Interaction of integrin alpha 7 beta 1 in C2C12 myotubes and in solution with laminin.
Exp Cell Res
; 240(1): 86-94, 1998 Apr 10.
Article
em En
| MEDLINE
| ID: mdl-9570924
ABSTRACT
The dimer of integrin alpha 7 and beta 1 is a major laminin-binding receptor in skeletal muscle. We studied interactions of integrin alpha 7 beta 1 with the extracellular matrix protein laminin in solution and in intact cells. Integrin alpha 7 beta 1 bound to EHS laminin (laminin-1, composed of alpha 1, beta 1, and gamma 1 chains), but not to endogenous laminin expressed in C2C12 myotubes. Northern blot analysis demonstrated that C2C12 myotubes synthesized laminin-1 alpha, beta, and gamma subunits mRNAs. C2C12 laminin was, however, immunologically distinct from EHS laminin; it was not recognized by 5D3 anti-laminin-1 monoclonal antibody, whereas 5A2 and LT3 antibodies reacted equally well with C2C12 and EHS laminins. Following deglycosylation of EHS laminin, separation of the subunits by SDS-PAGE, Western blotting, and partial amino acid sequencing of the protein bands, the epitope recognized by 5D3 antibody was localized to the gamma 1 laminin chain. Following binding in vitro, the complex of EHS laminin and integrin alpha 7 beta 1 was subject to chemical cross-linking. The two proteins did not undergo cross-linking at the cell surface, consistent with the fact that in intact, resting myotubes integrin alpha 7 beta 1 interacted poorly with EHS laminin, which may reflect a limited accessibility of integrin alpha 7 beta 1 in the membrane to laminin or an inactive state of the integrin.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Integrinas
/
Laminina
/
Receptores de Laminina
/
Músculo Esquelético
Limite:
Animals
Idioma:
En
Revista:
Exp Cell Res
Ano de publicação:
1998
Tipo de documento:
Article
País de afiliação:
Estados Unidos