Commitment to mitosis is regulated by a conserved protein kinase complex called MPF (mitosis-promoting factor). MPF activation triggers a positive-feedback loop that further promotes the activity of its activating phosphatase Cdc25 and is assumed to down-regulate the MPF-inhibitory kinase Wee1. Four protein kinases contribute to this amplification loop: MPF itself, Polo kinase, MAPK (mitogen-activated protein kinase) and Greatwall kinase. The fission yeast SPB (spindle pole body) component Cut12 plays a critical role in modulating mitotic commitment. In this review, I discuss the relationship between Cut12 and the fission yeast Polo kinase Plo1 in mitotic control. These results indicate that commitment to mitosis is co-ordinated by control networks on the spindle pole. I then describe how the Cut12/Plo1 control network links growth control signalling from TOR (target of rapamycin) and MAPK networks to the activation of MPF to regulate the timing of cell division.
The spindle pole body plays a key role in controlling mitotic commitment in the fission yeast Schizosaccharomyces pombe
Iain M. Hagan; The spindle pole body plays a key role in controlling mitotic commitment in the fission yeast Schizosaccharomyces pombe. Biochem Soc Trans 1 October 2008; 36 (5): 1097–1101. doi: https://doi.org/10.1042/BST0361097
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