title: A neural Wiskott-Aldrich Syndrome protein-mediated pathway for localized activation of actin polymerization that is regulated by cortactin.
abstract: Activation of the epidermal growth factor (EGF) receptor can stimulate actin polymerization via the Arp2/3 complex using a number of signaling pathways, and specific stimulation conditions may control which pathways are activated. We have previously shown that localized stimulation of EGF receptor with EGF bound to beads results in localized actin polymerization and protrusion. Here we show that the actin polymerization is dependent upon activation of the Arp2/3 complex by neural Wiskott-Aldrich Syndrome protein (N-WASP) via Grb2 and Nck2. Suppression of Grb2 or Nck2 results in loss of localization of N-WASP at the activation site and reduced actin polymerization. Although cortactin has been found to synergize with N-WASP for Arp2/3-dependent actin polymerization in vitro, we find that cortactin can restrict N-WASP localization around EGF-bead-induced protrusions. In addition, cortactin-deficient cells have increased lamellipod dynamics but show reduced net translocation, suggesting that cortactin can contribute to cell polarity by controlling the extent of Arp2/3 activation by WASP family members and the stability of the F-actin network.
authors.affiliation: Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
authors.forename: Stephan J
authors.initials: SJ
authors.lastname: Kempiak
authors.forename: Hideki
authors.initials: H
authors.lastname: Yamaguchi
authors.forename: Corina
authors.initials: C
authors.lastname: Sarmiento
authors.forename: Mazen
authors.initials: M
authors.lastname: Sidani
authors.forename: Mousumi
authors.initials: M
authors.lastname: Ghosh
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Eddy
authors.forename: Vera
authors.initials: V
authors.lastname: Desmarais
authors.forename: Michael
authors.initials: M
authors.lastname: Way
authors.forename: John
authors.initials: J
authors.lastname: Condeelis
authors.forename: Jeffrey E
authors.initials: JE
authors.lastname: Segall
mesh_terms: D000199:Actins / Q000737:chemistry* / Q000378:metabolism*; D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D000818:Animals; D002417:Cattle; D002460:Cell Line; D002465:Cell Movement; D051356:Cortactin; D003599:Cytoskeleton / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D004815:Epidermal Growth Factor / Q000494:pharmacology; D051380:GRB2 Adaptor Protein; D006801:Humans; D008840:Microfilament Proteins / Q000378:metabolism*; D009474:Neurons / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D015513:Oncogene Proteins / Q000378:metabolism; D021381:Protein Transport; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects; D051316:Wiskott-Aldrich Syndrome Protein; D051300:Wiskott-Aldrich Syndrome Protein Family
chemical_list: D000199:Actins; D048868:Adaptor Proteins, Signal Transducing; C495868:CTTN protein, human; D051356:Cortactin; C495870:Cttn protein, rat; D051380:GRB2 Adaptor Protein; C495948:GRB2 protein, human; C495950:Grb2 protein, rat; D008840:Microfilament Proteins; C485544:NCK2 protein, human; D015513:Oncogene Proteins; D011506:Proteins; C495767:WAS protein, human; C495769:Was protein, rat; D051316:Wiskott-Aldrich Syndrome Protein; D051300:Wiskott-Aldrich Syndrome Protein Family; D004815:Epidermal Growth Factor