Mutation of Thr115 in MyoD Positively Regulates Function in

Committed skeletal muscle myoblasts undergo terminal differentiation when shifted from a high-mitogen medium to a low-mftogen medium. However, expression of the myogenic regulatory factor MyoD seems to be similar in proliferating and differentiating cells, suggesting that its function is attenuated in proliferating myoblasts. To further understand the potential mechanisms that may attenuate MyoD function, we have examined the effect of posttranslational modification. By analogy with myogenin, we have examined the role of phosphorylation in regulating the function of MyoD. MyoD contains two putative protein kinase C (PKC) phosphorylation sites frhr115 and Ser#{176}#{176}).The forme