title: Evidence for cardiac sodium-calcium exchanger association with caveolin-3.
abstract: The interaction of cardiac Na+-Ca2+ exchange (NCX1) with caveolin proteins was investigated in sarcolemmal vesicles. Western blots of sarcolemmal vesicles revealed the presence of caveolin-1, -2, and -3. NCX1 co-fractionated more closely with caveolin-3 than caveolin-1 on sucrose density gradients. NCX1 has five possible caveolin-binding motifs and NCX1 co-precipitated specifically with caveolin-3. Molecular sieve column chromatography indicated that this co-precipitation was not due to incomplete solubilization of lipid raft microdomains. Cholesterol chelation in vesicles decreased NCX1 transport activity and caveolin-3 co-precipitation. NCX1 may play a role in caveolar transmembrane signaling in addition to its role in excitation-contraction coupling.
authors.affiliation: The Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO 65211, USA.
authors.forename: Julie
authors.initials: J
authors.lastname: Bossuyt
authors.forename: Bonnie E
authors.initials: BE
authors.lastname: Taylor
authors.forename: Marilyn
authors.initials: M
authors.lastname: James-Kracke
authors.forename: Calvin C
authors.initials: CC
authors.lastname: Hale
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D001665:Binding Sites; D015153:Blotting, Western; D002417:Cattle; D021941:Caveolae / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D051244:Caveolin 3; D022461:Caveolins / Q000378:metabolism*; D002499:Centrifugation, Density Gradient; D002784:Cholesterol / Q000378:metabolism; D002850:Chromatography, Gel; D003505:Cyclodextrins / Q000494:pharmacology; D009206:Myocardium / Q000378:metabolism*; D011233:Precipitin Tests; D011485:Protein Binding; D012508:Sarcolemma / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D019831:Sodium-Calcium Exchanger / Q000737:chemistry / Q000378:metabolism*
chemical_list: D051244:Caveolin 3; D022461:Caveolins; D003505:Cyclodextrins; D019831:Sodium-Calcium Exchanger; C110374:sodium-calcium exchanger 1; D002784:Cholesterol