Caveolin-3 and nitric oxide synthase I in healthy and diseased skeletal muscle.
Recently, it has been shown for mouse skeletal muscle that caveolin-3 is localized in the sarcolemma and cofractionates with the original dystrophin complex (DC). In order to find out whether caveolin-3 is a further component of the recently established and enlarged nitric oxide synthase (NOS) I-DC and whether members of this complex interact with and are potentially regulated by caveolin-3, mammalian and non-mammalian healthy and diseased (dystrophic) skeletal muscles were investigated using caveolin-3, NOS I, DC components and myosin immunohistochemistry as well as NOS I-associated diaphorase histochemistry. In healthy mammalian skeletal muscle, caveolin-3 was colocalized with the DC components in all extra- and intrafusal fibers. By contrast, NOS I was absent in type I extrafusal fibers of certain species. In patients with Duchenne muscular dystrophy and mdx mice the components of the NOS I-DC were not detected in all extra- and intrafusal fiber types, while caveolin-3 was found unchanged. In healthy non-mammalian skeletal muscle, i.e. of birds, reptiles and fishes, caveolin-3 immunoreactivity was lacking in the sarcolemma as was alpha-sarcoglycan; the other NOS I-DC components were either present or absent. In conclusion, although caveolin-3 is localized in the sarcolemma of mammalian myofibers, there are differences in the microarchitecture of the components of the DC complex and of caveolin-3 which does not appear to be linked with the NOS I-DC. Potential regulatory interactions between caveolin-3 and NOS I may nevertheless exist in those fibers where both molecules are colocalized. The absence of caveolin-3 and alpha-sarcoglycan immunoreactivities in non-mammalian myofibers may suggest that the functions of these proteins are subserved by other components of NOS I-DC complex.
Gossrau
R
R
Institute of Anatomy, University Clinic Benjamin Franklin, Free University of Berlin, Germany.
D000818:Animals; D051244:Caveolin 3; D022461:Caveolins; D002645:Chickens; D010856:Columbidae; D006224:Cricetinae; D005849:Gerbillinae; D006054:Goldfish; D006168:Guinea Pigs; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000032:analysis*; D051379:Mice; D008815:Mice, Inbred Strains; D018101:Mice, Inbred mdx; D018482:Muscle, Skeletal / Q000737:chemistry* / Q000166:cytology / Q000201:enzymology* / Q000473:pathology; D009136:Muscular Dystrophies / Q000201:enzymology* / Q000378:metabolism* / Q000473:pathology; D009419:Nerve Tissue Proteins; D019001:Nitric Oxide Synthase / Q000032:analysis*; D052248:Nitric Oxide Synthase Type I; D051381:Rats; D017208:Rats, Wistar; D014426:Turtles
C495548:Cav3 protein, mouse; C495549:Cav3 protein, rat; D051244:Caveolin 3; D022461:Caveolins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; C496320:NOS1 protein, human; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; C496321:Nos1 protein, mouse; C496322:Nos1 protein, rat