title: Cell-type-specific regulation of the human tumor necrosis factor alpha gene in B cells and T cells by NFATp and ATF-2/JUN.
abstract: The human tumor necrosis factor alpha (TNF-alpha) gene is one of the earliest genes transcribed after the stimulation of a B cell through its antigen receptor or via the CD-40 pathway. In both cases, induction of TNF-alpha gene transcription can be blocked by the immunosuppressants cyclosporin A and FK506, which suggested a role for the NFAT family of proteins in the regulation of the gene in B cells. Furthermore, in T cells, two molecules of NFATp bind to the TNF-alpha promoter element kappa 3 in association with ATF-2 and Jun proteins bound to an immediately adjacent cyclic AMP response element (CRE) site. Here, using the murine B-cell lymphoma cell line A20, we show that the TNF-alpha gene is regulated in a cell-type-specific manner. In A20 B cells, the TNF-alpha gene is not regulated by NFATp bound to the kappa 3 element. Instead, ATF-2 and Jun proteins bind to the composite kappa 3/CRE site and NFATp binds to a newly identified second NFAT site centered at -76 nucleotides relative to the TNF-alpha transcription start site. This new site plays a critical role in the calcium-mediated, cyclosporin A-sensitive induction of TNF-alpha in both A20 B cells and Ar-5 cells. Consistent with these results, quantitative DNase footprinting of the TNF-alpha promoter using increasing amounts of recombinant NFATp demonstrated that the -76 site binds to NFATp with a higher affinity than the kappa 3 site. Two other previously unrecognized NFATp-binding sites in the proximal TNF-alpha promoter were also identified by this analysis. Thus, through the differential use of the same promoter element, the composite kappa 3/CRE site, the TNF-alpha gene is regulated in a cell-type-specific manner in response to the same extracellular signal.
authors.affiliation: Department of Medicine, Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA.
authors.forename: E Y
authors.initials: EY
authors.lastname: Tsai
authors.forename: J
authors.initials: J
authors.lastname: Yie
authors.forename: D
authors.initials: D
authors.lastname: Thanos
authors.forename: A E
authors.initials: AE
authors.lastname: Goldfeld
mesh_terms: D051698:Activating Transcription Factor 2; D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D002467:Cell Nucleus / Q000378:metabolism; D002999:Clone Cells; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005786:Gene Expression Regulation; D006801:Humans; D016350:Leucine Zippers; D008223:Lymphoma; D051379:Mice; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D009928:Organ Specificity; D011401:Promoter Regions, Genetic; D011994:Recombinant Proteins / Q000096:biosynthesis; D013601:T-Lymphocytes / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D015533:Transcriptional Activation; D014162:Transfection; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000235:genetics*
chemical_list: C497105:ATF2 protein, human; D051698:Activating Transcription Factor 2; C497106:Atf2 protein, mouse; D017362:Cyclic AMP Response Element-Binding Protein; D004268:DNA-Binding Proteins; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D011994:Recombinant Proteins; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha