RYR1 and limb-girdle muscular dystrophy: In the present study we show that β-sarcoglycan-deficient mice (Sgcb−/− mice; an established murine model of LGMD) [3], display RyR1 phosphorylation, S-nitrosylation and oxidation, Ca2+ leak through RyR1, reduced tetanic Ca2+, and specific force in isolated fast twitch EDL muscles.