Ase1 domains dynamically slow anaphase spindle elongation and recruit Bim1 to the midzone

Mol Biol Cell. 2020 Nov 15;31(24):2733-2747. doi: 10.1091/mbc.E20-07-0493-T. Epub 2020 Sep 30.


How cells regulate microtubule cross-linking activity to control the rate and duration of spindle elongation during anaphase is poorly understood. In this study, we test the hypothesis that PRC1/Ase1 proteins use distinct microtubule-binding domains to control the spindle elongation rate. Using the budding yeast Ase1, we identify unique contributions for the spectrin and carboxy-terminal domains during different phases of spindle elongation. We show that the spectrin domain uses conserved basic residues to promote the recruitment of Ase1 to the midzone before anaphase onset and slow spindle elongation during early anaphase. In contrast, a partial Ase1 carboxy-terminal truncation fails to form a stable midzone in late anaphase, produces higher elongation rates after early anaphase, and exhibits frequent spindle collapses. We find that the carboxy-terminal domain interacts with the plus-end tracking protein EB1/Bim1 and recruits Bim1 to the midzone to maintain midzone length. Overall, our results suggest that the Ase1 domains provide cells with a modular system to tune midzone activity and control elongation rates.

Publication types

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

MeSH terms

  • Anaphase / physiology
  • Cell Cycle / physiology
  • Cell Cycle Proteins / metabolism*
  • Cell Cycle Proteins / physiology
  • Chromosome Segregation / physiology
  • Microtubule Proteins / metabolism*
  • Microtubule Proteins / physiology
  • Microtubule-Associated Proteins / metabolism*
  • Microtubule-Associated Proteins / physiology
  • Microtubules / metabolism
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Saccharomyces cerevisiae Proteins / physiology
  • Saccharomycetales / metabolism
  • Spindle Apparatus / metabolism*
  • Spindle Apparatus / physiology


  • Ase1 protein, S cerevisiae
  • BIM1 protein, S cerevisiae
  • Cell Cycle Proteins
  • Microtubule Proteins
  • Microtubule-Associated Proteins
  • Saccharomyces cerevisiae Proteins