title: An Engineered Minimal WASP-Myosin Fusion Protein Reveals Essential Functions for Endocytosis.
abstract: Actin polymerization powers membrane deformation during many processes, including clathrin-mediated endocytosis (CME). During CME in yeast, actin polymerization is triggered and coordinated by a six-protein WASP/Myosin complex that includes WASP, class I myosins (Myo3 and Myo5), WIP (Vrp1), and two other proteins. We show that a single engineered protein can replace this entire complex while still supporting CME. This engineered protein reveals that the WASP/Myosin complex has four essential activities: recruitment to endocytic sites, anchorage to the plasma membrane, Arp2/3 activation, and transient actin filament binding by the motor domain. The requirement for both membrane and F-actin binding reveals that myosin-mediated coupling between actin filaments and the base of endocytic sites is essential for allowing actin polymerization to drive membrane invagination.
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Department of Biology, Lawrence University, Appleton, WI 54911, USA.
authors.forename: Eric B
authors.initials: EB
authors.lastname: Lewellyn
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.
authors.forename: Ross T A
authors.initials: RT
authors.lastname: Pedersen
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.
authors.forename: Jessica
authors.initials: J
authors.lastname: Hong
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Lu
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.
authors.forename: Huntly M
authors.initials: HM
authors.lastname: Morrison
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA. Electronic address: drubin@berkeley.edu.
authors.forename: David G
authors.initials: DG
authors.lastname: Drubin
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism; D000199:Actins / Q000378:metabolism*; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D004705:Endocytosis / Q000502:physiology*; D009218:Myosins / Q000378:metabolism*; D011485:Protein Binding; D012441:Saccharomyces cerevisiae; D051316:Wiskott-Aldrich Syndrome Protein / Q000378:metabolism*
chemical_list: D000199:Actins; D051316:Wiskott-Aldrich Syndrome Protein; D009218:Myosins