Publications

Abstract

Human galanin receptor subtypes GALR1, GALR2, and GALR3 are encoded by separate genes that are located on human chromosomes 18q23, 17q25.3, and 22q13.1, respectively. The exon:intron organization of the gene encoding GALR2 (GALNR2) and GALR3 (GALNR3) is conserved, with exon 1 encoding the NH2-terminus to the end of transmembrane domain 3 and exon 2 encoding the remainder of the receptor, from the second intracellular loop to the COOH-terminus. This conservation of structural organization is indicative of a common evolutionary origin for GALNR2 and GALNR3. The exon:intron organization of the gene encoding GALR1 (GALNR1) is different from that of GALNR2 and GALNR3, with exon 1 encoding the NH2-terminus to the end of transmembrane domain 5, exon 2 encoding the third intracellular loop, and exon 3 encoding the remainder of the receptor, from transmembrane domain 6 to the COOH-terminus. The structural organization of GALNR1 suggests convergent evolution for this gene and represents a structural organization that is unique among genes encoding G-protein-coupled receptors.