G Protein Coupled Receptor 44 (GPR44)

G protein-coupled receptors (GPCRs), such as GPR44, 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.GPR44 has recently been found to belong to the prostanoid receptor family and named DP₂, with this becoming the official IUPHAR nomenclature.GPR44 encodes a 472-amino acid protein that is closely related to chemoattractant receptors. Northern blot analysis revealed a 3.5-kb GPR44 transcript primarily in thalamus, frontal cortex, pons, and hippocampus and at lower levels in hypothalamus and caudate/putamen. A 3.4-kb transcript was detected in fetal liver, leukocytes, and thymus.