The NF-kappa B-like site in the TNF-alpha repressor element is essential for its repressor function.
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.
Fong
C L
CL
Department of Microbial Chemotherapeutics and Molecular Genetics, Merck Research Laboratories, Rahway, NJ 07065, USA.
Mark
D F
DF
D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002460:Cell Line; D004247:DNA / Q000235:genetics; D017931:DNA Primers / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005809:Genes, Regulator; D006801:Humans; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D016328:NF-kappa B / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011487:Protein Conformation; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics; D050656:Transcription Factor AP-2; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
D017931:DNA Primers; D004268:DNA-Binding Proteins; D016328:NF-kappa B; D012097:Repressor Proteins; D050656:Transcription Factor AP-2; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha; D004247:DNA