The spindle pole body plays a key role in controlling mitotic commitment in the fission yeast Schizosaccharomyces pombe.
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.
Hagan
Iain M
IM
CRUK (Cancer Research UK) Cell Division Laboratory, Paterson Institute for Cancer Research, University of Manchester, Wilmslow Road, Manchester M20 4BX, UK. ihagan@picr.man.ac.uk
D004789:Enzyme Activation; D016200:Maturation-Promoting Factor / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D008938:Mitosis / Q000502:physiology*; D010750:Phosphoproteins / Q000378:metabolism; D011494:Protein Kinases / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D012568:Schizosaccharomyces / Q000166:cytology / Q000502:physiology*; D029702:Schizosaccharomyces pombe Proteins / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D008941:Spindle Apparatus / Q000378:metabolism*
C111708:Cut12 protein, S pombe; D008869:Microtubule-Associated Proteins; D010750:Phosphoproteins; D029702:Schizosaccharomyces pombe Proteins; D011494:Protein Kinases; C523461:Tor1 protein, S pombe; C501407:Plo1 protein, S pombe; D017346:Protein Serine-Threonine Kinases; D016200:Maturation-Promoting Factor; D020928:Mitogen-Activated Protein Kinases