Cdc42 is required for membrane dependent actin polymerization in vitro.
In vitro actin based motility assays with bacterial pathogens have provided powerful systems to both understand and dissect actin dynamics as well as cell motility. Taking advantage of endogenous membrane vesicles in Xenopus extracts we have developed an in vitro assay to study membrane dependent actin polymerization. Our results demonstrate that membrane dependent actin polymerization, in contrast to Listeria stimulated actin filament assembly, is dependent on small GTPases of the Rho family. Using a combination of depletion and reconstitution experiments we have shown that Cdc42 but not Rac or Rho is required to stimulate actin polymerization from membranes. The in vitro system we have described here is amenable to identification of the downstream effectors of Cdc42 required for membrane dependent actin polymerization.
Moreau
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Cell Biology Programme, European Molecular Biology Laboratory, Heidelberg, Germany.
Way
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M
D000199:Actins / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D001704:Biopolymers; D018797:Cell Cycle Proteins / Q000378:metabolism*; D002462:Cell Membrane / Q000201:enzymology / Q000378:metabolism; D002465:Cell Movement; D020558:GTP Phosphohydrolases / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000378:metabolism*; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000378:metabolism; D010063:Ovum / Q000201:enzymology / Q000378:metabolism; D014638:Vanadates / Q000494:pharmacology; D014982:Xenopus laevis; D020764:cdc42 GTP-Binding Protein; D020744:rac GTP-Binding Proteins; D020741:rho GTP-Binding Proteins
D000199:Actins; D001704:Biopolymers; D018797:Cell Cycle Proteins; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D014638:Vanadates; D020558:GTP Phosphohydrolases; D019204:GTP-Binding Proteins; D020764:cdc42 GTP-Binding Protein; D020744:rac GTP-Binding Proteins; D020741:rho GTP-Binding Proteins