Molecular cloning and functional expression of a human thyrotropin-releasing hormone (TRH) receptor gene.
In this study, we isolated genomic DNA fragments coding for the human thyrotropin-releasing hormone (TRH) receptor. Analysis of the nucleotide sequence revealed that the human TRH receptor gene had an exon-intron structure comprising at least two exons. A polypeptide encoded by the gene consisted of 398 amino acid residues with putative seven transmembrane domains. It showed high homology as a whole amino acid sequence with the rat and mouse TRH receptors except for considerable variation in the C-terminal region. Chromosomal mapping study indicated that the human TRH receptor gene was assigned to chromosome 8. Chinese hamster ovary (CHO) cells transfected with a DNA fragment containing the coding regions of the human TRH receptor bound with [3H]TRH. This binding was inhibited by adding unlabeled TRH in a dose-dependent fashion. Scatchard analysis indicated that the transfected CHO cells expressed a single class of high affinity binding sites at a dissociation constant (Kd) of approximately 1 nM. These results demonstrated that the isolated gene encoded a specific TRH receptor with high affinity.
Hinuma
S
S
Discovery Research Laboratories I, Takeda Chemical Industries, Ltd., Ibaraki, Japan.
Hosoya
M
M
Ogi
K
K
Tanaka
H
H
Nagai
Y
Y
Onda
H
H
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D016466:CHO Cells; D002898:Chromosomes, Human, Pair 8; D003001:Cloning, Molecular; D006224:Cricetinae; D017931:DNA Primers / Q000737:chemistry; D018076:DNA, Complementary / Q000235:genetics; D005796:Genes; D006801:Humans; D008024:Ligands; D008969:Molecular Sequence Data; D018025:Receptors, Thyrotropin-Releasing Hormone / Q000235:genetics* / Q000378:metabolism; D015183:Restriction Mapping; D013973:Thyrotropin-Releasing Hormone / Q000378:metabolism
D017931:DNA Primers; D018076:DNA, Complementary; D008024:Ligands; D018025:Receptors, Thyrotropin-Releasing Hormone; D013973:Thyrotropin-Releasing Hormone