Genomic organization and promoter function of the human thyrotropin-releasing hormone receptor gene.
We isolated and characterized the gene for the human thyrotropin-releasing hormone receptor. The gene spanned more than 30 kilobases and contained three exons and two introns. Intron 1 exists in the 5'-untranslated region, and intron 2 is more than 25 kilobases in length which interrupts the coding region before the beginning of the putative sixth transmembrane domain. Exon 3 encodes the rest of the coding region and the entire 3'-untranslated region. The 3'-flanking region contains four potential polyadenylation signals, and 3'-rapid amplification of cDNA ends studies showed that only a signal at 2076 base pairs downstream of the stop codon was functional in the anterior pituitary. Primer extension and anchor-polymerase chain reaction studies indicated a transcriptional start site at 344 base pairs upstream of the translational start site. The promoter region does not contain either a TATA box or a CAAT box in the appropriate location. Transient transfection study revealed significant activity of the promoter in GH4C1 cells, and the region between -338 and -933 bp from the transcriptional start site worked as a negative regulator. Knowledge of the genomic organization and the promoter region of thyrotropin-releasing hormone (TRH) receptor gene will allow further studies of possible disorders of the TRH receptor, as well as facilitate elucidation of transcriptional control of the human TRH receptor gene.
Iwasaki
T
T
First Department of Internal Medicine, Gunma University School of Medicine, Maebashi 371 Japan.
Yamada
M
M
Satoh
T
T
Konaka
S
S
Ren
Y
Y
Hashimoto
K
K
Kohga
H
H
Kato
Y
Y
Mori
M
M
D000595:Amino Acid Sequence; D001483:Base Sequence; D015139:Blotting, Southern; D004247:DNA; D006801:Humans; D007438:Introns; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D018025:Receptors, Thyrotropin-Releasing Hormone / Q000235:genetics*; D015183:Restriction Mapping
D018025:Receptors, Thyrotropin-Releasing Hormone; D004247:DNA