G protein-coupled receptor 146, member of the class A family of seven-transmembrane G protein-coupled receptors
GPR146 is an orphan G-protein coupled receptor that belongs to the class A of seven-transmembrane GPCR superfamily. The endogenous ligand for GPR146 is not known. It has been suggested that GPR146 may be a part of the C-peptide signaling complex. 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.
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