STRUCTURAL ORGANIZATION OF THE MOUSE AND HUMAN GALR1 GALANIN RECEPTORGENES (GALNR AND GALNR) AND CHROMOSOMAL LOCALIZATION OF THE MOUSE GENE

The neuropeptide galanin elicits a range of biological effects by inte raction with specific G-protein-coupled receptors. Human and rat GALR1 galanin receptor cDNA clones have previously been isolated using expr ession cloning. We have used the human GALR1 cDNA in hybridization scr eening to isolate the gene encoding GALR1 in both human (GALNR) and mo use (Galnr). The gene spans approximately 15-20 kb in both species; it s structural organization is conserved and is unique among G-protein-c oupled receptors. The coding sequence is contained on three exons, wit h exon 1 encoding the N-terminal end of the receptor and the first we transmembrane domains. Exon 2 encodes the third intracellular loop, wh ile exon 3 encodes the remainder of the receptor, hom transmembrane do main 6 to the C-terminus of the receptor protein. The mouse and human GALR1 receptor proteins are 348 and 349 amino acids long, respectively , and display 93% identity at the amino acid level. The mouse Galnr ge ne has been localized to Chromosome 18q4, homoeologous with the previo usly reported localization of the human GALNR gene to 18q23 in the sam e syntenic group as the genes encoding nuclear factor of activated T-c ells, cytoplasmic 1, and myelin basic protein. (C) 1997 Academic Press .