FIGURE 3.

Mutation of sumoylation sites abrogates the ability of Sharp-1 to suppress myogenesis. A, C2C12 cells were co-transfected with Sharp-1 or Sharp-1 2KR along with a puromycin resistance vector. Empty vector (pCS2) was transfected in control cells. Sharp-1 and Sharp-1 2KR expression was determined by Western blotting with anti-Myc antibody. B and C, MHC staining (B) and myogenic index (C) was assessed in Sharp-1- and 2KR-expressing cells compared with control cells at day 2 of differentiation. D, cell lysates at days 0, 1, and 2 of differentiation from control, Sharp-1, and Sharp-1 2KR cells were analyzed by Western blotting using troponin T antibody. Error bars indicate mean ± S.D. **, p < 0.01.