Reversible silencing of enhancers by sequences derived from the human IFN-alpha promoter.
The virus-responsive element of the IFN-alpha 1 promoter, VRE(IFN alpha), comprises two imperfect 19 bp repeats, repA and repB. VRE(IFN alpha), tetrameric repA, and tetrameric GAAAGT (a subsequence of repB) or tetrameric AAGTGA conferred inducibility on a reporter gene when placed upstream of a complete or truncated promoter. Induced transcription was weak with a minimal promoter (TATA box only), but was strongly stimulated by the SV40 enhancer placed immediately upstream of the inducible element. Surprisingly, under noninduced conditions, tetrameric repA, GAAAGT, and AAGTGA (but not VRE(IFN alpha)) completely silenced enhancement of constitutive transcription by the SV40 72 bp repeat when interposed between the latter and the TATA box; silencing was fully abrogated by induction.
D000818:Animals; D001483:Base Sequence; D004742:Enhancer Elements, Genetic; D005786:Gene Expression Regulation; D005796:Genes; D005809:Genes, Regulator; D005814:Genes, Viral; D006801:Humans; D007370:Interferon Type I / Q000096:biosynthesis / Q000235:genetics*; D007739:L Cells; D051379:Mice; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D012091:Repetitive Sequences, Nucleic Acid; D013539:Simian virus 40 / Q000235:genetics*; D014158:Transcription, Genetic
D007370:Interferon Type I; D011993:Recombinant Fusion Proteins