Cell adhesion in muscle.

Abstract

1. Attachment to extracellular matrix is thought to be particularly important for striated muscle cells, since skeletal and heart muscle have to withstand considerably strong forces. 2. We have recently shown that a defect in a protein of the muscle basement membrane, M-laminin, is correlated with muscular dystrophy in human and mouse. The disease associated with defects in M-laminin is thus analogous to that caused by defects in the cytoskeletal protein, dystrophin, the Duchenne/Becker muscular dystrophy. 3. One may propose the hypothesis that a pathway of interacting proteins is required to connect the cytoskeleton of the muscle fiber to the extracellular matrix, and that a defect in any protein in this chain would result in severe impairment of muscle cell attachment with resulting muscle damage upon use of the muscle. The existence of such chains of proteins may be expected from known mutations in muscle proteins in Drosophila and Caenorhabditis elegans. Some of these mutations cause phenotypes resembling muscular dystrophy in mammals. 4. It will be important to identify all the proteins that are participants in muscle cell attachment, including receptors for M-laminin and proteins associated with these receptors.