Identification of dystrophin-binding protein(s) in membranes from Torpedo electrocyte and rat muscle.
Using solubilized dystrophin isolated from torpedo electric tissue and in vitro blot overlay assay, we have identified dystrophin-binding proteins in membranes from Torpedo electrocyte and rat muscle. In acetylcholine receptor-rich membranes from Torpedo marmorata electric tissue, an extrinsic protein of M(r) 52,000, known as the 58-kDa protein (Froehner, S.C. (1984) J. Cell Biol. 99, 88-96), represents the major binding site for dystrophin. When membranes were solubilized by non-ionic detergents, the 52-kDa protein as well as a few proteins of M(r) 200,000, 87,000, and 45,000 co-extract and copurify with dystrophin. In rat sarcolemma, a protein doublet of approximately 58-60 kDa also binds dystrophin in vitro, this protein likely being the DAP 59 characterized by Ervasti and Campbell (Ervasti, J. M., and Campbell, K. P. (1991) Cell 66, 1121-1131). We postulate that the 52- and 59-kDa proteins are functional homologs that play the role of "receptors" for dystrophin in various specialized membrane domains.
Département de Biologie Supramoléculaire et Cellulaire, Institut Jacques Monod, Centre National de la Recherche Scientifique, Université Paris VII, France.
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Cartaud
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Stetzkowski-Marden
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D000818:Animals; D002462:Cell Membrane / Q000737:chemistry; D016189:Dystrophin / Q000378:metabolism*; D004557:Electric Organ / Q000737:chemistry* / Q000166:cytology; D009124:Muscle Proteins / Q000032:analysis* / Q000378:metabolism; D009132:Muscles / Q000737:chemistry*; D009419:Nerve Tissue Proteins / Q000032:analysis* / Q000378:metabolism; D051381:Rats; D012508:Sarcolemma / Q000737:chemistry; D013570:Synaptic Membranes / Q000737:chemistry; D014101:Torpedo
D016189:Dystrophin; D009124:Muscle Proteins; D009419:Nerve Tissue Proteins