Sandbox Reserved 467: Difference between revisions
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Cyclin-dependent kinase (Cdk) is a protein kinase family involved in regulation of the cell cycle. These Cdks are relatively small protein enzymes are responsible for mitosis, specifically transcriptional activity. They help activate DNA repair by being inhibited through phosphorylation during DNA damage response (DDR). They are also generally inactive during checkpoints along the cell cycle | Cyclin-dependent kinase (Cdk) is a protein kinase family involved in regulation of the cell cycle. These Cdks are relatively small protein enzymes are responsible for mitosis, specifically transcriptional activity. They help activate DNA repair by being inhibited through phosphorylation during DNA damage response (DDR). They are also generally inactive during checkpoints along the cell cycle <ref name="overall cdk">PMID: 19995934</ref>. More than one Cdk can be in charge of different phases of the cell cycle. Often times, DDR is controlled by overall level of Cdk activity, and not by individual Cdks. | ||
CDKs are activated through physical association with cyclin, a family of proteins, in which their abundance and proteolysis pattern within the cell vary according to the stage of cell cycle. Major transitions in the cell cycle are caused by activation of CDKs 1-4, which causes phosphorylation and dephosphorylation of key residues. Cells enter mitosis as protein-bound phosphates increase (Hames et al., 1998). In mammalian cells, it had been suggested that CDK-3, along with CDK-2, are required for G1/S stage (Hutchison p.111). Compared to CDK-1, 2, and 4, the role of CDK-3 is still unclear, as no cyclin partner had been found for it. However, it had been shown that it delays cells in the G1 phase (Hutchison, p.149). | CDKs are activated through physical association with cyclin, a family of proteins, in which their abundance and proteolysis pattern within the cell vary according to the stage of cell cycle. Major transitions in the cell cycle are caused by activation of CDKs 1-4, which causes phosphorylation and dephosphorylation of key residues. Cells enter mitosis as protein-bound phosphates increase (Hames et al., 1998). In mammalian cells, it had been suggested that CDK-3, along with CDK-2, are required for G1/S stage (Hutchison p.111). Compared to CDK-1, 2, and 4, the role of CDK-3 is still unclear, as no cyclin partner had been found for it. However, it had been shown that it delays cells in the G1 phase (Hutchison, p.149). | ||