COMMUNICATION - INTERACTION OF NEURONAL NITRIC-OXIDE SYNTHASE WITH CAVEOLIN-3 IN SKELETAL-MUSCLE - IDENTIFICATION OF A NOVEL CAVEOLIN SCAFFOLDING INHIBITORY DOMAIN/
Vj. Venema et al., COMMUNICATION - INTERACTION OF NEURONAL NITRIC-OXIDE SYNTHASE WITH CAVEOLIN-3 IN SKELETAL-MUSCLE - IDENTIFICATION OF A NOVEL CAVEOLIN SCAFFOLDING INHIBITORY DOMAIN/, The Journal of biological chemistry, 272(45), 1997, pp. 28187-28190
Neuronal nitric-oxide synthase (nNOS) has been shown previously to int
eract with alpha(1)-syntrophin in the dystrophin complex of skeletal m
uscle. In the present study, we have examined whether nNOS also intera
cts with caveolin-3 in skeletal muscle. nNOS and caveolin-3 are coimmu
noprecipitated from rat skeletal muscle homogenates by antibodies dire
cted against either of the two proteins. Synthetic peptides correspond
ing to the membrane-proximal caveolin-3 residues 65-84 and 109-130 and
homologous caveolin-1 residues 82-101 and 135-156 potently inhibit th
e catalytic activity of purified, recombinant nNOS. Purified nNOS also
binds to a glutathione S-transferase-caveolin-1 fusion protein in in
vitro binding assays. In vitro binding is completely abolished by prei
ncubation of nNOS with either of the two caveolin-3 inhibitory peptide
s. Interactions between nNOS and caveolin-3, therefore, appear to be d
irect and to involve two distinct caveolin scaffolding/inhibitory doma
ins. Other caveolin-interacting enzymes, including endothelial nitric-
oxide synthase and the c-Src tyrosine kinase, are also potently inhibi
ted by each of the four caveolin peptides. Inhibitory interactions med
iated by two different caveolin domains may thus be a general feature
of enzyme docking to caveolin proteins in plasmalemmal caveolae.