2.50
Hdl Handle:
http://hdl.handle.net/10033/48543
Title:
Filopodia formation induced by active mDia2/Drf3.
Authors:
Block, J; Stradal, T E B; Hänisch, J; Geffers, R ( 0000-0003-4409-016X ) ; Köstler, S A; Urban, E; Small, J V; Rottner, K; Faix, J
Abstract:
Filopodia are rod-shaped cell surface protrusions composed of a parallel bundle of actin filaments. Since filopodia frequently emanate from lamellipodia, it has been proposed that they form exclusively by the convergence and elongation of actin filaments generated in lamellipodia networks. However, filopodia form without Arp2/3-complex, which is essential for lamellipodia formation, indicating that actin filaments in filopodia may be generated by other nucleators. Here we analyzed the effects of ectopic expression of GFP-tagged full length or a constitutively active variant of the human formin mDia2/Drf3. By contrast to the full-length molecule, which did not affect cell behaviour and was entirely cytosolic, active Drf3 lacking the C-terminal regulatory region (Drf3DeltaDAD) induced the formation of filopodia and accumulated at their tips. Low expression of Drf3DeltaDAD induced rod-shaped or tapered filopodia, whereas over-expression resulted in multiple, club-shaped filopodia. The clubs were filled with densely bundled actin filaments, whose number but not packing density decreased further away from the tip. Interestingly, clubs frequently increased in width after protrusion beyond the cell periphery, which correlated with increased amounts of Drf3DeltaDAD at their tips. These data suggest Drf3-induced filopodia form and extend by de novo nucleation of actin filaments instead of convergent elongation. Finally, Drf3DeltaDAD also induced the formation of unusual, lamellipodia-like structures, which contained both lamellipodial markers and the prominent filopodial protein fascin. Microarray analyses revealed highly variable Drf3 expression levels in different commonly used cell lines, reflecting the need for more detailed analyses of the functions of distinct formins in actin cytoskeleton turnover and different cell types.
Affiliation:
Cytoskeleton Dynamics Group, Helmholtz Centre for Infection Research, Braunschweig, Germany.
Citation:
Filopodia formation induced by active mDia2/Drf3. 2008, 231 (3):506-17notJ Microsc
Journal:
Journal of microscopy
Issue Date:
Sep-2008
URI:
http://hdl.handle.net/10033/48543
DOI:
10.1111/j.1365-2818.2008.02063.x
PubMed ID:
18755006
Type:
Article
Language:
en
ISSN:
1365-2818
Appears in Collections:
Publications of RG Cytoskeleton Dynamics (CYD)

Full metadata record

DC FieldValue Language
dc.contributor.authorBlock, Jen
dc.contributor.authorStradal, T E Ben
dc.contributor.authorHänisch, Jen
dc.contributor.authorGeffers, Ren
dc.contributor.authorKöstler, S Aen
dc.contributor.authorUrban, Een
dc.contributor.authorSmall, J Ven
dc.contributor.authorRottner, Ken
dc.contributor.authorFaix, Jen
dc.date.accessioned2009-02-05T15:40:21Zen
dc.date.available2009-02-05T15:40:21Zen
dc.date.issued2008-09en
dc.identifier.citationFilopodia formation induced by active mDia2/Drf3. 2008, 231 (3):506-17notJ Microscen
dc.identifier.issn1365-2818en
dc.identifier.pmid18755006en
dc.identifier.doi10.1111/j.1365-2818.2008.02063.xen
dc.identifier.urihttp://hdl.handle.net/10033/48543en
dc.description.abstractFilopodia are rod-shaped cell surface protrusions composed of a parallel bundle of actin filaments. Since filopodia frequently emanate from lamellipodia, it has been proposed that they form exclusively by the convergence and elongation of actin filaments generated in lamellipodia networks. However, filopodia form without Arp2/3-complex, which is essential for lamellipodia formation, indicating that actin filaments in filopodia may be generated by other nucleators. Here we analyzed the effects of ectopic expression of GFP-tagged full length or a constitutively active variant of the human formin mDia2/Drf3. By contrast to the full-length molecule, which did not affect cell behaviour and was entirely cytosolic, active Drf3 lacking the C-terminal regulatory region (Drf3DeltaDAD) induced the formation of filopodia and accumulated at their tips. Low expression of Drf3DeltaDAD induced rod-shaped or tapered filopodia, whereas over-expression resulted in multiple, club-shaped filopodia. The clubs were filled with densely bundled actin filaments, whose number but not packing density decreased further away from the tip. Interestingly, clubs frequently increased in width after protrusion beyond the cell periphery, which correlated with increased amounts of Drf3DeltaDAD at their tips. These data suggest Drf3-induced filopodia form and extend by de novo nucleation of actin filaments instead of convergent elongation. Finally, Drf3DeltaDAD also induced the formation of unusual, lamellipodia-like structures, which contained both lamellipodial markers and the prominent filopodial protein fascin. Microarray analyses revealed highly variable Drf3 expression levels in different commonly used cell lines, reflecting the need for more detailed analyses of the functions of distinct formins in actin cytoskeleton turnover and different cell types.en
dc.language.isoenen
dc.subject.meshAnimalsen
dc.subject.meshArtificial Gene Fusionen
dc.subject.meshCarrier Proteinsen
dc.subject.meshCell Lineen
dc.subject.meshCells, Cultureden
dc.subject.meshGene Expression Profilingen
dc.subject.meshGreen Fluorescent Proteinsen
dc.subject.meshHumansen
dc.subject.meshMiceen
dc.subject.meshMicrofilament Proteinsen
dc.subject.meshMicrofilamentsen
dc.subject.meshOligonucleotide Array Sequence Analysisen
dc.subject.meshPseudopodiaen
dc.subject.meshRecombinant Fusion Proteinsen
dc.subject.meshSequence Deletionen
dc.titleFilopodia formation induced by active mDia2/Drf3.en
dc.typeArticleen
dc.contributor.departmentCytoskeleton Dynamics Group, Helmholtz Centre for Infection Research, Braunschweig, Germany.en
dc.identifier.journalJournal of microscopyen

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