Sequence of an intestinal cDNA encoding human gastric inhibitory polypeptide precursor.
Takeda J., Seino Y., Tanaka K., Fukumoto H., Kayano T., Takahashi H., Mitani T., Kurono M., Suzuki T., Tobe T., Imura H., et al.
Gastric inhibitory polypeptide (GIP) is a 42-amino acid hormone that stimulates insulin secretion in the presence of glucose. Complementary DNA clones encoding human GIP were isolated from a library prepared with RNA from duodenum. The predicted amino acid sequence indicates that GIP is derived by proteolytic processing of a 153-residue precursor, preproGIP. The GIP moiety is flanked by polypeptide segments of 51 and 60 amino acids at its NH2 and COOH termini, respectively. The former includes a signal peptide of about 21 residues and an NH2-terminal propeptide of 30 amino acids. GIP is released from the precursor by processing at single arginine residues. There is a region of nine amino acids in the COOH-terminal propeptide of the GIP precursor that has partial homology with a portion of chromogranin A as well as pancreastatin.
Proc. Natl. Acad. Sci. U.S.A. 84:7005-7008(1987) [PubMed] [Europe PMC]