Immunolocalization of Caveolin-1 and Caveolin-3 in Monkey Skeletal, Cardiac and Uterine Smooth Muscles.

Abstract

ABSTRACT. Caveolin, a 20-24 kDa integral membrane protein, is a principal component of caveolar domains. Caveolin-1 is expressed predominantly in endothelial cells, fibroblasts, and adipocytes, while the expression of caveolin-3 is confined to muscle cells. However, their localization in various muscles has not been well documented. Using double-immunofluorescence labeling and confocal laser microscopy, we examined the localization of caveolins-1 and 3 in adult monkey skeletal, cardiac and uterine smooth muscles and the co-immunolocalization of these caveolins with dystrophin, which is a product of the Duchenne muscular dystrophy gene. In the skeletal muscle tissue, caveolin-3 was localized along the sarcolemma except for the transverse tubules, and coimmunolocalized with dystrophin, whereas caveolin-1 was absent except in the blood vessels of the muscle tissue. In cardiac muscle cells, caveolins-1 and -3 and dystrophin were co-immunolocalized on the sarcolemma and transverse tubules. In uterine smooth muscle cells, caveolin-1, but not caveolin-3, was co-immunolocalized with dystrophin on the sarcolemma.

Maxi-K channels localize to caveolae in human myometrium: a role for an actin-channel-caveolin complex in the regulation of myometrial smooth muscle K+ current

“…Although caveolin-3 is found in vascular smooth muscle (12), our studies and others have not detected this isoform in great abundance in uterine tissue (18). In addition, we found only a weak association between the maxi-K channel and caveolin-3.…”

Caveolae as Organizers of Pharmacologically Relevant Signal Transduction Molecules

“…Recent studies have provided evidence for the existence of and a signaling role for caveolin-1 in cardiac myocytes (52). It was previously thought that caveolin-1 and caveolin-2 form hetero-oligomers and caveolin-3 forms homo-oligomers (131, 132); however, recent data indicate coexpression and interaction of caveolin-2 and -3 in neonatal cardiac myocytes (133) and interaction of caveolin-1, -2, and -3 in adult cardiac myocytes (86,134). Other findings have shown that cell type-specific environments may regulate the interaction of caveolins: In fibroblasts caveolins-1 and -2, but not caveolin-3, interact, but in myoblasts all three caveolin isoforms coimmunoprecipitate (135).…”

Caveolin-3 expression and caveolae are required for isoflurane-induced cardiac protection from hypoxia and ischemia/reperfusion injury

“…8-10 wk old caveolin-3 knockout mice (caveolin-3 −/− ) [13,25] or age-matched C57BL/6 mice (controls) were studied using an in vivo ischemia/reperfusion protocol [26]. Mice were anesthetized with sodium pentobarbital (80 mg/kg IP).…”

“…Cardiac myocytes (CM) express the muscle-specific isoform caveolin-3 [12] while other cell types in the heart express caveolin-1 and -2. Recent studies have shown: 1) the presence and interaction of all three caveolin isoforms in adult cardiac myocytes [13,14], 2) a signaling role for caveolin-1 in cardiac myocytes [15], and 3) that caveolins can scaffold proteins associated with cardiac protection [16,17].…”