Cdk1

Cell division cycle 2, G1 to S and G2 to M, also known as Cdk1 (CDC2), is a human gene. The protein encoded by this gene is called p34cdk1 and is a cyclin-dependent kinase in the Ser/Thr protein kinase family. This protein is a catalytic subunit of the highly conserved protein kinase complex known as maturation promoting factor (MPF), which is essential for G1/S and G2/M phase transitions of eukaryotic cell cycle. Mitotic cyclins stably associate with this protein and function as regulatory subunits. The kinase activity of this protein is controlled by cyclin accumulation and destruction through the cell cycle. The phosphorylation and dephosphorylation of this protein also play important regulatory roles in cell cycle control.

Cdk1 is one of the components of the maturation promoting factor (MPF) which controls the cell division cycle in yeast. Cdk1 is a cyclin-dependent kinase (CDK) which, when bound to cyclin B, allows a dividing cell to enter into mitosis from G2 (in the absence of inhibitory proteins such as Wee1). Cdk1 also permits the transition from G1 through S in conjunction with cyclin A and cyclin E.

In humans, the functions of cdc2 are divided between its homologues. Some important ones are Cdk1, Cdk2, Cdk4, and Cdk6 (See cyclin-dependent kinase), which associate with different cyclins and regulate stage transitions during the cell cycle.

Other "Cell division cycle" genes (cdc's) are also involved in complex regulatory pathways during the cell cycle. Cdc's were originally discovered in Saccharomyces cerevisiae, and are followed by a number which signifies the order in which they were discovered (e.g. cdc2, cdc20, cdc25, etc).