Identification of Novel Nuclear Factor of Activated T Cell (NFAT)-associated Proteins in T Cells

Abstract

Transcription factors of the nuclear factor of activated T cell (NFAT) family are essential for antigen-specific T cell activation and differentiation. Their cooperative DNA binding with other transcription factors, such as AP1 proteins (FOS, JUN, and JUNB), FOXP3, IRFs, and EGR1, dictates the gene regulatory action of NFATs. To identify as yet unknown interaction partners of NFAT, we purified biotin-tagged NFATc1/αA, NFATc1/βC, and NFATc2/C protein complexes and analyzed their components by stable isotope labeling by amino acids in cell culture-based mass spectrometry. We revealed more than 170 NFAT-associated proteins, half of which are involved in transcriptional regulation. Among them are many hitherto unknown interaction partners of NFATc1 and NFATc2 in T cells, such as Raptor, CHEK1, CREB1, RUNX1, SATB1, Ikaros, and Helios. The association of NFATc2 with several other transcription factors is DNA-dependent, indicating cooperative DNA binding. Moreover, our computational analysis discovered that binding motifs for RUNX and CREB1 are found preferentially in the direct vicinity of NFAT-binding motifs and in a distinct orientation to them. Furthermore, we provide evidence that mTOR and CHEK1 kinase activity influence NFAT's transcriptional potency. Finally, our dataset of NFAT-associated proteins provides a good basis to further study NFAT's diverse functions and how these are modulated due to the interplay of multiple interaction partners.

Participation of the AngII/TRPC6/NFAT axis in the pathogenesis of podocyte injury in rats with type 2 diabetes

“…NFAT is a transcription factor that is predominantly regulated by activation and the subsequent translocation from the cytoplasm to the nucleus. NFAT activation/regulation is measured by total NFAT2 protein/mRNA expression levels (45,46). The results demonstrated that the ARB VAL attenuated the HG-induced increase of TRPC6 and NFAT in podocytes in vivo and in vitro.…”

The polysaccharide ofAtractylodes macrocephala koidz(PAMK) alleviates cyclophosphamide-mediated immunosuppression in geese, possibly through novel_mir2 targeting of CTLA4 to upregulate the TCR-NFAT pathway

“…In addition, NFAT is an important nuclear transcription factor of T cell activation that is also regulated by miRNAs. 31,32 In the present study, we found that PAMK treatment signicantly increased the expression of NFAT in the presence of CTX, but not NF-kB, indicating that PAMK might upregulate the expression of novel_mir2 to inhibit CTLA4, leading to increased levels of nuclear transcription factor NFAT, which ultimately changes the expression of cytokines and promotes T cell activation. This means that the mechanism by which PAMK promotes T cell activation, inhibited by CTX in geese, is not the same as the mechanism by which CMP promotes macrophage activation.…”

Correlates of Protection Against SIVmac251 Infection in Rhesus Macaques Immunized With Chimpanzee-Derived Adenovirus Vectors

“…Pathway analyses showed that TNF signaling and downstream pathways such as IL-1B and NF-κB were more active in CD8 + T cells of resistant RMs, as were pathways initiated by TcR ligation such as CAVI and HIF-1α. CREB1, a transcription factor that binds to NFATc1 and 2 in activated T cells ( Gabriel et al, 2016 ) and RE1 Silencing Transcription Factor (REST), which reduces the activity of NFATs ( Ohba et al, 2006 )(Supplementary Table S5).…”