RflM mediates target specificity of the RcsCDB phosphorelay system for transcriptional repression of flagellar synthesis in Salmonella enterica.

2.50
Hdl Handle:
http://hdl.handle.net/10033/620518
Title:
RflM mediates target specificity of the RcsCDB phosphorelay system for transcriptional repression of flagellar synthesis in Salmonella enterica.
Authors:
Kühne, Caroline; Singer, Hanna M; Grabisch, Eva; Codutti, Luca; Carlomagno, Teresa; Scrima, Andrea; Erhardt, Marc ( 0000-0001-6292-619X )
Abstract:
The bacterial flagellum enables directed movement of Salmonella enterica towards favorable conditions in liquid environments. Regulation of flagellar synthesis is tightly controlled by various environmental signals at transcriptional and post-transcriptional levels. The flagellar master regulator FlhD4 C2 resides on top of the flagellar transcriptional hierarchy and is under autogenous control by FlhD4 C2 -dependent activation of the repressor rflM. The inhibitory activity of RflM depends on the presence of RcsB, the response regulator of the RcsCDB phosphorelay system. In this study, we elucidated the molecular mechanism of RflM-dependent repression of flhDC. We show that RcsB and RflM form a heterodimer that coordinately represses flhDC transcription independent of RcsB phosphorylation. RcsB-RflM complex binds to a RcsB box downstream the P1 transcriptional start site of the flhDC promoter with increased affinity compared to RcsB in the absence of RflM. We propose that RflM stabilizes binding of unphosphorylated RcsB to the flhDC promoter in absence of environmental cues. Thus, RflM is a novel auxiliary regulatory protein that mediates target specificity of RcsB for flhDC repression. The cooperative action of the RcsB-RflM repressor complex allows Salmonella to fine-tune initiation of flagellar gene expression and adds another level to the complex regulation of flagellar synthesis.
Affiliation:
Helmholtz Centre for infection research, Inhoffenstr. 7, 38124 Braunschweig.
Citation:
RflM mediates target specificity of the RcsCDB phosphorelay system for transcriptional repression of flagellar synthesis in Salmonella enterica. 2016, 101 (5):841-55 Mol. Microbiol.
Journal:
Molecular microbiology
Issue Date:
Sep-2016
URI:
http://hdl.handle.net/10033/620518
DOI:
10.1111/mmi.13427
PubMed ID:
27206164
Type:
Article
Language:
en
ISSN:
1365-2958
Appears in Collections:
publications of the junior research group infection biology of Salmonella (IBIS)

Full metadata record

DC FieldValue Language
dc.contributor.authorKühne, Carolineen
dc.contributor.authorSinger, Hanna Men
dc.contributor.authorGrabisch, Evaen
dc.contributor.authorCodutti, Lucaen
dc.contributor.authorCarlomagno, Teresaen
dc.contributor.authorScrima, Andreaen
dc.contributor.authorErhardt, Marcen
dc.date.accessioned2016-09-19T12:37:34Z-
dc.date.available2016-09-19T12:37:34Z-
dc.date.issued2016-09-
dc.identifier.citationRflM mediates target specificity of the RcsCDB phosphorelay system for transcriptional repression of flagellar synthesis in Salmonella enterica. 2016, 101 (5):841-55 Mol. Microbiol.en
dc.identifier.issn1365-2958-
dc.identifier.pmid27206164-
dc.identifier.doi10.1111/mmi.13427-
dc.identifier.urihttp://hdl.handle.net/10033/620518-
dc.description.abstractThe bacterial flagellum enables directed movement of Salmonella enterica towards favorable conditions in liquid environments. Regulation of flagellar synthesis is tightly controlled by various environmental signals at transcriptional and post-transcriptional levels. The flagellar master regulator FlhD4 C2 resides on top of the flagellar transcriptional hierarchy and is under autogenous control by FlhD4 C2 -dependent activation of the repressor rflM. The inhibitory activity of RflM depends on the presence of RcsB, the response regulator of the RcsCDB phosphorelay system. In this study, we elucidated the molecular mechanism of RflM-dependent repression of flhDC. We show that RcsB and RflM form a heterodimer that coordinately represses flhDC transcription independent of RcsB phosphorylation. RcsB-RflM complex binds to a RcsB box downstream the P1 transcriptional start site of the flhDC promoter with increased affinity compared to RcsB in the absence of RflM. We propose that RflM stabilizes binding of unphosphorylated RcsB to the flhDC promoter in absence of environmental cues. Thus, RflM is a novel auxiliary regulatory protein that mediates target specificity of RcsB for flhDC repression. The cooperative action of the RcsB-RflM repressor complex allows Salmonella to fine-tune initiation of flagellar gene expression and adds another level to the complex regulation of flagellar synthesis.en
dc.language.isoenen
dc.relation'info:eu-repo/grantAgreement/EC/FP7/334030en
dc.rightsopenAccessen
dc.rights.urihttp://creativecommons.org/licenses/by-nc-sa/4.0/*
dc.titleRflM mediates target specificity of the RcsCDB phosphorelay system for transcriptional repression of flagellar synthesis in Salmonella enterica.en
dc.typeArticleen
dc.contributor.departmentHelmholtz Centre for infection research, Inhoffenstr. 7, 38124 Braunschweig.en
dc.identifier.journalMolecular microbiologyen
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