@phdthesis{Chen2007, author = {Chen, Wen}, title = {Functional Role of NFATc1 in the Control of Life and Death of Lymphocytes}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-26675}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2007}, abstract = {In this study, murine ES cells and DT40 B cells were used in parallel to disrupt the Nfatc1 gene and to study the function of individual 6 Nfatc1 isoforms, especially the function of highly inducible NFATc1/aA.We found that the short isoform NFATc1/aA protects DT40 B cells against apoptosis while the long isoform NFATc1/aC appears to enforce apoptosis. DNA microarray studies have shown that in NFATc1" DT40 B cells expressing ectopically human NFATc1/aA, the pkc-theta gene is several fold stronger expressed as in wild type cells. Our results of EMSA (Electrophoretic Mobility Shift Assays) and ChIP (chromatin immuno-precipitation) experiments demonstrated the binding of NFATc1/aA to the pkc-theta promoter in vitro and in vivo. NF-kappa B was also found to bind to the NFATc1 P1-promoter in vitro and in vivo. These data suggest and further prove that NF-kappa B contributes to the induction of the NFATc1 P1 promoter upon activation of T cells. So, NFATc1/aA and NF-kappa B were found to cross-talk in the transcriptional upregulation of their target genes, such as the IL-2 gene and the Nfatc1 gene itself, at multiple steps upon induction of apoptosis. While the pro-apoptotic mechanism of NFATc1s long isoform(s) remains unclear, its corresponding "death partners" are worth further studies. The elucidation of functional roles of NFATc1s short or long isoforms in the control of apoptosis of lymphocytes helps to understand apoptosis regulation, and thereby, the fate of lymphocytes.}, subject = {Lymphozyten}, language = {en} }