Different distributions of dystrophin and related proteins at nerve-muscle junctions.
The distributions of dystrophin, 'dystrophin-related protein' (DRP) and beta-spectrin were compared with that of acetylcholine receptors (AChRs) at rat nerve-muscle junctions (NMJs) using immunofluorescence techniques. In sections, monoclonal antibodies (MAbs) to dystrophin and beta-spectrin labelled the entire sarcolemma but were concentrated at the NMJs while those to DRP labelled only NMJs. In permeabilized muscle fibres, DRP was precisely co-localized with the AChRs, whereas the zone of high density labelling of dystrophin and beta-spectrin extended 0.3-0.4 microns beyond the AChRs. Within the NMJ, the labelling of DRP appeared as a series of interconnecting lines similar to that of AChRs. However, labelling of dystrophin and beta-spectrin was consistently more punctate. These data suggest DRP is more closely associated with AChRs than are dystrophin or beta-spectrin.
Bewick
G S
GS
Muscular Dystrophy Group Research Laboratories, Newcastle General Hospital, Newcastle upon Tyne, UK.
Nicholson
L V
LV
Young
C
C
O'Donnell
E
E
Slater
C R
CR
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism; D016189:Dystrophin / Q000378:metabolism*; D005260:Female; D007150:Immunohistochemistry; D009469:Neuromuscular Junction / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D011950:Receptors, Cholinergic / Q000378:metabolism
D000911:Antibodies, Monoclonal; D016189:Dystrophin; D011950:Receptors, Cholinergic