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 (PubMed:19380584). Mediates the recruitment of CAVIN2 and CAVIN3 proteins to the caveolae (By similarity). 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 (By similarity). Interacts with TRIM72 (PubMed:19380584). Interacts with MUSK; may regulate MUSK signaling (PubMed:19940021). Interacts with BVES (PubMed:24066022). Interacts with CAVIN1, CAVIN2 and CAVIN4 (By similarity). Potential hairpin-like structure in the membrane. Membrane protein of caveolae (By similarity). Expressed predominantly in muscle. Sumoylation with SUMO3 by PIAS4 may reduce agonist-induced internalization and desensitization of adrenergic receptor ABRD2. Belongs to the caveolin family.