Cell Division Cycle Protein 25 (CDC25)

Cdc25 is a dual-specificity phosphatase first isolated from the yeast Schizosaccharomyces pombe as a cell cycle defective mutant. As with other cell cycle proteins such as Cdc2 and Cdc4, the "cdc" in its name refers to "cell division cycle". Dual-specificity phosphatases are considered a sub-class of protein tyrosine phosphatases. Cdc25A in Checkpoints and Cancer CDC25A is specifically degraded in response to DNA damage resulting in cell cycle arrest; this degradation thus represents one axis of a DNA damage checkpoint, complementing induction of p53 and p21 in the inhibition of Cdks. CDC25A is considered an 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.