Human cyclin-dependent kinase 2 is activated during the S and G2 phases of the cell cycle and associates with cyclin A.
We have analyzed the cell cycle regulation of human cyclin-dependent kinase 2 (CDK2), a protein closely related to the cell cycle-regulatory protein kinase CDC2. We find that CDK2 activity, like that of CDC2, oscillates during the cell cycle in cultured mammalian fibroblasts. Unlike CDC2 activity (which peaks during mitosis), CDK2 activity rises in late G1 or early S phase and declines during mitosis. Active S-phase CDK2 migrates in multiple large complexes on gel filtration, and CDK2 in one of these complexes is associated with cyclin A. These findings suggest that CDK2 and CDC2, in association with distinct cyclins, regulate separate functions in the mammalian cell cycle.
Rosenblatt
J
J
Department of Physiology, University of California, San Francisco 94143-0444.
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Morgan
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D000595:Amino Acid Sequence; D042846:CDC2-CDC28 Kinases; D002453:Cell Cycle; D003001:Cloning, Molecular; D051357:Cyclin-Dependent Kinase 2; D018844:Cyclin-Dependent Kinases; D016213:Cyclins / Q000378:metabolism*; D004247:DNA / Q000235:genetics; D004789:Enzyme Activation; D006367:HeLa Cells; D006801:Humans; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011494:Protein Kinases / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases; D016196:S Phase
D016213:Cyclins; D046911:Macromolecular Substances; D004247:DNA; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; D042846:CDC2-CDC28 Kinases; C495894:CDK2 protein, human; D051357:Cyclin-Dependent Kinase 2; D018844:Cyclin-Dependent Kinases