Moesin and its activating kinase Slik are required for cortical stability and microtubule organization in mitotic cells

J Cell Biol. 2008 Feb 25;180(4):739-46. doi: 10.1083/jcb.200709161. Epub 2008 Feb 18.

Abstract

Cell division requires cell shape changes involving the localized reorganization of cortical actin, which must be tightly linked with chromosome segregation operated by the mitotic spindle. How this multistep process is coordinated remains poorly understood. In this study, we show that the actin/membrane linker moesin, the single ERM (ezrin, radixin, and moesin) protein in Drosophila melanogaster, is required to maintain cortical stability during mitosis. Mitosis onset is characterized by a burst of moesin activation mediated by a Slik kinase-dependent phosphorylation. Activated moesin homogenously localizes at the cortex in prometaphase and is progressively restricted at the equator in later stages. Lack of moesin or inhibition of its activation destabilized the cortex throughout mitosis, resulting in severe cortical deformations and abnormal distribution of actomyosin regulators. Inhibiting moesin activation also impaired microtubule organization and precluded stable positioning of the mitotic spindle. We propose that the spatiotemporal control of moesin activation at the mitotic cortex provides localized cues to coordinate cortical contractility and microtubule interactions during cell division.

Publication types

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

MeSH terms

  • Actomyosin / metabolism
  • Animals
  • Cell Line
  • Cell Membrane / enzymology
  • Cell Membrane / ultrastructure
  • Cytokinesis / physiology
  • Cytoskeleton / enzymology*
  • Cytoskeleton / pathology
  • Cytoskeleton / ultrastructure
  • Down-Regulation / genetics
  • Drosophila Proteins / genetics
  • Drosophila Proteins / metabolism*
  • Drosophila melanogaster / enzymology*
  • Drosophila melanogaster / genetics
  • Drosophila melanogaster / ultrastructure
  • Enzyme Activation / genetics
  • Membrane Proteins / antagonists & inhibitors
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Microtubules / enzymology*
  • Microtubules / pathology
  • Microtubules / ultrastructure
  • Mitosis / physiology*
  • Mutation / genetics
  • Phosphorylation
  • Prometaphase / physiology
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / metabolism*
  • Spindle Apparatus / enzymology
  • Spindle Apparatus / ultrastructure

Substances

  • Drosophila Proteins
  • Membrane Proteins
  • moesin, Drosophila
  • Actomyosin
  • Protein-Serine-Threonine Kinases
  • Slik protein, Drosophila