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glucagon-like peptide-2 receptor, member of the class B family of seven-transmembrane G protein-coupled receptors Glucagon-like peptide-2 receptor (GLP2R) is a member of the glucagon receptor family of G protein-coupled receptors, which also includes glucagon receptor (GCGR) and GLP1R. GLP2R is activated by glucagon-like peptide 2, which is derived from the large proglucagon precursor. Activation of GLP1R stimulates glucose-dependent insulin secretion from pancreatic beta cells, whereas activation of GLP2R stimulates intestinal epithelial proliferation and increases villus height in the small intestine. GCGR regulates blood glucose levels by control of hepatic glycogenolysis and gluconeogenesis and by regulation of insulin secretion from the pancreatic beta-cells. GLP2R belongs to the B1 (or secretin-like) subfamily of class B GPCRs, which includes receptors for polypeptide hormones of 27-141 amino-acid residues such as secretin, calcitonin gene-related peptide, parathyroid hormone (PTH), and corticotropin-releasing factor. These receptors contain the large N-terminal extracellular domain (ECD), which plays a critical role in hormone recognition by binding to the C-terminal portion of the peptide. On the other hand, the N-terminal segment of the hormone induces receptor activation by interacting with the receptor transmembrane domains and connecting extracellular loops, triggering intracellular signaling pathways. All members of the B1 subfamily preferentially couple to G proteins of G(s) family, which positively stimulate adenylate cyclase, leading to increased intracellular cAMP formation and calcium influx. However, depending on their cellular location, GCGR and GLP receptors can activate multiple G proteins, which can in turn stimulate different second messenger pathways.
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