Phosphatidylinositol 4,5-biphosphate (PIP2)-induced vesicle movement depends on N-WASP and involves Nck, WIP, and Grb2

J Biol Chem. 2002 Oct 4;277(40):37771-6. doi: 10.1074/jbc.M204145200. Epub 2002 Jul 29.

Abstract

Wiskott-Aldrich syndrome protein (WASP)/Scar family proteins promote actin polymerization by stimulating the actin-nucleating activity of the Arp2/3 complex. While Scar/WAVE proteins are thought to be involved in lamellipodia protrusion, the hematopoietic WASP has been implicated in various actin-based processes such as chemotaxis, podosome formation, and phagocytosis. Here we show that the ubiquitously expressed N-WASP is essential for actin assembly at the surface of endomembranes induced as a consequence of increased phosphatidylinositol 4,5-biphosphate (PIP2) levels. This process resulting in the motility of intracellular vesicles at the tips of actin comets involved the recruitment of the Src homology 3 (SH3)-SH2 adaptor proteins Nck and Grb2 as well as of WASP interacting protein (WIP). Reconstitution of vesicle movement in N-WASP-defective cells by expression of various N-WASP mutant proteins revealed three independent domains capable of interaction with the vesicle surface, of which both the WH1 and the polyproline domains contributed significantly to N-WASP recruitment and/or activation. In contrast, the direct interaction of N-WASP with the Rho-GTPase Cdc42 was not required for reconstitution of vesicle motility. Our data reveal a distinct cellular phenotype for N-WASP loss of function, which adds to accumulating evidence that the proposed link between actin and membrane dynamics may, at least partially, be reflected by the actin-based movement of vesicles through the cytoplasm.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing*
  • Animals
  • Base Sequence
  • Brain / metabolism
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cytoskeletal Proteins
  • DNA Primers
  • Fibroblasts / cytology
  • Fibroblasts / physiology
  • GRB2 Adaptor Protein
  • Gene Deletion
  • Green Fluorescent Proteins
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • Luminescent Proteins / genetics
  • Mice
  • Mice, Inbred C57BL
  • Molecular Sequence Data
  • Movement / physiology
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • Oncogene Proteins / genetics
  • Oncogene Proteins / metabolism*
  • Phosphatidylinositol 4,5-Diphosphate / pharmacology*
  • Proteins / genetics
  • Proteins / metabolism*
  • Recombinant Fusion Proteins / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Wiskott-Aldrich Syndrome / genetics
  • Wiskott-Aldrich Syndrome Protein, Neuronal
  • src Homology Domains

Substances

  • Adaptor Proteins, Signal Transducing
  • Carrier Proteins
  • Cytoskeletal Proteins
  • DNA Primers
  • GRB2 Adaptor Protein
  • GRB2 protein, human
  • Grb2 protein, mouse
  • Intracellular Signaling Peptides and Proteins
  • Luminescent Proteins
  • Nck protein
  • Nerve Tissue Proteins
  • Oncogene Proteins
  • Phosphatidylinositol 4,5-Diphosphate
  • Proteins
  • Recombinant Fusion Proteins
  • WASL protein, human
  • WIPF1 protein, human
  • Wasl protein, mouse
  • Waspip protein, mouse
  • Wiskott-Aldrich Syndrome Protein, Neuronal
  • Green Fluorescent Proteins

Associated data

  • GENBANK/AJ437262