PT - JOURNAL ARTICLE AU - David M. Kern AU - Elizabeth M. Wilson-Kubalek AU - Iain M. Cheeseman TI - Astrin-SKAP complex reconstitution reveals its kinetochore interaction with microtubule-bound Ndc80 AID - 10.1101/151399 DP - 2017 Jan 01 TA - bioRxiv PG - 151399 4099 - http://biorxiv.org/content/early/2017/06/17/151399.short 4100 - http://biorxiv.org/content/early/2017/06/17/151399.full AB - 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, the core component of the kinetochore-microtubule interface, 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.