Central spindle assembly and cytokinesis require a kinesin-like protein/RhoGAP complex with microtubule bundling activity

Dev Cell. 2002 Jan;2(1):41-54. doi: 10.1016/s1534-5807(01)00110-1.

Abstract

A late step in cytokinesis requires the central spindle, which forms during anaphase by the bundling of antiparallel nonkinetochore microtubules. Microtubule bundling and completion of cytokinesis require ZEN-4/CeMKLP-1, a kinesin-like protein, and CYK-4, which contains a RhoGAP domain. We show that CYK-4 and ZEN-4 exist in a complex in vivo that can be reconstituted in vitro. The N terminus of CYK-4 binds the central region of ZEN-4, including the neck linker. Genetic suppression data prove the functional significance of this interaction. An analogous complex, containing equimolar amounts of a CYK-4 ortholog and MKLP-1, was purified from mammalian cells. Biochemical studies indicate that this complex, named centralspindlin, is a heterotetramer. Centralspindlin, but not its individual components, strongly promotes microtubule bundling in vitro.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Anaphase / physiology
  • Animals
  • Binding Sites / physiology
  • Caenorhabditis elegans
  • Caenorhabditis elegans Proteins*
  • Cell Division / physiology*
  • GTPase-Activating Proteins / chemistry
  • GTPase-Activating Proteins / genetics
  • GTPase-Activating Proteins / metabolism*
  • Humans
  • In Vitro Techniques
  • Kinesin / chemistry
  • Kinesin / genetics
  • Kinesin / metabolism*
  • Microtubules / metabolism*
  • Molecular Sequence Data
  • Protein Structure, Tertiary
  • Spindle Apparatus / metabolism*

Substances

  • Caenorhabditis elegans Proteins
  • GTPase-Activating Proteins
  • ZEN-4 protein, C elegans
  • rho GTPase-activating protein
  • Kinesin