Cloning of a novel biogenic amine receptor-like G protein-coupled receptor expressed in human brain.

We report the cloning and sequence of a novel gene, BALGR, which is coding for a candidate G protein-coupled receptor (GPCR) that is distantly related to the histamine, adrenergic, serotonin and dopamine receptors. The coding region of the human BALGR gene predicts a seven transmembrane domain receptor of 451 amino acids. BALGR has 42% amino acid identity to a Medaka fish 'orphan' GPCR. BALGR gene has been conserved throughout the mammalian evolution as indicated by Southern blot analysis. BALGR gene has been assigned to chromosome 1 by typing a panel of somatic cell hybrids and its exon/intron organization has been predicted. As determined by semiquantitative RT-PCR, expression of BALGR is relatively the highest in the human brain. A high level of BALGR transcript is also detected in testes. Within the brain, Northern blot analysis revealed relatively high expression in frontal and temporal lobes, occipital pole, amygdala and hippocampus. The preferential expression of BALGR in the areas of the human brain associated with cognition, learning and memory, and its conservation in evolution, indicate a potentially important biological function for this biogenic amine-like receptor and its putative neurotransmitter ligand.