InterPro: IPR001651 Gastrin/cholecystokinin peptide hormone

Gastrin and cholecystokinin (CCK) [1] are structurally and functionally related peptide hormones that function as hormonal regulators of various digestive processes and feeding behaviors. They are known to induce gastric secretion, stimulate pancreatic secretion, increase blood circulation and water secretion in the stomach and intestine, and stimulate smooth muscle contraction. Originally found in the gut, these hormones have since been shown to be present in various parts of the nervous system. Like many other active peptides they are synthesized as larger protein precursors that are enzymatically converted to their mature forms. They are found in several molecular forms due to tissue-specific post-translational processing. The biological activity of gastrin and CCK is associated with the last five C-terminal residues. One or two positions downstream, there is a conserved sulphated tyrosine residue. The amphibian caerulein skin peptide, the cockroach leukosulphakinin I and II (LSK) peptides, Drosophila melanogaster (Fruit fly) putative CCK-homologs Drosulphakinins I and II, cionin, a Gallus gallus (Chicken) gastrin/cholecystokinin-like peptide and cionin, a neuropeptide from the protochordate Ciona intestinalis belong to the same family.