Lecture 12 - 2 slides page

The g1 checkpoint is a crihcal step at which the cell

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Unformatted text preview: e shall discuss next lecture, the cell arrests mitosis unHl all the chromosomes are correctly a]ached to the spindle. This third checkpoint is called the checkpoint in mitosis. •  PhosphorylaHon and dephosphorylaHon reacHons are central to cell cycle regulaHon. •  The master kinases of the cell cycle are called Cdks for ‘cyclin- dependent kinases’ because they have to be associated with a protein called a cyclin to be acHve. These proteins are called cyclins because their abundance fluctuates during the cell cycle, whereas the levels of Cdks do not. For example, the cyclin that drives cells into M- phase by forming the M- cyclin- Cdk complex becomes acHve at the beginning of M- phase and phosphorylates many proteins to regulate their funcHons. Lecture 12 summary (Page 2 of 2) •  DisHnct cyclins associate with the Cdks to trigger different events in the cell cycle. Thus S cyclin is synthesized during G1 to allow acHve S- Cdk to drive the cell into S- phase, and then S cyclin is degraded at the beginning of M- phase. During G2, the M cyclin...
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This note was uploaded on 05/17/2013 for the course BIOMG 1350 taught by Professor Bretscher during the Spring '12 term at Cornell.

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