FIG 7.

USP20 controls ERK3 protein levels during myogenic differentiation. (A) C2C12 myoblasts were cultured in growth medium (GM) or switched to differentiation medium (DM) for 4 days. The expression of ERK3 and USP20 was analyzed by immunoblotting. (B) C2C12 cells were transfected with an empty vector (Ctl) or pCMV6-XL4-USP20 and cultured as described above. The expression of ERK3 and USP20 was analyzed by immunoblotting. (C) C2C12 cells were transfected with an empty vector (Ctl) or pCMV6-XL4-USP20. After 48 h, the levels of ERK3 mRNA were quantified by real-time qPCR. Results are expressed as means ± standard deviations (n = 3).