Cyclin-dependent kinase 2

Cyclin-dependent kinase 2, also known as cell division protein kinase 2, is an is_associated_with::enzyme that in humans is encoded by the CDK2 is_associated_with::gene.

Function
The is_associated_with::protein encoded by this gene is a member of the is_associated_with::cyclin-dependent kinase family of Ser/Thr protein kinases. This protein kinase is highly similar to the gene products of S. cerevisiae is_associated_with::cdc28, and S. pombe cdc2, also known as is_associated_with::Cdk1 in humans. It is a catalytic subunit of the is_associated_with::cyclin-dependent kinase complex, whose activity is restricted to the G1-S phase of the is_associated_with::cell cycle, and is essential for the is_associated_with::G1/S transition. This protein associates with and is regulated by the regulatory subunits of the complex including is_associated_with::cyclin E or A. Cyclin E binds G1 phase Cdk2, which is required for the transition from G1 to S phase while binding with Cyclin A is required to progress through the S phase. Its activity is also regulated by is_associated_with::phosphorylation. Two alternatively spliced variants and multiple transcription initiation sites of this gene have been reported.

The role of this protein in G1-S transition has been recently questioned as cells lacking Cdk2 are reported to have no problem during this transition.

Inhibitors
Known CDK inhibitors are p21Cip1 (CDKN1A) and p27Kip1 (is_associated_with::CDKN1B). Drugs that inhibit Cdk2 and arrest the cell cycle, such as GW8510 and the experimental cancer drug is_associated_with::seliciclib, may reduce the sensitivity of the epithelium to many cell cycle-active antitumor agents and, therefore, represent a strategy for prevention of chemotherapy-induced is_associated_with::alopecia.

Gene regulation
In melanocytic cell types, expression of the CDK2 gene is regulated by the is_associated_with::Microphthalmia-associated transcription factor.

Interactions
Cyclin-dependent kinase 2 has been shown to interact with:


 * is_associated_with::BRCA1,
 * is_associated_with::CDK2AP1,
 * is_associated_with::CDKN1B
 * is_associated_with::CDKN3,
 * is_associated_with::CEBPA,
 * is_associated_with::Cyclin A1,
 * is_associated_with::Cyclin E1,
 * is_associated_with::Flap structure-specific endonuclease 1,
 * is_associated_with::ORC1L,
 * is_associated_with::P21,
 * is_associated_with::PPM1B,
 * is_associated_with::PPP2CA,
 * is_associated_with::Retinoblastoma-like protein 1,
 * is_associated_with::Retinoblastoma-like protein 2,  and
 * is_associated_with::SKP2.