CyclinE1 Protein

Cyclin E1 belongs to the highly conserved cyclin family, whose members are characterized by a dramatic periodicity in protein abundance through the cell cycle that functions as regulators of CDK kinases. Cyclin E1 activity is required for centrosome duplication during S phase and this mechanism could coordinate centrosome reproduction with cycles of DNA synthesis and mitosis (1). The downregulation of cyclin E-CDK2 kinase activity following the G1/S-phase transition that is necessary for the maintenance of karyotypic stability. Cyclin E also has a modular centrosomal-targeting domain which is essential for promoting S phase entry in a Cdk2-independent manner (2).