CCAAT/ENHANCER BINDING PROTEIN IS INVOLVED IN THE EXPRESSION OF THE TUMOUR NECROSIS FACTOR GENE IN HUMAN MONOCYTES
| Autor: | A. Wedel, G. Sulski, H. W. L. Ziegler-Heitbrock |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Transcriptional Activation
Expression vector Ccaat-enhancer-binding proteins Tumor Necrosis Factor-alpha Immunology Wild type Nuclear Proteins Hematology Transfection Biology Biochemistry DNA-binding protein Molecular biology Monocytes DNA-Binding Proteins Transactivation Gene expression CCAAT-Enhancer-Binding Proteins Mutagenesis Site-Directed Humans Immunology and Allergy Nuclear protein Molecular Biology Cells Cultured |
| Zdroj: | Cytokine. 8:335-341 |
| ISSN: | 1043-4666 |
| DOI: | 10.1006/cyto.1996.0046 |
| Popis: | Within the human TNF promoter we have identified two sites at positions -189 and -101 that show C/EBP specific binding of nuclear proteins from cells of the human monocytic line Mono Mac 6. Supershift analysis with anti C/EBP antibodies revealed that the complexes formed consist of both C/EBP alpha and C/EBP beta. When studying reporter constructs with a 5'-deletion series of the TNF promoter in cotransfection experiments with a C/EBP beta expression plasmid, a construct with the -1064 TNF fragment gave 26-fold transactivation, the -630 fragment showed 23-fold transactivation and the -107 fragment (containing the -101 C/EBP binding motif) still gave 16-fold transactivation. Mutagenesis of the -101 site in the -630 construct resulted in a reduction of C/EBP driven transactivation from 26-fold to 7-fold. Finally, when Mono Mac 6 cells were transfected with these constructs, stimulation by LPS induced a 19-fold transactivation in the -630 wild type construct, while the -630 construct carrying the -101 mutation was transactivated only 4-fold. Hence, the data indicate that the -101 C/EBP motif is crucial for TNF gene expression in human monocytes. |
| Databáze: | OpenAIRE |
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