Astrin-SKAP complex reconstitution reveals its kinetochore interaction with microtubule-bound Ndc80

作者:Kern David M; Monda Julie K; Su Kuan Chung; Wilson Kubalek Elizabeth M; Cheeseman Iain M*
来源:eLife, 2017, 6: e26866.
DOI:10.7554/eLife.26866

摘要

Chromosome segregation requires robust interactions between the macromolecular kinetochore structure and dynamic microtubule polymers. A key outstanding question is how kinetochore-microtubule attachments are modulated to ensure that bi-oriented attachments are selectively stabilized and maintained. The Astrin-SKAP complex localizes preferentially to properly bi-oriented sister kinetochores, representing the final outer kinetochore component recruited prior to anaphase onset. Here, we reconstitute the 4-subunit Astrin-SKAP complex, including a novel MYCBP subunit. Our work demonstrates that the Astrin-SKAP complex contains separable kinetochore localization and microtubule binding domains. In addition, through cross-linking analysis in human cells and biochemical reconstitution, we show that the Astrin-SKAP complex binds synergistically to microtubules with the Ndc80 complex to form an integrated interface. We propose a model in which the Astrin-SKAP complex acts together with the Ndc80 complex to stabilize correctly formed kinetochore-microtubule interactions.

  • 出版日期2017-8-25
  • 单位MIT