Figure 2

The Na _V 1.4 is phosphorylated at similar levels in control and CIM muscle. ( A) To assess the degree of phosphorylation in CIM and control muscle, classically-purified sodium channel was stained with a dye that binds only phosphoproteins (Pro Q Diamond phosphoprotein dye) and the ratio of signal with this stain was compared to that of a dye that binds all proteins (SYPRO Ruby Red protein stain). As controls, a set of proteins that are non-phosphorylated (β-galactosidase, bovine serum albumin) or a known phosphoprotein (ovalbumin) were analyzed on the same gel (P/NP markers). Of these controls, only the ovalbumin stained on both gels, indicating that staining conditions were optimal for each dye. Control and CIM sodium channel, indicated by arrows, had similar phosphostaining. ( B) Quantification of the ratio of Pro Q: SYPRO protein stains for each of the experimental and control proteins. The control and CIM proteins had very similar degrees of phosphorylation, while only the ovalbumin standard was phosphorylated.