STRUCTURE, SEQUENCE, EXPRESSION, AND CHROMOSOMAL LOCALIZATION OF THE HUMAN V-1A VASOPRESSIN RECEPTOR GENE

We recently reported the structure and functional expression of a huma n V-1a, vasopressin receptor (V(1a)R) cDNA isolated from human liver c DNA libraries. To understand further the expression and regulation of the V(1a)R, we now describe the genomic characteristics, tissue expres sion, chromosomal localization, and regional mapping of the human V(1a )R gene, AVPR1A. Tissue distribution of the human VI,R mRNA explored b y Northern blot analysis of various human tissues or organs revealed t he presence of a 5.5-kb mRNA transcript expressed in the liver and to a lesser degree in the heart, the kidney, and skeletal muscle. Screeni ng of human genomic libraries revealed that the human AVPR1A gene is i ncluded entirely within a 6.4-kb EcoRI fragment and comprises two codi ng exons separated by a 2.2-kb intron located before the corresponding seventh transmembrane domain of the receptor sequence. The first exon also contains 2 kb of 5'-untranslated region, and the second exon inc ludes 1 kb of 3'-untranslated region. 5'-RACE analysis of human liver mRNA by PCR localized the V(1a)R mRNA transcription start site 1973 bp upstream of the translation initiation site. Specific oligonucleotide s derived from the intron sequence were used as primers in polymerase chain reaction (PCR) analysis of human/rodent somatic cell hybrids. AV PR1A was localized by PCR analysis of a somatic cell hybrid panel to c hromosome 12. Fluorescence in situ hybridization using a yeast artific ial chromosome physically mapped AVPR1A to region 12q14-q15. (C) 1996 Academic Press, Inc.