Stable kinetochore-microtubule attachment requires loop-dependent Ndc80-Ndc80 binding

Polley, S.; Müschenborn, H.; Terbeck, M.; De Antoni, A.; Vetter, I. R.; Dogterom, M.; Musacchio, A.; Volkov, V. A.; Huis in 't Veld, P. J.

doi:10.1101/2022.08.25.505310

bioRxiv · 10.1101/2022.08.25.505310

Stable kinetochore-microtubule attachment requires loop-dependent Ndc80-Ndc80 binding

Polley, S.·Müschenborn, H.·Terbeck, M.·De Antoni, A.·Vetter, I. R.·Dogterom, M.·Musacchio, A.·Volkov, V. A.·Huis in 't Veld, P. J.

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Abstract

During cell division, kinetochores link chromosomes to spindle microtubules. The Ndc80 complex, a crucial microtubule binder, populates each kinetochore with dozens of copies. Whether adjacent Ndc80 complexes cooperate to promote microtubule binding remains unclear. Here we demonstrate that the Ndc80 loop, a short sequence identified across eukaryotes and predicted to interrupt the Ndc80 coiled-coil, promotes direct interactions between full-length Ndc80 complexes. Both in dividing cells and in a fully reconstituted system, these interactions are essential for the formation of force-resistant kinetochore-microtubule attachments, explaining why deletion of the loop ablates chromosome congression. The loop may fold into a more rigid structure than previously assumed and we identify point mutations that impair Ndc80-Ndc80 interactions and recapitulate the effects of loop depletion. The loop also promotes spindle checkpoint signaling, suggesting that the organisation of adjacent Ndc80 complexes is crucial to couple kinetochore-microtubule binding to cell cycle control.

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Polley, S., Müschenborn, H., Terbeck, M., De Antoni, A., Vetter, I. R., Dogterom, M., Musacchio, A., Volkov, V. A., Huis in 't Veld, P. J.. 2022-08-26. Stable kinetochore-microtubule attachment requires loop-dependent Ndc80-Ndc80 binding. https://doi.org/10.1101/2022.08.25.505310

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