Integral membrane protein GPR137C, an orphan receptor member of the seven-transmembrane G protein-coupled receptor superfamily
GPR137C, also called transmembrane 7 superfamily member 1-like 2 protein (TM7SF1L2), is an orphan G protein-coupled receptor (GPCR) of unknown function. Bioinformatics analysis identified it as a likely key player in the prognosis of small cell lung cancer. GPCRs transmit physiological signals from the outside of the cell to the inside via G proteins. All GPCRs share 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.