title: Interference between pathway-specific transcription factors: glucocorticoids antagonize phorbol ester-induced AP-1 activity without altering AP-1 site occupation in vivo.
abstract: Phorbol esters stimulate and glucocorticoid hormones down-regulate a variety of promoters such as that of the collagenase gene through the transcription factor AP-1 (Fos/Jun). We now show by genomic footprinting of the collagenase promoter that phorbol ester treatment of cells results in the binding of AP-1 to its cognate DNA binding site in vivo. The DNA-protein contacts obtained in living cells are also found in vitro using cloned DNA and purified AP-1. Although in vitro synthesized glucocorticoid receptor can disturb the DNA binding of Jun homodimers, it does not interfere with the binding of Fos-Jun heterodimers or of purified AP-1 in vitro. Consistently, fully inhibitory doses of glucocorticoid hormone cause no change in apparent occupation of the AP-1 binding site in vivo. The hormone receptor acts without itself binding to DNA.
authors.affiliation: Kernforschungszentrum Karlsruhe, Institut für Genetik und Toxikologie, Germany.
authors.forename: H
authors.initials: H
authors.lastname: König
authors.forename: H
authors.initials: H
authors.lastname: Ponta
authors.forename: H J
authors.initials: HJ
authors.lastname: Rahmsdorf
authors.forename: P
authors.initials: P
authors.lastname: Herrlich
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D002467:Cell Nucleus / Q000502:physiology*; D004247:DNA / Q000235:genetics / Q000378:metabolism*; D003907:Dexamethasone / Q000494:pharmacology*; D006367:HeLa Cells; D006801:Humans; D008745:Methylation; D003012:Microbial Collagenase / Q000235:genetics; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D011401:Promoter Regions, Genetic; D014176:Protein Biosynthesis; D016755:Proto-Oncogene Proteins c-jun / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D015183:Restriction Mapping; D012867:Skin; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D009838:Oligodeoxyribonucleotides; D016755:Proto-Oncogene Proteins c-jun; D011994:Recombinant Proteins; D014157:Transcription Factors; D003907:Dexamethasone; D004247:DNA; D003012:Microbial Collagenase; D013755:Tetradecanoylphorbol Acetate