BubR1 acetylation at prometaphase is required for modulating APC/C activity and timing of mitosis.

ABSTRACT: Regulation of BubR1 is central to the control of APC/C activity. We have found that BubR1 forms a complex with PCAF and is acetylated at lysine 250. Using mass spectrometry and acetylated BubR1-specific antibodies, we have confirmed that BubR1 acetylation occurs at prometaphase. Importantly, BubR1 acetylation was required for checkpoint function, through the inhibition of ubiquitin-dependent BubR1 degradation. BubR1 degradation began before the onset of anaphase. It was noted that the pre-anaphase degradation was regulated by BubR1 acetylation. Degradation of an acetylation-mimetic form, BubR1-K250Q, was inhibited and chromosome segregation in cells expressing BubR1-K250Q was markedly delayed. By contrast, the acetylation-deficient mutant, BubR1-K250R, was unstable, and mitosis was acceler

SUBMITTER: Choi E 

PROVIDER: S-EPMC2684026 | biostudies-literature | 2009 Jul

REPOSITORIES: biostudies-literature