TY - JOUR A1 - Mueller, Kerstin A1 - Quandt, Jasmin A1 - Marienfeld, Ralf B. A1 - Weihrich, Petra A1 - Fiedler, Katja A1 - Claussnitzer, Melina A1 - Laumen, Helmut A1 - Vaeth, Martin A1 - Berberich-Siebelt, Frederike A1 - Serfling, Edgar A1 - Wirth, Thomas A1 - Brunner, Cornelia T1 - Octamer-dependent transcription in T cells is mediated by NFAT and \(NF-\kappa B\) JF - Nucleic Acids Research N2 - The transcriptional co-activator BOB.1/OBF.1 was originally identified in B cells and is constitutively expressed throughout B cell development. BOB.1/OBF.1 associates with the transcription factors Oct1 and Oct2, thereby enhancing octamer-dependent transcription. In contrast, in T cells, BOB.1/OBF.1 expression is inducible by treatment of cells with PMA/Ionomycin or by antigen receptor engagement, indicating a marked difference in the regulation of BOB.1/OBF.1 expression in B versus T cells. The molecular mechanisms underlying the differential expression of BOB.1/OBF.1 in T and B cells remain largely unknown. Therefore, the present study focuses on mechanisms controlling the transcriptional regulation of BOB.1/OBF.1 and Oct2 in T cells. We show that both calcineurin- and \(NF-\kappa B\)-inhibitors efficiently attenuate the expression of BOB.1/OBF.1 and Oct2 in T cells. In silico analyses of the BOB.1/OBF.1 promoter revealed the presence of previously unappreciated combined NFAT/\(NF-\kappa B\) sites. An array of genetic and biochemical analyses illustrates the involvement of the \(Ca^{2+}\)/calmodulin-dependent phosphatase calcineurin as well as NFAT and \(NF-\kappa B\) transcription factors in the transcriptional regulation of octamer-dependent transcription in T cells. Conclusively, impaired expression of BOB.1/OBF.1 and Oct2 and therefore a hampered octamer-dependent transcription may participate in T cell-mediated immunodeficiency caused by the deletion of NFAT or \(NF-\kappa B\) transcription factors. KW - germinal center formation KW - OBF-1 OCA-B KW - coactivator OBF-1 KW - gene expression KW - functional characterization KW - immunoglobulin promoters KW - OCT-1-deficient mice KW - embryonic lethality KW - endothelial cells KW - murine homolog Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-123280 SN - 1362-4962 VL - 41 IS - 4 ER -