neuropeptide B/W receptors, member of the class A family of seven-transmembrane G protein-coupled receptors
Neuropeptide B/W receptor 1 and 2 are members of the class A G-protein coupled receptors that bind the neuropeptides B and W, respectively. NPBWR1 (previously known as GPR7) is expressed predominantly in cerebellum and frontal cortex, while NPBWR2 (previously known as GPR8) is located mostly in the frontal cortex and is present in human, but not in rat and mice. These receptors are suggested to be involved in the regulation of food intake, neuroendocrine function, and modulation of inflammatory pain, among many others. All GPCRs have a common structural architecture comprising of seven-transmembrane (TM) alpha-helices interconnected by three extracellular and three intracellular loops. A general feature of GPCR signaling is agonist-induced conformational changes in the receptors, leading to activation of the heterotrimeric G proteins, which consist of the guanine nucleotide-binding G-alpha subunit and the dimeric G-beta-gamma subunits. The activated G proteins then bind to and activate numerous downstream effector proteins, which generate second messengers that mediate a broad range of cellular and physiological processes.
Comment:based on the structures of some class A family members with bound ligands (peptides or chemicals), agonists, or antagonists
Comment:Small-molecule chemical ligands tend to bind deeper within the receptor core, compared to a peptide ligand neurotensin, which binds towards the extracellular surface of its receptor.