scholarly journals NFATx, a novel member of the nuclear factor of activated T cells family that is expressed predominantly in the thymus.

1995 ◽  
Vol 15 (5) ◽  
pp. 2697-2706 ◽  
Author(s):  
E S Masuda ◽  
Y Naito ◽  
H Tokumitsu ◽  
D Campbell ◽  
F Saito ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
Regulation Of Gene Expression ◽  
Interleukin 2 ◽  
Calcium Ionophore ◽  
Cytokine Gene Expression ◽  
Nuclear Factor ◽  
Blood Leukocytes ◽  
Activated T Cells ◽  
Amino Terminal

The nuclear factor of activated T cells (NFAT) regulates cytokine gene expression in T cells through cis-acting elements located in the promoters of cytokine genes. Here, we report the cDNA cloning, chromosomal localization, and initial characterization of a transcription factor related to NFATp and NFATc. The novel molecule, designated NFATx, exhibits in its middle a region very similar to the Rel homology domain in NFATc and NFATp. The amino-terminal region of NFATx also shows significant similarities to corresponding sequences in NFATc and NFATp and contains three copies of a conspicuous 17-residue motif of unknown function. We provide evidence showing that NFATx can reconstitute binding to the NFAT-binding site from the interleukin 2 promoter when combined with AP1 (c-Fos/c-Jun) polypeptides and that NFATx is capable of activating transcription of the interleukin 2 promoter in COS-7 cells when stimulated with phorbol ester and calcium ionophore. NFATx mRNA is preferentially and remarkably found in the thymus and at lower levels in peripheral blood leukocytes. The expression pattern of NFATx, together with its functional activity, strongly suggests that NFATx plays a role in the regulation of gene expression in T cells and immature thymocytes.

scholarly journals Erythromycin Inhibits Transcriptional Activation of NF-κB, but not NFAT, through Calcineurin-Independent Signaling in T Cells

1999 ◽  
Vol 43 (11) ◽  
pp. 2678-2684 ◽  
Author(s):  
Yosuke Aoki ◽  
Peter N. Kao
Keyword(s):  
T Cells ◽  
Dna Binding ◽  
Transcriptional Activation ◽  
Calcium Ionophore ◽  
Inhibitory Effect ◽  
Binding Activity ◽  
Cytokine Gene Expression ◽  
Nuclear Factor ◽  
Mobility Shift ◽  
Activated T Cells

ABSTRACT The molecular mechanism of the anti-inflammatory effect of erythromycin (EM) was investigated at the level of transcriptional regulation of cytokine gene expression in T cells. EM (>10−6 M) significantly inhibited interleukin-8 (IL-8) expression but not IL-2 expression from T cells induced with 20 ng of phorbol 12-myristate 13-acetate (PMA) per ml plus 2 μM calcium ionophore (P-I). In electrophoretic mobility shift assays EM at 10−7 to 10−5 M concentrations inhibited nuclear factor kappa B (NF-κB) DNA-binding activities induced by P-I. Reporter gene assays also showed that EM (10−5 M) inhibited IL-8 NF-κB transcription by 37%. The inhibitory effects of EM on transcriptional activation of IL-2 and DNA-binding activity of nuclear factor of activated T cells (NFAT) were not seen in T cells. On the other hand, FK506, which is also a macrolide derivative, inhibited transcriptional activation of both NF-κB and NFAT more strongly than EM did. The mechanism of EM inhibition of transactivation of NF-κB was further investigated in transiently transfected T cells that express calcineurin A and B subunits. Expression of calcineurin did not render transactivation of NF-κB in T cells more resistant to EM, while the inhibitory effect of FK506 on transactivation of NF-κB was attenuated. These findings indicate that EM is capable of inhibiting expression of the IL-8 gene in T cells through transcriptional inhibition and that this inhibition is mediated through a non-calcineurin-dependent signaling event in T lymphocytes.

scholarly journals Nfat

2002 ◽  
Vol 156 (5) ◽  
pp. 771-774 ◽  
Author(s):  
Valerie Horsley ◽  
Grace K. Pavlath
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
Transcription Factors ◽  
Immune System ◽  
Cell Types ◽  
Cytokine Gene Expression ◽  
Nuclear Factor ◽  
Cytokine Gene ◽  
Activated T Cells ◽  
Control Of Gene Expression

The nuclear factor of activated T cells (NFAT) proteins are a family of transcription factors whose activation is controlled by calcineurin, a Ca2+-dependent phosphatase. Originally identified in T cells as inducers of cytokine gene expression, NFAT proteins play varied roles in cells outside of the immune system. This review addresses the recent data implicating NFAT in the control of gene expression influencing the development and adaptation of numerous mammalian cell types.

scholarly journals Blockade of T-cell activation by dithiocarbamates involves novel mechanisms of inhibition of nuclear factor of activated T cells.

1997 ◽  
Vol 17 (11) ◽  
pp. 6437-6447 ◽  
Author(s):  
S Martínez-Martínez ◽  
P Gómez del Arco ◽  
A L Armesilla ◽  
J Aramburu ◽  
C Luo ◽  
...  
Keyword(s):  
T Cells ◽  
Transcription Factor ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Regulation Of Gene Expression ◽  
Interleukin 2 ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Nf Kappab

Dithiocarbamates (DTCs) have recently been reported as powerful inhibitors of NF-kappaB activation in a number of cell types. Given the role of this transcription factor in the regulation of gene expression in the inflammatory response, NF-kappaB inhibitors have been suggested as potential therapeutic drugs for inflammatory diseases. We show here that DTCs inhibited both interleukin 2 (IL-2) synthesis and membrane expression of antigens which are induced during T-cell activation. This inhibition, which occurred with a parallel activation of c-Jun transactivating functions and expression, was reflected by transfection experiments at the IL-2 promoter level, and involved not only the inhibition of NF-kappaB-driven reporter activation but also that of nuclear factor of activated T cells (NFAT). Accordingly, electrophoretic mobility shift assays (EMSAs) indicated that pyrrolidine DTC (PDTC) prevented NF-kappaB, and NFAT DNA-binding activity in T cells stimulated with either phorbol myristate acetate plus ionophore or antibodies against the CD3-T-cell receptor complex and simultaneously activated the binding of AP-1. Furthermore, PDTC differentially targeted both NFATp and NFATc family members, inhibiting the transactivation functions of NFATp and mRNA induction of NFATc. Strikingly, Western blotting and immunocytochemical experiments indicated that PDTC promoted a transient and rapid shuttling of NFATp and NFATc, leading to their accelerated export from the nucleus of activated T cells. We propose that the activation of an NFAT kinase by PDTC could be responsible for the rapid shuttling of the NFAT, therefore transiently converting the sustained transactivation of this transcription factor that occurs during lymphocyte activation, and show that c-Jun NH2-terminal kinase (JNK) can act by directly phosphorylating NFATp. In addition, the combined inhibitory effects on NFAT and NF-KB support a potential use of DTCs as immunosuppressants.

scholarly journals Glucocorticoid receptor-mediated suppression of the interleukin 2 gene expression through impairment of the cooperativity between nuclear factor of activated T cells and AP-1 enhancer elements.

1992 ◽  
Vol 175 (3) ◽  
pp. 637-646 ◽  
Author(s):  
A Vacca ◽  
M P Felli ◽  
A R Farina ◽  
S Martinotti ◽  
M Maroder ◽  
...  
Keyword(s):  
T Cells ◽  
Glucocorticoid Receptor ◽  
Transcriptional Activation ◽  
Interleukin 2 ◽  
Calcium Ionophore ◽  
Nuclear Factor ◽  
Hormone Regulation ◽  
Activated T Cells ◽  
Dna Binding Domains ◽  
Binding Domains

The immunosuppressant hormone dexamethasone (Dex) interferes with T cell-specific signals activating the enhancer sequences directing interleukin 2 (IL-2) transcription. We report that the Dex-dependent downregulation of 12-O-tetradecanoyl-phorbol-13-acetate (TPA) and calcium ionophore-induced activity of the IL-2 enhancer are mediated by glucocorticoid receptor (GR) via a process that requires intact NH2- and COOH-terminal and DNA-binding domains. Functional analysis of chloramphenicol acetyltransferase (CAT) vectors containing internal deletions of the -317 to +47 bp IL-2 enhancer showed that the GR-responsive elements mapped to regions containing nuclear factor of activated T cells protein (NFAT) (-279 to -263 bp) and AP-1 (-160 to -150 bp) motifs. The AP-1 motif binds TPA and calcium ionophore-induced nuclear factor(s) containing fos protein. TPA and calcium ionophore-induced transcriptional activation of homo-oligomers of the NFAT element were not inhibited by Dex, while AP-1 motif concatemers were not stimulated by TPA and calcium ionophore. When combined, NFAT and AP-1 motifs significantly synergized in directing CAT transcription. Such a synergism was impaired by specific mutations affecting the trans-acting factor binding to either NFAT or AP-1 motifs. In spite of the lack of hormone regulation of isolated cis elements, TPA/calcium ionophore-mediated activation of CAT vectors containing a combination of the NFAT and the AP-1 motifs became suppressible by Dex. Our results show that the IL-2-AP-1 motif confers GR sensitivity to a flanking region containing a NFAT element and suggest that synergistic cooperativity between the NFAT and AP-1 sites allows GR to mediate the Dex inhibition of IL-2 gene transcription. Therefore, a Dex-modulated second level of IL-2 enhancer regulation, based on a combinatorial modular interplay, appears to be present.

scholarly journals Integration of Calcium and Cyclic AMP Signaling Pathways by 14-3-3

2000 ◽  
Vol 20 (2) ◽  
pp. 702-712 ◽  
Author(s):  
Chi-Wing Chow ◽  
Roger J. Davis
Keyword(s):  
T Cells ◽  
Cyclic Amp ◽  
Signaling Pathways ◽  
Interleukin 2 ◽  
Camp Signaling ◽  
Phosphorylation Sites ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Transcription Activity ◽  
Kinase A

ABSTRACT Calcium-stimulated nuclear factor of activated T cells (NFAT) transcription activity at the interleukin-2 promoter is negatively regulated by cyclic AMP (cAMP). This effect of cAMP is mediated, in part, by protein kinase A phosphorylation of NFAT. The mechanism of regulation involves the creation of a phosphorylation-dependent binding site for 14-3-3. Decreased NFAT phosphorylation caused by the calcium-stimulated phosphatase calcineurin, or mutation of the PKA phosphorylation sites, disrupted 14-3-3 binding and increased NFAT transcription activity. In contrast, NFAT phosphorylation caused by cAMP increased 14-3-3 binding and reduced NFAT transcription activity. The regulated interaction between NFAT and 14-3-3 provides a mechanism for the integration of calcium and cAMP signaling pathways.

scholarly journals Control of NFATx1 nuclear translocation by a calcineurin-regulated inhibitory domain.

1997 ◽  
Vol 17 (4) ◽  
pp. 2066-2075 ◽  
Author(s):  
E S Masuda ◽  
J Liu ◽  
R Imamura ◽  
S I Imai ◽  
K I Arai ◽  
...  
Keyword(s):  
T Cells ◽  
Calcium Signaling ◽  
Transcriptional Activation ◽  
Nuclear Translocation ◽  
Intracellular Localization ◽  
Binding Activity ◽  
Cytokine Gene Expression ◽  
Blood Leukocytes ◽  
Activated T Cells ◽  
Terminal Domain

The nuclear factor of activated T cells (NFAT) regulates cytokine gene expression in T cells through cis-acting elements located in the promoters of several cytokine genes. NFATx1, which is preferentially expressed in the thymus and peripheral blood leukocytes, is one of four members of the NFAT family of transcription factors. We have performed domain analysis of NFATx1 by examining the effects of deletion mutations. We found that NFATx1 DNA binding activity and interaction with AP-1 polypeptides were dependent on its central Rel similarity region and that transcriptional activation was reduced by deletions of either its N-terminal domain or its C-terminal domain, suggesting the presence of intrinsic transcriptional activation motifs in both regions. We also identified a potent inhibitory sequence within its N-terminal domain. We show that the inactivation of the inhibition was dependent on the activity of calcineurin, a calcium-calmodulin-dependent phosphatase. We also show that calcineurin associated with the N-terminal domain of NFATx1 at multiple docking sites and caused a reduction of size, indicative of dephosphorylation, in NFATx1. We have mapped the inhibitory activity to less than 60 residues, containing motifs that are conserved in all NFAT proteins. Finally, we demonstrate that deletion in NFATx1 of the mapped 60 residues leads to its nuclear translocation independent of calcium signaling. Our results support the model proposing that the N-terminal domain confers calcium-signaling dependence on NFATx1 transactivation activity by regulating its intracellular localization through a protein module that associates with calcineurin and is a target of its phosphatase activity.

Costimulatory action of glycoinositolphospholipids from Trypanosoma cruzi: increased interleukin 2 secretion and induction of nuclear translocation of the nuclear factor of activated T cells 1

1999 ◽  
Vol 13 (12) ◽  
pp. 1627-1636 ◽  
Author(s):  
Maria Bellio ◽  
Ana‐Carolina S. C. Oliveira ◽  
Claudia S. Mermelstein ◽  
Marcia A. M. Capella ◽  
João P. B. Viola ◽  
...  
Keyword(s):  
T Cells ◽  
Trypanosoma Cruzi ◽  
Nuclear Translocation ◽  
Interleukin 2 ◽  
Nuclear Factor ◽  
Activated T Cells

scholarly journals STIM2 targets Orai1/STIM1 to the AKAP79 signaling complex and confers coupling of Ca2+entry with NFAT1 activation

2020 ◽  
Vol 117 (28) ◽  
pp. 16638-16648 ◽  
Author(s):  
Ga-Yeon Son ◽  
Krishna Prasad Subedi ◽  
Hwei Ling Ong ◽  
Lucile Noyer ◽  
Hassan Saadi ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Unique Role ◽  
Signaling Complex ◽  
Contact Sites ◽  
Channel Function

The Orai1 channel is regulated by stromal interaction molecules STIM1 and STIM2 within endoplasmic reticulum (ER)-plasma membrane (PM) contact sites. Ca2+signals generated by Orai1 activate Ca2+-dependent gene expression. When compared with STIM1, STIM2 is a weak activator of Orai1, but it has been suggested to have a unique role in nuclear factor of activated T cells 1 (NFAT1) activation triggered by Orai1-mediated Ca2+entry. In this study, we examined the contribution of STIM2 in NFAT1 activation. We report that STIM2 recruitment of Orai1/STIM1 to ER-PM junctions in response to depletion of ER-Ca2+promotes assembly of the channel with AKAP79 to form a signaling complex that couples Orai1 channel function to the activation of NFAT1. Knockdown of STIM2 expression had relatively little effect on Orai1/STIM1 clustering or local and global [Ca2+]iincreases but significantly attenuated NFAT1 activation and assembly of Orai1 with AKAP79. STIM1ΔK, which lacks the PIP2-binding polybasic domain, was recruited to ER-PM junctions following ER-Ca2+depletion by binding to Orai1 and caused local and global [Ca2+]iincreases comparable to those induced by STIM1 activation of Orai1. However, in contrast to STIM1, STIM1ΔK induced less NFAT1 activation and attenuated the association of Orai1 with STIM2 and AKAP79. Orai1-AKAP79 interaction and NFAT1 activation were recovered by coexpressing STIM2 with STIM1ΔK. Replacing the PIP2-binding domain of STIM1 with that of STIM2 eliminated the requirement of STIM2 for NFAT1 activation. Together, these data demonstrate an important role for STIM2 in coupling Orai1-mediated Ca2+influx to NFAT1 activation.

scholarly journals Requirement for Transcription Factor NFAT in Interleukin-2 Expression

1999 ◽  
Vol 19 (3) ◽  
pp. 2300-2307 ◽  
Author(s):  
Chi-Wing Chow ◽  
Mercedes Rincón ◽  
Roger J. Davis
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
Transcription Factor ◽  
Nuclear Translocation ◽  
Interleukin 2 ◽  
Inhibitory Effect ◽  
Dominant Negative ◽  
Activated T Cells ◽  
Nfat Activation ◽  
Nfat Transcription Factor

ABSTRACT The nuclear factor of activated T cells (NFAT) transcription factor is implicated in expression of the cytokine interleukin-2 (IL-2). Binding sites for NFAT are located in the IL-2 promoter. Furthermore, pharmacological studies demonstrate that the drug cyclosporin A inhibits both NFAT activation and IL-2 expression. However, targeted disruption of the NFAT1 and NFAT2 genes in mice does not cause decreased IL-2 secretion. The role of NFAT in IL-2 gene expression is therefore unclear. Here we report the construction of a dominant-negative NFAT mutant (dnNFAT) that selectively inhibits NFAT-mediated gene expression. The inhibitory effect of dnNFAT is mediated by suppression of activation-induced nuclear translocation of NFAT. Expression of dnNFAT in cultured T cells caused inhibition of IL-2 promoter activity and decreased expression of IL-2 protein. Similarly, expression of dnNFAT in transgenic mice also caused decreased IL-2 gene expression. These data demonstrate that NFAT is a critical component of the signaling pathway that regulates IL-2 expression.

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