The function of GPBAR1 (G protein-coupled bile acid receptor 1, Ensembl gene identifier ENSG00000179921) is as follows. G protein-coupled receptor for bile acid (PubMed:12419312, PubMed:12524422, PubMed:32698187, PubMed:32747649, PubMed:35858343). Bile acid-binding causes a conformation change that triggers signaling via guanine nucleotide-binding proteins (G proteins) and modulates the activity of downstream effectors, such as adenylate cyclase (PubMed:12419312, PubMed:12524422, PubMed:32698187, PubMed:32747649, PubMed:35858343). GPBAR1 is coupled to G(s) G proteins and mediates activation of adenylate cyclase activity (PubMed:12419312, PubMed:12524422, PubMed:32698187, PubMed:32747649, PubMed:35858343). Activated by bile acids, such as lithocholate, deoxycholate, chenodeoxycholate and cholate, in descending order (PubMed:12524422, PubMed:32698187). Apart from their role in lipid dietary absorption and cholesterol catabolism, bile acids act as an important signaling molecule, involved in processes, such as energy expenditure or tissue inflammation (PubMed:26541439). GPBAR1-mediated signaling promotes energy expenditure and adiposity reduction in brown adipose tissue by activating adenylate cyclase, leading to DIO2 activation (By similarity). Involved in bile acid promoted GLP-1 secretion (By similarity). {ECO:0000250|UniProtKB:Q80SS6, ECO:0000269|PubMed:12419312, ECO:0000269|PubMed:12524422, ECO:0000269|PubMed:32698187, ECO:0000269|PubMed:32747649, ECO:0000269|PubMed:35858343, ECO:0000303|PubMed:26541439}.