3,5,3'-L-triiodothyronine (thyroid hormone)-induced protein-DNA interactions in the thyroid hormone response elements and cell type-specific elements of the rat growth hormone gene revealed by in vivo dimethyl sulfate footprinting.
The cell type-specific element and 3,5,3'-L-triiodothyronine (thyroid hormone) (T3) response element of the rat growth hormone gene act synergistically to produce cell type-specific, T3-regulated expression. Pit-1 is a pituitary cell type-specific transcription factor that binds the cell type-specific element and is essential to its activity. T3 receptors bind as homodimers and heterodimers to the T3 response element and are essential for its activity. Here, we report the use of ligation-mediated polymerase chain reaction in vivo dimethyl sulfate footprinting to study the effects of T3 on protein-DNA interactions in the rat growth hormone gene promoter in vivo. T3-responsive guanine methylation was detected only in and near the T3 response element and the Pit-1 binding sites. The results indicate that within 2 h, T3 induces occupancy of the T3 response element and Pit-1 sites by their respective trans-acting factors in vivo.
Force
W R
WR
Department of Biochemistry, University of California, Riverside 92521.
Spindler
S R
SR
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects*; D013006:Growth Hormone / Q000096:biosynthesis* / Q000235:genetics*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D051381:Rats; D013463:Sulfuric Acid Esters; D014284:Triiodothyronine / Q000494:pharmacology*
D017931:DNA Primers; D004268:DNA-Binding Proteins; D013463:Sulfuric Acid Esters; D014284:Triiodothyronine; D013006:Growth Hormone; D004247:DNA; C007482:dimethyl sulfate