Pyroglutamylated RFamide Peptide Receptor (QRFPR)

GPR103 shares between 35% and 38% sequence identity in the transmembrane regions with various peptide receptors, including neuropeptide FF2, neuropeptide Y2, and galanin GalR1 receptors. Northern blot analysis of human brain regions revealed widespread expression, including transcripts of 4.0, 2.6 and 1.4 kb in the thalamus and hypothalamus, with a further 9.5-kb transcript in the hypothalamus and a 1.4-kb transcript in the pituitary.The deduced 431-amino acid protein contains the 7-transmembrane structure typical of G protein-coupled receptors. GPR103 shares 49% identity with NPFF1 (GPR147) and NPFF2 (GPR74). Quantitative PCR analysis detected highest GPR103 expression in brain, predominantly in retina, trigeminal ganglion, hypothalamus, and vestibular nucleus.