The C-terminal region of human NFATc2 binds cJun to synergistically activate interleukin-2 transcription.
At eukaryotic promoters, multi-faceted protein-protein and protein-DNA interactions can result in synergistic transcriptional activation. NFAT and AP-1 proteins induce interleukin-2 (IL-2) transcription in stimulated T cells, but the contributions of individual members of these activator families to synergistically activating IL-2 transcription is not known. To investigate the combinatorial regulation of IL-2 transcription we tested the ability of different combinations of NFATc2, NFATc1, cJun, and cFos to synergistically activate transcription from the IL-2 promoter. We found that NFATc2 and cJun are exclusive in their ability to synergistically activate human IL-2 transcription. Protein-protein interaction assays revealed that in the absence of DNA, NFATc2, but not NFATc1, bound directly to cJun/cJun dimers, but not to cFos/cJun heterodimers. A region of NFATc2 C-terminal of the DNA binding domain was necessary and sufficient for interaction with cJun in the absence of DNA, and this same region of NFATc2 was required for the synergistic activation of IL-2 transcription in T cells. Moreover, expression of this C-terminal region of NFATc2 specifically repressed the synergistic activation of IL-2 transcription. These studies show that a previously unidentified interaction between human NFATc2 and cJun is necessary for synergistic activation of IL-2 transcription in T cells.
Nguyen
Tuan N
TN
University of Colorado, Department of Chemistry and Biochemistry, 215 UCB, Boulder, CO 80309-0215, USA.
Kim
Loree J
LJ
Walters
Ryan D
RD
Drullinger
Linda F
LF
Lively
Tricia N
TN
Kugel
Jennifer F
JF
Goodrich
James A
JA
D001483:Base Sequence; D001665:Binding Sites; D017931:DNA Primers / Q000235:genetics; D006801:Humans; D007376:Interleukin-2 / Q000235:genetics*; D019169:Jurkat Cells; D008954:Models, Biological; D050778:NFATC Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics / Q000378:metabolism; D016755:Proto-Oncogene Proteins c-jun / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D018808:Transcription Factor AP-1 / Q000378:metabolism; D015533:Transcriptional Activation
D017931:DNA Primers; C508594:IL2 protein, human; D007376:Interleukin-2; D050778:NFATC Transcription Factors; C494003:NFATC1 protein, human; C494006:NFATC2 protein, human; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D011994:Recombinant Proteins; D018808:Transcription Factor AP-1