title: WIP regulates N-WASP-mediated actin polymerization and filopodium formation.
abstract: Induction of filopodia is dependent on activation of the small GTPase Cdc42 and on neural Wiskott-Aldrich-syndrome protein (N-WASP). Here we show that WASP-interacting protein (WIP) interacts directly with N-WASP and actin. WIP retards N-WASP/Cdc42-activated actin polymerization mediated by the Arp2/3 complex, and stabilizes actin filaments. Microinjection of WIP into NIH 3T3 fibroblasts induces filopodia; this is inhibited by microinjection of anti-N-WASP antibody. Microinjection of anti-WIP antibody inhibits induction of filopodia by bradykinin, by an active Cdc42 mutant (Cdc42(V12)) and by N-WASP. Our results indicate that WIP and N-WASP may act as a functional unit in filopodium formation, which is consistent with their role in actin-tail formation in cells infected with vaccinia virus or Shigella.
authors.affiliation: Department of Pediatrics, Division of Immunology, Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors.forename: N
authors.initials: N
authors.lastname: Martinez-Quiles
authors.forename: R
authors.initials: R
authors.lastname: Rohatgi
authors.forename: I M
authors.initials: IM
authors.lastname: Antón
authors.forename: M
authors.initials: M
authors.lastname: Medina
authors.forename: S P
authors.initials: SP
authors.lastname: Saville
authors.forename: H
authors.initials: H
authors.lastname: Miki
authors.forename: H
authors.initials: H
authors.lastname: Yamaguchi
authors.forename: T
authors.initials: T
authors.lastname: Takenawa
authors.forename: J H
authors.initials: JH
authors.lastname: Hartwig
authors.forename: R S
authors.initials: RS
authors.lastname: Geha
authors.forename: N
authors.initials: N
authors.lastname: Ramesh
mesh_terms: D016475:3T3 Cells; D051377:Actin-Related Protein 2; D051378:Actin-Related Protein 3; D000199:Actins / Q000378:metabolism*; D000818:Animals; D015153:Blotting, Western; D001920:Bradykinin / Q000494:pharmacology; D002352:Carrier Proteins / Q000378:metabolism*; D002460:Cell Line; D003598:Cytoskeletal Proteins; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation; D005982:Glutathione Transferase / Q000378:metabolism; D051379:Mice; D008856:Microscopy, Fluorescence; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011554:Pseudopodia / Q000378:metabolism*; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D012760:Shigella / Q000378:metabolism; D015398:Signal Transduction; D013997:Time Factors; D020798:Two-Hybrid System Techniques; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal; D020764:cdc42 GTP-Binding Protein / Q000378:metabolism
chemical_list: D051377:Actin-Related Protein 2; D051378:Actin-Related Protein 3; D000199:Actins; C495927:Actr2 protein, mouse; C495929:Actr3 protein, mouse; D002352:Carrier Proteins; D003598:Cytoskeletal Proteins; D009419:Nerve Tissue Proteins; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; C495772:Wasl protein, mouse; C491671:Waspip protein, mouse; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal; D005982:Glutathione Transferase; D020764:cdc42 GTP-Binding Protein; D001920:Bradykinin