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.
DIMACS Home Page