Figure 1
Effect of PIF concentration on the chymotrypsin-like enzyme activity of the proteasome in C2C12 myotubes in the absence (×) and presence (▪) of (A) quinacrine (5 μ M) or (B) trifluoroacetyl AA (20 μ M). (C) The effect of quinacrine (5 μ M) (□), trifluoroacety l AA (20 μ M) (▪) and PD98059 (10 μ M) (□) on protein degradation determined by the release of phenylalanine as previously described (Gomes-Marcondes et al, 2002) in murine myotubes in the presence of PIF. The experiments were repeated three times (n=9). Differences from control are indicated as a, P<0.01 and b, P<0.001, while differences from those in the absence of the inhibitors are indicated as c, P<0.0001. The inhibitors were added to the cells 2 h prior to PIF.
