Cell Cycle

Regulating Cell Proliferation

Science's STKE  09 Oct 2001:
Vol. 2001, Issue 103, pp. tw373-TW373
DOI: 10.1126/stke.2001.103.tw373

Increased amounts of cyclin E and its protein kinase partner cyclin-dependent kinase 2 (CDK2) promote progression of cells from G1 to S phase of the cell cycle, and the abundance of cyclin E is regulated by proteolysis. Koepp et al. have identified the human ubiquitin ligase subunit, named Fbw7, that binds phosphorylated cyclin E and targets it to the SCF complex, where it is ubiquitinated and later degraded. Thus, similar mechanisms are used in yeast, worms, flies, and mammals to regulate abundance of cyclin E. The functional characterization of Fbw7 suggests that it could function as a tumor suppressor. A Perspective by Bartek and Lukas accompanies the report.

D. M. Koepp, L. K. Scjaefer, X. Ye, K. Keyomarsi, C. Chu, J. W. Harper, S. J. Elledge, Phosphorylation-dependent ubiquitination of cyclin E by the SCFFbw7 ubiquitin ligase. Science 294, 173-177 (2001). [Abstract] [Full Text]

J. Bartek, J. Lucas, Orders from destruction, Science 294, 66 (2001). [Full Text]