Functions of Vrp1p in cytokinesis and actin patches are distinct and neither requires a WH2/V domain

EMBO J. 2001 Dec 17;20(24):6979-89. doi: 10.1093/emboj/20.24.6979.

Abstract

Vrp1 (verprolin, End5) is a Saccharomyces cerevisiae actin-associated protein and is related to mammalian Wiskott-Aldrich syndrome protein (WASP)-interacting protein (WIP). Vrp1-deficient (vrp1 Delta) cells are inviable at high temperature, have partially depolarized cortical actin patches and have defects in both actomyosin ring-dependent and Hof1 (Cyk2)-dependent pathways of cytokinesis. We demonstrate here that N-Vrp1(1-364) and C-Vrp1(364-817) are each sufficient to restore viability, actomyosin ring constriction and Hof1 localization at 37 degrees C to vrp1 Delta. C-Vrp1, like Vrp1, partially co-localizes with cortical actin patches and restores actin patch polarization to vrp1 Delta. Cortical localization of C-Vrp1, but not Vrp1, requires Las17. N-Vrp1 exhibits diffuse cytoplasmic localization and functions in cytokinesis without efficiently restoring polarization of cortical actin patches. N-Vrp1 function is not abolished by mutations affecting the WASP homology 2 (WH2) [verprolin homology (V)] actin-binding domain. N-Vrp1 may function through the type I myosins and actin, while C-Vrp1 may function through both Las17 (Bee1) and type I myosins. The functions of Vrp1 in viability at 37 degrees C and cytokinesis do not require efficient localization to, and function in, the cortical actin cytoskeleton.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / chemistry
  • Actins / physiology*
  • Amino Acid Motifs
  • Amino Acid Sequence
  • Carrier Proteins / metabolism
  • Cell Cycle / physiology*
  • Cytoskeletal Proteins*
  • Fungal Proteins / chemistry
  • Fungal Proteins / physiology*
  • Hot Temperature
  • Microfilament Proteins / chemistry
  • Microfilament Proteins / physiology*
  • Microtubule-Associated Proteins*
  • Myosins / physiology
  • Saccharomyces cerevisiae / physiology
  • Saccharomyces cerevisiae Proteins*
  • Wiskott-Aldrich Syndrome Protein

Substances

  • Actins
  • Carrier Proteins
  • Cytoskeletal Proteins
  • Fungal Proteins
  • HOF1 protein, S cerevisiae
  • LAS17 protein, S cerevisiae
  • Microfilament Proteins
  • Microtubule-Associated Proteins
  • Saccharomyces cerevisiae Proteins
  • VRP1 protein, S cerevisiae
  • Wiskott-Aldrich Syndrome Protein
  • Myosins