Cdc25C is a protein phosphatase responsible for dephosphorylating and activating cdc2, a crucial step in regulating the entry of all eukaryotic cells into mitosis. Cdc25C is constitutively phosphorylated at Ser216 throughout interphase by c-TAK1, while phosphorylation at this site is DNA damage-dependent at the G2/M checkpoint. When phosphorylated at Ser216, Cdc25C binds to members of the 14-3-3 family of proteins, sequestering Cdc25C in the cytoplasm and thereby preventing premature mitosis. The checkpoint kinases Chk1 and Chk2 phosphorylate Cdc25C at Ser216 in response to DNA damage.
