Developmental downregulation of Xenopus cyclin E is phosphorylation and nuclear import dependent and is mediated by ubiquitination.

ABSTRACT: Cyclins are regulatory subunits that bind to and activate catalytic Cdks. Cyclin E associates with Cdk2 to mediate the G1/S transition of the cell cycle. Cyclin E is overexpressed in breast, lung, skin, gastrointestinal, cervical, and ovarian cancers. Its overexpression correlates with poor patient prognosis and is involved in the etiology of breast cancer. We have been studying how cyclin E is normally downregulated during development in order to determine if disruption of similar mechanisms could either contribute to its overexpression in cancer, or be exploited to decrease its expression. In Xenopus laevis embryos, cyclin E protein level is high and constant until its abrupt destabilization by an undefined mechanism after the 12th cell cycle, which corresponds to the midblastula transit

SUBMITTER: Brandt Y 

PROVIDER: S-EPMC3104060 | biostudies-literature | 2011 Jul

REPOSITORIES: biostudies-literature