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Cdc14 Inhibition by the Spindle Assembly Checkpoint Prevents Unscheduled Centrosome Separation in Budding Yeast

Authors :
Elena Chiroli
Ilaria Catusi
Giovanna Lucchini
Giulia Rancati
Simonetta Piatti
Chiroli, E
Rancati, G
Catusi, I
Lucchini, G
Piatti, S
Source :
Molecular Biology of the Cell. 20:2626-2637
Publication Year :
2009
Publisher :
American Society for Cell Biology (ASCB), 2009.

Abstract

The spindle assembly checkpoint (SAC) is an evolutionarily conserved surveillance mechanism that delays anaphase onset and mitotic exit in response to the lack of kinetochore attachment. The target of the SAC is the E3 ubiquitin ligase anaphase-promoting complex (APC) bound to its Cdc20 activator. The Cdc20/APC complex is in turn required for sister chromatid separation and mitotic exit through ubiquitin-mediated proteolysis of securin, thus relieving inhibition of separase that unties sister chromatids. Separase is also involved in the Cdc-fourteen early anaphase release (FEAR) pathway of nucleolar release and activation of the Cdc14 phosphatase, which regulates several microtubule-linked processes at the metaphase/anaphase transition and also drives mitotic exit. Here, we report that the SAC prevents separation of microtubule-organizing centers (spindle pole bodies [SPBs]) when spindle assembly is defective. Under these circumstances, failure of SAC activation causes unscheduled SPB separation, which requires Cdc20/APC, the FEAR pathway, cytoplasmic dynein, and the actin cytoskeleton. We propose that, besides inhibiting sister chromatid separation, the SAC preserves the accurate transmission of chromosomes also by preventing SPBs to migrate far apart until the conditions to assemble a bipolar spindle are satisfied.

Details

ISSN :
19394586 and 10591524
Volume :
20
Database :
OpenAIRE
Journal :
Molecular Biology of the Cell
Accession number :
edsair.doi.dedup.....7442abbec8d2e13670e29c44b28455c1
Full Text :
https://doi.org/10.1091/mbc.e08-11-1150