Transcriptional activity of the distal CD40 ligand promoter.
CD40 ligand (CD40L, CD154) is a T cell cytokine with highly regulated expression that requires the transcription factor nuclear factor of activated T cells (NF-AT) to bind at two sites in the proximal CD40L promoter. We have determined that the distal CD40L promoter (-500 to -1300 bp from start of transcription) conveys superior promoter activity in reporter gene assays. Within the distal promoter, we have identified a third NF-AT binding site, at -761 to -756. Oligonucleotides incorporating each of the three NF-AT sites cross-compete for binding of nuclear extracts from activated T cells and bind NF-ATc2 by antibody supershift. Mutation of the distal NF-AT site reduces activity of the 1300 bp CD40L promoter construct to that of the proximal 500 bp construct, which includes only two NF-AT sites. This suggests that the newly identified NF-AT site is the major mediator of transcriptional activation in the distal CD40L promoter.
Lobo
F M
FM
Yale Child Health Research Center, Yale University School of Medicine, New Haven, Connecticut, USA. francis.lobo@yale.edu
Xu
S
S
Lee
C
C
Fuleihan
R L
RL
D001483:Base Sequence; D023201:CD40 Ligand / Q000235:genetics*; D016572:Cyclosporine / Q000494:pharmacology; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000378:metabolism; D017930:Genes, Reporter; D006801:Humans; D019169:Jurkat Cells; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic
D017931:DNA Primers; D004268:DNA-Binding Proteins; D050778:NFATC Transcription Factors; C494006:NFATC2 protein, human; D009687:Nuclear Proteins; D014157:Transcription Factors; D023201:CD40 Ligand; D016572:Cyclosporine