Myosin II recruitment during cytokinesis independent of centralspindlin-mediated phosphorylation

J Biol Chem. 2009 Oct 2;284(40):27377-83. doi: 10.1074/jbc.M109.028316. Epub 2009 Aug 6.

Abstract

During cell division, the mechanisms by which myosin II is recruited to the contractile ring are not fully understood. Much recent work has focused on a model in which spatially restricted de novo filament assembly occurs at the cell equator via localized myosin II regulatory light chain (RLC) phosphorylation, stimulated by the RhoA-activating centralspindlin complex. Here, we show that a recombinant myosin IIA protein that assembles constitutively and is incapable of binding RLC still displays strong localization to the furrow in mammalian cells. Furthermore, this RLC-deficient myosin II efficiently drives cytokinesis, demonstrating that centralspindlin-based RLC phosphorylation is not necessary for myosin II localization during furrowing. Myosin II truncation analysis further reveals two distinct myosin II tail properties that contribute to furrow localization: a central tail domain mediating cortical furrow binding to heterologous binding partners and a carboxyl-terminal region mediating co-assembly with existing furrow myosin IIA or IIB filaments.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • COS Cells
  • Cell Cycle Proteins / metabolism*
  • Chlorocebus aethiops
  • Cytokinesis*
  • Gene Deletion
  • HLA-D Antigens / genetics
  • HLA-D Antigens / metabolism
  • HeLa Cells
  • Humans
  • Microtubule-Associated Proteins / metabolism*
  • Myosin Light Chains / deficiency
  • Myosin Light Chains / genetics
  • Myosin Light Chains / metabolism
  • Myosin Type II / genetics
  • Myosin Type II / metabolism*
  • Phosphoproteins / metabolism*
  • Phosphorylation
  • Protein Transport
  • Recombinant Fusion Proteins / metabolism

Substances

  • Cell Cycle Proteins
  • HLA-D Antigens
  • Microtubule-Associated Proteins
  • Myosin Light Chains
  • Phosphoproteins
  • Recombinant Fusion Proteins
  • spindlin
  • Myosin Type II