CCKAR is a G-protein coupled receptor that binds non-sulfated members of the cholecystokinin (CCK) family of peptide hormones. This receptor is a major physiologic mediator of pancreatic enzyme secretion and smooth muscle contraction of the gallbladder and stomach. In the central and peripheral nervous system this receptor regulates satiety and the release of beta-endorphin and dopamine.Ulrich et al. (1993) used a combination of hybridization screening of a cDNA library and PCR to clone a 2.1-kb cDNA that encodes the human gallbladder CCK receptor type A (CCKAR). Nucleotide sequence analysis revealed an open reading frame encoding a 428-amino acid protein, with 7 putative transmembrane domains and a high degree of homology with the cholecystokinin A receptor protein of rat and guinea pig.