Silencer Activity in the Interferon-A Gene Promoters

• Published in: The Journal of biological chemistry Vol. 272; no. 36; pp. 22788 - 22799
• Main Authors: Lopez, Sébastien, Reeves, Raymond, Island, Marie-Laure, Bandu, Marie-Thérèse, Christeff, Nicolas, Doly, Janine, Navarro, Sébastien
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 05-09-1997; American Society for Biochemistry and Molecular Biology
• Subjects: Base Sequence; Binding Sites; Cell Line; Cell Nucleus - metabolism; DNA; DNA Footprinting; HeLa Cells; High Mobility Group Proteins - metabolism; Humans; Interferon-alpha - genetics; Interferon-alpha - metabolism; Molecular Sequence Data; NAD(P)H Dehydrogenase (Quinone) - metabolism; Nuclear Proteins - metabolism; Promoter Regions, Genetic; Protein Binding; Regulatory Sequences, Nucleic Acid; Transcription, Genetic; Transfection
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.272.36.22788

Interferon-A (IFN-A) differential gene expression is modulated by a complex interplay between cis-acting DNA elements and the corresponding specific trans-regulating factors. Substitutions in the proximal virus-responsive element of the interferon-A (IFN-A) promoters contribute to their differential gene expression. The 5′ distal silencing region in the weakly virus-inducible murine IFN-A11 gene has been previously delimited. DNase I footprinting experiments and transient gene expression assays demonstrate identical silencing activity in equivalent regions of the genes for IFN-A11 and IFN-A4 promoters. A minimal 20-mer distal negative regulatory element (DNRE) in both promoters is necessary and sufficient for the silencing and a region in the highly inducible IFN-A4 promoter located between the silencer and the virus-responsive element overrides the silencer activity. Mutations in the central region of the DNRE, causing derepression, also altered the formation of one of the two major DNA-protein complexes. One of these contains a protein related to or identical to the high mobility group I(Y) proteins, while the other complex contains a major protein present in uninduced and virus-induced cells with a molecular mass of 38 kDa, which may be related to the silencer activity. Similar DNREs are present in other virus-uninducible IFN-A promoters, and these data suggest that a common silencer may mediate the transcriptional repression in different genes of this family.