The NF-kappa B-like site in the TNF-alpha repressor element is essential for its repressor function

Biochem Biophys Res Commun. 1995 Jul 26;212(3):879-86. doi: 10.1006/bbrc.1995.2051.

Abstract

We have previously identified a repressor element in the TNF-alpha promoter (-280 to -172) by deletion analysis. When this 108 bp repressor element was placed in front of a heterologous promoter containing an NF-kappa B binding site, less repression was observed. When this element was dimerized and placed in front of the positive element (-125 to -102) of the TNF-alpha promoter, instead of repression, activation was observed. There is an NF-kappa B-like site in the 108 bp repressor region (-211 to -202) and our gel retardation analysis showed that this site and a known NF-kappa B binding site both could compete for one of the specific protein complexes formed on the 108 bp probe. To test the functionality of this NF-kappa B-like site, we mutagenized the critical GGGG sequence to ATCC. Contrary to our prediction, such a mutation blocked the repressor function of the 108 bp element. This suggests that the NF-kappa B-like site is an essential sequence for the repressor function of the 108 bp repressor element.

MeSH terms

  • Base Sequence
  • Binding Sites / genetics
  • Cell Line
  • DNA / genetics
  • DNA Primers / genetics
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Genes, Regulator*
  • Humans
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • NF-kappa B / genetics*
  • NF-kappa B / metabolism
  • Promoter Regions, Genetic
  • Protein Conformation
  • Repressor Proteins / chemistry
  • Repressor Proteins / genetics
  • Transcription Factor AP-2
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Transcription, Genetic
  • Tumor Necrosis Factor-alpha / genetics*

Substances

  • DNA Primers
  • DNA-Binding Proteins
  • NF-kappa B
  • Repressor Proteins
  • Transcription Factor AP-2
  • Transcription Factors
  • Tumor Necrosis Factor-alpha
  • DNA