Caveolin 3

85912391ENSG00000182533ENSMUSG00000062694P56539P51637NM_033337NM_001234NM_007617NP_001225NP_203123NP_031643Caveolin-3 is a protein that in humans is encoded by the CAV3 gene. Alternative splicing has been identified for this locus, with inclusion or exclusion of a differentially spliced intron. In addition, transcripts utilize multiple polyA sites and contain two potential translation initiation sites. Caveolin-3 is a protein that in humans is encoded by the CAV3 gene. Alternative splicing has been identified for this locus, with inclusion or exclusion of a differentially spliced intron. In addition, transcripts utilize multiple polyA sites and contain two potential translation initiation sites. This gene encodes a caveolin family member, which functions as a component of the caveolae plasma membranes found in most cell types. Caveolin proteins are proposed to be scaffolding proteins for organizing and concentrating certain caveolin-interacting molecules. Mutations identified in this gene lead to interference with protein oligomerization or intra-cellular routing, disrupting caveolae formation and resulting in Limb-Girdle muscular dystrophy type-1C (LGMD-1C), HyperCKemia, distal myopathy or rippling muscle disease (RMD). Other mutations in Caveolin causes Long QT Syndrome or familial hypertrophic cardiomyopathy, although the role of Cav3 in Long QT syndrome has recently been disputed. Caveolin 3 has been shown to interact with a range of different proteins, including, but not limited to: Using transmission electron microscopy and single particle analysis methods, it has been shown that nine Caveolin-3 monomers assemble to form a complex that is toroidal in shape, ∼16.5 nm in diameter and ∼5.5 nm in height. Caveolin-3 is one of three isoforms of the protein caveolin. Caveolin-3 is concentrated in the caveolae of myocytes, and modulates numerous metabolic processes including: nitric oxide synthesis, cholesterol metabolism, and cardiac myocytes contraction. There are many proteins that associate with caveolin-3, including ion channels and exchangers. In cardiac myocytes, caveolin-3 negatively regulates ATP-dependent potassium channels (KATP) localized in caveolae. KATP channel opening decreases significantly when interacting with caveolin-3; other isoforms of caveolin do not show this type of effect on KATP channels. The amount of KATP activation during times of biological stress influences the amount of cellular damage that will occur, thus regulation of caveolin-3 expression during these times influences the amount of cellular damage. Caveolin-3 associates with the cardiac sodium-calcium exchanger (NCX) in caveolae of cardiac myocytes. This association occurs predominately in areas proximate to the peripheral membrane of cardiac myocytes. Interactions between caveolin-3 and cardiac NCX influence NCX-regulation of cellular signaling factors and excitation of cardiac myocytes. Caveolin-3 influences the opening of L-Type calcium channels (LTCC) which play a role in cardiac myocyte contraction. Disruption of interactions between caveolin-3 and its associated binding proteins has been shown to affect LTCC. Specifically, disruption of caveolin-3 decreases the basal and b2-adrenergic-stimulated opening probabilities of LTCC. This occurs by changing the PKA-mediated phosphorylation of caveolin-3-associated binding proteins, causing negative down-stream effects on LTCC activity.