Enhancer-like interferon responsive sequences of the human and murine (2′-5′) oligoadenylate synthetase gene promoters.

Open Access
Publisher Website
Google Scholar
Abstract
The human (2′‐5′) oligo(A) synthetase gene contains two independent cis‐acting DNA elements, A and B, which act as transcriptional enhancers. Element A alone is not activated by IFN treatment. Element B alone confers IFN‐inducibility to the herpes tk promoter. Two murine (2′‐5′) oligo(A) synthetase genes were isolated and their promoter sequences show high conservation of element A and B. A synthetic oligonucleotide, containing 16 bp of the human element B, or 14 bp of the homologue murine element B, was linked to a TK‐CAT construct. These oligonucleotides were shown to be sufficient to activate the TK promoter in the presence of IFN. When multiple repeats of the interferon‐responsive sequence (E‐IRS) were cloned in 5′ of the TK promoter, the activation ratio was increased. In vitro, specific binding of nuclear protein(s) is observed to the radiolabelled synthetic human E‐IRS. This binding is competed by the addition of cold synthetic mouse E‐IRS or fragments of genomic DNA containing the E‐IRS.