The CD40L promoter contains nuclear factor of activated T cells-binding motifs which require AP-1 binding for activation of transcription.
Four nuclear factor of activated T cells (NF-AT) binding motifs were found in the murine CD40 ligand promoter. Electrophoretic mobility shift assays using 18-base pair (bp) long oligonucleotides corresponding to the proximal site and nuclear extracts from activated T cells revealed two complexes which were inhibited by cyclosporin A and contained NF-ATc and NF-ATp. Neither complex contained AP-1 proteins. Multimers of the 18-bp oligonucleotides were not active in transient transfection assays using luciferase reporter gene constructs. In contrast, a 30-bp long oligonucleotide bound AP-1 proteins in addition to NF-AT proteins and its multimers strongly induced luciferase gene expression. These results suggested that NF-AT proteins play an important role in the expression of the CD40L gene and that their transcriptional activity requires AP-1 binding.
Tsytsykova
A V
AV
Division of Immunology, Children's Hospital and Departments of Pediatrics, Harvard Medical School, Boston, Massachusetts 02115, USA.
Tsitsikov
E N
EN
Geha
R S
RS
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D019013:CD40 Antigens / Q000276:immunology; D023201:CD40 Ligand; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D016384:Consensus Sequence; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005434:Flow Cytometry; D007376:Interleukin-2 / Q000235:genetics; D008156:Luciferases / Q000096:biosynthesis; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins / Q000378:metabolism; D009838:Oligodeoxyribonucleotides; D011401:Promoter Regions, Genetic; D011994:Recombinant Proteins / Q000096:biosynthesis; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D018808:Transcription Factor AP-1 / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D015533:Transcriptional Activation; D014407:Tumor Cells, Cultured
D019013:CD40 Antigens; D004268:DNA-Binding Proteins; D007376:Interleukin-2; D008562:Membrane Glycoproteins; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D009838:Oligodeoxyribonucleotides; D011994:Recombinant Proteins; D018808:Transcription Factor AP-1; D014157:Transcription Factors; D023201:CD40 Ligand; D008156:Luciferases