Toda K, Naito K, Mase S, Ueno M, Uritani M, Yamamoto A, Ushimaru T

ABSTRACT: BACKGROUND: The spindle assembly checkpoint (SAC) inhibits anaphase progression in the presence of insufficient kinetochore-microtubule attachments, but cells can eventually escape from this mitotic arrest by a process known as called mitotic slippage or adaptation. This is a problem for cancer chemotherapy using microtubule poisons. RESULTS: Here we describe ...

Read More

mitotic slippage in budding yeast. Precocious activation of anaphase promoting complex/cyclosome (APC/C)-Cdh1 caused mitotic slippage in the presence of nocodazole, while SAC was still active. APC/C-Cdh1, but not APC/C-Cdc20, triggered anaphase progression (securin degradation, separase-mediated cohesin cleavage and sister-chromatid separation), in addition to telophase onset (mitotic exit), during mitotic slippage. This demonstrates that an inhibitory system not only of APC/C-Cdc20 but also of APC/C-Cdh1 is critical for accurate chromosome segregation in the presence of unsatisfied kinetochore-microtubule attachments. CONCLUSIONS: The sequential activation of APC/C-Cdc20-to-APC/C-Cdh1 during mitosis is the heart of accurate mitosis. Precocious activation of APC/C-Cdh1 in metaphase (pre-anaphase) causes mitotic slippage in nocodazole-treated cells. For prevention of mitotic slippage, concomitant inhibition of APC/C-Cdh1 may be effective for tumor therapy with mitotic spindle poisons in human.

Date: Feb. 09, 2012

View in: Pubmed Google Scholar

129265