CDC25A

M-phase inducer phosphatase 1 also known as dual specificity phosphatase Cdc25A is a is_associated_with::protein that in humans is encoded by the cell division cycle 25 homolog A (CDC25A) is_associated_with::gene.

Function
CDC25A is a member of the CDC25 family of is_associated_with::dual-specificity phosphatases.

Dual-specificity protein is_associated_with::phosphatases remove is_associated_with::phosphate groups from phosphorylated is_associated_with::tyrosine and is_associated_with::serine / is_associated_with::threonine residues. They represent a subgroup of the is_associated_with::tyrosine phosphatase family (as opposed to the serine/threonine phosphatase family).

All mammals examined to date have three homologues of the ancestral Cdc25 gene (found e.g. in the is_associated_with::fungus species S. pombe, designated Cdc25A, Cdc25B, and Cdc25C. In contrast, some invertebrates harbour 2 (e.g., the is_associated_with::Drosophila proteins String and Twine) or four (e.g., C. elegans Cdc-25.1 - Cdc-25.4) homologues.  CDC25A is required for progression from G1 to the S phase of the is_associated_with::cell cycle, but also plays roles in later cell cycle events.  In particular, it is stabilized in metaphase cells and is degraded upon metaphase exit akin to is_associated_with::Cyclin B.  It is competent to activate the G1/S cyclin-dependent kinases is_associated_with::CDK4 and CDK2 by removing inhibitory phosphate groups from adjacent is_associated_with::tyrosine and is_associated_with::threonine residues; it can also activate is_associated_with::Cdc2 (Cdk1), the principal mitotic Cdk.

Involvement in cancer
CDC25A is specifically degraded in response to is_associated_with::DNA damage, resulting in cell cycle arrest. Thus, this degradation represents one axis of a DNA damage checkpoint, complementing induction of is_associated_with::p53 and is_associated_with::p21 in the inhibition of CDKs. CDC25A is considered an is_associated_with::oncogene, as it can cooperate with oncogenic RAS to transform rodent fibroblasts, and it is overexpressed in tumours from a variety of tissues, including breast and head & neck tumours. It is a target of the is_associated_with::E2F family of transcription factors. Therefore, its overexpression is a common consequence of dysregulation of the is_associated_with::p53-is_associated_with::p21-Cdk axis in is_associated_with::carcinogenesis.

Interactions
CDC25A has been shown to interact with:


 * is_associated_with::ASK1,
 * is_associated_with::C-Raf,
 * is_associated_with::CHEK1,
 * CCNE1,
 * EGFR,
 * is_associated_with::PIM1 and
 * is_associated_with::YWHAB.