Regulation of myosin II during cytokinesis in higher eukaryotes

Trends Cell Biol. 2005 Jul;15(7):371-7. doi: 10.1016/j.tcb.2005.05.004.


Cellular myosin II is the principal motor responsible for cytokinesis. In higher eukaryotes, phosphorylation of the regulatory light chain (MLC) of myosin II is a primary means of activating myosin II and is known to be crucial for the execution of cell division. Because signals transmitted by the mitotic spindle coordinate key spatial and temporal aspects of cytokinesis, such signals should ultimately function to activate myosin II. Thus, it follows that identification of regulatory factors involved in MLC phosphorylation should elucidate the nature of spindle-derived regulatory signals and lead to a model for how they control cytokinesis. However, the identity of these upstream molecules remains elusive. This review (which is part of the Cytokinesis series) summarizes current views of the regulatory pathway controlling MLC phosphorylation and features four candidate molecules that are likely immediate upstream myosin regulators. I discuss proposed functions for MLCK, ROCK, citron kinase and myosin phosphatase during cytokinesis and consider the possibility of a link between these molecules and the signals transmitted by the mitotic spindle.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.
  • Review

MeSH terms

  • Animals
  • Cell Cycle Proteins / metabolism
  • Cytokinesis* / physiology
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • Myosin Light Chains / metabolism*
  • Myosin Type II / metabolism*
  • Myosin-Light-Chain Kinase / metabolism
  • Myosin-Light-Chain Phosphatase / metabolism
  • Phosphorylation
  • Protein-Serine-Threonine Kinases / metabolism
  • Spindle Apparatus / metabolism*
  • rho-Associated Kinases


  • Cell Cycle Proteins
  • Intracellular Signaling Peptides and Proteins
  • Myosin Light Chains
  • citron-kinase
  • Protein-Serine-Threonine Kinases
  • rho-Associated Kinases
  • Myosin-Light-Chain Kinase
  • Myosin-Light-Chain Phosphatase
  • Myosin Type II