A novel neural Wiskott-Aldrich syndrome protein (N-WASP) binding protein, WISH, induces Arp2/3 complex activation independent of Cdc42

J Cell Biol. 2001 Feb 5;152(3):471-82. doi: 10.1083/jcb.152.3.471.

Abstract

We identified a novel adaptor protein that contains a Src homology (SH)3 domain, SH3 binding proline-rich sequences, and a leucine zipper-like motif and termed this protein WASP interacting SH3 protein (WISH). WISH is expressed predominantly in neural tissues and testis. It bound Ash/Grb2 through its proline-rich regions and neural Wiskott-Aldrich syndrome protein (N-WASP) through its SH3 domain. WISH strongly enhanced N-WASP-induced Arp2/3 complex activation independent of Cdc42 in vitro, resulting in rapid actin polymerization. Furthermore, coexpression of WISH and N-WASP induced marked formation of microspikes in Cos7 cells, even in the absence of stimuli. An N-WASP mutant (H208D) that cannot bind Cdc42 still induced microspike formation when coexpressed with WISH. We also examined the contribution of WISH to a rapid actin polymerization induced by brain extract in vitro. Arp2/3 complex was essential for brain extract-induced rapid actin polymerization. Addition of WISH to extracts increased actin polymerization as Cdc42 did. However, WISH unexpectedly could activate actin polymerization even in N-WASP-depleted extracts. These findings suggest that WISH activates Arp2/3 complex through N-WASP-dependent and -independent pathways without Cdc42, resulting in the rapid actin polymerization required for microspike formation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actin-Related Protein 2
  • Actin-Related Protein 3
  • Actins / metabolism*
  • Adaptor Proteins, Signal Transducing*
  • Amino Acid Sequence
  • Animals
  • Blotting, Northern
  • Blotting, Western
  • Brain Chemistry
  • Carrier Proteins / chemistry
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cattle
  • Cell Line
  • Cell Surface Extensions / metabolism
  • Culture Media, Serum-Free
  • Cytoskeletal Proteins*
  • GRB2 Adaptor Protein
  • Genes, Reporter
  • Humans
  • Leucine Zippers
  • Molecular Sequence Data
  • Muscle Proteins*
  • Nerve Tissue Proteins / metabolism*
  • Polymers / metabolism
  • Protein Binding
  • Proteins / metabolism
  • Rats
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Wiskott-Aldrich Syndrome
  • Wiskott-Aldrich Syndrome Protein, Neuronal
  • cdc42 GTP-Binding Protein / metabolism*
  • src Homology Domains

Substances

  • ACTR2 protein, human
  • ACTR3 protein, human
  • Actin-Related Protein 2
  • Actin-Related Protein 3
  • Actins
  • Adaptor Proteins, Signal Transducing
  • Carrier Proteins
  • Culture Media, Serum-Free
  • Cytoskeletal Proteins
  • GRB2 Adaptor Protein
  • GRB2 protein, human
  • Grb2 protein, rat
  • Muscle Proteins
  • NCKIPSD protein, human
  • Nckipsd protein, mouse
  • Nerve Tissue Proteins
  • Polymers
  • Proteins
  • Recombinant Fusion Proteins
  • WASL protein, human
  • Wasl protein, rat
  • Wiskott-Aldrich Syndrome Protein, Neuronal
  • cdc42 GTP-Binding Protein