Abstract.
Cyclin A is particularly interesting among the cyclin family because it can activate two different cyclin-dependent kinases (CDKs) and functions in both S phase and mitosis. An embryonic form of cyclin A that is only essential for spermatogenesis is also present in some organisms. In S phase, phosphorylation of components of the DNA replication machinery such as CDC6 by cyclin A-CDK is believed to be important for initiation of DNA replication and to restrict the initiation to only once per cell cycle. In mitosis, the precise role of cyclin A is still obscure, but it may contribute to the control of cyclin B stability. Cyclin A starts to accumulate during S phase and is abruptly destroyed before metaphase. The synthesis of cyclin A is mainly controlled at the transcription level, involving E2F and other transcription factors. Removal of cyclin A is carried out by ubiquitin-mediated proteolysis, but whether the same anaphase-promoting complex/cyclosome targeting subunits are used as for cyclin B is debatable. Consistent with its role as a key cell cycle regulator, expression of cyclin A is found to be elevated in a variety of tumors.
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Received 11 February 2002; received after revision 14 March 2002; accepted 20 March 2002
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Yam, C., Fung, T. & Poon, R. Cyclin A in cell cycle control and cancer. CMLS, Cell. Mol. Life Sci. 59, 1317–1326 (2002). https://doi.org/10.1007/s00018-002-8510-y
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DOI: https://doi.org/10.1007/s00018-002-8510-y