Functional Consequences of a Polymorphism Affecting NF-κB p50-p50 Binding to the TNF Promoter Region
Autor: | Agnes Denys, Dominic P. Kwiatkowski, Brian M. J. Foxwell, Clive Smith, Irina A. Udalova, Hans Ackerman, Anna Richardson |
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Rok vydání: | 2000 |
Předmět: |
Lipopolysaccharides
Transcriptional Activation Biology Cell Fractionation Monocytes Adenoviridae Cell Line Genes Reporter Gene expression Animals Humans Cloning Molecular Binding site Promoter Regions Genetic Enhancer Molecular Biology Gene Cells Cultured Transcriptional Regulation Regulation of gene expression Reporter gene Binding Sites Polymorphism Genetic Tumor Necrosis Factor-alpha Macrophages NF-kappa B NF-kappa B p50 Subunit Promoter Cell Biology NFKB1 Molecular biology Gene Expression Regulation COS Cells Dimerization |
Zdroj: | Molecular and Cellular Biology. 20:9113-9119 |
ISSN: | 1098-5549 |
DOI: | 10.1128/mcb.20.24.9113-9119.2000 |
Popis: | Stimulation of the NF-kappaB pathway often causes p65-p50 and p50-p50 dimers to be simultaneously present in the cell nucleus. A natural polymorphism at nucleotide -863 in the human TNF promoter (encoding tumor necrosis factor [TNF]) region provides an opportunity to dissect the functional interaction of p65-p50 and p50-p50 at a single NF-kappaB binding site. We found that this site normally binds both p65-p50 and p50-p50, but a single base change specifically inhibits p50-p50 binding. Reporter gene analysis in COS-7 cells expressing both p65-p50 and p50-p50 shows that the ability to bind p50-p50 reduces the enhancer effect of this NF-kappaB site. Using an adenoviral reporter assay, we found that the variant which binds p50-p50 results in a reduction of lipopolysaccharide-inducible gene expression in primary human monocytes. This finding adds to a growing body of experimental evidence that p50-p50 can inhibit the transactivating effects of p65-p50 and illustrates the potential for genetic modulation of inflammatory gene regulation in humans by subtle nucleotide changes that alter the relative binding affinities of different forms of the NF-kappaB complex. |
Databáze: | OpenAIRE |
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