Constitutive in vitro binding of nuclear proteins to the 5'-flanking region of 6-16, a human gene inducible by alpha, beta-interferons.

Proteins in nuclear extracts of HeLa cells that constitutively bound in vitro to three regions upstream of the interferon-inducible gene 6-16 were separated partially by chromatography on DEAE-Sepharose. Region one, a CCAAT box in the non-coding strand at position --63 to --67, was protected from DNase digestion by the bound protein(s) and was required for transcription in vitro. Region two, a tandem duplication sequence at position --89 to --168 contains two copies of a sequence essential for strong induction of the 6-16 gene by interferon in vitro. Region three, a palindromic sequence at position --449 to --465, not necessary for induction of 6-16 by interferon, was also protected from DNase digestion by nuclear protein(s). Templates with or without regions of two and three were transcribed equally well in extracts from interferon-treated or untreated cells.