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Cdk1 promotes kinetochore bi‐orientation and regulates Cdc20 expression during recovery from spindle checkpoint arrest
Author(s) -
Liang Hongqing,
Lim Hong Hwa,
Venkitaraman Ashok,
Surana Uttam
Publication year - 2012
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/emboj.2011.385
Subject(s) - biology , microbiology and biotechnology , kinetochore , spindle checkpoint , cell cycle checkpoint , g2 m dna damage checkpoint , genetics , cell cycle , apoptosis , chromosome , gene
The spindle assembly checkpoint (SAC), an evolutionarily conserved surveillance pathway, prevents chromosome segregation in response to conditions that disrupt the kinetochore‐microtubule attachment. Removal of the checkpoint‐activating stimulus initiates recovery during which spindle integrity is restored, kinetochores become bi‐oriented, and cells initiate anaphase. Whether recovery ensues passively after the removal of checkpoint stimulus, or requires mediation by specific effectors remains uncertain. Here, we report two unrecognized functions of yeast Cdk1 required for efficient recovery from SAC‐induced arrest. We show that Cdk1 promotes kinetochore bi‐orientation during recovery by restraining premature spindle elongation thereby extinguishing SAC signalling. Moreover, Cdk1 is essential for sustaining the expression of Cdc20, an activator of the anaphase promoting complex/cyclosome (APC/C) required for anaphase progression. We suggest a model in which Cdk1 activity promotes recovery from SAC‐induced mitotic arrest by regulating bi‐orientation and APC/C activity. Our findings provide fresh insights into the regulation of mitosis and have implications for the therapeutic efficacy of anti‐mitotic drugs.