Fig. 1

Illustration of CDC25C regulation (Green arrows indicate the enhancement effects and red indicator lines indicate the inhibitory effect). This illustration characterizes the role and activity of CDC25C in regulating the cell cycle. CDC25C and 14-3-3 protein chelate together in the cytoplasm during the interphase, and PP1 can dephosphorylate CDC25C, which can induce the releases of CDC25C in the cytoplasm in the prophase. Then CDC25C activates CDK1 to further promote the nuclear location of cyclin B1/CDK1 to initiate mitosis. In the G2/M phase, CDC25C and the cyclin B1/CDK1 complex constitutes the activation loop as the most important factor in the initiation of M phase transition and the activity of CDC25C is positively regulated by PLK1 and Aurora A. When DNA damage occurs, CHK1/CHK2, Wee1/MYT1 negatively regulates the activity of cyclin B1/CDK1 and degrades CDC25C. CDC25C is also involved in p53-mediated cell cycle arrest (other proteins including P21, P38/MAPK, PIN1/PP2A and P53 can also involve in G2/M arrest). PTX-2 can induce CDC25C phosphorylation by activating ERK-JNK pathway and decrease the level of cyclin B1-CDK1