May act as a scaffolding protein within caveolar membranes. Interacts directly with G-protein alpha subunits and can functionally regulate their activity. May also regulate voltage-gated potassium channels. Plays a role in the sarcolemma repair mechanism of both skeletal muscle and cardiomyocytes that permits rapid resealing of membranes disrupted by mechanical stress. Mediates the recruitment of CAVIN2 and CAVIN3 proteins to the caveolae. Homooligomer. Interacts with DYSF. Interacts with DLG1 and KCNA5; forms a ternary complex. Interacts with DAG1 (via its C-terminal); the interaction prevents binding of DAG1 with DMD. Interacts with TRIM72. Interacts with MUSK; may regulate MUSK signaling. Interacts with BVES. Interacts with CAVIN1, CAVIN2 and CAVIN4. Potential hairpin-like structure in the membrane. Membrane protein of caveolae (By similarity). Sumoylation with SUMO3 by PIAS4 may reduce agonist-induced internalization and desensitization of adrenergic receptor ABRD2. Belongs to the caveolin family.