The alpha 5 beta 1 integrin associates with a dystrophin-containing lattice during muscle development

Dev Biol. 1992 Aug;152(2):209-20. doi: 10.1016/0012-1606(92)90129-5.


The organization of the alpha 5 beta 1 integrin on skeletal muscle was studied in culture and in sections from adult and embryonic tissue using monoclonal antibodies specific for the alpha 5 subunit. The alpha 5 beta 1 integrin showed changes in organization and in the molecules with which it colocalizes. On early myoblasts, possessing a fibroblast-like morphology, the alpha 5 integrin organization was indistinguishable from that on fibroblasts; it was expressed prominently and localized in numerous focal contacts around the cell periphery. In bipolar myoblasts and early myotubes, the alpha 5 integrin was expressed only weakly and localized in a small number of focal contact-like structures. As myogenesis proceeded there was an apparent increase in integrin expression and a change in organization. In addition to the focal contact-like structures that persist throughout myogenesis in vitro, a dense lattice-like structure of integrin appeared. Fibrillar fibronectin, talin, and non-muscle alpha-actinin did not colocalize with the alpha 5 beta 1 integrin in the lattice structure as they did in the focal contact-like structures. However, dystrophin, which displayed a diffuse distribution earlier, now colocalized with the alpha 5 beta 1 integrin in the punctate lattice. Coincident with the registration of myofibrils into visible sarcomeres, the prominent dense, lattice structure disappeared leaving the focal contact-like structures as the only regions of organized alpha 5 beta 1 integrin. Despite the presence of the beta 1 integrin in neuromuscular or myotendinous junctions in vivo and on myotubes in vitro, the alpha 5 beta 1 integrin was not present in either junction. These observations suggest that the alpha 5 beta 1 integrin is involved in the adhesion of muscle to the extracellular matrix, the organization of the dystrophin-containing lattice, and the organization of nascent myofibrils which emanate from the focal contact- and stress fiber-like structures in muscle. Other integrins appear to anchor myofibrils at the myotendinous and neuromuscular junctions.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Binding Sites
  • Cell Adhesion
  • Cell Differentiation
  • Chick Embryo
  • Chickens
  • Dystrophin / analysis
  • Dystrophin / metabolism*
  • Extracellular Matrix / chemistry
  • Extracellular Matrix / metabolism*
  • Integrins / analysis
  • Integrins / metabolism*
  • Muscles / chemistry
  • Muscles / embryology*


  • Dystrophin
  • Integrins