DIMACS TR: 2004-57

Does Wee1 inhibits the entry to M phase?

Author: Liming Wang

It is widely believed that active Wee1 has negative effect on the entry to M phase. At the first glance, it is quite obvious since active Wee1 helps adding a phosphate to the tyrosine-15 (Tyr15) site of the active M phase promoting factor (MPF-P) to make it inactive. But on the other hand, acitve Wee1 can also adds a phosphate to the non-phosphorylated MPF (MPF), the product then has a great chance to be phosphorylated at the threonine-161 (Thr161) site. And active cdc25 will help to remove the phospate at Tyr15 to make it active. In this way, Wee1 act positively on the entry to M phase. This paper addressed the question that whether Wee1 inhibits or promotes M phase through a mathematical point of view. Both assumptions, the mass action and the Michaelis-Menten, are discussed. Under the assumption of mass action Wee1 always inhibits the M phase, while under Michaelis-Menten, it depends on certain parameters. And biological experiments suggest that the parameters are in the right range such that Wee1 inhibits M phase.

Paper Available at: ftp://dimacs.rutgers.edu/pub/dimacs/TechnicalReports/TechReports/2004/2004-57.ps.gz
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