THE HUMAN GONADOTROPIN-RELEASING-HORMONE (GNRH) RECEPTOR GENE - CLONING, GENOMIC ORGANIZATION AND CHROMOSOMAL ASSIGNMENT

The cDNA encoding the gonadotropin-releasing hormone (GnRH) receptor has recently been cloned and characterized in several species, including human. To determine the structure of the gene encoding the human GnRH receptor, we have screened a human genomic library and isolated seven positive clones, using cDNA probes derived from a human pituitary cDNA library. The isolated genomic clone contains the entire protein coding region of the GnRH receptor which is distributed between three exons and spans over 18.9 kb. Sequence analysis and restriction endonuclease mapping revealed the presence of two introns of 4.2 and 5.0 kb, respectively, both located within the open reading frame, designating the human GnRH receptor gene to the intron-containing class of the G-protein coupled receptor superfamily. Genomic Southern blot analysis indicated the presence of a single copy of the gene encoding for the GnRH receptor within the human genome. Using DNA from human-hamster somatic hybrid cell lines, the GnRH receptor gene was assigned to human chromosome 4, by means of PCR. The present study represents the first report on the GnRH receptor gene and its partial characterization should facilitate further investigation of the mechanisms by which expression of this gene is regulated.