G protein-coupled receptors(GPRs or GPCRs), also known asseven transmembrane receptors, heptahelical receptors or 7TMreceptors, aremembers of the largest protein family and play a role in many differentstimulus-response pathways. G protein-coupled receptors mediate extracellularsignals into intracellularsignals(G protein activation). Theyrespond to awide variety of signaling molecules, including hormones, neurotransmitters and other proteins and peptides. GPR proteins are usuallyintegralseven passmembrane proteins with some conserved amino acid regions. GPR112 (G protein-coupled receptor 112) is a 3,080 amino acid multi-pass membrane protein that belongsto the G-protein coupled receptor 2 family and LN-TM7 subfamily. Localizing to cell membrane, GPR112 is highly expressed in normal enterochromaffin cells, aswell as neuroendocrine and primarylivercarcinoma. GPR112 contains one GPS domain andmayfunction as an orphan receptor.