An essential role of the nuclear factor of activated T cells in the regulation of the expression of the cyclooxygenase-2 gene in human T lymphocytes.
We have previously reported that transcriptional induction of cyclooxygenase-2 (COX-2) isoenzyme occurs early after T cell receptor triggering, suggesting functional implications of cyclooxygenase activity in this process. Here, we identify the cis-acting elements responsible for the transcriptional activation of this gene in human T lymphocytes. COX-2 promoter activity was induced upon T cell activation both in primary resting T lymphocytes and in Jurkat cells. This induction was abrogated by inhibition of calcineurin phosphatase with the immunosuppressive drug cyclosporin A, whereas expression of an active calcineurin catalytic subunit enhanced COX-2 transcriptional activation. Moreover, cotransfection of nuclear factor of activated T cells (NFAT) wild type protein transactivated COX-2 promoter activity. Conversely, dominant negative mutants of NFATc or c-Jun proteins inhibited COX-2 induction. Electrophoretic mobility shift assays and site-directed mutagenesis allowed the identification of two regions of DNA located in the positions -117 and -58 relative to the transcriptional start site that serves as NFAT recognition sequences. These results emphasize the central role that the Ca(2+)/calcineurin pathway plays in COX-2 transcriptional regulation in T lymphocytes pointing to NFAT/activator protein-1 transcription factors as essential for COX-2 promoter regulation in these cells.
Iñiguez
M A
MA
Centro de Biologia Molecular, Consejo Superior de Investigaciones Cientificas, Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid, Spain.
Martinez-Martinez
S
S
Punzón
C
C
Redondo
J M
JM
Fresno
M
M
D000818:Animals; D001665:Binding Sites; D019703:Calcineurin / Q000378:metabolism; D051546:Cyclooxygenase 2; D004252:DNA Mutational Analysis; D004268:DNA-Binding Proteins / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D007527:Isoenzymes / Q000096:biosynthesis / Q000235:genetics*; D019169:Jurkat Cells; D008213:Lymphocyte Activation; D008565:Membrane Proteins; D051379:Mice; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D011401:Promoter Regions, Genetic; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis / Q000235:genetics*; D011485:Protein Binding; D011493:Protein Kinase C / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000378:metabolism*; D018808:Transcription Factor AP-1 / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*; D015533:Transcriptional Activation
D004268:DNA-Binding Proteins; D007527:Isoenzymes; D008565:Membrane Proteins; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D012333:RNA, Messenger; D018808:Transcription Factor AP-1; D014157:Transcription Factors; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D011493:Protein Kinase C; D019703:Calcineurin