Phospho-regulated interaction between kinesin-6 Klp9p and microtubule bundler Ase1p promotes spindle elongation

Dev Cell. 2009 Aug;17(2):257-67. doi: 10.1016/j.devcel.2009.06.012.

Abstract

The spindle midzone-composed of antiparallel microtubules, microtubule-associated proteins (MAPs), and motors-is the structure responsible for microtubule organization and sliding during anaphase B. In general, MAPs and motors stabilize the midzone and motors produce sliding. We show that fission yeast kinesin-6 motor klp9p binds to the microtubule antiparallel bundler ase1p at the midzone at anaphase B onset. This interaction depends upon the phosphorylation states of klp9p and ase1p. The cyclin-dependent kinase cdc2p phosphorylates and its antagonist phosphatase clp1p dephosphorylates klp9p and ase1p to control the position and timing of klp9p-ase1p interaction. Failure of klp9p-ase1p binding leads to decreased spindle elongation velocity. The ase1p-mediated recruitment of klp9p to the midzone accelerates pole separation, as suggested by computer simulation. Our findings indicate that a phosphorylation switch controls the spatial-temporal interactions of motors and MAPs for proper anaphase B, and suggest a mechanism whereby a specific motor-MAP conformation enables efficient microtubule sliding.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anaphase / physiology
  • CDC2 Protein Kinase / genetics
  • CDC2 Protein Kinase / metabolism
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism
  • Cyclin B / genetics
  • Cyclin B / metabolism
  • Kinesin / genetics
  • Kinesin / metabolism*
  • Microtubule-Associated Proteins / genetics
  • Microtubule-Associated Proteins / metabolism*
  • Microtubules / metabolism*
  • Models, Biological
  • Molecular Motor Proteins / genetics
  • Molecular Motor Proteins / metabolism*
  • Phosphorylation
  • Protein Binding
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism*
  • Protein Tyrosine Phosphatases / genetics
  • Protein Tyrosine Phosphatases / metabolism
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Schizosaccharomyces / cytology*
  • Schizosaccharomyces / metabolism
  • Schizosaccharomyces pombe Proteins / genetics
  • Schizosaccharomyces pombe Proteins / metabolism*
  • Spindle Apparatus / metabolism*

Substances

  • Ase1 protein, S pombe
  • Cdc13 protein, S pombe
  • Cell Cycle Proteins
  • Cyclin B
  • Microtubule-Associated Proteins
  • Molecular Motor Proteins
  • Protein Isoforms
  • Recombinant Fusion Proteins
  • Schizosaccharomyces pombe Proteins
  • CDC2 Protein Kinase
  • cdc2 protein, S pombe
  • Clp1 protein, S. pombe
  • Protein Tyrosine Phosphatases
  • Kinesin