2025-09-17 マックス・プランク研究所(MPI)
Microscopy image of kinetochore coronas (green) during cell division. © MPI MOPH
<関連情報>
- https://www.mpg.de/25413752/two-routes-one-goal-how-the-crown-of-cell-division-is-manufactured
- https://www.science.org/doi/10.1126/sciadv.ady6890
BUB1およびBUBR1パラログは動原体繊維冠を構築する The BUB1 and BUBR1 paralogs scaffold the kinetochore fibrous corona
Verena Cmentowski and Andrea Musacchio
Science Advances Published:12 Sep 2025
DOI:https://doi.org/10.1126/sciadv.ady6890
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 explains how the SAC protein MAD1 fits this corona assembly scheme. Our findings solve the long-standing puzzle of corona assembly and demonstrate the intimate interweaving of chromosome biorientation and checkpoint signaling.
