RT Journal Article SR Electronic T1 Astrin-SKAP complex reconstitution reveals its kinetochore interaction with microtubule-bound Ndc80 JF bioRxiv FD Cold Spring Harbor Laboratory SP 151399 DO 10.1101/151399 A1 David M. Kern A1 Elizabeth M. Wilson-Kubalek A1 Iain M. Cheeseman YR 2017 UL http://biorxiv.org/content/early/2017/06/17/151399.abstract 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.