promotes the activity of proinvasive proteases. An alternative, not yet explored possibility is that V-ATPase regulates the signaling machinery responsible for tumor cell migration. Here, we show that pharmacologic or genetic reduction of V-ATPase activity significantly reduces migration of invasive tumor cells in vitro. Importantly, the V-ATPase inhibitor archazolid abrogates tumor dissemination in a syngeneic mouse 4T1 breast tumor metastasis model. Pretreatment of cancer cells with archazolid impairs directional motility by preventing spatially restricted, leading edge localization of epidermal growth factor receptor (EGFR) as well as of phosphorylated Akt. Archazolid treatment or silencing of V-ATPase inhibited Rac1 activation, as well as Rac1-dependent dorsal and peripheral ruffles by inhibiting Rab5-mediated endocytotic/exocytotic trafficking of Rac1. The results indicate that archazolid effectively decreases metastatic dissemination of breast tumors by impairing the trafficking and spatially restricted activation of EGFR and Rho-GTPase Rac1, which are pivotal for directed movement of cells. Thus, our data reveals a novel mechanism underlying the role of V-ATPase in tumor dissemination.
The V-ATPase-inhibitor archazolid abrogates tumor metastasis via inhibition of endocytic activation of the Rho-GTPase Rac1. 2012, 72 (22):5976-87 Cancer Res.
1538-7445
22986742
10.1158/0008-5472.CAN-12-1772
http://hdl.handle.net/10033/266912
Cancer research
The V-ATPase-inhibitor archazolid abrogates tumor metastasis via inhibition of endocytic activation of the Rho-GTPase Rac1.
oai:repository.helmholtz-hzi.de:10033/2709212019-08-30T11:30:58Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Kaufmann, Katrin
author
Simmons, Luke
author
Herrmann, Jennifer
author
Schwär, Gertrud
author
Luniak, Nora
author
Müller, Rolf
author
2013-01
Using an in vitro cell-based assay in a flow-design, we have applied activity-guided screening to search for new bioactive compounds isolated from microorganisms. A first assay employs the stable expression of nuclear factor kappa B (NF-κB) while a second assay utilizes the glucocorticoid receptor (GR) coupled to green fluorescent protein. A specialized assay was implemented for both the translocation of NF-κB and to inhibit the translocation of cytokine-mediated NF-κB. In addition, we developed in a wide palette of cell lines used for a highly specialized GR-translocation assay to detect anti-inflammatory effects. This approach demonstrates the straight-forward combination of cell-based assays arranged with an automated fluorescence microscope. This allows for the direct sorting of extracts which are acting in a pharmaceutically interesting way. Initial results using this technique have led to the detection of new anti-inflammatory steroids from bacterial crude extracts.
Activity-guided screening of bioactive natural compounds implementing a new glucocorticoid-receptor-translocation assay and detection of new anti-inflammatory steroids from bacteria. 2013, 35 (1):11-20 Biotechnol. Lett.
1573-6776
22983717
10.1007/s10529-012-1042-0
http://hdl.handle.net/10033/270921
Biotechnology letters
Activity-guided screening of bioactive natural compounds implementing a new glucocorticoid-receptor-translocation assay and detection of new anti-inflammatory steroids from bacteria.
oai:repository.helmholtz-hzi.de:10033/2761642019-08-30T11:33:57Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Takacs, Constantin N
author
Hocking, Jason
author
Cabeen, Matthew T
author
Bui, Nhat Khai
author
Poggio, Sebastian
author
Vollmer, Waldemar
author
Jacobs-Wagner, Christine
author
2013
The peptidoglycan (PG) is a macromolecular component of the bacterial cell wall that maintains the shape and integrity of the cell. The PG of , unlike that of many other Gram-negative bacteria, has repeatedly been shown to contain significant amounts of glycine. This compositional peculiarity has been deemed an intrinsic characteristic of this species. By performing a comprehensive qualitative and quantitative analysis of the PG by high-performance liquid chromatography (HPLC) and mass spectrometry (MS), we show here that glycine incorporation into the PG depends on the presence of exogenous glycine in the growth medium. High levels of glycine were detected at the fifth position of the peptide side chains of PG isolated from cells grown in the complex laboratory medium PYE or in defined medium (M2G) supplemented with casamino acids or glycine alone. In contrast, glycine incorporation was undetectable when cells were grown in M2G medium lacking glycine. Remarkably, glycine incorporation into peptidoglycan occurred even in the presence of low millimolar to sub-millimolar concentrations of free glycine. High glycine content in the PG had no obvious effects on growth rates, mode of PG incorporation or cell morphology. Hence, the PG is able to retain its physiological functions in cell growth and morphogenesis despite significant alterations in its composition, in what we deem to be unprecedented plasticity.
Growth Medium-Dependent Glycine Incorporation into the Peptidoglycan of Caulobacter crescentus. 2013, 8 (2):e57579 PLoS ONE
1932-6203
23469030
10.1371/journal.pone.0057579
http://hdl.handle.net/10033/276164
PloS one
Growth Medium-Dependent Glycine Incorporation into the Peptidoglycan of Caulobacter crescentus.
oai:repository.helmholtz-hzi.de:10033/3045682019-08-30T11:37:44Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Kühlhorn, Franziska
author
Rath, Matthias
author
Schmoeckel, Katrin
author
Cziupka, Katharina
author
Nguyen, Huu Hung
author
Hildebrandt, Petra
author
Hünig, Thomas
author
Sparwasser, Tim
author
Huehn, Jochen
author
Pötschke, Christian
author
Bröker, Barbara M
author
2013
The role of regulatory T cells (Tregs) in bacterial sepsis remains controversial because antibody-mediated depletion experiments gave conflicting results. We employed DEREG mice (DEpletion of REGulatory T cells) and a caecal ligation and puncture model to elucidate the role of CD4(+)Foxp3(+) Tregs in sepsis. In DEREG mice natural Tregs can be visualized easily and selectively depleted by diphtheria toxin because the animals express the diphtheria toxin receptor and enhanced green fluorescent protein as a fusion protein under the control of the foxp3 locus. We confirmed rapid Treg-activation and an increased ratio of Tregs to Teffs in sepsis. Nevertheless, 24 h after sepsis induction, Treg-depleted and control mice showed equally strong inflammation, immune cell immigration into the peritoneum and bacterial dissemination. During the first 36 h of disease survival was not influenced by Treg-depletion. Later, however, only Treg-competent animals recovered from the insult. We conclude that the suppressive capacity of Tregs is not sufficient to control overwhelming inflammation and early mortality, but is a prerequisite for the recovery from severe sepsis.
Foxp3+ regulatory T cells are required for recovery from severe sepsis. 2013, 8 (5):e65109 PLoS ONE
1932-6203
23724126
10.1371/journal.pone.0065109
http://hdl.handle.net/10033/304568
PloS one
Foxp3+ regulatory T cells are required for recovery from severe sepsis.
oai:repository.helmholtz-hzi.de:10033/3047022019-08-30T11:37:23Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Li, Xu-Wen
author
Herrmann, Jennifer
author
Zang, Yi
author
Grellier, Philippe
author
Prado, Soizic
author
Müller, Rolf
author
Nay, Bastien
author
2013
Aurachins are myxobacterial 3-farnesyl-4(1H)-quinolone derived compounds initially described as respiratory chain inhibitors, more specifically as inhibitors of various cytochrome complexes. They are also known as potent antibiotic compounds. We describe herein the first synthesis of aurachin D through a key Conrad-Limpach reaction. The same strategy was used to reach some ring as opposed to chain analogues, allowing for the description of structure-activity relationships. Biological screening of the analogues showed antiparasitic, cytotoxic, antibacterial and antifungal activities, and depletion of the mitochondrial membrane potential. The strongest activity was found on Plasmodium falciparum with a selectivity index of 345, compared to Vero cells, for the natural product and its geranyl analogue. The loss of mitochondrial membrane potential induced by aurachins in human U-2 OS osteosarcoma cells was studied, showing the best activity for aurachin D and a naphthalene analogue, yet without totally explaining the observed cytotoxic activity of the compounds. Finally, a synthetic entry is given to the complete carboheterocyclic core of aurachin H through the N-oxidation/epoxidation of aurachin D and a shorter chain analogue, followed by subsequent biomimetic cyclization.
Synthesis and biological activities of the respiratory chain inhibitor aurachin D and new ring versus chain analogues. 2013, 9:1551-8 Beilstein J Org Chem
1860-5397
23946854
10.3762/bjoc.9.176
http://hdl.handle.net/10033/304702
Beilstein journal of organic chemistry
Synthesis and biological activities of the respiratory chain inhibitor aurachin D and new ring versus chain analogues.
oai:repository.helmholtz-hzi.de:10033/3067122019-08-30T11:26:42Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Gross, Peter C
author
Burkart, Sonja C
author
Müller, Rolf
author
2014-01
Purification and quality control of therapeutic peptides is often performed by one single method, RP-HPLC. As usage of an orthogonal technique is highly advisable for quality assurance, capillary electrophoresis (CE) employing a coated capillary coupled via a sheathless interface to a mass spectrometer was applied in parallel. The basic therapeutic peptide aviptadil served as a model substance to study the impurity profiles revealing 15 detectable impurities using CE-MS, two were detected by an appropriate nanoRP-HPLC-MS method. None of the impurities detected by CE were observed in LC and vice versa. The LOD in CE-MS was determined in the base peak electropherogram at ∼1fmol, a value 2500 times smaller than the LOD found in nanoRP-HPLC-MS (3pmol). In nanoRP-HPLC-MS only 0.2% of the extrapolated CE-MS signal for a 25ng aviptadil load was observed. We conclude that both, the LOD as well as the impurity profile of aviptadil, as analyzed by nanoRP-HPLC are influenced by both, the ligand-derivatized silica matrix and the flow-rate. Peptides may disappear completely and their variable emergence may lead to the determination of incorrect ratios as present in the sample.
Analytics of the therapeutic peptide aviptadil by sheathless CE-MS and comparison with nanoRP-HPLC-MS. 2014, 88:477-82 J Pharm Biomed Anal
1873-264X
24176753
10.1016/j.jpba.2013.09.024
http://hdl.handle.net/10033/306712
Journal of pharmaceutical and biomedical analysis
Analytics of the therapeutic peptide aviptadil by sheathless CE-MS and comparison with nanoRP-HPLC-MS.
oai:repository.helmholtz-hzi.de:10033/3326032019-08-30T11:35:39Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Foerster, F
author
Braig, S
author
Moser, C
author
Kubisch, R
author
Busse, J
author
Wagner, E
author
Schmoeckel, E
author
Mayr, D
author
Schmitt, S
author
Huettel, S
author
Zischka, H
author
Mueller, R
author
Vollmar, A M
author
2014
Targeting the actin cytoskeleton (CSK) of cancer cells offers a valuable strategy in cancer therapy. There are a number of natural compounds that interfere with the actin CSK, but the mode of their cytotoxic action and, moreover, their tumor-specific mechanisms are quite elusive. We used the myxobacterial compound Chondramide as a tool to first elucidate the mechanisms of cytotoxicity of actin targeting in breast cancer cells (MCF7, MDA-MB-231). Chondramide inhibits cellular actin filament dynamics shown by a fluorescence-based analysis (fluorescence recovery after photobleaching (FRAP)) and leads to apoptosis characterized by phosphatidylserine exposure, release of cytochrome C from mitochondria and finally activation of caspases. Chondramide enhances the occurrence of mitochondrial permeability transition (MPT) by affecting known MPT modulators: Hexokinase II bound to the voltage-dependent anion channel (VDAC) translocated from the outer mitochondrial membrane to the cytosol and the proapoptotic protein Bad were recruited to the mitochondria. Importantly, protein kinase C-ɛ (PKCɛ), a prosurvival kinase possessing an actin-binding site and known to regulate the hexokinase/VDAC interaction as well as Bad phosphorylation was identified as the link between actin CSK and apoptosis induction. PKCɛ, which was found overexpressed in breast cancer cells, accumulated in actin bundles induced by Chondramide and lost its activity. Our second goal was to characterize the potential tumor-specific action of actin-binding agents. As the nontumor breast epithelial cell line MCF-10A in fact shows resistance to Chondramide-induced apoptosis and notably express low level of PKCɛ, we suggest that trapping PKCɛ via Chondramide-induced actin hyperpolymerization displays tumor cell specificity. Our work provides a link between targeting the ubiquitously occurring actin CSK and selective inhibition of pro-tumorigenic PKCɛ, thus setting the stage for actin-stabilizing agents as innovative cancer drugs. This is moreover supported by the in vivo efficacy of Chondramide triggered by abrogation of PKCɛ signaling shown in a xenograft breast cancer model.
Targeting the actin cytoskeleton: selective antitumor action via trapping PKCɛ. 2014, 5:e1398 Cell Death Dis
2041-4889
25165884
10.1038/cddis.2014.363
http://hdl.handle.net/10033/332603
Cell death & disease
Targeting the actin cytoskeleton: selective antitumor action via trapping PKCɛ.
oai:repository.helmholtz-hzi.de:10033/3328032019-08-30T11:35:39Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Kessler, Sonja M
author
Simon, Yvette
author
Gemperlein, Katja
author
Gianmoena, Kathrin
author
Cadenas, Cristina
author
Zimmer, Vincent
author
Pokorny, Juliane
author
Barghash, Ahmad
author
Helms, Volkhard
author
van Rooijen, Nico
author
Bohle, Rainer M
author
Lammert, Frank
author
Hengstler, Jan G
author
Mueller, Rolf
author
Haybaeck, Johannes
author
Kiemer, Alexandra K
author
2014
Non-alcoholic steatohepatitis (NASH) represents a risk factor for the development of hepatocellular carcinoma (HCC) and is characterized by quantitative and qualitative changes in hepatic lipids. Since elongation of fatty acids from C16 to C18 has recently been reported to promote both hepatic lipid accumulation and inflammation we aimed to investigate whether a frequently used mouse NASH model reflects this clinically relevant feature and whether C16 to C18 elongation can be observed in HCC development. Feeding mice a methionine and choline deficient diet to model NASH not only increased total hepatic fatty acids and cholesterol, but also distinctly elevated the C18/C16 ratio, which was not changed in a model of simple steatosis (ob/ob mice). Depletion of Kupffer cells abrogated both quantitative and qualitative methionine-and-choline deficient (MCD)-induced alterations in hepatic lipids. Interestingly, mimicking inflammatory events in early hepatocarcinogenesis by diethylnitrosamine-induced carcinogenesis (48 h) increased hepatic lipids and the C18/C16 ratio. Analyses of human liver samples from patients with NASH or NASH-related HCC showed an elevated expression of the elongase ELOVL6, which is responsible for the elongation of C16 fatty acids. Taken together, our findings suggest a detrimental role of an altered fatty acid pattern in the progression of NASH-related liver disease.
Fatty acid elongation in non-alcoholic steatohepatitis and hepatocellular carcinoma. 2014, 15 (4):5762-73 Int J Mol Sci
1422-0067
24714086
10.3390/ijms15045762
http://hdl.handle.net/10033/332803
International journal of molecular sciences
Fatty acid elongation in non-alcoholic steatohepatitis and hepatocellular carcinoma.
oai:repository.helmholtz-hzi.de:10033/3349112019-08-30T11:35:39Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Kolinko, Isabel
author
Lohße, Anna
author
Borg, Sarah
author
Raschdorf, Oliver
author
Jogler, Christian
author
Tu, Qiang
author
Pósfai, Mihály
author
Tompa, Eva
author
Plitzko, Jürgen M
author
Brachmann, Andreas
author
Wanner, Gerhard
author
Müller, Rolf
author
Zhang, Youming
author
Schüler, Dirk
author
2014-03
The synthetic production of monodisperse single magnetic domain nanoparticles at ambient temperature is challenging. In nature, magnetosomes--membrane-bound magnetic nanocrystals with unprecedented magnetic properties--can be biomineralized by magnetotactic bacteria. However, these microbes are difficult to handle. Expression of the underlying biosynthetic pathway from these fastidious microorganisms within other organisms could therefore greatly expand their nanotechnological and biomedical applications. So far, this has been hindered by the structural and genetic complexity of the magnetosome organelle and insufficient knowledge of the biosynthetic functions involved. Here, we show that the ability to biomineralize highly ordered magnetic nanostructures can be transferred to a foreign recipient. Expression of a minimal set of genes from the magnetotactic bacterium Magnetospirillum gryphiswaldense resulted in magnetosome biosynthesis within the photosynthetic model organism Rhodospirillum rubrum. Our findings will enable the sustainable production of tailored magnetic nanostructures in biotechnologically relevant hosts and represent a step towards the endogenous magnetization of various organisms by synthetic biology.
Biosynthesis of magnetic nanostructures in a foreign organism by transfer of bacterial magnetosome gene clusters. 2014, 9 (3):193-7 Nat Nanotechnol
1748-3395
24561353
10.1038/nnano.2014.13
http://hdl.handle.net/10033/334911
Nature nanotechnology
Biosynthesis of magnetic nanostructures in a foreign organism by transfer of bacterial magnetosome gene clusters.
oai:repository.helmholtz-hzi.de:10033/3384892019-08-30T11:35:39Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Held, Jana
author
Gebru, Tamirat
author
Kalesse, Markus
author
Jansen, Rolf
author
Gerth, Klaus
author
Müller, Rolf
author
Mordmüller, Benjamin
author
2014-11
Myxobacteria are Gram-negative soil-dwelling bacteria belonging to the phylum Proteobacteria. They are a rich source of promising compounds for clinical application, such as epothilones for cancer therapy and several new antibiotics. In the course of a bioactivity screening program of secondary metabolites produced by Sorangium cellulosum strains, the macrolide chlorotonil A was found to exhibit promising antimalarial activity. Subsequently, we evaluated chlorotonil A against Plasmodium falciparum laboratory strains and clinical isolates from Gabon. Chlorotonil A was highly active, with a 50% inhibitory concentration between 4 and 32 nM; additionally, no correlations between the activities of chlorotonil A and artesunate (rho, 0.208) or chloroquine (rho, -0.046) were observed. Per os treatment of Plasmodium berghei-infected mice with four doses of as little as 36 mg of chlorotonil A per kg of body weight led to the suppression of parasitemia with no obvious signs of toxicity. Chlorotonil A acts against all stages of intraerythrocytic parasite development, including ring-stage parasites and stage IV to V gametocytes, and it requires only a very short exposure to the parasite to exert its antimalarial action. Conclusively, chlorotonil A has an exceptional and unprecedented profile of action and represents an urgently required novel antimalarial chemical scaffold. Therefore, we propose it as a lead structure for further development as an antimalarial chemotherapeutic.
Antimalarial activity of the myxobacterial macrolide chlorotonil a. 2014, 58 (11):6378-84 Antimicrob. Agents Chemother.
1098-6596
25114138
10.1128/AAC.03326-14
http://hdl.handle.net/10033/338489
Antimicrobial agents and chemotherapy
Antimalarial activity of the myxobacterial macrolide chlorotonil a.
oai:repository.helmholtz-hzi.de:10033/3443442019-08-30T11:37:23Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Simon, Yvette
author
Kessler, Sonja M
author
Gemperlein, Katja
author
Bohle, Rainer M
author
Müller, Rolf
author
Haybaeck, Johannes
author
Kiemer, Alexandra K
author
2014-12-21
To characterize how insulin-like growth factor 2 (IGF2) mRNA binding protein p62/IMP2-2 promotes steatohepatitis in the absence of dietary cholesterol.
Elevated free cholesterol in a p62 overexpression model of non-alcoholic steatohepatitis. 2014, 20 (47):17839-50 World J. Gastroenterol.
2219-2840
25548482
10.3748/wjg.v20.i47.17839
http://hdl.handle.net/10033/344344
World journal of gastroenterology : WJG
Elevated free cholesterol in a p62 overexpression model of non-alcoholic steatohepatitis.
oai:repository.helmholtz-hzi.de:10033/3443862019-08-30T11:37:44Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Garcia, Ronald
author
Pistorius, Dominik
author
Stadler, Marc
author
Müller, Rolf
author
2011-04
In an analysis of 47 aerobic myxobacterial strains, representing 19 genera in suborders Cystobacterineae, Nannocystineae, Sorangiineae, and a novel isolate, "Aetherobacter" SBSr008, an enormously diverse array of fatty acids (FAs) was found. The distribution of straight-chain fatty acids (SCFAs) and branched-chain fatty acids (BCFAs) supports the reported clustering of strains in the phylogenetic tree based on 16S rRNA genes. This finding additionally allows the prediction and assignment of the novel isolate SBSr008 into its corresponding taxon. Sorangiineae predominantly contains larger amounts of SCFA (57 to 84%) than BCFA. On the other hand, Cystobacterineae exhibit significant BCFA content (53 to 90%), with the exception of the genus Stigmatella. In Nannocystineae, the ratio of BCFA and SCFA seems dependent on the taxonomic clade. Myxobacteria could also be identified and classified by using their specific and predominant FAs as biomarkers. Nannocystineae is remarkably unique among the suborders for its absence of hydroxy FAs. After the identification of arachidonic (AA) FA in Phaselicystidaceae, eight additional polyunsaturated fatty acids (PUFAs) belonging to the omega-6 and omega-3 families were discovered. Here we present a comprehensive report of FAs found in aerobic myxobacteria. Gliding bacteria belonging to Flexibacter and Herpetosiphon were chosen for comparative analysis to determine their FA profiles in relation to the myxobacteria.
Fatty acid-related phylogeny of myxobacteria as an approach to discover polyunsaturated omega-3/6 Fatty acids. 2011, 193 (8):1930-42 J. Bacteriol.
1098-5530
21317327
10.1128/JB.01091-10
http://hdl.handle.net/10033/344386
Journal of bacteriology
Fatty acid-related phylogeny of myxobacteria as an approach to discover polyunsaturated omega-3/6 Fatty acids.
oai:repository.helmholtz-hzi.de:10033/3454072019-08-30T11:31:23Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Khatri, Yogan
author
Hannemann, Frank
author
Perlova, Olena
author
Müller, Rolf
author
Bernhardt, Rita
author
2011-06-06
The exploitation of cytochromes P450 for novel biotechnological application and for the investigation of their physiological function is of great scientific interest in this post genomic era, where an extraordinary biodiversity of P450 genes has been derived from all forms of life. The study of P450s in the myxobacterium Sorangium cellulosum strain So ce56, the producer of novel secondary metabolites of pharmaceutical interest is the research topic, in which we were engaged since the beginning of its genome sequencing project. We herein disclosed the cytochrome P450 complements (CYPomes) of spore-forming myxobacterial species, Stigmatella aurantiaca DW4/3-1, Haliangium ochraceum DSM 14365 and Myxococcus xanthus DK1622, and their potential pharmaceutical significance has been discussed.
Investigation of cytochromes P450 in myxobacteria: excavation of cytochromes P450 from the genome of Sorangium cellulosum So ce56. 2011, 585 (11):1506-13 FEBS Lett.
1873-3468
21521637
10.1016/j.febslet.2011.04.035
http://hdl.handle.net/10033/345407
FEBS letters
Investigation of cytochromes P450 in myxobacteria: excavation of cytochromes P450 from the genome of Sorangium cellulosum So ce56.
oai:repository.helmholtz-hzi.de:10033/3461552019-08-30T11:30:58Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Scherer, Olga
author
Steinmetz, Heinrich
author
Kaether, Christoph
author
Weinigel, Christina
author
Barz, Dagmar
author
Kleinert, Hartmut
author
Menche, Dirk
author
Müller, Rolf
author
Pergola, Carlo
author
Werz, Oliver
author
2014-10-15
The macrolide archazolid inhibits vacuolar-type H(+)-ATPase (V-ATPase), a proton-translocating enzyme involved in protein transport and pH regulation of cell organelles, and potently suppresses cancer cell growth at low nanomolar concentrations. In view of the growing link between inflammation and cancer, we investigated whether inhibition of V-ATPase by archazolid may affect primary human monocytes that can promote cancer by sustaining inflammation through the release of tumor-promoting cytokines. Human primary monocytes express V-ATPase, and archazolid (10-100nM) increases the vesicular pH in these cells. Archazolid (10nM) markedly reduced the release of pro-inflammatory (TNF-α, interleukin-6 and -8) but also of anti-inflammatory (interleukin-10) cytokines in monocytes stimulated with LPS, without affecting cell viability up to 1000nM. Of interest, secretion of interleukin-1β was increased by archazolid. Comparable effects were obtained by the V-ATPase inhibitors bafilomycin and apicularen. The phosphorylation of p38 MAPK and ERK-1/2, Akt, SAPK/JNK or of the inhibitor of NFκB (IκBα) as well as mRNA expression of IL-8 were not altered by archazolid in LPS-stimulated monocytes. Instead, archazolid caused endoplasmic reticulum (ER) stress response visualized by increased BiP expression and accumulation of IL-8 (and TNF-α) at the ER, indicating a perturbation of protein secretion. In conclusion, by interference with V-ATPase, archazolid significantly affects the secretion of cytokines due to accumulation at the ER which might be of relevance when using these agents for cancer therapy.
Targeting V-ATPase in primary human monocytes by archazolid potently represses the classical secretion of cytokines due to accumulation at the endoplasmic reticulum. 2014, 91 (4):490-500 Biochem. Pharmacol.
1873-2968
25107704
10.1016/j.bcp.2014.07.028
http://hdl.handle.net/10033/346155
Biochemical pharmacology
Targeting V-ATPase in primary human monocytes by archazolid potently represses the classical secretion of cytokines due to accumulation at the endoplasmic reticulum.
oai:repository.helmholtz-hzi.de:10033/3461992019-08-30T11:30:58Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Sours, Kevin M
author
Xiao, Yao
author
Ahn, Natalie G
author
2014-05-01
Protein motions underlie conformational and entropic contributions to enzyme catalysis; however, relatively little is known about the ways in which this occurs. Studies of the mitogen-activated protein kinase ERK2 (extracellular-regulated protein kinase 2) by hydrogen-exchange mass spectrometry suggest that activation enhances backbone flexibility at the linker between N- and C-terminal domains while altering nucleotide binding mode. Here, we address the hypothesis that enhanced backbone flexibility within the hinge region facilitates kinase activation. We show that hinge mutations enhancing flexibility promote changes in the nucleotide binding mode consistent with domain movement, without requiring phosphorylation. They also lead to the activation of monophosphorylated ERK2, a form that is normally inactive. The hinge mutations bypass the need for pTyr but not pThr, suggesting that Tyr phosphorylation controls hinge motions. In agreement, monophosphorylation of pTyr enhances both hinge flexibility and nucleotide binding mode, measured by hydrogen-exchange mass spectrometry. Our findings demonstrate that regulated protein motions underlie kinase activation. Our working model is that constraints to domain movement in ERK2 are overcome by phosphorylation at pTyr, which increases hinge dynamics to promote the active conformation of the catalytic site.
Extracellular-regulated kinase 2 is activated by the enhancement of hinge flexibility. 2014, 426 (9):1925-35 J. Mol. Biol.
1089-8638
24534729
10.1016/j.jmb.2014.02.011
http://hdl.handle.net/10033/346199
Journal of molecular biology
Extracellular-regulated kinase 2 is activated by the enhancement of hinge flexibility.
oai:repository.helmholtz-hzi.de:10033/3468722019-08-30T11:37:44Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Rachid, Shwan
author
Huo, Liujie
author
Herrmann, Jennifer
author
Stadler, Marc
author
Köpcke, Bärbel
author
Bitzer, Jens
author
Müller, Rolf
author
2011-04-11
The cinnabaramides and salinosporamides are mixed PKS/NRPS natural products isolated from a terrestrial streptomycete and a marine actinomycete, respectively. They interfere with the proteasome and thus potentially inhibit the growth of cancer cells. The compounds exhibit a γ-lactam-β-lactone bicyclic ring structure attached to a cyclohexenyl unit and a PKS side chain. As a first step towards improving anticancer activity and permitting genetic approaches to novel analogues, we have cloned and characterized the cinnabaramide biosynthetic genes from Streptomyces sp. JS360. In addition to the expected PKS and NRPS genes, the cluster encodes functionalities for the assembly of the hexyl side chain precursor. The corresponding enzymes exhibit relaxed substrate specificities towards a number of synthesized precursors, enabling production of novel chlorinated cinnabaramides. These were isolated and analyzed for activity, revealing that derivatives bearing a chlorine atom in the PKS side chain show higher inhibitory potentials towards the proteasome's proteolytic subunits (especially the trypsin and chymotrypsin units) and higher cytotoxicities towards human tumor cell lines than the parent cinnabaramide A. Although their activities towards the proteasome were weaker than that of salinosporamide A, the cinnabaramides were found to inhibit the growth of various fungi with greater potency.
Mining the cinnabaramide biosynthetic pathway to generate novel proteasome inhibitors. 2011, 12 (6):922-31 Chembiochem
1439-7633
21387511
10.1002/cbic.201100024
http://hdl.handle.net/10033/346872
Chembiochem : a European journal of chemical biology
Mining the cinnabaramide biosynthetic pathway to generate novel proteasome inhibitors.
oai:repository.helmholtz-hzi.de:10033/3468962019-08-30T11:32:16Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Proschak, Anna
author
Schultz, Katharina
author
Herrmann, Jennifer
author
Dowling, Andrea J
author
Brachmann, Alexander O
author
ffrench-Constant, Richard
author
Müller, Rolf
author
Bode, Helge B
author
2011-09-05
Cytotoxic fatty acid amides from Xenorhabdus. 2011, 12 (13):2011-5 Chembiochem
1439-7633
21751325
10.1002/cbic.201100223
http://hdl.handle.net/10033/346896
Chembiochem : a European journal of chemical biology
Cytotoxic fatty acid amides from Xenorhabdus.
oai:repository.helmholtz-hzi.de:10033/5285702019-08-30T11:25:43Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Menhofer, Magdalena H
author
Kubisch, Rebekka
author
Schreiner, Laura
author
Zorn, Matthias
author
Foerster, Florian
author
Mueller, Rolf
author
Raedler, Joachim O
author
Wagner, Ernst
author
Vollmar, Angelika M
author
Zahler, Stefan
author
2014
A major player in the process of metastasis is the actin cytoskeleton as it forms key structures in both invasion mechanisms, mesenchymal and amoeboid migration. We tested the actin binding compound Chondramide as potential anti-metastatic agent.
The actin targeting compound Chondramide inhibits breast cancer metastasis via reduction of cellular contractility. 2014, 9 (11):e112542 PLoS ONE
1932-6203
25391145
10.1371/journal.pone.0112542
http://hdl.handle.net/10033/528570
PloS one
The actin targeting compound Chondramide inhibits breast cancer metastasis via reduction of cellular contractility.
oai:repository.helmholtz-hzi.de:10033/5554752019-08-30T11:26:13Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Weber, Tilmann
author
Blin, Kai
author
Duddela, Srikanth
author
Krug, Daniel
author
Kim, Hyun Uk
author
Bruccoleri, Robert
author
Lee, Sang Yup
author
Fischbach, Michael A
author
Müller, Rolf
author
Wohlleben, Wolfgang
author
Breitling, Rainer
author
Takano, Eriko
author
Medema, Marnix H
author
2015-05-06
Microbial secondary metabolism constitutes a rich source of antibiotics, chemotherapeutics, insecticides and other high-value chemicals. Genome mining of gene clusters that encode the biosynthetic pathways for these metabolites has become a key methodology for novel compound discovery. In 2011, we introduced antiSMASH, a web server and stand-alone tool for the automatic genomic identification and analysis of biosynthetic gene clusters, available at http://antismash.secondarymetabolites.org. Here, we present version 3.0 of antiSMASH, which has undergone major improvements. A full integration of the recently published ClusterFinder algorithm now allows using this probabilistic algorithm to detect putative gene clusters of unknown types. Also, a new dereplication variant of the ClusterBlast module now identifies similarities of identified clusters to any of 1172 clusters with known end products. At the enzyme level, active sites of key biosynthetic enzymes are now pinpointed through a curated pattern-matching procedure and Enzyme Commission numbers are assigned to functionally classify all enzyme-coding genes. Additionally, chemical structure prediction has been improved by incorporating polyketide reduction states. Finally, in order for users to be able to organize and analyze multiple antiSMASH outputs in a private setting, a new XML output module allows offline editing of antiSMASH annotations within the Geneious software.
antiSMASH 3.0-a comprehensive resource for the genome mining of biosynthetic gene clusters. 2015: Nucleic Acids Res.
1362-4962
25948579
10.1093/nar/gkv437
http://hdl.handle.net/10033/555475
Nucleic acids research
antiSMASH 3.0-a comprehensive resource for the genome mining of biosynthetic gene clusters.
oai:repository.helmholtz-hzi.de:10033/6207662019-08-30T11:31:23Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Perlova, Olena
author
Gerth, Klaus
author
Kuhlmann, Silvia
author
Zhang, Youming
author
Müller, Rolf
author
2009-01-06
Abstract Although many secondary metabolites with diverse biological activities have been isolated from myxobacteria, most strains of these biotechnologically important gliding prokaryotes remain difficult to handle genetically. In this study we describe the new fast growing myxobacterial thermophilic isolate GT-2 as a heterologous host for the expression of natural product biosynthetic pathways isolated from other myxobacteria. According to the results of sequence analysis of the 16S rDNA, this moderately thermophilic isolate is closely related to Corallococcus macrosporus and was therefore named C. macrosporus GT-2. Fast growth of moderately thermophilic strains results in shorter fermentation and generation times, aspects which are of significant interest for molecular biological work as well as production of secondary metabolites. Development of a genetic manipulation system allowed the introduction of the complete myxochromide biosynthetic gene cluster, located on a transposable fragment, into the chromosome of GT-2. Genetic engineering of the biosynthetic gene cluster by promoter exchange leads to much higher production of myxochromides in the heterologous host C. macrosporus GT-2 in comparison to the original producer Stigmatella aurantiaca and to the previously described heterologous host Pseudomonas putida (600 mg/L versus 8 mg/L and 40 mg/L, respectively).
Microbial Cell Factories. 2009 Jan 06;8(1):1
http://dx.doi.org/10.1186/1475-2859-8-1
http://hdl.handle.net/10033/620766
Novel expression hosts for complex secondary metabolite megasynthetases: Production of myxochromide in the thermopilic isolate Corallococcus macrosporus GT-2
oai:repository.helmholtz-hzi.de:10033/5785862019-08-30T11:29:46Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Medema, Marnix H
author
Kottmann, Renzo
author
Yilmaz, Pelin
author
Cummings, Matthew
author
Biggins, John B
author
Blin, Kai
author
de Bruijn, Irene
author
Chooi, Yit Heng
author
Claesen, Jan
author
Coates, R Cameron
author
Cruz-Morales, Pablo
author
Luzhetskyy, Andriy N
author
Mahmud, Taifo
author
Mast, Yvonne
author
Méndez, Carmen
author
Metsä-Ketelä, Mikko
author
Micklefield, Jason
author
Mitchell, Douglas A
author
Moore, Bradley S
author
Moreira, Leonilde M
author
Müller, Rolf
author
Duddela, Srikanth
author
Neilan, Brett A
author
Nett, Markus
author
Nielsen, Jens
author
O'Gara, Fergal
author
Oikawa, Hideaki
author
Osbourn, Anne
author
Osburne, Marcia S
author
Ostash, Bohdan
author
Payne, Shelley M
author
Pernodet, Jean-Luc
author
Düsterhus, Stephanie
author
Petricek, Miroslav
author
Piel, Jörn
author
Ploux, Olivier
author
Raaijmakers, Jos M
author
Salas, José A
author
Schmitt, Esther K
author
Scott, Barry
author
Seipke, Ryan F
author
Shen, Ben
author
Sherman, David H
author
Edwards, Daniel J
author
Sivonen, Kaarina
author
Smanski, Michael J
author
Sosio, Margherita
author
Stegmann, Evi
author
Süssmuth, Roderich D
author
Tahlan, Kapil
author
Thomas, Christopher M
author
Tang, Yi
author
Truman, Andrew W
author
Viaud, Muriel
author
Fewer, David P
author
Walton, Jonathan D
author
Walsh, Christopher T
author
Weber, Tilmann
author
van Wezel, Gilles P
author
Wilkinson, Barrie
author
Willey, Joanne M
author
Wohlleben, Wolfgang
author
Wright, Gerard D
author
Ziemert, Nadine
author
Zhang, Changsheng
author
Garg, Neha
author
Zotchev, Sergey B
author
Breitling, Rainer
author
Takano, Eriko
author
Glöckner, Frank Oliver
author
Geiger, Christoph
author
Gomez-Escribano, Juan Pablo
author
Greule, Anja
author
Hadjithomas, Michalis
author
Haines, Anthony S
author
Helfrich, Eric J N
author
Hillwig, Matthew L
author
Ishida, Keishi
author
Jones, Adam C
author
Jones, Carla S
author
Jungmann, Katrin
author
Kegler, Carsten
author
Kim, Hyun Uk
author
Kötter, Peter
author
Krug, Daniel
author
Masschelein, Joleen
author
Melnik, Alexey V
author
Mantovani, Simone M
author
Monroe, Emily A
author
Moore, Marcus
author
Moss, Nathan
author
Nützmann, Hans-Wilhelm
author
Pan, Guohui
author
Pati, Amrita
author
Petras, Daniel
author
Reen, F Jerry
author
Rosconi, Federico
author
Rui, Zhe
author
Tian, Zhenhua
author
Tobias, Nicholas J
author
Tsunematsu, Yuta
author
Wiemann, Philipp
author
Wyckoff, Elizabeth
author
Yan, Xiaohui
author
Yim, Grace
author
Yu, Fengan
author
Xie, Yunchang
author
Aigle, Bertrand
author
Apel, Alexander K
author
Balibar, Carl J
author
Balskus, Emily P
author
Barona-Gómez, Francisco
author
Bechthold, Andreas
author
Bode, Helge B
author
Borriss, Rainer
author
Brady, Sean F
author
Brakhage, Axel A
author
Caffrey, Patrick
author
Cheng, Yi-Qiang
author
Clardy, Jon
author
Cox, Russell J
author
De Mot, René
author
Donadio, Stefano
author
Donia, Mohamed S
author
van der Donk, Wilfred A
author
Dorrestein, Pieter C
author
Doyle, Sean
author
Driessen, Arnold J M
author
Ehling-Schulz, Monika
author
Entian, Karl-Dieter
author
Fischbach, Michael A
author
Gerwick, Lena
author
Gerwick, William H
author
Gross, Harald
author
Gust, Bertolt
author
Hertweck, Christian
author
Höfte, Monica
author
Jensen, Susan E
author
Ju, Jianhua
author
Katz, Leonard
author
Kaysser, Leonard
author
Klassen, Jonathan L
author
Keller, Nancy P
author
Kormanec, Jan
author
Kuipers, Oscar P
author
Kuzuyama, Tomohisa
author
Kyrpides, Nikos C
author
Kwon, Hyung-Jin
author
Lautru, Sylvie
author
Lavigne, Rob
author
Lee, Chia Y
author
Linquan, Bai
author
Liu, Xinyu
author
Liu, Wen
author
2015-08-18
Minimum Information about a Biosynthetic Gene cluster. 2015, 11 (9):625-31 Nat. Chem. Biol.
1552-4469
26284661
10.1038/nchembio.1890
http://hdl.handle.net/10033/578586
Nature chemical biology
Minimum Information about a Biosynthetic Gene cluster.
oai:repository.helmholtz-hzi.de:10033/5825302019-08-30T11:35:39Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Yin, Jia
author
Hoffmann, Michael
author
Bian, Xiaoying
author
Tu, Qiang
author
Yan, Fu
author
Xia, Liqiu
author
Ding, Xuezhi
author
Stewart, A Francis
author
Müller, Rolf
author
Fu, Jun
author
Zhang, Youming
author
2015
Linear plus linear homologous recombination-mediated recombineering (LLHR) is ideal for obtaining natural product biosynthetic gene clusters from pre-digested bacterial genomic DNA in one or two steps of recombineering. The natural product salinomycin has a potent and selective activity against cancer stem cells and is therefore a potential anti-cancer drug. Herein, we separately isolated three fragments of the salinomycin gene cluster (salO-orf18) from Streptomyces albus (S. albus) DSM41398 using LLHR and assembled them into intact gene cluster (106 kb) by Red/ET and expressed it in the heterologous host Streptomyces coelicolor (S. coelicolor) A3(2). We are the first to report a large genomic region from a Gram-positive strain has been cloned using LLHR. The successful reconstitution and heterologous expression of the salinomycin gene cluster offer an attractive system for studying the function of the individual genes and identifying novel and potential analogues of complex natural products in the recipient strain.
Direct cloning and heterologous expression of the salinomycin biosynthetic gene cluster from Streptomyces albus DSM41398 in Streptomyces coelicolor A3(2). 2015, 5:15081 Sci Rep
2045-2322
26459865
10.1038/srep15081
http://hdl.handle.net/10033/582530
Scientific reports
Direct cloning and heterologous expression of the salinomycin biosynthetic gene cluster from Streptomyces albus DSM41398 in Streptomyces coelicolor A3(2).
oai:repository.helmholtz-hzi.de:10033/6010412019-08-30T11:35:39Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
A Elnakady, Yasser
author
Chatterjee, Indranil
author
Bischoff, Markus
author
Rohde, Manfred
author
Josten, Michaele
author
Sahl, Hans-Georg
author
Herrmann, Mathias
author
Müller, Rolf
author
2016
The emergence of bacteria that are resistant to many currently used drugs emphasizes the need to discover and develop new antibiotics that are effective against such multi-resistant strains. Kendomycin is a novel polyketide that has a unique quinone methide ansa structure and various biological properties. This compound exhibits strong antibacterial activity against Gram-negative and Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). Despite the promise of kendomycinin in several therapeutic areas, its mode of action has yet to be identified.
Investigations to the Antibacterial Mechanism of Action of Kendomycin. 2016, 11 (1):e0146165 PLoS ONE
1932-6203
26795276
10.1371/journal.pone.0146165
http://hdl.handle.net/10033/601041
PloS one
Investigations to the Antibacterial Mechanism of Action of Kendomycin.
oai:repository.helmholtz-hzi.de:10033/6013662019-08-30T11:36:05Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Tu, Qiang
author
Herrmann, Jennifer
author
Hu, Shengbiao
author
Raju, Ritesh
author
Bian, Xiaoying
author
Zhang, Youming
author
Müller, Rolf
author
2016
Disorazol, a macrocyclic polykitide produced by the myxobacterium Sorangium cellulosum So ce12 and it is reported to have potential cytotoxic activity towards several cancer cell lines, including multi-drug resistant cells. The disorazol biosynthetic gene cluster (dis) from Sorangium cellulosum (So ce12) was identified by transposon mutagenesis and cloned in a bacterial artificial chromosome (BAC) library. The 58-kb dis core gene cluster was reconstituted from BACs via Red/ET recombineering and expressed in Myxococcus xanthus DK1622. For the first time ever, a myxobacterial trans-AT polyketide synthase has been expressed heterologously in this study. Expression in M. xanthus allowed us to optimize the yield of several biosynthetic products using promoter engineering. The insertion of an artificial synthetic promoter upstream of the disD gene encoding a discrete acyl transferase (AT), together with an oxidoreductase (Or), resulted in 7-fold increase in disorazol production. The successful reconstitution and expression of the genetic sequences encoding for these promising cytotoxic compounds will allow combinatorial biosynthesis to generate novel disorazol derivatives for further bioactivity evaluation.
Genetic engineering and heterologous expression of the disorazol biosynthetic gene cluster via Red/ET recombineering. 2016, 6:21066 Sci Rep
2045-2322
26875499
10.1038/srep21066
http://hdl.handle.net/10033/601366
Scientific reports
Genetic engineering and heterologous expression of the disorazol biosynthetic gene cluster via Red/ET recombineering.
oai:repository.helmholtz-hzi.de:10033/6020942019-08-30T11:36:04Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Preisitsch, Michael
author
Heiden, Stefan E
author
Beerbaum, Monika
author
Niedermeyer, Timo H J
author
Schneefeld, Marie
author
Herrmann, Jennifer
author
Kumpfmüller, Jana
author
Thürmer, Andrea
author
Neidhardt, Inga
author
Wiesner, Christoph
author
Daniel, Rolf
author
Müller, Rolf
author
Bange, Franz-Christoph
author
Schmieder, Peter
author
Schweder, Thomas
author
Mundt, Sabine
author
2016
In this study, the influence of halide ions on [7.7]paracyclophane biosynthesis in the cyanobacterium Nostoc sp. CAVN2 was investigated. In contrast to KI and KF, supplementation of the culture medium with KCl or KBr resulted not only in an increase of growth but also in an up-regulation of carbamidocyclophane production. LC-MS analysis indicated the presence of chlorinated, brominated, but also non-halogenated derivatives. In addition to 22 known cylindrocyclophanes and carbamidocyclophanes, 27 putative congeners have been detected. Nine compounds, carbamidocyclophanes M-U, were isolated, and their structural elucidation by 1D and 2D NMR experiments in combination with HRMS and ECD analysis revealed that they are brominated analogues of chlorinated carbamidocyclophanes. Quantification of the carbamidocyclophanes showed that chloride is the preferably utilized halide, but incorporation is reduced in the presence of bromide. Evaluation of the antibacterial activity of 30 [7.7]paracyclophanes and related derivatives against selected pathogenic Gram-positive and Gram-negative bacteria exhibited remarkable effects especially against methicillin- and vancomycin-resistant staphylococci and Mycobacterium tuberculosis. For deeper insights into the mechanisms of biosynthesis, the carbamidocyclophane biosynthetic gene cluster in Nostoc sp. CAVN2 was studied. The gene putatively coding for the carbamoyltransferase has been identified. Based on bioinformatic analyses, a possible biosynthetic assembly is discussed.
Effects of Halide Ions on the Carbamidocyclophane Biosynthesis in Nostoc sp. CAVN2. 2016, 14 (1): Mar Drugs
1660-3397
26805858
10.3390/md14010021
http://hdl.handle.net/10033/602094
Marine drugs
Effects of Halide Ions on the Carbamidocyclophane Biosynthesis in Nostoc sp. CAVN2.
oai:repository.helmholtz-hzi.de:10033/6052862019-08-30T11:33:30Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Zaburannyi, Nestor
author
Bunk, Boyke
author
Maier, Josef
author
Overmann, Jörg
author
Müller, Rolf
author
2016
Here, we report the complete genome sequence of the type strain of the myxobacterial genus Chondromyces, Chondromyces crocatus Cm c5. It presents one of the largest prokaryotic genomes featuring a single circular chromosome and no plasmids. Analysis revealed an enlarged set of tRNA genes, along with reduced pressure on preferred codon usage compared to that of other bacterial genomes. The large coding capacity and the plethora of encoded secondary metabolite biosynthetic gene clusters are in line with the capability of Cm c5 to produce an arsenal of antibacterial, antifungal, and cytotoxic compounds. Known pathways of the ajudazol, chondramide, chondrochloren, crocacin, crocapeptin, and thuggacin compound families are complemented by many more natural compound biosynthetic gene clusters in the chromosome. Whole-genome comparison of the fruiting-body-forming type strain (Cm c5, DSM 14714) to an accustomed laboratory strain which has lost this ability (nonfruiting phenotype, Cm c5 fr-) revealed genetic changes in three loci. In addition to the low synteny found with the closest sequenced representative of the same family, Sorangium cellulosum, extensive genetic information duplication and broad application of eukaryotic-type signal transduction systems are hallmarks of this 11.3-Mbp prokaryotic genome.
Genome Analysis of the Fruiting Body-Forming Myxobacterium Chondromyces crocatus Reveals High Potential for Natural Product Biosynthesis. 2016, 82 (6):1945-57 Appl. Environ. Microbiol.
1098-5336
26773087
10.1128/AEM.03011-15
http://hdl.handle.net/10033/605286
Applied and environmental microbiology
Genome Analysis of the Fruiting Body-Forming Myxobacterium Chondromyces crocatus Reveals High Potential for Natural Product Biosynthesis.
oai:repository.helmholtz-hzi.de:10033/6058602019-08-30T11:32:16Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Knapp, Andreas
author
Voget, Sonja
author
Gao, Rong
author
Zaburannyi, Nestor
author
Krysciak, Dagmar
author
Breuer, Michael
author
Hauer, Bernhard
author
Streit, Wolfgang R
author
Müller, Rolf
author
Daniel, Rolf
author
Jaeger, Karl-Erich
author
2015-10-17
Burkholderia glumae is a Gram-negative phytopathogenic bacterium known as the causative agent of rice panicle blight. Strain B. glumae PG1 is used for the production of a biotechnologically relevant lipase, which is secreted into the culture supernatant via a type II secretion pathway. We have comparatively analyzed the genome sequences of B. glumae PG1 wild type and a lipase overproducing strain obtained by classical strain mutagenesis. Among a total number of 72 single nucleotide polymorphisms (SNPs) identified in the genome of the production strain, two were localized in front of the lipAB operon and were analyzed in detail. Both mutations contribute to a 100-fold overproduction of extracellular lipase in B. glumae PG1 by affecting transcription of the lipAB operon and efficiency of lipase secretion. We analyzed each of the two SNPs separately and observed a stronger influence of the promoter mutation than of the signal peptide modification but also a cumulative effect of both mutations. Furthermore, fusion of the mutated LipA signal peptide resulted in a 2-fold increase in secretion of the heterologous reporter alkaline phosphatase from Escherichia coli.
Mutations improving production and secretion of extracellular lipase by Burkholderia glumae PG1. 2015: Appl. Microbiol. Biotechnol.
1432-0614
26476653
10.1007/s00253-015-7041-z
http://hdl.handle.net/10033/605860
Applied microbiology and biotechnology
Mutations improving production and secretion of extracellular lipase by Burkholderia glumae PG1.
oai:repository.helmholtz-hzi.de:10033/6112562019-08-30T11:31:49Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Lohße, Anna
author
Kolinko, Isabel
author
Raschdorf, Oliver
author
Uebe, René
author
Borg, Sarah
author
Brachmann, Andreas
author
Plitzko, Jürgen M
author
Müller, Rolf
author
Zhang, Youming
author
Schüler, Dirk
author
2016-05-15
Magnetotactic bacteria biosynthesize specific organelles, the magnetosomes, which are membrane-enclosed crystals of a magnetic iron mineral that are aligned in a linear chain. The number and size of magnetosome particles have to be critically controlled to build a sensor sufficiently strong to ensure the efficient alignment of cells within Earth's weak magnetic field while at the same time minimizing the metabolic costs imposed by excessive magnetosome biosynthesis. Apart from their biological function, bacterial magnetosomes have gained considerable interest since they provide a highly useful model for prokaryotic organelle formation and represent biogenic magnetic nanoparticles with exceptional properties. However, potential applications have been hampered by the difficult cultivation of these fastidious bacteria and their poor yields of magnetosomes. In this study, we found that the size and number of magnetosomes within the cell are controlled by many different Mam and Mms proteins. We present a strategy for the overexpression of magnetosome biosynthesis genes in the alphaproteobacterium Magnetospirillum gryphiswaldense by chromosomal multiplication of individual and multiple magnetosome gene clusters via transposition. While stepwise amplification of the mms6 operon resulted in the formation of increasingly larger crystals (increase of ∼35%), the duplication of all major magnetosome operons (mamGFDC, mamAB, mms6, and mamXY, comprising 29 genes in total) yielded an overproducing strain in which magnetosome numbers were 2.2-fold increased. We demonstrate that the tuned expression of the mam and mms clusters provides a powerful strategy for the control of magnetosome size and number, thereby setting the stage for high-yield production of tailored magnetic nanoparticles by synthetic biology approaches.
Overproduction of Magnetosomes by Genomic Amplification of Biosynthesis-Related Gene Clusters in a Magnetotactic Bacterium. 2016, 82 (10):3032-41 Appl. Environ. Microbiol.
1098-5336
26969709
10.1128/AEM.03860-15
http://hdl.handle.net/10033/611256
Applied and environmental microbiology
Overproduction of Magnetosomes by Genomic Amplification of Biosynthesis-Related Gene Clusters in a Magnetotactic Bacterium.
oai:repository.helmholtz-hzi.de:10033/6115312019-08-30T11:26:13Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Fengler, Vera H I
author
Macheiner, Tanja
author
Kessler, Sonja M
author
Czepukojc, Beate
author
Gemperlein, Katja
author
Müller, Rolf
author
Kiemer, Alexandra K
author
Magnes, Christoph
author
Haybaeck, Johannes
author
Lackner, Carolin
author
Sargsyan, Karine
author
2016
Although non-alcoholic and alcoholic fatty liver disease have been intensively studied, concerning pathophysiological mechanisms are still incompletely understood. This may be due to the use of different animal models and resulting model-associated variation. Therefore, this study aimed to compare three frequently used wild type mouse strains in their susceptibility to develop diet-induced features of non-alcoholic/alcoholic fatty liver disease. Fatty liver disease associated clinical, biochemical, and histological features in C57BL/6, CD-1, and 129Sv WT mice were induced by (i) high-fat diet feeding, (ii) ethanol feeding only, and (iii) the combination of high-fat diet and ethanol feeding. Hepatic and subcutaneous adipose lipid profiles were compared in CD-1 and 129Sv mice. Additionally hepatic fatty acid composition was determined in 129Sv mice. In C57BL/6 mice dietary regimens resulted in heterogeneous hepatic responses, ranging from pronounced steatosis and inflammation to a lack of any features of fatty liver disease. Liver-related serum biochemistry showed high deviations within the regimen groups. CD-1 mice did not exhibit significant changes in metabolic and liver markers and developed no significant steatosis or inflammation as a response to dietary regimens. Although 129Sv mice showed no weight gain, this strain achieved most consistent features of fatty liver disease, apparent from concentration alterations of liver-related serum biochemistry as well as moderate steatosis and inflammation as a result of all dietary regimens. Furthermore, the hepatic lipid profile as well as the fatty acid composition of 129Sv mice were considerably altered, upon feeding the different dietary regimens. Accordingly, diet-induced non-alcoholic/alcoholic fatty liver disease is most consistently promoted in 129Sv mice compared to C57BL/6 and CD-1 mice. As a conclusion, this study demonstrates the importance of genetic background of used mouse strains for modeling diet-induced non-alcoholic/alcoholic fatty liver disease.
Susceptibility of Different Mouse Wild Type Strains to Develop Diet-Induced NAFLD/AFLD-Associated Liver Disease. 2016, 11 (5):e0155163 PLoS ONE
1932-6203
27167736
10.1371/journal.pone.0155163
http://hdl.handle.net/10033/611531
PloS one
Susceptibility of Different Mouse Wild Type Strains to Develop Diet-Induced NAFLD/AFLD-Associated Liver Disease.
oai:repository.helmholtz-hzi.de:10033/6137112019-08-30T11:33:24Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Braig, Simone
author
Sebastian Schmidt, B U
author
Stoiber, Katharina
author
Händel, Chris
author
Möhn, Till
author
Werz, Oliver
author
Müller, Rolf
author
Zahler, Stefan
author
Koeberle, Andreas
author
Käs, Josef A
author
Vollmar, Angelika M
author
2015-08-05
Pharmacological targeting of membrane rigidity: implications on cancer cell migration and invasion 2015, 17 (8):083007 New Journal of Physics
1367-2630
10.1088/1367-2630/17/8/083007
http://hdl.handle.net/10033/613711
New Journal of Physics
Pharmacological targeting of membrane rigidity: implications on cancer cell migration and invasion
oai:repository.helmholtz-hzi.de:10033/6148892019-08-30T11:26:13Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Wenzel, Silke C
author
Hoffmann, Holger
author
Zhang, Jidong
author
Debussche, Laurent
author
Haag-Richter, Sabine
author
Kurz, Michael
author
Nardi, Frederico
author
Lukat, Peer
author
Kochems, Irene
author
Tietgen, Heiko
author
Schummer, Dietmar
author
Nicolas, Jean-Paul
author
Calvet, Loreley
author
Czepczor, Valerie
author
Vrignaud, Patricia
author
Mühlenweg, Agnes
author
Pelzer, Stefan
author
Müller, Rolf
author
Brönstrup, Mark
author
2015-12-14
The bengamides, sponge-derived natural products that have been characterized as inhibitors of methionine aminopeptidases (MetAPs), have been intensively investigated as anticancer compounds. We embarked on a multidisciplinary project to supply bengamides by fermentation of the terrestrial myxobacterium M. virescens, decipher their biosynthesis, and optimize their properties as drug leads. The characterization of the biosynthetic pathway revealed that bacterial resistance to bengamides is conferred by Leu 154 of the myxobacterial MetAP protein, and enabled transfer of the entire gene cluster into the more suitable production host M. xanthus DK1622. A combination of semisynthesis of microbially derived bengamides and total synthesis resulted in an optimized derivative that combined high cellular potency in the nanomolar range with high metabolic stability, which translated to an improved half-life in mice and antitumor efficacy in a melanoma mouse model.
Production of the Bengamide Class of Marine Natural Products in Myxobacteria: Biosynthesis and Structure-Activity Relationships. 2015, 54 (51):15560-4 Angew. Chem. Int. Ed. Engl.
1521-3773
26514647
10.1002/anie.201508277
http://hdl.handle.net/10033/614889
Angewandte Chemie (International ed. in English)
Production of the Bengamide Class of Marine Natural Products in Myxobacteria: Biosynthesis and Structure-Activity Relationships.
oai:repository.helmholtz-hzi.de:10033/6149182019-08-30T11:26:13Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Kessler, Sonja M
author
Laggai, Stephan
author
Van Wonterg, Elien
author
Gemperlein, Katja
author
Müller, Rolf
author
Haybaeck, Johannes
author
Vandenbroucke, Roosmarijn E
author
Ogris, Manfred
author
Libert, Claude
author
Kiemer, Alexandra K
author
2016
Although insulin-like growth factor 2 (IGF2) has been reported to be overexpressed in steatosis and steatohepatitis, a causal role of IGF2 in steatosis development remains elusive. Aim of our study was to decipher the role of IGF2 in steatosis development. Hydrodynamic gene delivery of an Igf2 plasmid used for transient Igf2 overexpression employing codon-optimized plasmid DNA resulted in a strong induction of hepatic Igf2 expression. The exogenously delivered Igf2 had no influence on endogenous Igf2 expression. The downstream kinase AKT was activated in Igf2 animals. Decreased ALT levels mirrored the cytoprotective effect of IGF2. Serum cholesterol was increased and sulfo-phospho-vanillin colorimetric assay confirmed lipid accumulation in Igf2-livers while no signs of inflammation were observed. Interestingly, hepatic cholesterol and phospholipids, determined by thin layer chromatography, and free cholesterol by filipin staining, were specifically increased. Lipid droplet (LD) size was not changed, but their number was significantly elevated. Furthermore, free cholesterol, which can be stored in LDs and has been reported to be critical for steatosis progression, was elevated in Igf2 overexpressing mice. Accordingly, Hmgcr/HmgCoAR was upregulated. To have a closer look at de novo lipid synthesis we investigated expression of the lipogenic transcription factor SREBF1 and its target genes. SREBF1 was induced and also SREBF1 target genes were slightly upregulated. Interestingly, the expression of Cpt1a, which is responsible for mitochondrial fatty acid oxidation, was induced. Hepatic IGF2 expression induces a fatty liver, characterized by increased cholesterol and phospholipids leading to accumulation of LDs. We therefore suggest a causal role for IGF2 in hepatic lipid accumulation.
Transient Hepatic Overexpression of Insulin-Like Growth Factor 2 Induces Free Cholesterol and Lipid Droplet Formation. 2016, 7:147 Front Physiol
1664-042X
27199763
10.3389/fphys.2016.00147
http://hdl.handle.net/10033/614918
Frontiers in physiology
Transient Hepatic Overexpression of Insulin-Like Growth Factor 2 Induces Free Cholesterol and Lipid Droplet Formation.
oai:repository.helmholtz-hzi.de:10033/6159792019-08-30T11:26:42Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Zhang, Siwei
author
Schneider, Lina S
author
Vick, Binje
author
Grunert, Michaela
author
Jeremias, Irmela
author
Menche, Dirk
author
Müller, Rolf
author
Vollmar, Angelika M
author
Liebl, Johanna
author
2015-12-22
Prognosis for patients suffering from T-ALL is still very poor and new strategies for T-ALL treatment are urgently needed. Our study shows potent anti-leukemic effects of the myxobacterial V-ATPase inhibitor Archazolid A. Archazolid A reduced growth and potently induced death of leukemic cell lines and human leukemic samples. By inhibiting lysosomal acidification, Archazolid A blocked activation of the Notch pathway, however, this was not the mechanism of V-ATPase inhibition relevant for cell death induction. In fact, V-ATPase inhibition by Archazolid A decreased the anti-apoptotic protein survivin. As underlying mode of action, this work is in line with recent studies from our group demonstrating that Archazolid A induced S-phase cell cycle arrest by interfering with the iron metabolism in leukemic cells. Our study provides evidence for V-ATPase inhibition as a potential new therapeutic option for T-ALL.
Anti-leukemic effects of the V-ATPase inhibitor Archazolid A. 2015, 6 (41):43508-28 Oncotarget
1949-2553
26496038
10.18632/oncotarget.6180
http://hdl.handle.net/10033/615979
Oncotarget
Anti-leukemic effects of the V-ATPase inhibitor Archazolid A.
oai:repository.helmholtz-hzi.de:10033/6169542019-08-30T11:25:43Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Tu, Qiang
author
Yin, Jia
author
Fu, Jun
author
Herrmann, Jennifer
author
Li, Yuezhong
author
Yin, Yulong
author
Stewart, A Francis
author
Müller, Rolf
author
Zhang, Youming
author
2016
Bacterial competent cells are essential for cloning, construction of DNA libraries, and mutagenesis in every molecular biology laboratory. Among various transformation methods, electroporation is found to own the best transformation efficiency. Previous electroporation methods are based on washing and electroporating the bacterial cells in ice-cold condition that make them fragile and prone to death. Here we present simple temperature shift based methods that improve DNA transformation and recombineering efficiency in E. coli and several other gram-negative bacteria thereby economizing time and cost. Increased transformation efficiency of large DNA molecules is a significant advantage that might facilitate the cloning of large fragments from genomic DNA preparations and metagenomics samples.
Room temperature electrocompetent bacterial cells improve DNA transformation and recombineering efficiency. 2016, 6:24648 Sci Rep
2045-2322
27095488
10.1038/srep24648
http://hdl.handle.net/10033/616954
Scientific reports
Room temperature electrocompetent bacterial cells improve DNA transformation and recombineering efficiency.
oai:repository.helmholtz-hzi.de:10033/6205642019-08-30T11:25:43Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Wang, Mingxun
author
Carver, Jeremy J
author
Phelan, Vanessa V
author
Sanchez, Laura M
author
Garg, Neha
author
Peng, Yao
author
Nguyen, Don Duy
author
Watrous, Jeramie
author
Kapono, Clifford A
author
Luzzatto-Knaan, Tal
author
Porto, Carla
author
Bouslimani, Amina
author
Melnik, Alexey V
author
Meehan, Michael J
author
Liu, Wei-Ting
author
Crüsemann, Max
author
Boudreau, Paul D
author
Esquenazi, Eduardo
author
Sandoval-Calderón, Mario
author
Kersten, Roland D
author
Pace, Laura A
author
Quinn, Robert A
author
Duncan, Katherine R
author
Hsu, Cheng-Chih
author
Floros, Dimitrios J
author
Gavilan, Ronnie G
author
Kleigrewe, Karin
author
Northen, Trent
author
Dutton, Rachel J
author
Parrot, Delphine
author
Carlson, Erin E
author
Aigle, Bertrand
author
Michelsen, Charlotte F
author
Jelsbak, Lars
author
Sohlenkamp, Christian
author
Pevzner, Pavel
author
Edlund, Anna
author
McLean, Jeffrey
author
Piel, Jörn
author
Murphy, Brian T
author
Gerwick, Lena
author
Liaw, Chih-Chuang
author
Yang, Yu-Liang
author
Humpf, Hans-Ulrich
author
Maansson, Maria
author
Keyzers, Robert A
author
Sims, Amy C
author
Johnson, Andrew R
author
Sidebottom, Ashley M
author
Sedio, Brian E
author
Klitgaard, Andreas
author
Larson, Charles B
author
Boya P, Cristopher A
author
Torres-Mendoza, Daniel
author
Gonzalez, David J
author
Silva, Denise B
author
Marques, Lucas M
author
Demarque, Daniel P
author
Pociute, Egle
author
O'Neill, Ellis C
author
Briand, Enora
author
Helfrich, Eric J N
author
Granatosky, Eve A
author
Glukhov, Evgenia
author
Ryffel, Florian
author
Houson, Hailey
author
Mohimani, Hosein
author
Kharbush, Jenan J
author
Zeng, Yi
author
Vorholt, Julia A
author
Kurita, Kenji L
author
Charusanti, Pep
author
McPhail, Kerry L
author
Nielsen, Kristian Fog
author
Vuong, Lisa
author
Elfeki, Maryam
author
Traxler, Matthew F
author
Engene, Niclas
author
Koyama, Nobuhiro
author
Vining, Oliver B
author
Baric, Ralph
author
Silva, Ricardo R
author
Mascuch, Samantha J
author
Tomasi, Sophie
author
Jenkins, Stefan
author
Macherla, Venkat
author
Hoffman, Thomas
author
Agarwal, Vinayak
author
Williams, Philip G
author
Dai, Jingqui
author
Neupane, Ram
author
Gurr, Joshua
author
Rodríguez, Andrés M C
author
Lamsa, Anne
author
Zhang, Chen
author
Dorrestein, Kathleen
author
Duggan, Brendan M
author
Almaliti, Jehad
author
Allard, Pierre-Marie
author
Phapale, Prasad
author
Nothias, Louis-Felix
author
Alexandrov, Theodore
author
Litaudon, Marc
author
Wolfender, Jean-Luc
author
Kyle, Jennifer E
author
Metz, Thomas O
author
Peryea, Tyler
author
Nguyen, Dac-Trung
author
VanLeer, Danielle
author
Shinn, Paul
author
Jadhav, Ajit
author
Müller, Rolf
author
Waters, Katrina M
author
Shi, Wenyuan
author
Liu, Xueting
author
Zhang, Lixin
author
Knight, Rob
author
Jensen, Paul R
author
Palsson, Bernhard Ø
author
Pogliano, Kit
author
Linington, Roger G
author
Gutiérrez, Marcelino
author
Lopes, Norberto P
author
Gerwick, William H
author
Moore, Bradley S
author
Dorrestein, Pieter C
author
Bandeira, Nuno
author
2016-08-09
The potential of the diverse chemistries present in natural products (NP) for biotechnology and medicine remains untapped because NP databases are not searchable with raw data and the NP community has no way to share data other than in published papers. Although mass spectrometry (MS) techniques are well-suited to high-throughput characterization of NP, there is a pressing need for an infrastructure to enable sharing and curation of data. We present Global Natural Products Social Molecular Networking (GNPS; http://gnps.ucsd.edu), an open-access knowledge base for community-wide organization and sharing of raw, processed or identified tandem mass (MS/MS) spectrometry data. In GNPS, crowdsourced curation of freely available community-wide reference MS libraries will underpin improved annotations. Data-driven social-networking should facilitate identification of spectra and foster collaborations. We also introduce the concept of 'living data' through continuous reanalysis of deposited data.
Sharing and community curation of mass spectrometry data with Global Natural Products Social Molecular Networking. 2016, 34 (8):828-37 Nat. Biotechnol.
1546-1696
27504778
10.1038/nbt.3597
http://hdl.handle.net/10033/620564
Nature biotechnology
Sharing and community curation of mass spectrometry data with Global Natural Products Social Molecular Networking.
oai:repository.helmholtz-hzi.de:10033/6206172019-08-30T11:34:18Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Chen, Jinsong
author
Liu, Mei
author
Liu, Xueting
author
Miao, Jin
author
Fu, Chengzhang
author
Gao, Heyong
author
Müller, Rolf
author
Zhang, Qing
author
Zhang, Lixin
author
2016-03
Interrogation of Streptomyces avermitilis for efficient production of avermectins 2016, 1 (1):7 Synthetic and Systems Biotechnology
2405805X
10.1016/j.synbio.2016.03.002
http://hdl.handle.net/10033/620617
Synthetic and Systems Biotechnology
Interrogation of Streptomyces avermitilis for efficient production of avermectins
oai:repository.helmholtz-hzi.de:10033/6206882019-08-30T11:33:57Zcom_10033_311308com_10033_620618col_10033_620619col_10033_559591col_10033_620561
00925njm 22002777a 4500
dc
Bock, Tobias
author
Volz, Carsten
author
Hering, Vanessa
author
Scrima, Andrea
author
Müller, Rolf
author
Blankenfeldt, Wulf
author
2016-12-09
Isovaleryl coenzyme A (IV-CoA) is an important building block of iso-fatty acids. In myxobacteria, IV-CoA is essential for the formation of signaling molecules involved in fruiting body formation. Leucine degradation is the common source of IV-CoA, but a second, de novo biosynthetic route to IV-CoA termed AIB (alternative IV-CoA biosynthesis) was recently discovered in M. xanthus The AIB-operon contains the TetR-like transcriptional regulator AibR, which we characterize in this study. We demonstrate that IV-CoA binds AibR with micromolar affinity and show by gelshift experiments that AibR interacts with the promoter region of the AIB-operon once IV-CoA is present. We identify an 18-bp near-perfect palindromic repeat as containing the AibR operator and provide evidence that AibR also controls an additional genomic locus coding for a putative acetyl-CoA acetyltransferase. To elucidate atomic details, we determined crystal structures of AibR in the apo, the IV-CoA- and the IV-CoA-DNA-bound state to 1.7 Å, 2.35 Å and 2.92 Å, respectively. IV-CoA induces partial unfolding of an α-helix, which allows sequence-specific interactions between AibR and its operator. This study provides insights into AibR-mediated regulation and shows that AibR functions in an unusual TetR-like manner by blocking transcription not in the ligand-free but in the effector-bound state.
The AibR-isovaleryl coenzyme A regulator and its DNA binding site - a model for the regulation of alternative de novo isovaleryl coenzyme A biosynthesis in Myxococcus xanthus. 2016 Nucleic Acids Res.
1362-4962
27940564
10.1093/nar/gkw1238
http://hdl.handle.net/10033/620688
Nucleic acids research
The AibR-isovaleryl coenzyme A regulator and its DNA binding site - a model for the regulation of alternative de novo isovaleryl coenzyme A biosynthesis in Myxococcus xanthus.
oai:repository.helmholtz-hzi.de:10033/6208472019-08-30T11:27:16Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Awal, Ram Prasad
author
Garcia, Ronald
author
Gemperlein, Katja
author
Wink, Joachim
author
Kunwar, Bikram
author
Parajuli, Niranjan
author
Müller, Rolf
author
2017-01-28
Bacterial strains designated MCy10943T and MCy10944T were isolated in 2014 from dried Nepalese soil samples collected in 2013 from Phukot, Kalikot, Western Nepal and Godawari, Lalitpur, Central Nepal. The novel organisms showed typical myxobacterial growth characteristics which include swarming colony and fruiting body formation on solid surfaces, and a predatory ability to lyse microorganisms. The strains were aerobic, mesophilic, chemoheterotrophic and showed resistance to various antibiotics. The major cellular fatty acids common to both organisms were C17:0 2-OH, iso-C15:0, C16:1 and iso-C17:0. The G + C content of the genomic DNA was 72-75 mol %. Phylogenetic analysis showed that the strains belong to the family Cystobacteraceae, suborder Cystobacterineae, order Myxococcales. The 16S rRNA gene sequences of both strains showed 97-98 % similarity to Archangium gephyra DSM 2261T, Cystobacter violaceus DSM 14727T, and 96.7-97 % to Cystobacter fuscus DSM 2262T and Angiococcus disciformis DSM 52716T. Polyphasic taxonomic characterisation suggested that strains MCy10943T and MCy10944T represent two distinct species of a novel genus, for which the names Vitiosangium cumulatum and Vitiosangium subalbum are proposed. The type strain of Vitiosangium cumulatum is MCy10943T (=DSM 102952T =NCCB 100600T) while for Vitiosangium subalbum is MCy10944T (=DSM 102953T =NCCB 100601T). In addition, the genera Archangium and Angiococcus, and the family Cystobacteraceae is herewith emended.
Vitiosangium cumulatum gen. nov., sp. nov. and Vitiosangium subalbum sp. nov., novel soil myxobacteria from Nepal , and emended descriptions of genus Archangium and Angiococcus, and of Cystobacteraceae family. 2017 Int. J. Syst. Evol. Microbiol.
1466-5034
28141508
10.1099/ijsem.0.001829
http://hdl.handle.net/10033/620847
International journal of systematic and evolutionary microbiology
Vitiosangium cumulatum gen. nov., sp. nov. and Vitiosangium subalbum sp. nov., novel soil myxobacteria from Nepal , and emended descriptions of genus Archangium and Angiococcus, and of Cystobacteraceae family.
oai:repository.helmholtz-hzi.de:10033/6208482019-08-30T11:34:22Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Thomas, Lea
author
Rao, Zhigang
author
Gerstmeier, Jana
author
Raasch, Martin
author
Weinigel, Christina
author
Rummler, Silke
author
Menche, Dirk
author
Müller, Rolf
author
Pergola, Carlo
author
Mosig, Alexander
author
Werz, Oliver
author
2017-02-09
Pharmacological interference with vacuolar-type H(+)-ATPase (V-ATPase), a proton-translocating enzyme involved in protein transport and pH regulation of cell organelles, is considered a potential strategy for cancer therapy. Macrophages are critically involved in tumor progression and may occur as pro-tumoral M2 phenotype, whereas classically-activated M1 can inhibit tumor development for example by releasing tumor-suppressing molecules, including tumor necrosis factor (TNF)α. Here, we show that targeting V-ATPase by selective inhibitors such as archazolid upregulates the expression and secretion of TNFα in lipopolysaccharide (LPS)- or LPS/interferon (INF)γ-activated M1-like macrophages derived from human blood monocytes. In contrast, archazolid failed to elevate TNFα production from uncommitted (M0) or interleukin (IL)-4-treated M2-like macrophages. Secretion of other relevant cytokines (i.e., IL-1β, IL-6, IL-10) or chemokines (i.e. IL-8 and monocyte chemotactic protein-1) from M1 was not affected by archazolid. Though V-ATPase inhibitors elevated the lysosomal pH in M1 comparable to chloroquine or ammonium chloride, the latter agents suppressed TNFα secretion. Archazolid selectively increased TNFα mRNA levels, which was abolished by dexamethasone. Interestingly, archazolid enhanced the phosphorylation and nuclear translocation of the p65 subunit of NFκB and stimulated phosphorylation of SAPK/JNK. In a microfluidically-supported human tumor biochip model, archazolid-treated M1 significantly reduced tumor cell viability. Together, our data show that V-ATPase inhibition selectively upregulates TNFα production in classically-activated macrophages along with NFκB and SAPK/JNK activation. Such increased TNFα release caused by V-ATPase inhibitors may contribute to tumor suppression in addition to direct targeting cancer cells.
Selective upregulation of TNFα expression in classically-activated human monocyte-derived macrophages (M1) through pharmacological interference with V-ATPase. 2017 Biochem. Pharmacol.
1873-2968
28189727
10.1016/j.bcp.2017.02.004
http://hdl.handle.net/10033/620848
Biochemical pharmacology
Selective upregulation of TNFα expression in classically-activated human monocyte-derived macrophages (M1) through pharmacological interference with V-ATPase.
oai:repository.helmholtz-hzi.de:10033/6208732019-08-30T11:33:51Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Schmidt, Witali
author
Jones, Peter
author
Herrmann, Jennifer
author
Müller, Rolf
author
Schulz, Stefan
author
2016-11-18
An Unprecedented Octahydro-3H-oxeto[2,3,4-ij]isochromene Ring System Formed by a Trichloromethyl-Anion-Induced Reaction Cascade 2016, 28 (04):467 Synlett
0936-5214
1437-2096
10.1055/s-0036-1588917
http://hdl.handle.net/10033/620873
Synlett
An Unprecedented Octahydro-3H-oxeto[2,3,4-ij]isochromene Ring System Formed by a Trichloromethyl-Anion-Induced Reaction Cascade
oai:repository.helmholtz-hzi.de:10033/6209272019-08-30T11:35:39Zcom_10033_311308com_10033_620618col_10033_620619col_10033_620619col_10033_559591
00925njm 22002777a 4500
dc
Bock, Tobias
author
Kasten, Janin
author
Müller, Rolf
author
Blankenfeldt, Wulf
author
2016-07-01
A critical step in bacterial isoprenoid production is the synthesis of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) catalyzed by HMG-CoA synthase (HMGCS). In myxobacteria, this enzyme is also involved in a recently discovered alternative and acetyl-CoA-dependent isovaleryl CoA biosynthesis pathway. Here we present crystal structures of MvaS, the HMGCS from Myxococcus xanthus, in complex with CoA and acetylated active site Cys115, with the second substrate acetoacetyl CoA and with the product of the condensation reaction, 3-hydroxy-3-methylglutaryl CoA. With these structures, we show that MvaS uses the common HMGCS enzymatic mechanism and provide evidence that dimerization plays a role in the formation and stability of the active site. Overall, MvaS shows features typical of the eukaryotic HMGCS and exhibits differences from homologues from Gram-positive bacteria. This study provides insights into myxobacterial alternative isovaleryl CoA biosynthesis and thereby extends the toolbox for the biotechnological production of renewable fuel and chemicals.
Crystal Structure of the HMG-CoA Synthase MvaS from the Gram-Negative Bacterium Myxococcus xanthus. 2016, 17 (13):1257-62 Chembiochem
1439-7633
27124816
10.1002/cbic.201600070
http://hdl.handle.net/10033/620927
Chembiochem : a European journal of chemical biology
Crystal Structure of the HMG-CoA Synthase MvaS from the Gram-Negative Bacterium Myxococcus xanthus.
oai:repository.helmholtz-hzi.de:10033/6210042019-08-30T11:31:23Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Pergola, Carlo
author
Schubert, Katrin
author
Pace, Simona
author
Ziereisen, Jana
author
Nikels, Felix
author
Scherer, Olga
author
Hüttel, Stephan
author
Zahler, Stefan
author
Vollmar, Angelika M
author
Weinigel, Christina
author
Rummler, Silke
author
Müller, Rolf
author
Raasch, Martin
author
Mosig, Alexander
author
Koeberle, Andreas
author
Werz, Oliver
author
2017-01-30
Tumour-associated macrophages mainly comprise immunosuppressive M2 phenotypes that promote tumour progression besides anti-tumoural M1 subsets. Selective depletion or reprogramming of M2 may represent an innovative anti-cancer strategy. The actin cytoskeleton is central for cellular homeostasis and is targeted for anti-cancer chemotherapy. Here, we show that targeting G-actin nucleation using chondramide A (ChA) predominantly depletes human M2 while promoting the tumour-suppressive M1 phenotype. ChA reduced the viability of M2, with minor effects on M1, but increased tumour necrosis factor (TNF)α release from M1. Interestingly, ChA caused rapid disruption of dynamic F-actin filaments and polymerization of G-actin, followed by reduction of cell size, binucleation and cell division, without cellular collapse. In M1, but not in M2, ChA caused marked activation of SAPK/JNK and NFκB, with slight or no effects on Akt, STAT-1/-3, ERK-1/2, and p38 MAPK, seemingly accounting for the better survival of M1 and TNFα secretion. In a microfluidically-supported human tumour biochip model, circulating ChA-treated M1 markedly reduced tumour cell viability through enhanced release of TNFα. Together, ChA may cause an anti-tumoural microenvironment by depletion of M2 and activation of M1, suggesting induction of G-actin nucleation as potential strategy to target tumour-associated macrophages in addition to neoplastic cells.
Modulation of actin dynamics as potential macrophage subtype-targeting anti-tumour strategy. 2017, 7:41434 Sci Rep
2045-2322
28134280
10.1038/srep41434
http://hdl.handle.net/10033/621004
Scientific reports
Modulation of actin dynamics as potential macrophage subtype-targeting anti-tumour strategy.
oai:repository.helmholtz-hzi.de:10033/6210722019-08-30T11:26:42Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Petković, Hrvoje
author
Lukežič, Tadeja
author
Šušković, Jagoda
author
2017-03
Natural tetracycline (TC) antibiotics were the first major class of therapeutics to earn the distinction of 'broad-spectrum antibiotics' and they have been used since the 1940s against a wide range of both Gram-positive and Gram-negative pathogens, mycoplasmas, intracellular chlamydiae, rickettsiae and protozoan parasites. The second generation of semisynthetic tetracyclines, such as minocycline and doxycycline, with improved antimicrobial potency, were introduced during the 1960s. Despite emerging resistance to TCs erupting during the 1980s, it was not until 2006, more than four decades later, that a third--generation TC, named tigecycline, was launched. In addition, two TC analogues, omadacycline and eravacycline, developed via (semi)synthetic and fully synthetic routes, respectively, are at present under clinical evaluation. Interestingly, despite very productive early work on the isolation of a Streptomyces aureofaciens mutant strain that produced 6-demethyl-7-chlortetracycline, the key intermediate in the production of second- and third-generation TCs, biosynthetic approaches in TC development have not been productive for more than 50 years. Relatively slow and tedious molecular biology approaches for the genetic manipulation of TC-producing actinobacteria, as well as an insufficient understanding of the enzymatic mechanisms involved in TC biosynthesis have significantly contributed to the low success of such biosynthetic engineering efforts. However, new opportunities in TC drug development have arisen thanks to a significant progress in the development of affordable and versatile biosynthetic engineering and synthetic biology approaches, and, importantly, to a much deeper understanding of TC biosynthesis, mostly gained over the last two decades.
Biosynthesis of Oxytetracycline by Streptomyces rimosus:
Past, Present and Future Directions in the Development
of Tetracycline Antibiotics. 2017, 55 (1):3-13 Food Technol. Biotechnol.
1330-9862
28559729
10.17113/ftb.55.01.17.4617
http://hdl.handle.net/10033/621072
Food technology and biotechnology
Biosynthesis of Oxytetracycline by Streptomyces rimosus:
Past, Present and Future Directions in the Development
of Tetracycline Antibiotics.
oai:repository.helmholtz-hzi.de:10033/6210922019-08-30T11:27:16Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Bartel, Karin
author
Winzi, Maria
author
Ulrich, Melanie
author
Koeberle, Andreas
author
Menche, Dirk
author
Werz, Oliver
author
Müller, Rolf
author
Guck, Jochen
author
Vollmar, Angelika M
author
von Schwarzenberg, Karin
author
2017-02-07
Hepatocellular carcinoma (HCC) is the fifth most frequent cancer worldwide and the third leading cause of cancer-related death. However, therapy options are limited leaving an urgent need to develop new strategies. Currently, targeting cancer cell lipid and cholesterol metabolism is gaining interest especially regarding HCC. High cholesterol levels support proliferation, membrane-related mitogenic signaling and increase cell softness, leading to tumor progression, malignancy and invasive potential. However, effective ways to target cholesterol metabolism for cancer therapy are still missing. The V-ATPase inhibitor archazolid was recently shown to interfere with cholesterol metabolism. In our study, we report a novel therapeutic potential of V-ATPase inhibition in HCC by altering the mechanical phenotype of cancer cells leading to reduced proliferative signaling. Archazolid causes cellular depletion of free cholesterol leading to an increase in cell stiffness and membrane polarity of cancer cells, while hepatocytes remain unaffected. The altered membrane composition decreases membrane fluidity and leads to an inhibition of membrane-related Ras signaling resulting decreased proliferation in vitro and in vivo. V-ATPase inhibition represents a novel link between cell biophysical properties and proliferative signaling selectively in malignant HCC cells, providing the basis for an attractive and innovative strategy against HCC.
V-ATPase inhibition increases cancer cell stiffness and blocks membrane related Ras signaling - a new option for HCC therapy. 2017, 8 (6):9476-9487 Oncotarget
1949-2553
28036299
10.18632/oncotarget.14339
http://hdl.handle.net/10033/621092
Oncotarget
V-ATPase inhibition increases cancer cell stiffness and blocks membrane related Ras signaling - a new option for HCC therapy.
oai:repository.helmholtz-hzi.de:10033/6211022019-08-30T11:33:57Zcom_10033_620857com_10033_620618col_10033_620858col_10033_620619
00925njm 22002777a 4500
dc
Beckmann, Amelie
author
Hüttel, Stephan
author
Schmitt, Viktoria
author
Müller, Rolf
author
Stadler, Marc
author
2017-08-17
Recently, the discovery of the elansolids, a group of macrolides, was reported. The molecules show activity against methicillin-resistant Staphylococcus aureus as well as other gram-positive organisms. This fact renders those substances a promising starting point for future chemical development. The active atropisomers A1/A2 are formed by macrolactonization of the biosynthesis product A3 but are prone to ring opening and subsequent formation of several unwanted side products. Recently it could be shown that addition of different nucleophiles to culture extracts of Chitinophaga sancti enable the formation of new stable elansolid derivatives. Furthermore, addition of such a nucleophile directly into the culture led exclusively to formation of a single active elansolid derivative. Due to low product yields, methods for production of gram amounts of these molecules have to be established to enable further development of this promising compound class.
Optimization of the biotechnological production of a novel class of anti-MRSA antibiotics from Chitinophaga sancti. 2017, 16 (1):143 Microb. Cell Fact.
1475-2859
28818083
10.1186/s12934-017-0756-z
http://hdl.handle.net/10033/621102
Microbial cell factories
Optimization of the biotechnological production of a novel class of anti-MRSA antibiotics from Chitinophaga sancti.
oai:repository.helmholtz-hzi.de:10033/6211362019-08-30T11:27:16Zcom_10033_311624com_10033_6839com_10033_620618col_10033_311625col_10033_620619
00925njm 22002777a 4500
dc
Rox, Katharina
author
Jansen, Rolf
author
Loof, Torsten G.
author
Gillen, Christine M.
author
Bernecker, Steffen
author
Walker, Mark J.
author
Chhatwal, Gursharan Singh
author
Müller, Rolf
author
2017-09-18
In contrast to mild infections of Group A Streptococcus (GAS) invasive infections of GAS still pose a serious health hazard: GAS disseminates from sterile sites into the blood stream or deep tissues and causes sepsis or necrotizing fasciitis. In this case antibiotics do not provide an effective cure as the bacteria are capable to hide from them very quickly. Therefore, new remedies are urgently needed. Starting from a myxobacterial natural products screening campaign, we identified two fatty acids isolated from myxobacteria, linoleic and palmitoleic acid, specifically blocking streptokinase-mediated activation of plasminogen and thereby preventing streptococci from hijacking the host’s plasminogen/plasmin system. This activity is not inherited by other fatty acids such as oleic acid and is not attributable to the killing of streptococci. Moreover, both fatty acids are superior in their inhibitory properties compared to two clinically used drugs (tranexamic or ε-amino caproic acid) as they show 500–1000 fold lower IC50 values. Using a humanized plasminogen mouse model mimicking the clinical situation of a local GAS infection that becomes systemic, we demonstrate that these fatty acids ameliorate invasive GAS infection significantly. Consequently, linoleic and palmitoleic acid are possible new options to combat GAS invasive diseases.
Linoleic and palmitoleic acid block streptokinase-mediated plasminogen activation and reduce severity of invasive group A streptococcal infection 2017, 7 (1) Scientific Reports
2045-2322
10.1038/s41598-017-11276-z
http://hdl.handle.net/10033/621136
Scientific Reports
Linoleic and palmitoleic acid block streptokinase-mediated plasminogen activation and reduce severity of invasive group A streptococcal infection
oai:repository.helmholtz-hzi.de:10033/6211512019-08-30T11:33:57Zcom_10033_620636com_10033_620644com_10033_620618col_10033_620619col_10033_620638col_10033_620647
00925njm 22002777a 4500
dc
Donner, Jannik
author
Reck, Michael
author
Bunk, Boyke
author
Jarek, Michael
author
App, Constantin Benjamin
author
Meier-Kolthoff, Jan P
author
Overmann, Jörg
author
Müller, Rolf
author
Kirschning, Andreas
author
Wagner-Döbler, Irene
author
2017-11-01
The myxobacterial secondary metabolite carolacton inhibits growth of Streptococcus pneumoniae and kills biofilm cells of the caries- and endocarditis-associated pathogen Streptococcus mutans at nanomolar concentrations. Here, we studied the response to carolacton of an Escherichia coli strain that lacked the outer membrane protein TolC. Whole-genome sequencing of the laboratory E. coli strain TolC revealed the integration of an insertion element, IS5, at the tolC locus and a close phylogenetic relationship to the ancient E. coli K-12. We demonstrated via transcriptome sequencing (RNA-seq) and determination of MIC values that carolacton penetrates the phospholipid bilayer of the Gram-negative cell envelope and inhibits growth of E. coli TolC at similar concentrations as for streptococci. This inhibition is completely lost for a C-9 (R) epimer of carolacton, a derivative with an inverted stereocenter at carbon atom 9 [(S) → (R)] as the sole difference from the native molecule, which is also inactive in S. pneumoniae and S. mutans, suggesting a specific interaction of native carolacton with a conserved cellular target present in bacterial phyla as distantly related as Firmicutes and Proteobacteria. The efflux pump inhibitor (EPI) phenylalanine arginine β-naphthylamide (PAβN), which specifically inhibits AcrAB-TolC, renders E. coli susceptible to carolacton. Our data indicate that carolacton has potential for use in antimicrobial chemotherapy against Gram-negative bacteria, as a single drug or in combination with EPIs. Strain E. coli TolC has been deposited at the DSMZ; together with the associated RNA-seq data and MIC values, it can be used as a reference during future screenings for novel bioactive compounds. IMPORTANCE The emergence of pathogens resistant against most or all of the antibiotics currently used in human therapy is a global threat, and therefore the search for antimicrobials with novel targets and modes of action is of utmost importance. The myxobacterial secondary metabolite carolacton had previously been shown to inhibit biofilm formation and growth of streptococci. Here, we investigated if carolacton could act against Gram-negative bacteria, which are difficult targets because of their double-layered cytoplasmic envelope. We found that the model organism Escherichia coli is susceptible to carolacton, similar to the Gram-positive Streptococcus pneumoniae, if its multidrug efflux system AcrAB-TolC is either inactivated genetically, by disruption of the tolC gene, or physiologically by coadministering an efflux pump inhibitor. A carolacton epimer that has a different steric configuration at carbon atom 9 is completely inactive, suggesting that carolacton may interact with the same molecular target in both Gram-positive and Gram-negative bacteria.
The Biofilm Inhibitor Carolacton Enters Gram-Negative Cells: Studies Using a TolC-Deficient Strain of Escherichia coli., 2 (5) mSphere
2379-5042
28959742
10.1128/mSphereDirect.00375-17
http://hdl.handle.net/10033/621151
mSphere
The Biofilm Inhibitor Carolacton Enters Gram-Negative Cells: Studies Using a TolC-Deficient Strain of Escherichia coli.
oai:repository.helmholtz-hzi.de:10033/6211842019-08-30T11:25:11Zcom_10033_620533com_10033_311308com_10033_620618col_10033_620534col_10033_620619col_10033_559591
00925njm 22002777a 4500
dc
Lukat, Peer
author
Katsuyama, Yohei
author
Wenzel, Silke
author
Binz, Tina
author
König, Claudia
author
Blankenfeldt, Wulf
author
Brönstrup, Mark
author
Müller, Rolf
author
2017-11-01
Griselimycins (GMs) are depsidecapeptides with superb anti-tuberculosis activity. They contain up to three (2S,4R)-4-methyl-prolines (4-MePro), of which one blocks oxidative degradation and increases metabolic stability in animal models. The natural congener with this substitution is only a minor component in fermentation cultures. We showed that this product can be significantly increased by feeding the reaction with 4-MePro and we investigated the molecular basis of 4-MePro biosynthesis and incorporation. We identified the GM biosynthetic gene cluster as encoding a nonribosomal peptide synthetase and a sub-operon for 4-MePro formation. Using heterologous expression, gene inactivation, and in vitro experiments, we showed that 4-MePro is generated by leucine hydroxylation, oxidation to an aldehyde, and ring closure with subsequent reduction. The crystal structures of the leucine hydroxylase GriE have been determined in complex with substrates and products, providing insight into the stereospecificity of the reaction.
Biosynthesis of methyl-proline containing griselimycins, natural products with anti-tuberculosis activity. 2017, 8 (11):7521-7527 Chem Sci
2041-6520
29163906
10.1039/c7sc02622f
http://hdl.handle.net/10033/621184
Chemical science
Biosynthesis of methyl-proline containing griselimycins, natural products with anti-tuberculosis activity.
oai:repository.helmholtz-hzi.de:10033/6211902019-08-30T11:36:32Zcom_10033_620644com_10033_620618col_10033_620619col_10033_620647
00925njm 22002777a 4500
dc
Fu, Chengzhang
author
Sikandar, Asfandyar
author
Donner, Jannik
author
Zaburannyi, Nestor
author
Herrmann, Jennifer
author
Reck, Michael
author
Wagner-Döbler, Irene
author
Koehnke, Jesko
author
Müller, Rolf
author
2017-11-16
The natural product carolacton is a macrolide keto-carboxylic acid produced by the myxobacterium Sorangium cellulosum, and was originally described as an antibacterial compound. Here we show that carolacton targets FolD, a key enzyme from the folate-dependent C1 metabolism. We characterize the interaction between bacterial FolD and carolacton biophysically, structurally and biochemically. Carolacton binds FolD with nanomolar affinity, and the crystal structure of the FolD-carolacton complex reveals the mode of binding. We show that the human FolD orthologs, MTHFD1 and MTHFD2, are also inhibited in the low nM range, and that micromolar concentrations of carolacton inhibit the growth of cancer cell lines. As mitochondrial MTHFD2 is known to be upregulated in cancer cells, it may be possible to use carolacton as an inhibitor tool compound to assess MTHFD2 as an anti-cancer target.
The natural product carolacton inhibits folate-dependent C1 metabolism by targeting FolD/MTHFD. 2017, 8 (1):1529 Nat Commun
2041-1723
29142318
10.1038/s41467-017-01671-5
http://hdl.handle.net/10033/621190
Nature communications
The natural product carolacton inhibits folate-dependent C1 metabolism by targeting FolD/MTHFD.
oai:repository.helmholtz-hzi.de:10033/6212122019-08-30T11:34:22Zcom_10033_620656com_10033_620618col_10033_620658col_10033_620619
00925njm 22002777a 4500
dc
Wagner, Stefanie
author
Hauck, Dirk
author
Hoffmann, Michael
author
Sommer, Roman
author
Joachim, Ines
author
Müller, Rolf
author
Imberty, Anne
author
Varrot, Annabelle
author
Titz, Alexander
author
2017-09-28
Biofilm formation by pathogenic bacteria is a hallmark of chronic infections. In many cases, lectins play key roles in establishing biofilms. The pathogen Pseudomonas aeruginosa often exhibiting various drug resistances employs its lectins LecA and LecB as virulence factors and biofilm building blocks. Therefore, inhibition of the function of these proteins is thought to have potential in developing "pathoblockers" preventing biofilm formation and virulence. A covalent lectin inhibitor specific to a carbohydrate binding site is described for the first time. Its application in the LecA-specific in vitro imaging of biofilms formed by P. aeruginosa is also reported.
Covalent Lectin Inhibition and Application in Bacterial Biofilm Imaging. 2017 Angew. Chem. Int. Ed. Engl.
1521-3773
28960731
10.1002/anie.201709368
http://hdl.handle.net/10033/621212
Angewandte Chemie (International ed. in English)
Covalent Lectin Inhibition and Application in Bacterial Biofilm Imaging.
oai:repository.helmholtz-hzi.de:10033/6212152019-08-30T11:31:49Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Corr, M J
author
Sharma, S V
author
Pubill-Ulldemolins, C
author
Bown, R T
author
Poirot, P
author
Smith, D R M
author
Cartmell, C
author
Abou Fayad, A
author
Goss, R J M
author
2017-03-01
The blending together of synthetic chemistry with natural product biosynthesis represents a potentially powerful approach to synthesis; to enable this, further synthetic tools and methodologies are needed. To this end, we have explored the first Sonogashira cross-coupling to halotryptophans in water. Broad reaction scope is demonstrated and we have explored the limits of the scope of the reaction. We have demonstrated this methodology to work excellently in the modification of model tripeptides. Furthermore, through precursor directed biosynthesis, we have generated for the first time a new to nature brominated natural product bromo-cystargamide, and demonstrated the applicability of our reaction conditions to modify this novel metabolite.
Sonogashira diversification of unprotected halotryptophans, halotryptophan containing tripeptides; and generation of a new to nature bromo-natural product and its diversification in water. 2017, 8 (3):2039-2046 Chem Sci
2041-6520
28451322
10.1039/c6sc04423a
http://hdl.handle.net/10033/621215
Chemical science
Sonogashira diversification of unprotected halotryptophans, halotryptophan containing tripeptides; and generation of a new to nature bromo-natural product and its diversification in water.
oai:repository.helmholtz-hzi.de:10033/6212222019-08-30T11:25:43Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Hamed, Mostafa M
author
Darwish, Sarah S
author
Herrmann, Jennifer
author
Abadi, Ashraf H
author
Engel, Matthias
author
2017-04-13
The activation of the NF-κB transcription factor is a major adaptive response induced upon treatment with EGFR kinase inhibitors, leading to the emergence of resistance in nonsmall cell lung cancer and other tumor types. To suppress this survival mechanism, we developed new thiourea quinazoline derivatives that are dual inhibitors of both EGFR kinase and the NF-κB activity. Optimization of the hit compound, identified in a NF-κB reporter gene assay, led to compound 9b, exhibiting a cellular IC50 for NF-κB inhibition of 0.3 μM while retaining a potent EGFR kinase inhibition (IC50 = 60 nM). The dual inhibitors showed a higher potency than gefitinib to inhibit cell growth of EGFR-overexpressing tumor cell lines in vitro and in a xenograft model in vivo, while no signs of toxicity were observed. An investigation of the molecular mechanism of NF-κB suppression revealed that the dual inhibitors depleted the transcriptional coactivator CREB-binding protein from the NF-κB complex in the nucleus.
First Bispecific Inhibitors of the Epidermal Growth Factor Receptor Kinase and the NF-κB Activity As Novel Anticancer Agents. 2017, 60 (7):2853-2868 J. Med. Chem.
1520-4804
28291344
10.1021/acs.jmedchem.6b01774
http://hdl.handle.net/10033/621222
Journal of medicinal chemistry
First Bispecific Inhibitors of the Epidermal Growth Factor Receptor Kinase and the NF-κB Activity As Novel Anticancer Agents.
oai:repository.helmholtz-hzi.de:10033/6212312019-08-30T11:34:48Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Wu, Hang
author
Wang, Yansheng
author
Yuan, Li
author
Mao, Yongrong
author
Wang, Weiwei
author
Zhu, Lin
author
Wu, Panpan
author
Fu, Chengzhang
author
Müller, Rolf
author
Weaver, David T
author
Zhang, Lixin
author
Zhang, Buchang
author
2016-03
Erythromycin A is a widely used antibiotic produced by Saccharopolyspora erythraea; however, its biosynthetic cluster lacks a regulatory gene, limiting the yield enhancement via regulation engineering of S. erythraea. Herein, six TetR family transcriptional regulators (TFRs) belonging to three genomic context types were individually inactivated in S. erythraea A226, and one of them, SACE_3446, was proved to play a negative role in regulating erythromycin biosynthesis. EMSA and qRT-PCR analysis revealed that SACE_3446 covering intact N-terminal DNA binding domain specifically bound to the promoter regions of erythromycin biosynthetic gene eryAI, the resistant gene ermE and the adjacent gene SACE_3447 (encoding a long-chain fatty-acid CoA ligase), and repressed their transcription. Furthermore, we explored the interaction relationships of SACE_3446 and previously identified TFRs (SACE_3986 and SACE_7301) associated with erythromycin production. Given demonstrated relatively independent regulation mode of SACE_3446 and SACE_3986 in erythromycin biosynthesis, we individually and concomitantly inactivated them in an industrial S. erythraea WB. Compared with WB, the WBΔ3446 and WBΔ3446Δ3986 mutants respectively displayed 36% and 65% yield enhancement of erythromycin A, following significantly elevated transcription of eryAI and ermE. When cultured in a 5 L fermentor, erythromycin A of WBΔ3446 and WBΔ3446Δ3986 successively reached 4095 mg/L and 4670 mg/L with 23% and 41% production improvement relative to WB. The strategy reported here will be useful to improve antibiotics production in other industrial actinomycete.
Inactivation of SACE_3446, a TetR family transcriptional regulator, stimulates erythromycin production in Saccharopolyspora erythraea. 2016, 1 (1):39-46 Synth Syst Biotechnol
2405-805X
29062926
10.1016/j.synbio.2016.01.004
http://hdl.handle.net/10033/621231
Synthetic and systems biotechnology
Inactivation of SACE_3446, a TetR family transcriptional regulator, stimulates erythromycin production in Saccharopolyspora erythraea.
oai:repository.helmholtz-hzi.de:10033/6212342019-11-28T09:39:39Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Wang, Hailong
author
Li, Zhen
author
Jia, Ruonan
author
Yin, Jia
author
Li, Aiying
author
Xia, Liqiu
author
Yin, Yulong
author
Müller, Rolf
author
Fu, Jun
author
Stewart, A Francis
author
Zhang, Youming
author
2017-12-12
The exponentially increasing volumes of DNA sequence data highlight the need for new DNA cloning methods to explore the new information. Here, we describe 'ExoCET' (Exonuclease Combined with RecET recombination) to directly clone any chosen region from bacterial and mammalian genomes with nucleotide precision into operational plasmids. ExoCET combines in vitro exonuclease and annealing with the remarkable capacity of full length RecET homologous recombination (HR) to retrieve specified regions from genomic DNA preparations. Using T4 polymerase (T4pol) as the in vitro exonuclease for ExoCET, we directly cloned large regions (>50 kb) from bacterial and mammalian genomes, including DNA isolated from blood. Employing RecET HR or Cas9 cleavage in vitro, the directly cloned region can be chosen with nucleotide precision to position, for example, a gene into an expression vector without the need for further subcloning. In addition to its utility for bioprospecting in bacterial genomes, ExoCET presents straightforward access to mammalian genomes for various applications such as region-specific DNA sequencing that retains haplotype phasing, the rapid construction of optimal, haplotypic, isogenic targeting constructs or a new way to genotype that presents advantages over Southern blotting or polymerase chain reaction. The direct cloning capacities of ExoCET present new freedoms in recombinant DNA technology.
ExoCET: exonuclease in vitro assembly combined with RecET recombination for highly efficient direct DNA cloning from complex genomes. 2017 Nucleic Acids Res.
1362-4962
29240926
10.1093/nar/gkx1249
http://hdl.handle.net/10033/621234
, Erratum exists
http://hdl.handle.net/10033/621872
Nucleic acids research
ExoCET: exonuclease in vitro assembly combined with RecET recombination for highly efficient direct DNA cloning from complex genomes.
oai:repository.helmholtz-hzi.de:10033/6212672019-08-30T11:37:24Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Zaburannyi, Nestor
author
Grosser, Katrin
author
Gasparoni, Gilles
author
Müller, Rolf
author
Schrallhammer, Martina
author
Simon, Martin
author
2018-01-18
Caedibacter taeniospiralis is an obligate endosymbiont living in the cytoplasm of Paramecium tetraureliaC. taeniospiralis causes the so-called killer trait, eliminating intraspecific competitors of its host when released into the medium by the concerted action of the unusual protein structure R-body (refractile body) in addition to an as-yet-unknown toxin.
Draft Genome Sequence and Annotation of the Obligate Bacterial Endosymbiont Caedibacter taeniospiralis, Causative Agent of the Killer Phenotype in Paramecium tetraurelia. 2018, 6 (3) Genome Announc
2169-8287
29348333
10.1128/genomeA.01418-17
http://hdl.handle.net/10033/621267
Genome announcements
Draft Genome Sequence and Annotation of the Obligate Bacterial Endosymbiont Caedibacter taeniospiralis, Causative Agent of the Killer Phenotype in Paramecium tetraurelia.
oai:repository.helmholtz-hzi.de:10033/6213062019-08-30T11:30:58Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Hoffmann, Thomas
author
Krug, Daniel
author
Bozkurt, Nisa
author
Duddela, Srikanth
author
Jansen, Rolf
author
Garcia, Ronald
author
Gerth, Klaus
author
Steinmetz, Heinrich
author
Müller, Rolf
author
2018-02-23
Some bacterial clades are important sources of novel bioactive natural products. Estimating the magnitude of chemical diversity available from such a resource is complicated by issues including cultivability, isolation bias and limited analytical data sets. Here we perform a systematic metabolite survey of ~2300 bacterial strains of the order Myxococcales, a well-established source of natural products, using mass spectrometry. Our analysis encompasses both known and previously unidentified metabolites detected under laboratory cultivation conditions, thereby enabling large-scale comparison of production profiles in relation to myxobacterial taxonomy. We find a correlation between taxonomic distance and the production of distinct secondary metabolite families, further supporting the idea that the chances of discovering novel metabolites are greater by examining strains from new genera rather than additional representatives within the same genus. In addition, we report the discovery and structure elucidation of rowithocin, a myxobacterial secondary metabolite featuring an uncommon phosphorylated polyketide scaffold.
Correlating chemical diversity with taxonomic distance for discovery of natural products in myxobacteria. 2018, 9 (1):803 Nat Commun
2041-1723
29476047
10.1038/s41467-018-03184-1
http://hdl.handle.net/10033/621306
Nature communications
Correlating chemical diversity with taxonomic distance for discovery of natural products in myxobacteria.
oai:repository.helmholtz-hzi.de:10033/6213652019-08-30T11:36:59Zcom_10033_620857com_10033_620618col_10033_620858col_10033_620619
00925njm 22002777a 4500
dc
Glatzel, Daniel K
author
Koeberle, Andreas
author
Pein, Helmut
author
Löser, Konstantin
author
Stark, Anna
author
Keksel, Nelli
author
Werz, Oliver
author
Müller, Rolf
author
Bischoff, Iris
author
Fürst, Robert
author
2018-02
The enzyme acetyl-CoA carboxylase (ACC) plays a crucial role in fatty acid metabolism. In recent years, ACC has been recognized as a promising drug target for treating different diseases. However, the role of ACC in vascular endothelial cells (ECs) has been neglected so far. To characterize the role of ACC, we used the ACC inhibitor, soraphen A, as a chemical tool, and also a gene silencing approach. We found that ACC1 was the predominant isoform in human umbilical vein ECs as well as in human microvascular ECs and that soraphen A reduced the levels of malonyl-CoA. We revealed that ACC inhibition shifted the lipid composition of EC membranes. Accordingly, membrane fluidity, filopodia formation, and migratory capacity were reduced. The antimigratory action of soraphen A depended on an increase in the cellular proportion of PUFAs and, most importantly, on a decreased level of phosphatidylglycerol. Our study provides a causal link between ACC, membrane lipid composition, and cell migration in ECs. Soraphen A represents a useful chemical tool to investigate the role of fatty acid metabolism in ECs and ACC inhibition offers a new and valuable therapeutic perspective for the treatment of EC migration-related diseases.
Acetyl-CoA carboxylase 1 regulates endothelial cell migration by shifting the phospholipid composition. 2018, 59 (2):298-311 J. Lipid Res.
1539-7262
29208696
10.1194/jlr.M080101
http://hdl.handle.net/10033/621365
Journal of lipid research
Acetyl-CoA carboxylase 1 regulates endothelial cell migration by shifting the phospholipid composition.
oai:repository.helmholtz-hzi.de:10033/6213942019-08-30T11:27:08Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Wang, Xue
author
Zhou, Haibo
author
Chen, Hanna
author
Jing, Xiaoshu
author
Zheng, Wentao
author
Li, Ruijuan
author
Sun, Tao
author
Liu, Jiaqi
author
Fu, Jun
author
Huo, Liujie
author
Li, Yue-Zhong
author
Shen, Yuemao
author
Ding, Xiaoming
author
Müller, Rolf
author
Bian, Xiaoying
author
Zhang, Youming
author
2018-05-01
Bacterial genomes encode numerous cryptic biosynthetic gene clusters (BGCs) that represent a largely untapped source of drugs or pesticides. Mining of the cryptic products is limited by the unavailability of streamlined genetic tools in native producers. Precise genome engineering using bacteriophage recombinases is particularly useful for genome mining. However, recombinases are usually host-specific. The genome-guided discovery of novel recombinases and their transient expression could boost cryptic BGC mining. Herein, we reported a genetic system employing Red recombinases from Burkholderiales strain DSM 7029 for efficient genome engineering in several Burkholderiales species that currently lack effective genetic tools. Using specialized recombinases-assisted in situ insertion of functional promoters, we successfully mined five cryptic nonribosomal peptide synthetase/polyketide synthase BGCs, two of which were silent. Two classes of lipopeptides, glidopeptins and rhizomides, were identified through extensive spectroscopic characterization. This recombinase expression strategy offers utility within other bacteria species, allowing bioprospecting for potentially scalable discovery of novel metabolites with attractive bioactivities.
29666226
http://hdl.handle.net/10033/621394
Burkholderiales
genome mining
lipopeptide
natural product
recombinases
Discovery of recombinases enables genome mining of cryptic biosynthetic gene clusters in Burkholderiales species.
oai:repository.helmholtz-hzi.de:10033/6213972019-08-30T11:27:08Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Menchon, Grégory
author
Prota, Andrea E
author
Lucena-Agell, Daniel
author
Bucher, Pascal
author
Jansen, Rolf
author
Irschik, Herbert
author
Müller, Rolf
author
Paterson, Ian
author
Díaz, J Fernando
author
Altmann, Karl-Heinz
author
Steinmetz, Michel O
author
2018-05-29
Microtubule-targeting agents (MTAs) like taxol and vinblastine are among the most successful chemotherapeutic drugs against cancer. Here, we describe a fluorescence anisotropy-based assay that specifically probes for ligands targeting the recently discovered maytansine site of tubulin. Using this assay, we have determined the dissociation constants of known maytansine site ligands, including the pharmacologically active degradation product of the clinical antibody-drug conjugate trastuzumab emtansine. In addition, we discovered that the two natural products spongistatin-1 and disorazole Z with established cellular potency bind to the maytansine site on β-tubulin. The high-resolution crystal structures of spongistatin-1 and disorazole Z in complex with tubulin allowed the definition of an additional sub-site adjacent to the pocket shared by all maytansine-site ligands, which could be exploitable as a distinct, separate target site for small molecules. Our study provides a basis for the discovery and development of next-generation MTAs for the treatment of cancer.
2041-1723
29844393
10.1038/s41467-018-04535-8
http://hdl.handle.net/10033/621397
A fluorescence anisotropy assay to discover and characterize ligands targeting the maytansine site of tubulin.
oai:repository.helmholtz-hzi.de:10033/6214162019-08-30T11:32:36Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Panter, Fabian
author
Krug, Daniel
author
Baumann, Sascha
author
Müller, Rolf
author
2018-06-07
There is astounding discrepancy between the genome-inscribed production capacity and the set of known secondary metabolite classes from many microorganisms as detected under laboratory cultivation conditions. Genome-mining techniques are meant to fill this gap, but in order to favor discovery of structurally novel as well as bioactive compounds it is crucial to amend genomics-based strategies with selective filtering principles. In this study, we followed a self-resistance guided approach aiming at the discovery of inhibitors of topoisomerase, known as valid target in both cancer and antibiotic therapy. A common host self-defense mechanism against such inhibitors in bacteria is mediated by so-called pentapeptide repeat proteins (PRP). Genes encoding the biosynthetic machinery for production of an alleged topoisomerase inhibitor were found on the basis of their collocation adjacent to a predicted PRP in the genome of the myxobacterium
2041-6520
29910943
10.1039/c8sc01325j
http://hdl.handle.net/10033/621416
Self-resistance guided genome mining uncovers new topoisomerase inhibitors from myxobacteria.
oai:repository.helmholtz-hzi.de:10033/6214992018-09-27T13:32:53Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Garcia, Ronald
author
La Clair, James J
author
Müller, Rolf
author
2018-08-29
Over the last two decades, halophilic (organisms that thrive at high salt concentrations) and halotolerant (organisms that have adapted to high salt concentrations) myxobacteria emerged as an important source of structurally diverse secondary metabolites from the marine environment. This review explores the advance of metagenomics analysis and 16S rRNA gene phylogeny of the cultured and uncultured myxobacteria from marine and other salt-environments up to July 2018. The diversity of novel groups of myxobacteria in these environments appears unprecedented, especially in the
1660-3397
30158489
10.3390/md16090303
http://hdl.handle.net/10033/621499
16S rRNA
Nannocystineae
Sandaracinaceae related clades
Sorangiineae
anaerobic
halophilic organisms
marine myxobacteria
marine myxobacterial clusters
metagenomics
uncultured
Future Directions of Marine Myxobacterial Natural Product Discovery Inferred from Metagenomics.
oai:repository.helmholtz-hzi.de:10033/6214912019-08-30T11:29:45Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Garcia, Ronald
author
La Clair, James J
author
Müller, Rolf
author
2018-08-29
Over the last two decades, halophilic (organisms that thrive at high salt concentrations) and halotolerant (organisms that have adapted to high salt concentrations) myxobacteria emerged as an important source of structurally diverse secondary metabolites from the marine environment. This review explores the advance of metagenomics analysis and 16S rRNA gene phylogeny of the cultured and uncultured myxobacteria from marine and other salt-environments up to July 2018. The diversity of novel groups of myxobacteria in these environments appears unprecedented, especially in the
1660-3397
30158489
10.3390/md16090303
http://hdl.handle.net/10033/621491
16S rRNA
Nannocystineae
Sandaracinaceae related clades
Sorangiineae
anaerobic
halophilic organisms
marine myxobacteria
marine myxobacterial clusters
metagenomics
uncultured
Future Directions of Marine Myxobacterial Natural Product Discovery Inferred from Metagenomics.
oai:repository.helmholtz-hzi.de:10033/6215302019-08-30T11:29:17Zcom_10033_620857com_10033_620618col_10033_620858col_10033_620619
00925njm 22002777a 4500
dc
Meng, Zhanchao
author
Souillart, Laetitia
author
Monks, Brendan
author
Huwyler, Nikolas
author
Herrmann, Jennifer
author
Müller, Rolf
author
Fürstner, Alois
author
2018-07-06
The highly cytotoxic cyclodepsipeptides of the nannocystin family are known to bind to the eukaryotic translation elongation factor 1α (EF-1α). Analysis of the docking pose, as proposed by a previous in silico study, suggested that the trisubstituted alkene moiety and the neighboring methyl ether form a domain that might be closely correlated with biological activity. This hypothesis sponsored a synthetic campaign which was designed to be "motif-oriented": specifically, a sequence of ring closing alkyne metathesis (RCAM) followed by hydroxy-directed trans-hydrostannation of the resulting cycloalkyne was conceived, which allowed this potentially anchoring substructure to be systematically addressed at a late stage. This inherently flexible approach opened access to nannocystin Ax (1) itself as well as to 10 non-natural analogues. While the biological data confirmed the remarkable potency of this class of compounds and showed that the domain in question is indeed an innate part of the pharmacophore, the specific structure/activity relationships can only partly be reconciled with the original in silico docking study; therefore, we conclude that this model needs to be carefully revisited.
1520-6904
29265814
10.1021/acs.joc.7b02871
http://hdl.handle.net/10033/621530
A "Motif-Oriented" Total Synthesis of Nannocystin Ax. Preparation and Biological Assessment of Analogues.
oai:repository.helmholtz-hzi.de:10033/6215242019-08-30T11:29:11Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Wang, Yuanyou
author
Schnell, Bastien
author
Baumann, Sascha
author
Müller, Rolf
author
Begley, Tadhg P
author
2017-02-08
The biosynthesis of branched alkoxy groups, such as the unique t-butyl group found in a variety of natural products, is still poorly understood. Recently, cystobactamids were isolated and identified from Cystobacter sp as novel antibacterials. These metabolites contain an isopropyl group proposed to be formed using CysS, a cobalamin-dependent radical S-adenosylmethionine (SAM) methyltransferase. Here, we reconstitute the CysS-catalyzed reaction, on p-aminobenzoate thioester substrates, and demonstrate that it not only catalyzes sequential methylations of a methyl group to form ethyl and isopropyl groups but remarkably also sec-butyl and t-butyl groups. To our knowledge, this is the first in vitro reconstitution of a cobalamin-dependent radical SAM enzyme catalyzing the conversion of a methyl group to a t-butyl group.
1520-5126
28040895
10.1021/jacs.6b10901
http://hdl.handle.net/10033/621524
Biosynthesis of Branched Alkoxy Groups: Iterative Methyl Group Alkylation by a Cobalamin-Dependent Radical SAM Enzyme.
oai:repository.helmholtz-hzi.de:10033/6215292019-08-30T11:29:41Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Yan, Fu
author
Burgard, Christian
author
Popoff, Alexander
author
Zaburannyi, Nestor
author
Zipf, Gregor
author
Maier, Josef
author
Bernauer, Hubert S
author
Wenzel, Silke C
author
Müller, Rolf
author
2018-10-14
Synthetic biology techniques coupled with heterologous secondary metabolite production offer
opportunities for the discovery and optimisation of natural products. Here we developed a new assembly
strategy based on type IIS endonucleases and elaborate synthetic DNA platforms, which could be used
to seamlessly assemble and engineer biosynthetic gene clusters (BGCs). By applying this versatile tool,
we designed and assembled more than thirty different artificial myxochromide BGCs, each around 30 kb
in size, and established heterologous expression platforms using a derivative of Myxococcus xanthus
DK1622 as a host. In addition to the five native types of myxochromides (A, B, C, D and S), novel
lipopeptide structures were produced by combinatorial exchange of nonribosomal peptide synthetase
(NRPS) encoding genes from different myxochromide BGCs. Inspired by the evolutionary diversification
of the native myxochromide megasynthetases, the ancestral A-type NRPS was engineered by
inactivation, deletion, or duplication of catalytic domains and successfully converted into functional B-,
C- and D-type megasynthetases. The constructional design approach applied in this study enables
combinatorial engineering of complex synthetic BGCs and has great potential for the exploitation of
other natural product biosynthetic pathways.
2041-6520
30319751
10.1039/c8sc02046a
http://hdl.handle.net/10033/621529
Synthetic biology approaches and combinatorial biosynthesis towards heterologous lipopeptide production.
oai:repository.helmholtz-hzi.de:10033/6215472019-08-30T11:27:39Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Luong, Betty
author
Schwenk, Rebecca
author
Bräutigam, Jacqueline
author
Müller, Rolf
author
Menche, Dirk
author
Bischoff, Iris
author
Fürst, Robert
author
2018-01-01
The vacuolar-type H+-ATPase (v-ATPase) is the major proton pump that acidifies intracellular compartments of eukaryotic cells. Since the inhibition of v-ATPase resulted in anti-tumor and anti-metastatic effects in different tumor models, this enzyme has emerged as promising strategy against cancer. Here, we used the well-established v-ATPase inhibitor archazolid, a natural product first isolated from the myxobacterium Archangium gephyra, to study the consequences of v-ATPase inhibition in endothelial cells (ECs), in particular on the interaction between ECs and cancer cells, which has been neglected so far. Human endothelial cells treated with archazolid showed an increased adhesion of tumor cells, whereas the transendothelial migration of tumor cells was reduced. The adhesion process was independent from the EC adhesion molecules ICAM-1, VCAM-1, E-selectin and N-cadherin. Instead, the adhesion was mediated by β1-integrins expressed on tumor cells, as blocking of the integrin β1 subunit reversed this process. Tumor cells preferentially adhered to the β1-integrin ligand collagen and archazolid led to an increase in the amount of collagen on the surface of ECs. The accumulation of collagen was accompanied by a strong decrease of the expression and activity of the protease cathepsin B. Overexpression of cathepsin B in ECs prevented the capability of archazolid to increase the adhesion of tumor cells onto ECs. Our study demonstrates that the inhibition of v-ATPase by archazolid induces a pro-adhesive phenotype in endothelial cells that promotes their interaction with cancer cells, whereas the transmigration of tumor cells was reduced. These findings further support archazolid as a promising anti-metastatic compound.
1932-6203
30204757
10.1371/journal.pone.0203053
http://hdl.handle.net/10033/621547
The vacuolar-type ATPase inhibitor archazolid increases tumor cell adhesion to endothelial cells by accumulating extracellular collagen.
oai:repository.helmholtz-hzi.de:10033/6216052019-08-30T11:27:40Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Gemperlein, Katja
author
Zaburannyi, Nestor
author
Garcia, Ronald
author
La Clair, James J
author
Müller, Rolf
author
2018-09-05
Prior to 2005, the vast majority of characterized myxobacteria were obtained from terrestrial habitats. Since then, several species of halotolerant and even obligate marine myxobacteria have been described. Chemical analyses of extracts from these organisms have confirmed their ability to produce secondary metabolites with unique chemical scaffolds. Indeed, new genera of marine-derived myxobacteria, particularly Enhygromyxa, have been shown to produce novel chemical scaffolds that differ from those observed in soil myxobacteria. Further studies have shown that marine sponges and terrestrial myxobacteria are capable of producing similar or even identical secondary metabolites, suggesting that myxobacterial symbionts may have been the true producers. Recent in silico analysis of the genome sequences available from six marine myxobacteria disclosed a remarkably versatile biosynthetic potential. With access to ever-advancing tools for small molecule and genetic evaluation, these studies suggest a bright future for expeditions into this yet untapped resource for secondary metabolites
1660-3397
30189599
10.3390/md16090314
http://hdl.handle.net/10033/621605
biosynthesis
diversity
genomics
marine myxobacteria
natural products
secondary metabolism
Metabolic and Biosynthetic Diversity in Marine Myxobacteria.
oai:repository.helmholtz-hzi.de:10033/6215642018-11-15T01:20:57Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Gemperlein, Katja
author
Zaburannyi, Nestor
author
Garcia, Ronald
author
La Clair, James J
author
Müller, Rolf
author
2018-09-05
Prior to 2005, the vast majority of characterized myxobacteria were obtained from terrestrial
habitats. Since then, several species of halotolerant and even obligate marine myxobacteria have been
described. Chemical analyses of extracts from these organisms have confirmed their ability to produce
secondary metabolites with unique chemical scaffolds. Indeed, new genera of marine-derived
myxobacteria, particularly Enhygromyxa, have been shown to produce novel chemical scaffolds
that differ from those observed in soil myxobacteria. Further studies have shown that marine
sponges and terrestrial myxobacteria are capable of producing similar or even identical secondary
metabolites, suggesting that myxobacterial symbionts may have been the true producers. Recent
in silico analysis of the genome sequences available from six marine myxobacteria disclosed a
remarkably versatile biosynthetic potential. With access to ever-advancing tools for small molecule
and genetic evaluation, these studies suggest a bright future for expeditions into this yet untapped
resource for secondary metabolites
1660-3397
30189599
10.3390/md16090314
http://hdl.handle.net/10033/621564
biosynthesis
diversity
genomics
marine myxobacteria
natural products
secondary metabolism
Metabolic and Biosynthetic Diversity in Marine Myxobacteria.
oai:repository.helmholtz-hzi.de:10033/6216002019-08-30T11:30:27Zcom_10033_620618col_10033_620619col_10033_620621
00925njm 22002777a 4500
dc
Dudeck, Anne
author
Köberle, Martin
author
Goldmann, Oliver
author
Meyer, Nicole
author
Dudeck, Jan
author
Lemmens, Stefanie
author
Rohde, M
author
Roldán, Nestor González
author
Dietze-Schwonberg, Kirsten
author
Orinska, Zane
author
Medina, Eva
author
Hendrix, Sven
author
Metz, Martin
author
Zenclussen, Ana Claudia
author
von Stebut, Esther
author
Biedermann, Tilo
author
2018-11-20
Mast cells (MC), well known for their effector functions in Th2 skewed allergic and also autoimmune inflammation, become increasingly acknowledged for their role in protection of health. It is now clear that they are also key modulators of immune responses at interface organs like skin or gut. MC can prime tissues for adequate inflammatory responses and cooperate with dendritic cells in T cell activation. They also regulate harmful immune responses in trauma and help to successfully orchestrate pregnancy. This review focusses on the beneficial effects of mast cells on tissue homeostasis and elimination of toxins or venoms. MC can enhance pathogen clearance in many bacterial, viral, and parasite infections, e.g. by TLR2 triggered degranulation, secretion of antimicrobial cathelicidins, recruiting neutrophils or by providing extracellular DNA traps. The role of MC in tumors is more ambiguous, however, encouraging new findings show they can change the tumor microenvironment towards anti-tumor immunity when adequately triggered. Uterine tissue remodeling by α-chymase (MCP-5) is crucial for successful embryo implantation. MCP-4 and the tryptase MCP-6 emerge to be protective in CNS trauma by reducing inflammatory damage and excessive scar formation, thereby protecting axon growth. Last but not least, we see proteases like carboxypeptidase A released by FcεRI activated MC detoxify an increasing number of venoms and endogenous toxins. A better understanding of the plasticity of MC will help to improve these advantageous effects, and hint on ways to cut down detrimental MC actions.
1097-6825
30468774
10.1016/j.jaci.2018.10.054
http://hdl.handle.net/10033/621600
CNS trauma
infection
innate immunity
mast cell
mast cell protease
pregnancy
toxin
tumor
venom
Mast cells as protectors of health.
oai:repository.helmholtz-hzi.de:10033/6216112019-08-30T11:30:28Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Hug, Joachim J
author
Bader, Chantal D
author
Remškar, Maja
author
Cirnski, Katarina
author
Müller, Rolf
author
2018-05-22
Actinomycetes have been proven to be an excellent source of secondary metabolites for more than half a century. Exhibiting various bioactivities, they provide valuable approved drugs in clinical use. Most microorganisms are still untapped in terms of their capacity to produce secondary metabolites, since only a small fraction can be cultured in the laboratory. Thus, improving cultivation techniques to extend the range of secondary metabolite producers accessible under laboratory conditions is an important first step in prospecting underexplored sources for the isolation of novel antibiotics. Currently uncultured actinobacteria can be made available by bioprospecting extreme or simply habitats other than soil. Furthermore, bioinformatic analysis of genomes reveals most producers to harbour many more biosynthetic gene clusters than compounds identified from any single strain, which translates into a silent biosynthetic potential of the microbial world for the production of yet unknown natural products. This review covers discovery strategies and innovative methods recently employed to access the untapped reservoir of natural products. The focus is the order of actinomycetes although most approaches are similarly applicable to other microbes. Advanced cultivation methods, genomics- and metagenomics-based approaches, as well as modern metabolomics-inspired methods are highlighted to emphasise the interplay of different disciplines to improve access to novel natural products.
2079-6382
29789481
10.3390/antibiotics7020044
http://hdl.handle.net/10033/621611
dereplication
genome mining
metabolomics
metagenomics
natural products
rare actinomycetes
Concepts and Methods to Access Novel Antibiotics from Actinomycetes.
oai:repository.helmholtz-hzi.de:10033/6216192019-08-30T11:33:02Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Kappler, Sarah
author
Karmann, Lisa
author
Prudel, Cynthia
author
Herrmann, Jennifer
author
Caddeu, Giulia
author
Müller, Rolf
author
Vollmar, Angelika M.
author
Zahler, Stefan
author
Kazmaier, Uli
author
1434193X
10.1002/ejoc.201801391
http://hdl.handle.net/10033/621619
Synthesis and Biological Evaluation of Modified Miuraenamides
oai:repository.helmholtz-hzi.de:10033/6216332019-08-30T11:31:46Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Bruns, Hilke
author
Ziesche, Lisa
author
Taniwal, Nargis Khakin
author
Wolter, Laura
author
Brinkhoff, Thorsten
author
Herrmann, Jennifer
author
Müller, Rolf
author
Schulz, Stefan
author
2018-01-01
The human gut microbiome matures towards the adult composition during the first years of life and is implicated in early immune development. Here, we investigate the effects of microbial genomic diversity on gut microbiome development using integrated early childhood data sets collected in the DIABIMMUNE study in Finland, Estonia and Russian Karelia. We show that gut microbial diversity is associated with household location and linear growth of children. Single nucleotide polymorphism- and metagenomic assembly-based strain tracking revealed large and highly dynamic microbial pangenomes, especially in the genus Bacteroides, in which we identified evidence of variability deriving from Bacteroides-targeting bacteriophages. Our analyses revealed functional consequences of strain diversity; only 10% of Finnish infants harboured Bifidobacterium longum subsp. infantis, a subspecies specialized in human milk metabolism, whereas Russian infants commonly maintained a probiotic Bifidobacterium bifidum strain in infancy. Groups of bacteria contributing to diverse, characterized metabolic pathways converged to highly subject-specific configurations over the first two years of life. This longitudinal study extends the current view of early gut microbial community assembly based on strain-level genomic variation.
Beilstein J Org Chem. 2018 Dec 3;14:2964-2973. doi: 10.3762/bjoc.14.276. eCollection 2018.
1860-5397
30591820
10.3762/bjoc.14.276
http://hdl.handle.net/10033/621633
2-aminobutyric acid
amino acid derivatives
homoserine lactones
natural products
quorum sensing
N-Acylated amino acid methyl esters from marine group bacteria.
oai:repository.helmholtz-hzi.de:10033/6216632019-08-30T11:33:27Zcom_10033_620613com_10033_620656com_10033_620644com_10033_620618col_10033_620614col_10033_620657col_10033_620619col_10033_620646
00925njm 22002777a 4500
dc
Castoldi, Arianna
author
Empting, Martin
author
De Rossi, Chiara
author
Mayr, Karsten
author
Dersch, Petra
author
Hartmann, Rolf
author
Müller, Rolf
author
Gordon, Sarah
author
Lehr, Claus-Michael
author
2018-12-05
The objective of this work was to evaluate the potential of polymeric spherical and aspherical invasive nanocarriers, loaded with antibiotic, to access and treat intracellular bacterial infections. Aspherical nanocarriers were prepared by stretching of spherical precursors, and both aspherical and spherical nanocarriers were surface-functionalized with the invasive protein InvA497. The relative uptake of nanocarriers into HEp-2 epithelial cells was then assessed. Nanocarriers were subsequently loaded with a preparation of the non-permeable antibiotic gentamicin, and tested for their ability to treat HEp-2 cells infected with the enteroinvasive bacterium Shigella flexneri. InvA497-functionalized nanocarriers of both spherical and aspherical shape showed a significantly improved rate and extent of uptake into HEp-2 cells in comparison to non-functionalized nanocarriers. Functionalized and antibiotic-loaded nanocarriers demonstrated a dose dependent killing of intracellular S. flexneri. A slight but significant enhancement of intracellular bacterial killing was also observed with aspherical as compared to spherical functionalized nanocarriers at the highest tested concentration. InvA497-functionalized, polymer-based nanocarriers were able to efficiently deliver a non-permeable antibiotic across host cell membranes to affect killing of intracellular bacteria. Functionalized nanocarriers with an aspherical shape showed an interesting future potential for intracellular infection therapy.
Pharm Res. 2018 Dec 5;36(1):22. doi: 10.1007/s11095-018-2521-3.
1573-904X
30519925
10.1007/s11095-018-2521-3
http://hdl.handle.net/10033/621663
Pharmaceutical research
AOT-gentamicin
aspherical nanoparticles
bacteriomimetic nanocarriers
intracellular infection
invasin
Aspherical and Spherical InvA497-Functionalized Nanocarriers for Intracellular Delivery of Anti-Infective Agents.
oai:repository.helmholtz-hzi.de:10033/6216652019-08-30T11:34:20Zcom_10033_620613com_10033_620618col_10033_620685col_10033_620619
00925njm 22002777a 4500
dc
Schulz, Eilien
author
Goes, Adriely
author
Garcia, Ronald
author
Panter, Fabian
author
Koch, Marcus
author
Müller, Rolf
author
Fuhrmann, Kathrin
author
Fuhrmann, Gregor
author
2018-11-28
Up to 25,000 people die each year from resistant infections in Europe alone, with increasing incidence. It is estimated that a continued rise in bacterial resistance by 2050 would lead up to 10 million annual deaths worldwide, exceeding the incidence of cancer deaths. Although the design of new antibiotics is still one way to tackle the problem, pharmaceutical companies investigate far less into new drugs than 30 years ago. Incorporation of antibiotics into nanoparticle drug carriers ("nanoantibiotics") is currently investigated as a promising strategy to make existing antibiotics regain antimicrobial strength and overcome certain types of microbial drug resistance. Many of these synthetic systems enhance the antimicrobial effect of drugs by protecting antibiotics from degradation and reducing their side effects. Nevertheless, they often cannot selectively target pathogenic bacteria and - due to their synthetic origin - may induce side-effects themselves. In this work, we present the characterisation of naturally derived outer membrane vesicles (OMVs) as biocompatible and inherently antibiotic drug carriers. We isolated OMVs from two representative strains of myxobacteria, Cystobacter velatus Cbv34 and Sorangiineae species strain SBSr073, a bacterial order with the ability of lysing other bacterial strains and currently investigated as sources of new secondary metabolites. We investigated the myxobacterias' inherent antibacterial properties after isolation by differential centrifugation and purification by size-exclusion chromatography. OMVs have an average size range of 145-194 nm. We characterised their morphology by electron cryomicroscopy and found that OMVs are biocompatible with epithelial cells and differentiated macrophages. They showed a low endotoxin activity comparable to those of control samples, indicating a low acute inflammatory potential. In addition, OMVs showed inherent stability under different storage conditions, including 4 °C, -20 °C, -80 °C and freeze-drying. OMV uptake in Gram-negative model bacterium Escherichia coli (E. coli) showed similar to better incorporation than liposome controls, indicating the OMVs may interact with model bacteria via membrane fusion. Bacterial uptake correlated with antimicrobial activity of OMVs as measured by growth inhibition of E. coli. OMVs from Cbv34 inhibited growth of E. coli to a comparable extent as the clinically established antibiotic gentamicin. Liquid-chromatography coupled mass spectrometry analyses revealed the presence of cystobactamids in OMVs, inhibitors of bacterial topoisomerase currently studied to treat different Gram-negative and Gram-positive pathogens. This work, may serve as an important basis for further evaluation of OMVs derived from myxobacteria as novel therapeutic delivery systems against bacterial infections.
1873-4995
30292423
10.1016/j.jconrel.2018.09.030
http://hdl.handle.net/10033/621665
Journal of Controlled Release
Biogenic drug carriers
Electron cryomicroscopy
Extracellular vesicles
Myxobacteria
Nanoantibiotics
Outer membrane vesicles
Biocompatible bacteria-derived vesicles show inherent antimicrobial activity.
oai:repository.helmholtz-hzi.de:10033/6216712019-08-30T11:30:30Zcom_10033_311624com_10033_6839com_10033_620857com_10033_620652com_10033_620618col_10033_620672col_10033_311625col_10033_620858col_10033_620619
00925njm 22002777a 4500
dc
Dubich, Tatyana
author
Lieske, Anna
author
Santag, Susann
author
Beauclair, Guillaume
author
Rückert, Jessica
author
Herrmann, Jennifer
author
Gorges, Jan
author
Büsche, Guntram
author
Kazmaier, Uli
author
Hauser, Hansjörg
author
Stadler, Marc
author
Schulz, Thomas F
author
Wirth, Dagmar
author
2019-01-04
Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiological agent of Kaposi's sarcoma (KS), a tumor of endothelial origin predominantly affecting immunosuppressed individuals. Up to date, vaccines and targeted therapies are not available. Screening and identification of anti-viral compounds are compromised by the lack of scalable cell culture systems reflecting properties of virus-transformed cells in patients. Further, the strict specificity of the virus for humans limits the development of in vivo models. In this study, we exploited a conditionally immortalized human endothelial cell line for establishment of in vitro 2D and 3D KSHV latency models and the generation of KS-like xenograft tumors in mice. Importantly, the invasive properties and tumor formation could be completely reverted by purging KSHV from the cells, confirming that tumor formation is dependent on the continued presence of KSHV, rather than being a consequence of irreversible transformation of the infected cells. Upon testing a library of 260 natural metabolites, we selected the compounds that induced viral loss or reduced the invasiveness of infected cells in 2D and 3D endothelial cell culture systems. The efficacy of selected compounds against KSHV-induced tumor formation was verified in the xenograft model. Together, this study shows that the combined use of anti-viral and anti-tumor assays based on the same cell line is predictive for tumor reduction in vivo and therefore allows faithful selection of novel drug candidates against Kaposi's sarcoma. KEY MESSAGES: Novel 2D, 3D, and xenograft mouse models mimic the consequences of KSHV infection. KSHV-induced tumorigenesis can be reverted upon purging the cells from the virus. A 3D invasiveness assay is predictive for tumor reduction in vivo. Chondramid B, epothilone B, and pretubulysin D diminish KS-like lesions in vivo.
1432-1440
30610257
10.1007/s00109-018-01733-1
http://hdl.handle.net/10033/621671
3D culture system
Drug validation
Humanized mouse model
KSHV
Novel anti-viral drugs
An endothelial cell line infected by Kaposi's sarcoma-associated herpes virus (KSHV) allows the investigation of Kaposi's sarcoma and the validation of novel viral inhibitors in vitro and in vivo.
oai:repository.helmholtz-hzi.de:10033/6216942019-08-30T11:32:40Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Hauf, Samuel
author
Herrmann, Jennifer
author
Miethke, Marcus
author
Gibhardt, Johannes
author
Commichau, Fabian M
author
Müller, Rolf
author
Fuchs, Stephan
author
Halbedel, Sven
author
2019-01-15
Bacteria can cope with toxic compounds such as antibiotics by inducing genes for their detoxification. A common detoxification strategy is compound excretion by ATP-binding cassette (ABC) transporters, which are synthesized upon compound contact. We previously identified the multi drug resistance ABC transporter LieAB in Listeria monocytogenes, a Gram-positive bacterium that occurs ubiquitously in the environment, but also causes severe infections in humans upon ingestion. Expression of the lieAB genes is strongly induced in cells lacking the PadR-type transcriptional repressor LftR, but compounds leading to relief of this repression in wild type cells were not known. Using RNA-Seq and promoter-lacZ fusions we demonstrate highly specific repression of the lieAB and lftRS promoters through LftR. Screening of a natural compound library yielded the depsipeptide aurantimycin A - synthesized by the soil-dwelling Streptomyces aurantiacus - as the first known naturally occurring inducer of lieAB expression. Genetic and phenotypic experiments concordantly show that aurantimycin A is a substrate of the LieAB transporter and thus, lftRS and lieAB represent the first known genetic module conferring and regulating aurantimycin A resistance. Collectively, these genes may support the survival of L. monocytogenes when it comes into contact with antibiotic-producing bacteria in the soil. This article is protected by copyright. All rights reserved.
1365-2958
30648305
10.1111/mmi.14205
http://hdl.handle.net/10033/621694
Molecular Microbiology
antibiotic resistance
antimicrobial peptides
depsipeptide
drug efflux
multi drug resistance
Aurantimycin resistance genes contribute to survival of Listeria monocytogenes during life in the environment.
oai:repository.helmholtz-hzi.de:10033/6217102019-08-30T11:35:13Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Richter, Lilian H J
author
Herrmann, Jennifer
author
Andreas, Anastasia
author
Park, Yu Mi
author
Wagmann, Lea
author
Flockerzi, Veit
author
Müller, Rolf
author
Meyer, Markus R
author
2019-05-01
New psychoactive substances (NPS) are an emerging topic amongst abused compounds. New varieties appear constantly on the market, without any knowledge about their toxicodynamic and/or -kinetic properties and knowledge of their metabolism is crucial for the development of analytical methods employed for their detection. Controlled human studies would of course be best suited but due to ethical reasons and lack of preclinical safety data, they are usually not available. Often, in vitro models are used to evaluate similarities to human in vivo hepatic phase I and II metabolism and systems explored include primary human hepatocytes, pooled human S9 fraction, and HepaRG, a human hepatic cell line. All these in vitro models have considerable limitations and drug distribution, reabsorption, enterohepatic circulation, and renal elimination cannot be studied. In the recent years, zebrafish (Danio rerio) larvae (embryos) were discussed as a potential in vivo model to overcome these limitations. To date, no studies demonstrating its suitability for studying NPS metabolism in the context of analytical toxicology are available. The aim of this study was to elucidate whether zebrafish larvae can serve as a surrogate for human hepatic metabolism of NPS to develop toxicological screening procedures. Here, we used methyl 2-(1-(5-fluoropentyl)-1H-pyrrolo[2,3-b]pyridine-3-carboxamido)-3,3-dimethylbutanoate (7'N-5F-ADB), a new synthetic cannabinoid, whose human metabolism was recently described in the literature, as a model compound to evaluate zebrafish larvae as a new tool for metabolism studies. Different conditions for zebrafish larvae and HepaRG protocols were tested. As zebrafish larvae and HepaRG cell incubations provided the highest number of metabolites and the most authentic spectrum of human metabolites. The most suitable larvae protocol was the incubation via medium and the analysis of the extracted zebrafish larvae. The zebrafish larvae model might be a promising preclinical surrogate for human hepatic metabolism of NPS.
Toxicol Lett. 2019 May 1;305:73-80. doi: 10.1016/j.toxlet.2019.01.010. Epub 2019 Jan 22.
1879-3169
30682400
10.1016/j.toxlet.2019.01.010
http://hdl.handle.net/10033/621710
Toxicology Letters
HepaRG
High resolution mass spectrometry
Metabolism
Toxicological analysis
Zebrafish larvae
Tools for studying the metabolism of new psychoactive substances for toxicological screening purposes - A comparative study using pooled human liver S9, HepaRG cells, and zebrafish larvae.
oai:repository.helmholtz-hzi.de:10033/6217492019-08-30T11:32:10Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Chauhan, Dhruv
author
Bartok, Eva
author
Gaidt, Moritz M
author
Bock, Florian J
author
Herrmann, Jennifer
author
Seeger, Jens M
author
Broz, Petr
author
Beckmann, Roland
author
Kashkar, Hamid
author
Tait, Stephen W G
author
Müller, Rolf
author
Hornung, Veit
author
2018-11-27
IL-1β is a cytokine of pivotal importance to the orchestration of inflammatory responses. Synthesized as an inactive pro-cytokine, IL-1β requires proteolytic maturation to gain biological activity. Here, we identify intrinsic apoptosis as a non-canonical trigger of IL-1β maturation. Guided by the discovery of the immunomodulatory activity of vioprolides, cyclic peptides isolated from myxobacteria, we observe IL-1β maturation independent of canonical inflammasome pathways, yet dependent on intrinsic apoptosis. Mechanistically, vioprolides inhibit MCL-1 and BCL2, which in turn triggers BAX/BAK-dependent mitochondrial outer membrane permeabilization (MOMP). Induction of MOMP results in the release of pro-apoptotic factors initiating intrinsic apoptosis, as well as the depletion of IAPs (inhibitors of apoptosis proteins). IAP depletion, in turn, operates upstream of ripoptosome complex formation, subsequently resulting in caspase-8-dependent IL-1β maturation. These results establish the ripoptosome/caspase-8 complex as a pro-inflammatory checkpoint that senses the perturbation of mitochondrial integrity.
Cell Rep. 2018 Nov 27;25(9):2354-2368.e5. doi: 10.1016/j.celrep.2018.10.087
2211-1247
30485805
10.1016/j.celrep.2018.10.087
http://hdl.handle.net/10033/621749
Cell Reports
BAX/BAK
BCL2
IAP depletion
IL-1β
MCL-1
NLRP3
caspase-8
intrinsic apoptosis
ripoptosome
BAX/BAK-Induced Apoptosis Results in Caspase-8-Dependent IL-1β Maturation in Macrophages.
oai:repository.helmholtz-hzi.de:10033/6217562019-08-30T11:32:11Zcom_10033_620857com_10033_620618col_10033_620858col_10033_620619
00925njm 22002777a 4500
dc
Planke, Therese
author
Moreno, María
author
Hüttel, Stephan
author
Fohrer, Jörg
author
Gille, Franziska
author
Norris, Matthew D
author
Siebke, Maik
author
Wang, Liangliang
author
Müller, Rolf
author
Kirschning, Andreas
author
2019-03-01
Total synthesis of cystobactamid 920-1 and its epimer has allowed an unambiguous assignment of the relative and absolute configuration of the natural product. A careful structural analysis of each isomer using both NMR and computational techniques also prompted a constitutional revision of the structures originally reported for cystobactamids 920-1 and 920-2, and has provided further insight into the unique conformational preferences of the cystobactamid family
Org Lett. 2019 Mar 1;21(5):1359-1363. doi: 10.1021/acs.orglett.9b00058. Epub 2019 Feb 8.
1523-7052
30735398
10.1021/acs.orglett.9b00058
http://hdl.handle.net/10033/621756
Organic Letters
Cystobactamids 920-1 and 920-2: Assignment of the Constitution and Relative Configuration by Total Synthesis.
oai:repository.helmholtz-hzi.de:10033/6217762019-08-30T11:24:25Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Pfitzer, Lisa
author
Moser, Christina
author
Gegenfurtner, Florian
author
Arner, Anja
author
Foerster, Florian
author
Atzberger, Carina
author
Zisis, Themistoklis
author
Kubisch-Dohmen, Rebekka
author
Busse, Johanna
author
Smith, Rebecca
author
Timinszky, Gyula
author
Kalinina, Olga V
author
Müller, Rolf
author
Wagner, Ernst
author
Vollmar, Angelika M
author
Zahler, Stefan
author
2019-04-03
Severe side effects often restrict clinical application of the widely used chemotherapeutic drug doxorubicin. In order to decrease required substance concentrations, new concepts for successful combination therapy are needed. Since doxorubicin causes DNA damage, combination with compounds that modulate DNA repair could be a promising strategy. Very recently, a role of nuclear actin for DNA damage repair has been proposed, making actin a potential target for cancer therapy in combination with DNA-damaging therapeutics. This is of special interest, since actin-binding compounds have not yet found their way into clinics. We find that low-dose combination treatment of doxorubicin with the actin polymerizer chondramide B (ChB) synergistically inhibits tumor growth in vivo. On the cellular level we demonstrate that actin binders inhibit distinctive double strand break (DSB) repair pathways. Actin manipulation impairs the recruitment of replication factor A (RPA) to the site of damage, a process crucial for homologous recombination. In addition, actin binders reduce autophosphorylation of DNA-dependent protein kinase (DNA-PK) during nonhomologous end joining. Our findings substantiate a direct involvement of actin in nuclear DSB repair pathways, and propose actin as a therapeutic target for combination therapy with DNA-damaging agents such as doxorubicin.
Cell Death Dis. 2019 Apr 3;10(4):302. doi: 10.1038/s41419-019-1546-9.
2041-4889
30944311
10.1038/s41419-019-1546-9
http://hdl.handle.net/10033/621776
Cell Death and Disease
Targeting actin inhibits repair of doxorubicin-induced DNA damage: a novel therapeutic approach for combination therapy.
oai:repository.helmholtz-hzi.de:10033/6217932019-09-23T08:51:31Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Grüter, Andreas
author
Hoffmann, Michael
author
Müller, Rolf
author
Wohland, Thorsten
author
Jung, Gregor
author
2019-04-26
Copper is one of the most important transition metals in many organisms where it catalyzes a manifold of different processes. As a result of copper's redox activity, organisms have to avoid unbound ions, and a dysfunctional copper homeostasis may lead to multifarious pathological processes in cells with very severe ramifications for the affected organisms. In many neurodegenerative diseases, however, the exact role of copper ions is still not completely clarified. In this work, a high-affinity and highly selective copper probe molecule, based on the naturally occurring tetrapeptide DAHK is synthesized. The sensor (log KD = - 12.8 ± 0.1) is tagged with a fluorescent BODIPY dye whose fluorescence lifetime distinctly decreases from 5.8 ns ± 0.2 ns to 0.4 ns ± 0.1 ns on binding to copper(II) cations. It is shown by using fluorescence lifetime correlation spectroscopy that the concentration of both probe and probe-copper complex can be simultaneously measured even at nanomolar concentration levels. This work presents a possible starting point for a new type of probe and method for future in vivo studies to further reveal the exact role of copper ions in organisms. Graphical abstract.
Anal Bioanal Chem. 2019 Apr 26. pii: 10.1007/s00216-019-01798-y. doi:10.1007/s00216-019-01798-y.
1618-2650
31025181
10.1007/s00216-019-01798-y
http://hdl.handle.net/10033/621793
Analytical and Bioanalytical Chemistry
ATCUN motif
Alzheimer
BODIPY
DAHK
FLIM
Parkinson
Single molecule detection
A high-affinity fluorescence probe for copper(II) ions and its application in fluorescence lifetime correlation spectroscopy.
oai:repository.helmholtz-hzi.de:10033/6218022019-08-30T11:33:01Zcom_10033_620589com_10033_620618col_10033_620619col_10033_620590
00925njm 22002777a 4500
dc
Banda, Dominic H
author
Perin, Paula M
author
Brown, Richard J P
author
Todt, Daniel
author
Solodenko, Wladimir
author
Hoffmeyer, Patrick
author
Kumar Sahu, Kamlesh
author
Houghton, Michael
author
Meuleman, Philip
author
Müller, Rolf
author
Kirschning, Andreas
author
Pietschmann, Thomas
author
2019-06-01
J Hepatol. 2019 Jun;70(6):1082-1092. doi: 10.1016/j.jhep.2019.01.033. Epub 2019 Feb 13.
1600-0641
30769006
10.1016/j.jhep.2019.01.033
http://hdl.handle.net/10033/621802
Journal of Hepatology
Antivirals
Fusion inhibitors
Hepatitis C virus (HCV)
Membrane fusion
Resistance
A central hydrophobic E1 region controls the pH range of hepatitis C virus membrane fusion and susceptibility to fusion inhibitors.
oai:repository.helmholtz-hzi.de:10033/6218262019-06-28T08:59:04Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Sandargo, Birthe
author
Michehl, Maira
author
Praditya, Dimas
author
Steinmann, Eike
author
Stadler, Marc
author
Surup, Frank
author
2019-05-03
Rhodatin (1), a meroterpenoid featuring a unique pentacyclic scaffold with both spiro and spiroketal centers, and five unusual acorane-type sesquiterpenoids, named rhodocoranes A-E (2-6, respectively), are the first natural products isolated from the basidiomycete Rhodotus palmatus. Their structures were elucidated by two-dimensional NMR experiments and HRESIMS, while the absolute configuration of the substance family was determined by Mosher's method utilizing 2. Rhodatin strongly inhibited hepatitis C virus, whereas 4 displayed cytotoxicity and selective antifungal activity.
Org Lett. 2019 May 3;21(9):3286-3289. doi: 10.1021/acs.orglett.9b01017. Epub 2019 Apr 22.
1523-7052
31008606
10.1021/acs.orglett.9b01017
http://hdl.handle.net/10033/621826
Organic Letters
Antiviral Meroterpenoid Rhodatin and Sesquiterpenoids Rhodocoranes A-E from the Wrinkled Peach Mushroom, Rhodotus palmatus.
oai:repository.helmholtz-hzi.de:10033/6218432019-08-30T11:26:39Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Galata, Valentina
author
Laczny, Cédric C
author
Backes, Christina
author
Hemmrich-Stanisak, Georg
author
Schmolke, Susanne
author
Franke, Andre
author
Meese, Eckart
author
Herrmann, Mathias
author
von Müller, Lutz
author
Plum, Achim
author
Müller, Rolf
author
Stähler, Cord
author
Posch, Andreas E
author
Keller, Andreas
author
2019-05-14
Emergingantibiotic resistanceis a major global health threat. The analysis of nucleic acidsequences linked to susceptibility phenotypes facilitates the study of genetic antibiotic resistancedeterminants to inform molecular diagnostics and drug development. We collected genetic data(11,087 newly-sequenced whole genomes) and culture-based resistance profiles (10,991 out of the11,087 isolates comprehensively tested against 22 antibiotics in total) of clinical isolates including18 main species spanning a time period of 30 years. Species and drug specific resistance patternswere observed including increased resistance rates forAcinetobacter baumanniito carbapenemsand forEscherichia colito fluoroquinolones. Species-levelpan-genomeswere constructed to reflectthe genetic repertoire of the respective species, including conserved essential genes and known resis-tance factors. Integrating phenotypes and genotypes through species-level pan-genomes allowed toinfer gene–drug resistance associations using statistical testing. The isolate collection and the analysis results have been integrated into GEAR-base, a resource available for academic research use free of charge athttps://gear-base.com
Genomics Proteomics Bioinformatics. 2019 May 14. pii: S1672-0229(19)30092-0. doi: 10.1016/j.gpb.2018.11.002.
2210-3244
31100356
10.1016/j.gpb.2018.11.002
http://hdl.handle.net/10033/621843
Genomics Proteomics Bioinformatics
Antibiotic resistance
Bacteria
Pan-genome
Whole-genome sequencing
Integrating Culture-based Antibiotic Resistance Profiles with Whole-genome Sequencing Data for 11,087 Clinical Isolates.
oai:repository.helmholtz-hzi.de:10033/6218722019-11-28T09:35:06Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Wang, Hailong
author
Li, Zhen
author
Jia, Ruonan
author
Yin, Jia
author
Li, Aiying
author
Xia, Liqiu
author
Yin, Yulong
author
Müller, Rolf
author
Fu, Jun
author
Stewart, A Francis
author
Zhang, Youming
author
2018-03-16
The exponentially increasing volumes of DNA sequence data highlight the need for new DNA cloning methods to explore the new information. Here, we describe ‘ExoCET’ (Exonuclease Combined with RecET recombination) to directly clone any chosen region from bacterial and mammalian genomes with nucleotide precision into operational plasmids. ExoCET combines in vitro exonuclease and annealing with the remarkable capacity of full length RecET homologous recombination (HR) to retrieve specified regions from genomic DNA preparations. Using T4 polymerase (T4pol) as the in vitro exonuclease for ExoCET, we directly cloned large regions (>50 kb) from bacterial and mammalian genomes, including DNA isolated from blood. Employing RecET HR or Cas9 cleavage in vitro, the directly cloned region can be chosen with nucleotide precision to position, for example, a gene into an expression vector without the need for further subcloning. In addition to its utility for bioprospecting in bacterial genomes, ExoCET presents straightforward access to mammalian genomes for various applications such as region-specific DNA sequencing that retains haplotype phasing, the rapid construction of optimal, haplotypic, isogenic targeting constructs or a new way to genotype that presents advantages over Southern blotting or polymerase chain reaction. The direct cloning capacities of ExoCET present new freedoms in recombinant DNA technology.
Nucleic Acids Res. 2018 Mar 16;46(5):2697. doi: 10.1093/nar/gkx1296.
1362-4962
29272442
10.1093/nar/gkx1296
, Erratum to
10.1093/nar/gkx1249
http://hdl.handle.net/10033/621872
Erratum to
http://hdl.handle.net/10033/621234
Nucleic Acids Research
ExoCET: exonuclease in vitro assembly combined with RecET recombination for highly efficient direct DNA cloning from complex genomes. (Erratum)
oai:repository.helmholtz-hzi.de:10033/6219002019-08-30T11:26:11Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Trojanowski, Damian
author
Kołodziej, Marta
author
Hołówka, Joanna
author
Müller, Rolf
author
Zakrzewska-Czerwińska, Jolanta
author
2019-08-05
Spreading resistance to antibiotics and the emergence of multidrug-resistant strains have become frequent in many bacterial species, including mycobacteria - a causative agents of severe diseases and have profound impacts on global health. Here, we used a system of microfluidics, fluorescence microscopy and target-tagged fluorescent reporter strains of Mycobacterium smegmatis to perform real-time monitoring of replisome and chromosome dynamics following the addition of replication-altering drugs (novobiocin, nalidixic acid and griselimycin) at the single-cell level. We found that novobiocin stalled replication forks and caused relaxation of the nucleoid, nalidixic acid triggered rapid replisome collapse and compaction of the nucleoid, while griselimycin caused replisome instability with subsequent over-initiation of chromosome replication and over-relaxation of the nucleoid. In addition to study target-drug interactions, our system also enabled to observe how the tested antibiotics affected the physiology of mycobacterial cells (i.e., growth, chromosome segregation, etc.).
Antimicrob Agents Chemother. 2019 Aug 5. pii: AAC.00739-19. doi: 10.1128/AAC.00739-19.
1098-6596
31383667
10.1128/AAC.00739-19
http://hdl.handle.net/10033/621900
Antimicrobial agents and chemotherapy
Watching DNA replication inhibitors in action: Exploiting time-lapse microfluidic microscopy as a tool for target-drug interaction studies in Mycobacterium .
oai:repository.helmholtz-hzi.de:10033/6219322019-09-12T01:27:22Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Volz, Carsten
author
Ramoni, Jonas
author
Beisken, Stephan
author
Galata, Valentina
author
Keller, Andreas
author
Plum, Achim
author
Posch, Andreas E
author
Müller, Rolf
author
2019-01-01
Multidrug-resistant pathogens represent one of the biggest global healthcare challenges. Molecular diagnostics can guide effective antibiotics therapy but relies on validated, predictive biomarkers. Here we present a novel, universally applicable workflow for rapid identification of antimicrobial resistance (AMR) biomarkers from clinical Escherichia coli isolates and quantitatively evaluate the potential to recover causal biomarkers for observed resistance phenotypes. For this, a metagenomic plasmid library from 1,110 clinical E. coli isolates was created and used for high-throughput screening to identify biomarker candidates against Tobramycin (TOB), Ciprofloxacin (CIP), and Trimethoprim-Sulfamethoxazole (TMP-SMX). Identified candidates were further validated in vitro and also evaluated in silico for their diagnostic performance based on matched genotype-phenotype data. AMR biomarkers recovered by the metagenomics screening approach mechanistically explained 77% of observed resistance phenotypes for Tobramycin, 76% for Trimethoprim-Sulfamethoxazole, and 20% Ciprofloxacin. Sensitivity for Ciprofloxacin resistance detection could be improved to 97% by complementing results with AMR biomarkers that are undiscoverable due to intrinsic limitations of the workflow. Additionally, when combined in a multiplex diagnostic in silico panel, the identified AMR biomarkers reached promising positive and negative predictive values of up to 97 and 99%, respectively. Finally, we demonstrate that the developed workflow can be used to identify potential novel resistance mechanisms.
Front Microbiol. 2019 Aug 13;10:1671. doi: 10.3389/fmicb.2019.01671. eCollection 2019.
1664-302X
31456751
10.3389/fmicb.2019.01671
http://hdl.handle.net/10033/621932
Frontiers in Microbiology
antibiotic resistance
bioinformatics
biomarkers
biostatistics
functional metagenomics
high-throughput screening
next-generation sequencing
Clinical Resistome Screening of 1,110 Escherichia coli Isolates Efficiently Recovers Diagnostically Relevant Antibiotic Resistance Biomarkers and Potential Novel Resistance Mechanisms.
oai:repository.helmholtz-hzi.de:10033/6219382019-09-17T02:30:33Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Gemperlein, Katja
author
Dietrich, Demian
author
Kohlstedt, Michael
author
Zipf, Gregor
author
Bernauer, Hubert S
author
Wittmann, Christoph
author
Wenzel, Silke C
author
Müller, Rolf
author
2019-09-06
Long-chain polyunsaturated fatty acids (LC-PUFAs), particularly the omega-3 LC-PUFAs eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA), have been associated with beneficial health effects. Consequently, sustainable sources have to be developed to meet the increasing demand for these PUFAs. Here, we demonstrate the design and construction of artificial PUFA biosynthetic gene clusters (BGCs) encoding polyketide synthase-like PUFA synthases from myxobacteria adapted for the oleaginous yeast Yarrowia lipolytica. Genomic integration and heterologous expression of unmodified or hybrid PUFA BGCs yielded different yeast strains with specific LC-PUFA production profiles at promising yield and thus valuable for the biotechnological production of distinct PUFAs. Nutrient screening revealed a strong enhancement of PUFA production, when cells were phosphate limited. This represents, to the best of our knowledge, highest concentration of DHA (16.8 %) in total fatty acids among all published PUFA-producing Y. lipolytica strains.
Nat Commun. 2019 Sep 6;10(1):4055. doi: 10.1038/s41467-019-12025-8.
2041-1723
31492836
10.1038/s41467-019-12025-8
http://hdl.handle.net/10033/621938
Nature Communications
Polyunsaturated fatty acid production by Yarrowia lipolytica employing designed myxobacterial PUFA synthases.
oai:repository.helmholtz-hzi.de:10033/6219452019-09-18T03:36:45Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Bartel, Karin
author
Pein, Helmut
author
Popper, Bastian
author
Schmitt, Sabine
author
Janaki-Raman, Sudha
author
Schulze, Almut
author
Lengauer, Florian
author
Koeberle, Andreas
author
Werz, Oliver
author
Zischka, Hans
author
Müller, Rolf
author
Vollmar, Angelika M
author
von Schwarzenberg, Karin
author
2019-07-29
BACKGROUND:
The understanding of lysosomes has been expanded in recent research way beyond their view as cellular trash can. Lysosomes are pivotal in regulating metabolism, endocytosis and autophagy and are implicated in cancer. Recently it was discovered that the lysosomal V-ATPase, which is known to induce apoptosis, interferes with lipid metabolism in cancer, yet the interplay between these organelles is poorly understood.
METHODS:
LC-MS/MS analysis was performed to investigate lipid distribution in cells. Cell survival and signaling pathways were analyzed by means of cell biological methods (qPCR, Western Blot, flow cytometry, CellTiter-Blue). Mitochondrial structure was analyzed by confocal imaging and electron microscopy, their function was determined by flow cytometry and seahorse measurements.
RESULTS:
Our data reveal that interfering with lysosomal function changes composition and subcellular localization of triacylglycerids accompanied by an upregulation of PGC1α and PPARα expression, master regulators of energy and lipid metabolism. Furthermore, cardiolipin content is reduced driving mitochondria into fission, accompanied by a loss of membrane potential and reduction in oxidative capacity, which leads to a deregulation in cellular ROS and induction of mitochondria-driven apoptosis. Additionally, cells undergo a metabolic shift to glutamine dependency, correlated with the fission phenotype and sensitivity to lysosomal inhibition, most prominent in Ras mutated cells.
CONCLUSION:
This study sheds mechanistic light on a largely uninvestigated triangle between lysosomes, lipid metabolism and mitochondrial function. Insight into this organelle crosstalk increases our understanding of mitochondria-driven cell death. Our findings furthermore provide a first hint on a connection of Ras pathway mutations and sensitivity towards lysosomal inhibitors.
Cell Commun Signal. 2019 Jul 29;17(1):87. doi: 10.1186/s12964-019-0399-2.
1478-811X
31358011
10.1186/s12964-019-0399-2
http://hdl.handle.net/10033/621945
Cell Communication and Signaling
Apoptosis
Cardiolipin
Fission
Lipid metabolism
Lysosome
Mitochondria
V-ATPase
Connecting lysosomes and mitochondria - a novel role for lipid metabolism in cancer cell death.
oai:repository.helmholtz-hzi.de:10033/6219492019-09-19T01:31:08Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Gross, Angelina S
author
Zimmermann, Andreas
author
Pendl, Tobias
author
Schroeder, Sabrina
author
Schoenlechner, Hannes
author
Knittelfelder, Oskar
author
Lamplmayr, Laura
author
Santiso, Ana
author
Aufschnaiter, Andreas
author
Waltenstorfer, Daniel
author
Ortonobes Lara, Sandra
author
Stryeck, Sarah
author
Kast, Christina
author
Ruckenstuhl, Christoph
author
Hofer, Sebastian J
author
Michelitsch, Birgit
author
Woelflingseder, Martina
author
Müller, Rolf
author
Carmona-Gutierrez, Didac
author
Madl, Tobias
author
Büttner, Sabrina
author
Fröhlich, Kai-Uwe
author
Shevchenko, Andrej
author
Eisenberg, Tobias
author
2019-08-09
Autophagy, a membrane-dependent catabolic process, ensures survival of aging cells and depends on the cellular energetic status. Acetyl-CoA carboxylase 1 (Acc1) connects central energy metabolism to lipid biosynthesis and is rate-limiting for the de novo synthesis of lipids. However, it is unclear how de novo lipogenesis and its metabolic consequences affect autophagic activity. Here, we show that in aging yeast, autophagy levels highly depend on the activity of Acc1. Constitutively active Acc1 (acc1S/A ) or a deletion of the Acc1 negative regulator, Snf1 (yeast AMPK), shows elevated autophagy levels, which can be reversed by the Acc1 inhibitor soraphen A. Vice versa, pharmacological inhibition of Acc1 drastically reduces cell survival and results in the accumulation of Atg8-positive structures at the vacuolar membrane, suggesting late defects in the autophagic cascade. As expected, acc1S/A cells exhibit a reduction in acetate/acetyl-CoA availability along with elevated cellular lipid content. However, concomitant administration of acetate fails to fully revert the increase in autophagy exerted by acc1S/A Instead, administration of oleate, while mimicking constitutively active Acc1 in WT cells, alleviates the vacuolar fusion defects induced by Acc1 inhibition. Our results argue for a largely lipid-dependent process of autophagy regulation downstream of Acc1. We present a versatile genetic model to investigate the complex relationship between acetate metabolism, lipid homeostasis, and autophagy and propose Acc1-dependent lipogenesis as a fundamental metabolic path downstream of Snf1 to maintain autophagy and survival during cellular aging.
J Biol Chem. 2019 Aug 9;294(32):12020-12039. doi: 10.1074/jbc.RA118.007020. Epub 2019 Jun 17.
1083-351X
31209110
10.1074/jbc.RA118.007020
http://hdl.handle.net/10033/621949
Journal of Biological Chemistry
AMPK
Acc1
Snf1
acetate
acetyl coenzyme A (acetyl-CoA)
acetyl-CoA carboxylase 1
aging
autophagy
lipid metabolism
lipogenesis
oleate
yeast
Acetyl-CoA carboxylase 1-dependent lipogenesis promotes autophagy downstream of AMPK.
oai:repository.helmholtz-hzi.de:10033/6220162019-11-15T02:00:57Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Bartel, Karin
author
Müller, Rolf
author
von Schwarzenberg, Karin
author
2019-10-11
The cellular energy sensor AMP-activated protein kinase (AMPK) is a metabolic hub regulating various pathways involved in tumor metabolism. Here, we report that vacuolar H+-ATPase (V-ATPase) inhibition differentially affects regulation of AMPK in tumor and non-tumor cells and that this differential regulation contributes to the selectivity of V-ATPase inhibitors for tumor cells. In non-malignant cells, the V-ATPase inhibitor archazolid increased phosphorylation and lysosomal localization of AMPK. We noted that AMPK localization has a pro-survival role, as AMPK silencing decreased cellular growth rates. In contrast, in cancer cells, we found that AMPK is constitutively active and that archazolid does not affect its phosphorylation and localization. Moreover, V-ATPase-independent AMPK induction in the tumor cells protected them from archazolid-induced cytotoxicity, further underlining the role of AMPK as a pro-survival mediator. These observations indicate that AMPK regulation is uncoupled from V-ATPase activity in cancer cells and that this makes them more susceptible to cell death induction by V-ATPase inhibitors. In both tumor and healthy cells, V-ATPase inhibition induced a distinct metabolic regulatory cascade downstream of AMPK, affecting ATP and NADPH levels, glucose uptake, and reactive oxygen species (ROS) production. We could attribute the pro-survival effects to AMPK's ability to maintain redox homeostasis by inhibiting ROS production and maintaining NADPH levels. In summary, the results of our work indicate that V-ATPase inhibition has differential effects on AMPK-mediated metabolic regulation in cancer and healthy cells and explain the tumor-specific cytotoxicity of V-ATPase inhibition.
J Biol Chem. 2019 Oct 11. pii: RA119.010243. doi: 10.1074/jbc.RA119.010243
1083-351X
31604821
10.1074/jbc.RA119.010243
http://hdl.handle.net/10033/622016
Journal of biological chemistry
AMP-activated kinase (AMPK)
apoptosis
archazolid
cancer
glucose starvation
metabolism
pH homeostasis
reactive oxygen species (ROS)
tumor suppressor
vacuolar ATPase
Differential regulation of AMP-activated protein kinase in healthy and cancer cells explains why V-ATPase inhibition selectively kills cancer cells.
oai:repository.helmholtz-hzi.de:10033/6220212019-11-21T02:06:51Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Kröhler, Tarek
author
Kessler, Sonja M
author
Hosseini, Kevan
author
List, Markus
author
Barghash, Ahmad
author
Patial, Sonika
author
Laggai, Stephan
author
Gemperlein, Katja
author
Haybaeck, Johannes
author
Müller, Rolf
author
Helms, Volkhard
author
Schulz, Marcel H
author
Hoppstädter, Jessica
author
Blackshear, Perry J
author
Kiemer, Alexandra K
author
2019-11-08
Hepatic lipid deposition and inflammation represent risk factors for hepatocellular carcinoma (HCC). The mRNA-binding protein tristetraprolin (TTP, gene name ZFP36) has been suggested as a tumor suppressor in several malignancies, but it increases insulin resistance. The aim of this study was to elucidate the role of TTP in hepatocarcinogenesis and HCC progression. Employing liver-specific TTP-knockout (lsTtp-KO) mice in the diethylnitrosamine (DEN) hepatocarcinogenesis model, we observed a significantly reduced tumor burden compared to wild-type animals. Upon short-term DEN treatment, modelling early inflammatory processes in hepatocarcinogenesis, lsTtp-KO mice exhibited a reduced monocyte/macrophage ratio as compared to wild-type mice. While short-term DEN strongly induced an abundance of saturated and poly-unsaturated hepatic fatty acids, lsTtp-KO mice did not show these changes. These findings suggested anti-carcinogenic actions of TTP deletion due to effects on inflammation and metabolism. Interestingly, though, investigating effects of TTP on different hallmarks of cancer suggested tumor-suppressing actions: TTP inhibited proliferation, attenuated migration, and slightly increased chemosensitivity. In line with a tumor-suppressing activity, we observed a reduced expression of several oncogenes in TTP-overexpressing cells. Accordingly, ZFP36 expression was downregulated in tumor tissues in three large human data sets. Taken together, this study suggests that hepatocytic TTP promotes hepatocarcinogenesis, while it shows tumor-suppressive actions during hepatic tumor progression.
Cancers (Basel). 2019 Nov 8;11(11). pii: cancers11111754. doi: 10.3390/cancers11111754.
2072-6694
31717307
10.3390/cancers11111754
http://hdl.handle.net/10033/622021
Cancers
BCL2
HepG2
Huh7
MYC
NASH
NEAT1
VEGFA
chemoresistance
flow cytometry
liver cancer
The mRNA-binding Protein TTP/ZFP36 in Hepatocarcinogenesis and Hepatocellular Carcinoma.
oai:repository.helmholtz-hzi.de:10033/6220412019-12-06T16:22:32Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Theßeling, Alexander
author
Rasmussen, Tim
author
Burschel, Sabrina
author
Wohlwend, Daniel
author
Kägi, Jan
author
Müller, Rolf
author
Böttcher, Bettina
author
Friedrich, Thorsten
author
2019-11-13
Cytochrome bd oxidases are terminal reductases of bacterial and archaeal respiratory chains. The enzyme couples the oxidation of ubiquinol or menaquinol with the reduction of dioxygen to water, thus contributing to the generation of the protonmotive force. Here, we determine the structure of the Escherichia coli bd oxidase treated with the specific inhibitor aurachin by cryo-electron microscopy (cryo-EM). The major subunits CydA and CydB are related by a pseudo two fold symmetry. The heme b and d cofactors are found in CydA, while ubiquinone-8 is bound at the homologous positions in CydB to stabilize its structure. The architecture of the E. coli enzyme is highly similar to that of Geobacillus thermodenitrificans, however, the positions of heme b595 and d are interchanged, and a common oxygen channel is blocked by a fourth subunit and substituted by a more narrow, alternative channel. Thus, with the same overall fold, the homologous enzymes exhibit a different mechanism.
Nat Commun. 2019 Nov 13;10(1):5138. doi: 10.1038/s41467-019-13122-4.
2041-1723
31723136
10.1038/s41467-019-13122-4
http://hdl.handle.net/10033/622041
Nature communications
Homologous bd oxidases share the same architecture but differ in mechanism.
oai:repository.helmholtz-hzi.de:10033/6220562020-01-04T02:01:12Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
De Rycker, Manu
author
Horn, David
author
Aldridge, Bree
author
Amewu, Richard K
author
Barry, Clifton E
author
Buckner, Frederick S
author
Cook, Sarah
author
Ferguson, Michael A J
author
Gobeau, Nathalie
author
Herrmann, Jennifer
author
Herrling, Paul
author
Hope, William
author
Keiser, Jennifer
author
Lafuente-Monasterio, Maria Jose
author
Leeson, Paul D
author
Leroy, Didier
author
Manjunatha, Ujjini H
author
McCarthy, James
author
Miles, Timothy J
author
Mizrahi, Valerie
author
Moshynets, Olena
author
Niles, Jacquin
author
Overington, John P
author
Pottage, John
author
Rao, Srinivasa P S
author
Read, Kevin D
author
Ribeiro, Isabela
author
Silver, Lynn L
author
Southern, Jen
author
Spangenberg, Thomas
author
Sundar, Shyam
author
Taylor, Caitlin
author
Van Voorhis, Wes
author
White, Nicholas J
author
Wyllie, Susan
author
Wyatt, Paul G
author
Gilbert, Ian H
author
2019-12-06
In May 2019, the Wellcome Centre for Anti-Infectives Research (WCAIR) at the University of Dundee, UK, held an international conference with the aim of discussing some key questions around discovering new medicines for infectious diseases and a particular focus on diseases affecting Low and Middle Income Countries. There is an urgent need for new drugs to treat most infectious diseases. We were keen to see if there were lessons that we could learn across different disease areas and between the preclinical and clinical phases with the aim of exploring how we can improve and speed up the drug discovery, translational, and clinical development processes. We started with an introductory session on the current situation and then worked backward from clinical development to combination therapy, pharmacokinetic/pharmacodynamic (PK/PD) studies, drug discovery pathways, and new starting points and targets. This Viewpoint aims to capture some of the learnings.
ACS Infect Dis. 2019 Dec 6. doi: 10.1021/acsinfecdis.9b00371.
2373-8227
31808676
10.1021/acsinfecdis.9b00371
http://hdl.handle.net/10033/622056
ACS Infectious Diseases
Setting Our Sights on Infectious Diseases.
oai:repository.helmholtz-hzi.de:10033/6220592020-01-04T02:02:30Zcom_10033_620613com_10033_620618col_10033_620614col_10033_620619
00925njm 22002777a 4500
dc
Anversa Dimer, Frantiescoli
author
de Souza Carvalho-Wodarz, Cristiane
author
Goes, Adriely
author
Cirnski, Katarina
author
Herrmann, Jennifer
author
Schmitt, Viktoria
author
Pätzold, Linda
author
Abed, Nadia
author
de Rossi, Chiara
author
Bischoff, Markus
author
Couvreur, Patrick
author
Müller, Rolf
author
Lehr, Claus-Michael
author
2019-11-18
Drug delivery systems are promising for targeting antibiotics directly to infected tissues. To reach intracellular Staphylococcus aureus and Mycobacterium abscessus, we encapsulated clarithromycin in PLGA nanocapsules, suitable for aerosol delivery by nebulization of an aqueous dispersion. Compared to the same dose of free clarithromycin, nanoencapsulation reduced 1000 times the number of intracellular S. aureus in vitro. In RAW cells, while untreated S. aureus was located in acidic compartments, the treated ones were mostly situated in non-acidic compartments. Clarithromycin-nanocapsules were also effective against M. abscessus (70-80% killing efficacy). The activity of clarithromycin-nanocapsules against S. aureus was also confirmed in vivo, using a murine wound model as well as in zebrafish. The permeability of clarithromycin-nanocapsules across Calu-3 monolayers increased in comparison to the free drug, suggesting an improved delivery to sub-epithelial tissues. Thus, clarithromycin-nanocapsules are a promising strategy to target intracellular S. aureus and M. abscessus.
Nanomedicine. 2019 Nov 18;24:102125. doi: 10.1016/j.nano.2019.102125.
1549-9642
31751769
10.1016/j.nano.2019.102125
http://hdl.handle.net/10033/622059
Nanomedicine: Nanotechnology, Biology, and Medicine
Clarithromycin
Mycobacterium abscessus
Nanoparticle
Permeability
Staphylococcus aureus
PLGA nanocapsules improve the delivery of clarithromycin to kill intracellular Staphylococcus aureus and Mycobacterium abscessus.
oai:repository.helmholtz-hzi.de:10033/6220722020-01-10T02:13:36Zcom_10033_620618col_10033_620619
00925njm 22002777a 4500
dc
Herrmann, Jennifer
author
2018-02-22
J Infect Dev Ctries. 2018 Feb 22;12(2.1):24S. doi: 10.3855/jidc.10096.
1972-2680
31804999
10.3855/jidc.10096
http://hdl.handle.net/10033/622072
Journal of infection in developing countries
myxobacteria
streptomyces
natural products
Search for hits and early leads from soil bacteria to combat infectious diseases.
oai:repository.helmholtz-hzi.de:10033/6220752020-01-14T02:20:50Zcom_10033_620656com_10033_620618col_10033_620658col_10033_620619
00925njm 22002777a 4500
dc
Siebert, David C B
author
Sommer, Roman
author
Pogorevc, Domen
author
Hoffmann, Michael
author
Wenzel, Silke C
author
Müller, Rolf
author
Titz, Alexander
author
2019-01-01
The argyrins are secondary metabolites from myxobacteria with antibiotic activity against Pseudomonas aeruginosa. Studying their structure-activity relationship is hampered by the complexity of the chemical total synthesis. Mutasynthesis is a promising approach where simpler and fully synthetic intermediates of the natural product's biosynthesis can be biotechnologically incorporated. Here, we report the synthesis of a series of tripeptide thioesters as mutasynthons containing the native sequence with a dehydroalanine (Dha) Michael acceptor attached to a sarcosine (Sar) and derivatives. Chemical synthesis of the native sequence ᴅ-Ala-Dha-Sar thioester required revision of the sequential peptide synthesis into a convergent strategy where the thioester with sarcosine was formed before coupling to the Dha-containing dipeptide.
Beilstein J Org Chem. 2019 Dec 5;15:2922-2929. doi: 10.3762/bjoc.15.286. eCollection 2019.
1860-5397
31839838
10.3762/bjoc.15.286
http://hdl.handle.net/10033/622075
Beilstein Journal of Organic Chemistry
NRPS
antibiotic
argyrin
mutasynthesis
peptide synthesis
Chemical synthesis of tripeptide thioesters for the biotechnological incorporation into the myxobacterial secondary metabolite argyrin via mutasynthesis.
marc///col_10033_620619/100