Characterization of cloned human cholecystokinin-B receptor as a gastrin receptor

• Published in: Biochemical pharmacology Vol. 47; no. 8; pp. 1339 - 1343
• Main Authors: Akira, Miyake, Shinobu, Mochizuki, Hiroyuki, Kawashima
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 20.04.1994; Elsevier Science
• Subjects: Amino Acid Sequence; Animals; Binding, Competitive - drug effects; Biological and medical sciences; Cell Line; Cell receptors; Cell structures and functions; cholecystokinin; cloned CCK-B receptor; Cloning, Molecular; Fundamental and applied biological sciences. Psychology; gastrin; Gastrins - metabolism; Guanosine 5'-O-(3-Thiotriphosphate) - pharmacology; Haplorhini; Hormone receptors. Growth factor receptors. Cytokine receptors. Prostaglandin receptors; Humans; Iodine Radioisotopes; Molecular and cellular biology; Molecular Sequence Data; Receptor, Cholecystokinin B; Receptors, Cholecystokinin - genetics; Receptors, Cholecystokinin - metabolism; Signal Transduction; Sincalide - metabolism; Transfection; Xenopus; YM022; cholecystokinin; CCK; YM022; RT-PCR; gastrin; cloned CCK-B receptor; Xenopus laevis; Peptide hormone; Amphibia; Salientia; Gene expression; In vitro; Genetic transfer; Cholecystokinin receptor; Vertebrata; Biological fixation; Gastrointestinal hormone; Gastrin; Established cell line; Recombinant protein; Oocyte; Hormonal receptor
• ISSN: 0006-2952; 1873-2968
• DOI: 10.1016/0006-2952(94)90332-8

The cholecystokinin (CCK)-B receptor cloned from human brain was characterized as a gastrin receptor by using heterologous expression systems of COS-7 cells and Xenopus oocytes. 125I-gastrin binding to human CCK-B receptor expressed in COS-7 was time-dependent, saturable and also specific, as well as 125-I-CCK-8. The binding of 125I-gastrin was inhibited by CCK-8 about 10-fold more potently than by gastrin. The rank order of potency of several antagonists to 125I-gastrin binding was YM022 > CI-988 > L-365,260 > L-364,718. Addition of GTP γS, a nonhydrolysable analog of GTP, dose-dependently inhibited 125I-gastrin binding, and lowered the gastrin binding affinity, Gastrin (10 −9–10 −7 M) also evoked a Ca 2+-dependent Cl − current in Xenopus oocytes expressing CCK-B receptors. These results suggest that the pharmacological profile of the cloned human CCK-B receptor using 125I-gastrin is closely parallel to that reported in gastric mucosa, and that the receptor transduces cellular signals of gastrin as well as those of CCK-8.