P21 REGULATION AND FUNCTION DURING MYOGENESIS

Skeletal muscle terminal differentiation involves a highly ordered seq uence of events that include permanent cell cycle withdrawal, the indu ction of contractile proteins and cell fusion. Recently it has been sh own that the expression of the cdk inhibitor p21 is markedly upregulat ed during myogenesis. Here we review what is currently known about the regulation and functions of p21 during skeletal muscle differentiatio n. Specifically we report on the features of the myogenic system that contribute to the induction and sustained expression of p21 and discus s how this factor influences the growth, differentiation and viability of the developing myocyte.