p-Cdc25C Anticuerpo(Ser 216): sc-12354

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The Cdc2/cyclin B enzyme, involved in regulating mitosis in eukaryotic cells, is subject to multiple levels of control (1,2). Among these, the regulation of the catalytic subunit by tyrosine phosphorylation is the best understood. Tyrosine phosphorylation inhibits the Cdc2/cyclin B complex, while tyrosine dephospho-rylation, which occurs at the onset of mitosis, directly activates the pre-MPH complex (3,4). The tyrosine phosphotase Cdc25 serves as a rate-limiting mitotic activator by regulating Cdc2 tyrosine phosphatase (5,6). In the absence of Cdc25, Cdc2 accumulates in a tyrosine phosphorylated state (5,6). In addition, Cdc25 proteins from a variety of species have been shown to share a low degree of sequence similarity with other tyrosine phosphatases (7,8). Activation of the Cdc25C is proposed to occur through an autocatalytic feedback loop mechanism involving nuclear Cdc2 (9). The nuclear accumulation of Cdc25C is negatively regulated by phosphorylation at Ser 216. This phosphorylation event enables binding to 14–3–3 proteins, which then shuttle the phosphorylated Cdc25 out of the nucleus after DNA damage (9).