Role of the X2 box in activated transcription from the DRA promoter in B cells.
We investigated the function of the evolutionary conserved X2 box in the promoter of the HLA-DRA gene from the human major histocompatibility complex (MHC) in resting and activated B cells. NF-X2, which contains members of the AP-1/ATF/CREB families of transcription factors, interacts with the X2 box (5'-TGCGTCA-3') from positions -97 to -91 in the DRA promoter. In resting Raji cells, little to no binding to the X2 box was observed. In sharp contrast, in B cells treated with the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA), strong interactions between the X2 box and NF-X2 containing c-Fos were observed. As determined by transient expression and RNA analyses, the activation of protein kinase C (PKC) also increased rates of transcription from the wild-type DRA promoter but not from a DRA promoter bearing clustered point mutations in the X2 box. Since the co-expression with a dominant negative c-Fos abolished the responsiveness to TPA, we conclude that activated transcription of the DRA gene depends on interactions between the X2 box and NF-X2, which contains c-Fos.
Setterblad
N
N
Department of Cell Research, Uppsala Genetic Center, Swedish University of Agricultural Sciences, Box 7055, S-750 07 Uppsala, Sweden.
Peterlin
B M
BM
Andersson
G
G
D000818:Animals; D001402:B-Lymphocytes / Q000187:drug effects / Q000378:metabolism*; D001665:Binding Sites / Q000235:genetics; D004268:DNA-Binding Proteins / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D005786:Gene Expression Regulation; D005802:Genes, MHC Class II; D006684:HLA-DR Antigens / Q000235:genetics*; D059805:HLA-DR alpha-Chains; D004854:Herpesvirus 4, Human; D006801:Humans; D017354:Point Mutation; D011401:Promoter Regions, Genetic; D011493:Protein Kinase C / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000037:antagonists & inhibitors / Q000378:metabolism; D000071701:Regulatory Factor X Transcription Factors; D017422:Sequence Analysis, DNA; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014407:Tumor Cells, Cultured
D004268:DNA-Binding Proteins; D006684:HLA-DR Antigens; D059805:HLA-DR alpha-Chains; D016760:Proto-Oncogene Proteins c-fos; D000071701:Regulatory Factor X Transcription Factors; D014157:Transcription Factors; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate