AHNAK, a novel component of the dysferlin protein complex, redistributes to the cytoplasm with dysferlin during skeletal muscle regeneration.
FASEB J
; 21(3): 732-42, 2007 Mar.
Article
em En
| MEDLINE
| ID: mdl-17185750
ABSTRACT
Mutations in dysferlin cause limb girdle muscular dystrophy 2B, Miyoshi myopathy and distal anterior compartment myopathy. Dysferlin is proposed to play a role in muscle membrane repair. To gain functional insight into the molecular mechanisms of dysferlin, we have searched for dysferlin-interacting proteins in skeletal muscle. By coimmunoprecipitation coupled with mass spectrometry, we demonstrate that AHNAK interacts with dysferlin. We defined the binding sites in dysferlin and AHNAK as the C2A domain in dysferlin and the carboxyterminal domain of AHNAK by glutathione S-transferase (GST)-pull down assays. As expected, the N-terminal domain of myoferlin also interacts with the carboxyterminal domain of AHNAK. In normal skeletal muscle, dysferlin and AHNAK colocalize at the sarcolemmal membrane and T-tubules. In dysferlinopathies, reduction or absence of dysferlin correlates with a secondary muscle-specific loss of AHNAK. Moreover, in regenerating rat muscle, dysferlin and AHNAK showed a marked increase and cytoplasmic localization, consistent with the direct interaction between them. Our data suggest that dysferlin participates in the recruitment and stabilization of AHNAK to the sarcolemma and that AHNAK plays a role in dysferlin membrane repair process. It may also have significant implications for understanding the biology of AHNAK-containing exocytotic vesicles, "enlargosomes," in plasma membrane remodeling and repair.
Buscar no Google
Base de dados:
MEDLINE
Assunto principal:
Regeneração
/
Músculo Esquelético
/
Proteínas de Membrana
/
Proteínas Musculares
/
Proteínas de Neoplasias
Limite:
Animals
/
Female
/
Humans
Idioma:
En
Ano de publicação:
2007
Tipo de documento:
Article