Phosphodependent recruitment of Bub1 and Bub3 to Spc7/KNL1 by Mph1 kinase maintains the spindle checkpoint.

ABSTRACT: The spindle assembly checkpoint (SAC) is the major surveillance system that ensures that sister chromatids do not separate until all chromosomes are correctly bioriented during mitosis. Components of the checkpoint include Mad1, Mad2, Mad3 (BubR1), Bub3, and the kinases Bub1, Mph1 (Mps1), and Aurora B. Checkpoint proteins are recruited to kinetochores when individual kinetochores are not bound to spindle microtubules or not under tension. Kinetochore association of Mad2 causes it to undergo a conformational change, which promotes its association to Mad3 and Cdc20 to form the mitotic checkpoint complex (MCC). The MCC inhibits the anaphase-promoting complex/cyclosome (APC/C) until the checkpoint is satisfied. SAC silencing derepresses Cdc20-APC/C activity. This triggers the polyubiquitinatio

SUBMITTER: Shepperd LA 

PROVIDER: S-EPMC3780767 | biostudies-literature | 2012 May

REPOSITORIES: biostudies-literature