BIO 121 Lecture Notes - Lecture 19: Cyclin-Dependent Kinase, Maturation Promoting Factor, Tunxis Community College
23 Nov 2020
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Document Summary
Injected m-phase cytoplasm in g2 arrested oocyte works. Triggers formation of mitotic spindle in g2 oocyte something in m-phase cytosol that contains factors allowing g2 cell to proceed. When purified discovery of kinase (phosphorylates target proteins) Kinase did nott act alone (m-cyclin is bound to it to function) Injected interphase cytoplasm in g2 arrested oocyte does not enter m phase. Mpf kinase levels stay constant in cell cycle but activity oscillates (activity in mitosis) Cyclin must be bound for the kinase to be active. Cdk binding to cyclin is necessary but not sufficient for enzyme activity. G2/m checkpoint controlled by cyclical activities of mitotic cyclin dependent kinase (m- M g2 recipient initiates mitosis. S g1 recipient initiates dna synthesis. (must be another factor for entry into s phase) Association with cyclin (influenced by increased production of cyclin) Cdc25 is an activating protein of mitotic cdk (activates phosphatase) Wee1 protein is inhibitory kinase of mitotic cdk (advances cells into division)
