The BUB1 and BUBR1 paralogs scaffold the kinetochore fibrous corona.

ABSTRACT: The kinetochore corona, a polymeric fibrous structure, facilitates chromosome biorientation and mitotic checkpoint signaling during mitosis. How its main building block, the ROD-Zwilch-ZW10 (RZZ) complex, assembles on the outer kinetochore remains poorly understood. Harnessing corona biochemical reconstitutions and cell biology, we reveal that the paralogous spindle assembly checkpoint (SAC) proteins BUB1 and BUBR1 promote nonredundant branches of corona assembly. MPS1 kinase-dependent kinetochore docking of BUB1 and subsequent recruitment of BUBR1 initiates assembly. Disrupting the first branch by depleting CENP-E, a kinesin that links BUBR1 to RZZ, uncovered a second assembly pathway mediated by a direct interaction between BUB1 and ROD. Discovery of a direct interaction with the RZZ exp

SUBMITTER: Cmentowski V 

PROVIDER: S-EPMC12429063 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature