May act as a scaffolding protein within caveolar membranes (PubMed:11751885). Forms a stable heterooligomeric complex with CAV2 that targets to lipid rafts and drives caveolae formation. Mediates the recruitment of CAVIN proteins (CAVIN1/2/3/4) to the caveolae (PubMed:19262564). Interacts directly with G-protein alpha subunits and can functionally regulate their activity (By similarity). Involved in the costimulatory signal essential for T-cell receptor (TCR)-mediated T-cell activation. Its binding to DPP4 induces T-cell proliferation and NF-kappa-B activation in a T-cell receptor/CD3-dependent manner (PubMed:17287217). Recruits CTNNB1 to caveolar membranes and may regulate CTNNB1-mediated signaling through the Wnt pathway (By similarity). Negatively regulates TGFB1-mediated activation of SMAD2/3 by mediating the internalization of TGFBR1 from membrane rafts leading to its subsequent degradation (PubMed:25893292). Homooligomer (PubMed:25588833). Interacts with GLIPR2 (PubMed:11865038). Interacts with NOSTRIN (PubMed:16807357). Interacts with SNAP25 and STX1A (By similarity). Interacts (via the N-terminus) with DPP4; the interaction is direct (PubMed:17287217). Interacts with CTNNB1, CDH1 and JUP. Interacts with PACSIN2; this interaction induces membrane tubulation (By similarity). Interacts with SLC7A9 (By similarity). Interacts with BMX and BTK (PubMed:11751885). Interacts with TGFBR1 (PubMed:25893292). Interacts with CAVIN3 (via leucine-zipper domain) in a cholesterol-sensitive manner (PubMed:25588833, PubMed:19262564). Interacts with CAVIN1 (PubMed:25588833). Interacts with EHD2 in a cholesterol-dependent manner (PubMed:25588833). Forms a ternary complex with UBXN6 and VCP; mediates CAV1 targeting to lysosomes for degradation (PubMed:21822278, PubMed:23335559). Interacts with ABCG1; this interaction regulates ABCG1-mediated cholesterol efflux (PubMed:24576892). Interacts with NEU3; this interaction enhances NEU3 sialidase activity within caveola. Interacts (via C-terminus) with SPRY1, SPRY2 (via C-terminus), SPRY3, and SPRY4 (By similarity). (Microbial infection) Interacts with rotavirus A NSP4. (Microbial infection) Interacts with human respiratory syncytial virus (HRSV) matrix protein; this interaction probably facilitates viral budding. Colocalized with DPP4 in membrane rafts. Potential hairpin-like structure in the membrane. Membrane protein of caveolae. Skeletal muscle, liver, stomach, lung, kidney and heart (at protein level). Expressed in the brain. Ubiquitinated. Undergo monoubiquitination and multi- and/or polyubiquitination (PubMed:21822278). Monoubiquitination of N-terminal lysines promotes integration in a ternary complex with UBXN6 and VCP which promotes oligomeric CAV1 targeting to lysosomes for degradation (PubMed:23335559). The initiator methionine for isoform 2 is removed during or just after translation. The new N-terminal amino acid is then N-acetylated. Phosphorylated at Tyr-14 by ABL1 in response to oxidative stress. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. Belongs to the caveolin family. Caveolin entry