A novel thyroid hormone receptor encoded by a cDNA clone from a human testis library.
The c-erbA gene belongs to a multigene family that encodes transcriptional regulatory proteins including the v-erbA oncogene product, steroid hormone receptors, and the vitamin D3 receptor. A v-erbA DNA probe encoding the DNA-binding region of the v-erbA protein was used to screen a human complementary DNA testis library. One of the clones isolated, erbA-T-1, was found to encode a 490-amino acid protein (erbA-T). The erbA-T polypeptide shows high homology with the proteins encoded by both the chicken c-erbA and the human c-erbA-beta genes but is most closely related to the chicken gene. The chicken c-erbA and the human c-erbA-beta genes encode high-affinity receptors for thyroid hormone, and here it is shown that the erbA-T protein binds specifically to 3,5,3'-triiodo-L-thyronine with a dissociation constant of 3.8 +/- 0.2 x 10(-10) M. These data imply that more than one thyroid hormone receptor exists in humans and that these receptors might have different tissue- and gene-activating specificities.
Benbrook
D
D
Cancer Research Center, La Jolla Cancer Research Foundation, CA 92037.
Pfahl
M
M
D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism*; D005796:Genes; D006801:Humans; D007700:Kinetics; D008297:Male; D014176:Protein Biosynthesis; D011519:Proto-Oncogenes; D011988:Receptors, Thyroid Hormone / Q000235:genetics* / Q000378:metabolism; D013737:Testis / Q000378:metabolism*; D014158:Transcription, Genetic
D011988:Receptors, Thyroid Hormone; D004247:DNA