The critical regulatory step in activating cdc2 during progression into mitosis appears to be dephosphorylation of cdc2 at Tyr15 and Thr14 (1). Phosphorylation of cdc2 by the protein kinases Wee1 and Myt1 at Thr14 and

The entry of eukaryotic cells into mitosis is regulated by cdc2/CDK1 kinase activation, a process controlled at several steps including cyclin B1 nuclear accumulation and binding, and phosphorylation of cdc2/CDK1 at Thr161 (1). At the

The cell division cycle demands accuracy to avoid the accumulation of genetic damage. This process is controlled by molecular circuits called ",checkpoints", that are common to all eukaryotic cells (1). Checkpoints monitor DNA integrity and

Eukaryotic cell cycle progression is dependent, in part, on the tightly regulated activity of cyclin dependent kinases (CDKs). Cyclin D/CDK4/6 activity occurs in mid-late G1 phase, upstream of CDK2/cyclin E activity. Both of these activities