Evidence for the identities of five proteins decreased in skeletal muscle of dystrophic mice

Abstract

In a previous study, protein distributions in normal and dystrophic soleus and EDL were examined using polyacrylamide isoelectric focusing. Whereas normally protein distributions in these two muscles were characteristically different, in dystrophic muscles they were strikingly similar. The soleus-specific proteins were identified as the myosin light chains LCls and LC2s. The EDL-amplified proteins were the myosin light chains LC1f, LC2f, the phosphorylated form of LC2f (LC2f-P), and LC3f. In addition, evidence is presented that one protein, which had not been identified in two-dimensional gels, is parvalbumin. The decreased proportion of parvalbumin, LC2f-P, and LC3f in the dystrophic EDL was also shown in other fast-twitch muscles of the mouse. We suggest that these changes in protein distributions in dystrophic muscles reflect a loss of their acquired state of differentiation.