Gastrin releasing peptide (IPR015674)

Short name: Gastrin-RP

Family relationships


Bombesin-like peptides comprise a large group of peptides which were initially isolated from amphibian skin, where they stimulate smooth muscle contraction. They were later found to be widely distributed in mammalian neural and endocrine cells. The amphibian peptides which belong to this entry are currently classified into three subfamilies [PMID: 3868775]; the Bombesin group, which includes bombesin and alytesin; the Ranatensin group, which includes ranatensins, litorin, and Rohdei litorin; and the Phyllolitorin group, which includes Leu(8)- and Phe(8)-phyllolitorins. In mammals and birds two categories of bombesin-like peptides are known [PMID: 2458345], gastrin-releasing peptide (GRP), that stimulates the release of gastrin as well as other gastrointestinal hormones, and neuromedin B (NMB), a neuropeptide whose function is not yet clear. Bombesin-like peptides, like many other active peptides, are synthesized as larger protein precursors that are enzymatically converted to their mature forms. The final peptides are eight to fourteen residues long.

Mammalian bombesins are encoded by 2 genes. The preproGRP gene transcript encodes a precursor of 147 amino acids, which gives GRP and GRP18-27. The preproNMB gene transcript encodes a precursor of 117 amino acids, which is metabolised to neuromedin B. Receptors for these peptides have widespread distribution in peripheral tissue. High levels are found in smooth muscle and in the brain.

The gastrin-releasing peptide receptor has a wide distribution in peripheral tissue. High levels are found in smooth muscle (e.g., intestine, stomach and bladder) and in secretory glands (e.g., pancreas). In the brain, it is found in high levels in the hypothalamus, and is present in other areas in lower levels (e.g., the olfactory tract, dendate gyrus and cortex). It is also found in various cell lines (e.g., Swiss 3T3 fibroblasts and small-cell lung carcinomas). GRP receptors activate the phosphoinositide pathway via a pertussis-toxin-insensitive G-protein, probably of the Gq/G11 class [PMID: 6207529, PMID: 3027901].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.