Determination of the promoter elements that mediate repression of c-fos gene transcription by thyroid hormone and retinoic acid receptors.
Basal and stimulated activity of the c-fos promoter is reduced by triiodothyronine (T3) and retinoic acid (RA) in GH1 cells. We examined the influence of these ligands on the activity of reporter constructs containing the AP-1 site, the serum response element (SRE) and the cyclic AMP responsive element (CRE) of the c-fos promoter under control of an heterologous promoter. T3 and RA decreased the response of AP-1 and SRE sequences to phorbol esters, forskolin or serum but they did not reduce basal or forskolin-stimulated activity mediated by the CRE. Therefore, repression of c-fos gene expression by T3 and RA receptors appears to be exerted through transcriptional interference with the SRE and the AP-1 binding site of the promoter.
Perez
P
P
Instituto de Investigaciones Biomedicas, C.S.I.C., Madrid, Spain.
Palomino
T
T
Schönthal
A
A
Aranda
A
A
D001483:Base Sequence; D002478:Cells, Cultured; D005576:Colforsin / Q000494:pharmacology; D016762:Genes, fos; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D011401:Promoter Regions, Genetic; D018168:Receptors, Retinoic Acid / Q000502:physiology*; D011988:Receptors, Thyroid Hormone / Q000502:physiology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014158:Transcription, Genetic / Q000187:drug effects / Q000502:physiology*
D009838:Oligodeoxyribonucleotides; D018168:Receptors, Retinoic Acid; D011988:Receptors, Thyroid Hormone; D005576:Colforsin; D013755:Tetradecanoylphorbol Acetate