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Obscurin is required for ankyrinB-dependent dystrophin localization and sarcolemma integrity

Obscurin is a large myofibrillar protein that contains several interacting modules, one of which mediates binding to muscle-specific ankyrins. Interaction between obscurin and the muscle-specific ankyrin sAnk1.5 regulates the organization of the sarcoplasmic reticulum in striated muscles. Additional...

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Detalles Bibliográficos
Autores principales: Randazzo, Davide, Giacomello, Emiliana, Lorenzini, Stefania, Rossi, Daniela, Pierantozzi, Enrico, Blaauw, Bert, Reggiani, Carlo, Lange, Stephan, Peter, Angela K., Chen, Ju, Sorrentino, Vincenzo
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Rockefeller University Press 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3575540/
https://www.ncbi.nlm.nih.gov/pubmed/23420875
http://dx.doi.org/10.1083/jcb.201205118
Descripción
Sumario:Obscurin is a large myofibrillar protein that contains several interacting modules, one of which mediates binding to muscle-specific ankyrins. Interaction between obscurin and the muscle-specific ankyrin sAnk1.5 regulates the organization of the sarcoplasmic reticulum in striated muscles. Additional muscle-specific ankyrin isoforms, ankB and ankG, are localized at the subsarcolemma level, at which they contribute to the organization of dystrophin and β-dystroglycan at costameres. In this paper, we report that in mice deficient for obscurin, ankB was displaced from its localization at the M band, whereas localization of ankG at the Z disk was not affected. In obscurin KO mice, localization at costameres of dystrophin, but not of β-dystroglycan, was altered, and the subsarcolemma microtubule cytoskeleton was disrupted. In addition, these mutant mice displayed marked sarcolemmal fragility and reduced muscle exercise tolerance. Altogether, the results support a model in which obscurin, by targeting ankB at the M band, contributes to the organization of subsarcolemma microtubules, localization of dystrophin at costameres, and maintenance of sarcolemmal integrity.