Membrane organization of the dystrophin-glycoprotein complex.
The stoichiometry, cellular location, glycosylation, and hydrophobic properties of the components in the dystrophin-glycoprotein complex were examined. The 156, 59, 50, 43, and 35 kd dystrophin-associated proteins each possess unique antigenic determinants, enrich quantitatively with dystrophin, and were localized to the skeletal muscle sarcolemma. The 156, 50, 43, and 35 kd dystrophin-associated proteins contained Asn-linked oligosaccharides. The 156 kd dystrophin-associated glycoprotein contained terminally sialylated Ser/Thr-linked oligosaccharides. Dystrophin, the 156 kd, and the 59 kd dystrophin-associated proteins were found to be peripheral membrane proteins, while the 50 kd, 43 kd, and 35 kd dystrophin-associated glycoproteins and the 25 kd dystrophin-associated protein were confirmed as integral membrane proteins. These results demonstrate that dystrophin and its 59 kd associated protein are cytoskeletal elements that are tightly linked to a 156 kd extracellular glycoprotein by way of a complex of transmembrane proteins.
Howard Hughes Medical Institute, University of Iowa College of Medicine, Iowa City 52242.
J M
JM
Ervasti
K P
KP
Campbell
D000199:Actins / Q000378:metabolism; D000818:Animals; D000911:Antibodies, Monoclonal; D003599:Cytoskeleton / Q000648:ultrastructure; D016189:Dystrophin / Q000737:chemistry / Q000502:physiology*; D005455:Fluorescent Antibody Technique; D006023:Glycoproteins / Q000737:chemistry / Q000502:physiology*; D006026:Glycoside Hydrolases / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D046911:Macromolecular Substances; D008970:Molecular Weight; D009124:Muscle Proteins / Q000502:physiology*; D009439:Neuraminidase / Q000494:pharmacology; D011817:Rabbits; D012508:Sarcolemma / Q000648:ultrastructure*; D012995:Solubility
D000199:Actins; D000911:Antibodies, Monoclonal; D016189:Dystrophin; D006023:Glycoproteins; D046911:Macromolecular Substances; D009124:Muscle Proteins; D006026:Glycoside Hydrolases; D009439:Neuraminidase