BIO 201LLB Lecture Notes - Lecture 26: Maturation Promoting Factor, Cdk Inhibitor, G1 Phase
1 Nov 2018
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Fusion of g1 phase cell with a cell in mitosis. G1 chromatin becomes compacted due to exposure to the cytoplasm of a mitotic cell. Does this mean that this cell will go through mitosis: no because it hasn"t gone through s-phase, not enough dna no mitosis. Fusion of g2 phase cell with a mitotic cell. A soluble factor from the mitotic cell causes the g2 chromatin to condense mitosis. What are these soluble factors: a soluble factor that causes progression from a g1 to s-phase, another soluble factor that causes progression from g2 to mitosis. Mpf (maturation promoting factor): this stimulates entry into mitosis, as seen by compaction of dna. Mpf activity is a protein kinase activity: kinases are enzymes that phosphorylate specific proteins. Cyclin: part of the mpf complex which regulates its activity. The mpf isn"t active until cyclin binds to it. Cdk is a kinase/mpf (cyclin activates the mpf: activated mpf phosphorylates a protein.
