G Protein Coupled Receptor 45 (GPR45)

G protein-coupled receptors (GPCRs) are integral membrane proteins containing 7 putative transmembrane domains (TMs). These proteins mediate signals to the interior of the cell via activation of heterotrimeric G proteins that in turn activate various effector proteins, ultimately resulting in a physiologic response.GPR45, which is 11-kb long, encodes a 372-amino acid protein that shows 70% amino acid sequence identity to the Xenopus oocyte receptor PSP24, a putative lysophosphatidic acid receptor. Northern blot analysis detected a 4.25-kb transcript in basal forebrain, frontal cortex, and caudate, but not in thalamus, hippocampus, or putamen. A 3.0-kb transcript was detected in liver.