【背景资料】:The transcription factor c-Myc is a short-lived nuclear phosphoprotein involved in cell proliferation, differentiation and cancer regulation. c-Myc binds to DNA and activates transcription as a heterodimeric complex with Max. c-Myc is phosphorylated in vitro by MAP Kinase at Ser62 and in vivo c-Myc is phosphorylated at both Thr58 and Ser62. Mutation of The58 and Ser62 to Ala inhibits the ability of c-Myc to activate transcription, suggesting that phosphorylation regulates the ability of c-Myc to stimulate transcription. c-Myc appears to regulate multiple aspects of growth control: it promotes cell proliferation in the presence of cdk inhibitors and induces apoptosis with overexpression in serum deprived cells.