Small changes in phospho-occupancy at the kinetochore-microtubule interface drive mitotic fidelity.

ABSTRACT: Kinetochore protein phosphorylation promotes the correction of erroneous microtubule attachments to ensure faithful chromosome segregation during cell division. Determining how phosphorylation executes error correction requires an understanding of whether kinetochore substrates are completely (i.e., all-or-none) or only fractionally phosphorylated. Using quantitative mass spectrometry (MS), we measured phospho-occupancy on the conserved kinetochore protein Hec1 (NDC80) that directly binds microtubules. None of the positions measured exceeded ∼50% phospho-occupancy, and the cumulative phospho-occupancy changed by only ∼20% in response to changes in microtubule attachment status. The narrow dynamic range of phospho-occupancy is maintained, in part, by the ongoing phosphatase activity. Furthe

SUBMITTER: Kucharski TJ 

PROVIDER: S-EPMC9351707 | biostudies-literature | 2022 Sep

REPOSITORIES: biostudies-literature