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Tension directly stabilizes reconstituted kinetochore-microtubule attachments.

Kinetochores are macromolecular machines that couple chromosomes to dynamic microtubule tips during cell division, thereby generating force to segregate the chromosomes. Accurate segregation depends on selective stabilization of correct 'bi-oriented' kinetochore-microtubule attachments, which come under tension as the result of opposing forces exerted by microtubules. Tension is thought to stabilize these bi-oriented attachments indirectly, by suppressing the destabilizing activity of a kinase, Aurora B. However, a complete mechanistic understanding of the role of tension requires reconstitution of kinetochore-microtubule attachments for biochemical and biophysical analyses in vitro. Here we show that native kinetochore particles retaining the majority of kinetochore proteins can be purified from budding yeast and used to reconstitute dynamic microtubule attachments. Individual kinetochore particles maintain load-bearing associations with assembling and disassembling ends of single microtubules for >30 min, providing a close match to the persistent coupling seen in vivo between budding yeast kinetochores and single microtubules. Moreover, tension increases the lifetimes of the reconstituted attachments directly, through a catch bond-like mechanism that does not require Aurora B. On the basis of these findings, we propose that tension selectively stabilizes proper kinetochore-microtubule attachments in vivo through a combination of direct mechanical stabilization and tension-dependent phosphoregulation.

Pubmed ID: 21107429

Authors

  • Akiyoshi B
  • Sarangapani KK
  • Powers AF
  • Nelson CR
  • Reichow SL
  • Arellano-Santoyo H
  • Gonen T
  • Ranish JA
  • Asbury CL
  • Biggins S

Journal

Nature

Publication Data

November 25, 2010

Associated Grants

  • Agency: NCI NIH HHS, Id: CA015704
  • Agency: NIGMS NIH HHS, Id: GM064386
  • Agency: NIGMS NIH HHS, Id: GM078069
  • Agency: NCI NIH HHS, Id: P30 CA015704-27
  • Agency: NIGMS NIH HHS, Id: P50 GM076547
  • Agency: NIGMS NIH HHS, Id: P50 GM076547-05
  • Agency: NIGMS NIH HHS, Id: PM50 GM076547
  • Agency: NIGMS NIH HHS, Id: R01 GM064386
  • Agency: NIGMS NIH HHS, Id: R01 GM064386-09
  • Agency: NIGMS NIH HHS, Id: R01 GM078069
  • Agency: NIGMS NIH HHS, Id: R01 GM078069-04
  • Agency: NIGMS NIH HHS, Id: R01 GM079373
  • Agency: NIGMS NIH HHS, Id: R01 GM079373-05
  • Agency: NIGMS NIH HHS, Id: R01GM79373
  • Agency: NIGMS NIH HHS, Id: T32 GM007270
  • Agency: NIGMS NIH HHS, Id: T32 GM007270-35
  • Agency: NHLBI NIH HHS, Id: T32 HL007312-26
  • Agency: NIGMS NIH HHS, Id: T32GM07270
  • Agency: NHLBI NIH HHS, Id: T32HL007312
  • Agency: Howard Hughes Medical Institute, Id:

Mesh Terms

  • Chromosomes
  • Fungal Proteins
  • Kinetochores
  • Microtubules
  • Saccharomyces cerevisiae