Figure 4.

A proteasome inhibitor prevented AChR degradation in cells transfected with shRNA(αkap). A, Myotubes transfected with shRNA(αkap), scrambled shRNA (Scram), or untransfected myotubes (Cont) were treated with the proteasome inhibitor MG132 (at 5 μm), and lysates were immunoblotted with MAB210 antibody against AChRα. Tubulin was used as a loading control. B, Quantification of three independent experiments as in A. 100% was the average intensity of the samples from untransfected myotubes in the absence of MG132. C, Myotubes transfected with plasmids encoding shRNA(αkap) or the scrambled shRNA were treated with leupeptin (20 μg/ml). D, Quantification of three independent experiments as in C. 100% was the average intensity of the samples from myotubes transfected with the scrambled shRNA in the absence of leupeptin.