The rat growth hormone gene contains multiple thyroid response elements.
The thyroid hormone receptor exerts transcriptional control over a variety of genes. This report describes four sites that bind this receptor with high affinity within the 5'-flanking DNA of the rat growth hormone gene, approximately centered at -180, -160, -60 and -20 nucleotides from the transcription start site. These sites were defined by gel retardation of short synthetic oligonucleotides using native receptor purified several hundred-fold from rat liver. Binding sites were also defined by methylation interference and methidium-propyl-EDTA footprinting. Alignment of the four binding sites suggests that each contains two purine-rich regions, the more downstream of which, GGGATCGC, is highly conserved. Mutations made within each of the two upstream sites reduce receptor binding affinity. For one mutation, a partial loss of receptor binding strength correlated with a change in electrophoretic mobility, indicating that receptor binding may alter DNA conformation. Mutations at each of the four sites also reduce thyroid hormone responsiveness of the -237/+11 promoter linked to the chloramphenicol acetyltransferase gene coding sequences and transfected into cultured pituitary (GC) cells. These results suggest that several different receptor-binding elements interact to control thyroid hormone responsiveness of the rat growth hormone gene and reveal common sequences that may be important for receptor-DNA recognition.
Norman
M F
MF
Metabolic Research Unit, University of California, San Francisco 94143.
Lavin
T N
TN
Baxter
J D
JD
West
B L
BL
D000818:Animals; D001483:Base Sequence; D004247:DNA / Q000378:metabolism; D004587:Electrophoresis, Agar Gel; D013006:Growth Hormone / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D051381:Rats; D011988:Receptors, Thyroid Hormone / Q000378:metabolism*; D015183:Restriction Mapping
D011988:Receptors, Thyroid Hormone; D013006:Growth Hormone; D004247:DNA