Alteration of Sarcoplasmic ReticulumCa2+Release in Skeletal Muscle from Calpain 3-Deficient Mice

Autor: Cedric Viero, Jean Valmier, Isabelle Richard, Elsa Mazuc, Muriel Herasse, Govindan Dayanithi, Nathalie Bourg, Sylvie Mallie, Paul Mangeat, Gérard Lefranc, Isabelle Marty, Stephen Baghdiguian
Rok vydání: 2009
Předmět:
Zdroj: International Journal of Cell Biology. 2009:1-12
ISSN: 1687-8884
1687-8876
DOI: 10.1155/2009/340346
Popis: Mutations ofCa2+-activated proteases (calpains) cause muscular dystrophies. Nevertheless, the specific role of calpains inCa2+signalling during the onset of dystrophies remains unclear. We investigatedCa2+handling in skeletal cells from calpain 3-deficient mice.[Ca2+]iresponses to caffeine, a ryanodine receptor (RyR) agonist, were decreased in −/− myotubes and absent in −/− myoblasts. The −/− myotubes displayed smaller amplitudes of theCa2+transients induced by cyclopiazonic acid in comparison to wild type cells. Inhibition of L-typeCa2+channels (LCC) suppressed the caffeine-induced[Ca2+]iresponses in −/− myotubes. Hence, the absence of calpain 3 modifies the sarcoplasmic reticulum (SR)Ca2+release, by a decrease of the SR content, an impairment of RyR signalling, and an increase of LCC activity. We propose that calpain 3-dependent proteolysis plays a role in activating support proteins of intracellularCa2+signalling at a stage of cellular differentiation which is crucial for skeletal muscle regeneration.
Databáze: OpenAIRE
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