scholarly journals Chromatin-Independent Interplay of NFATc1 and EZH2 in Pancreatic Cancer

Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3463
Author(s):  
Shilpa Patil ◽  
Teresa Forster ◽  
Kristina Reutlinger ◽  
Waltraut Kopp ◽  
Lennart Versemann ◽  
...  
Keyword(s):  
Complex Formation ◽  
Transcriptional Activation ◽  
Chromatin Immunoprecipitation ◽  
Ductal Adenocarcinoma ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Genome Wide ◽  
Independent Functions ◽  
Integrative Analyses ◽  
Mrna And Protein Expression

Background: The Nuclear Factor of Activated T-cells 1 (NFATc1) transcription factor and the methyltransferase Enhancer of Zeste Homolog 2 (EZH2) significantly contribute to the aggressive phenotype of pancreatic ductal adenocarcinoma (PDAC). Herein, we aimed at dissecting the mechanistic background of their interplay in PDAC progression. Methods: NFATc1 and EZH2 mRNA and protein expression and complex formation were determined in transgenic PDAC models and human PDAC specimens. NFATc1 binding on the Ezh2 gene and the consequences of perturbed NFATc1 expression on Ezh2 transcription were explored by Chromatin Immunoprecipitation (ChIP) and upon transgenic or siRNA-mediated interference with NFATc1 expression, respectively. Integrative analyses of RNA- and ChIP-seq data was performed to explore NFATc1-/EZH2-dependent gene signatures. Results: NFATc1 targets the Ezh2 gene for transcriptional activation and biochemically interacts with the methyltransferase in murine and human PDAC. Surprisingly, our genome-wide binding and expression analyses do not link the protein complex to joint gene regulation. In contrast, our findings provide evidence for chromatin-independent functions of the NFATc1:EZH2 complex and reveal posttranslational EZH2 phosphorylation at serine 21 as a prerequisite for robust complex formation. Conclusion: Our findings disclose a previously unknown NFATc1-EZH2 axis operational in the pancreas and provide mechanistic insights into the conditions fostering NFATc1:EZH2 complex formation in PDAC.

scholarly journals Akt-Dependent Cytokine Production in Mast Cells

2000 ◽  
Vol 192 (5) ◽  
pp. 729-740 ◽  
Author(s):  
Jiro Kitaura ◽  
Koichi Asai ◽  
Mari Maeda-Yamamoto ◽  
Yuko Kawakami ◽  
Ushio Kikkawa ◽  
...  
Keyword(s):  
Mast Cells ◽  
Transcriptional Activation ◽  
Tyrosine Kinases ◽  
Nuclear Export ◽  
Nuclear Translocation ◽  
Glycogen Synthase ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Proinflammatory Mediators ◽  
Tnf Α

Cross-linking of FcεRI induces the activation of three protein tyrosine kinases, Lyn, Syk, and Bruton's tyrosine kinase (Btk), leading to the secretion of a panel of proinflammatory mediators from mast cells. This study showed phosphorylation at Ser-473 and enzymatic activation of Akt/protein kinase B, the crucial survival kinase, upon FcεRI stimulation in mouse mast cells. Phosphorylation of Akt is regulated positively by Btk and Syk and negatively by Lyn. Akt in turn can regulate positively the transcriptional activity of interleukin (IL)-2 and tumor necrosis factor (TNF)-α promoters. Transcription from the nuclear factor κB (NF-κB), nuclear factor of activated T cells (NF-AT), and activator protein 1 (AP-1) sites within these promoters is under the control of Akt activity. Accordingly, the signaling pathway involving IκB-α, a cytoplasmic protein that binds NF-κB and inhibits its nuclear translocation, appears to be regulated by Akt in mast cells. Catalytic activity of glycogen synthase kinase (GSK)-3β, a serine/threonine kinase that phosphorylates NF-AT and promotes its nuclear export, seems to be inhibited by Akt. Importantly, Akt regulates the production and secretion of IL-2 and TNF-α in FcεRI-stimulated mast cells. Altogether, these results revealed a novel function of Akt in transcriptional activation of cytokine genes via NF-κB, NF-AT, and AP-1 that contributes to the production of cytokines.

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.

Nuclear Factor of Activated T Cells (NFAT) Is Involved in the Depolarization-Induced Activation of Growth Hormone-Releasing Hormone Gene Transcription in Vitro

2004 ◽  
Vol 18 (12) ◽  
pp. 3011-3019 ◽  
Author(s):  
Masato Asai ◽  
Yasumasa Iwasaki ◽  
Masanori Yoshida ◽  
Noriko Mutsuga-Nakayama ◽  
Hiroshi Arima ◽  
...  
Keyword(s):  
T Cells ◽  
Transcription Factor ◽  
Gene Transcription ◽  
Transcriptional Activation ◽  
Site Directed Mutagenesis ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
High Potassium ◽  
Direct Binding

Abstract GHRH plays a pivotal role in the regulation of both synthesis and secretion of GH in the anterior pituitary. In this study, we examined the molecular mechanism of depolarization-induced GHRH gene transcription using the hypothalamus cell line, Gsh+/+, revealing the involvement of the transcription factor called nuclear factor of activated T cells (NFAT). GHRH, NFAT1, NFAT4, and related genes were endogenously expressed in Gsh+/+ cells and the rat arcuate nucleus, where NFAT1 and GHRH were colocalized. Cellular excitation with high potassium potently stimulated endogenous GHRH gene 5′-promoter activity as well as the NFAT-mediated gene transcription, the former being further enhanced by coexpression of NFAT. On the other hand, cyclosporin A (a calcineurin-NFAT inhibitor) or EGTA (a calcium chelator) significantly blocked the depolarization-induced GHRH gene transcription. EMSA and site-directed mutagenesis experiments showed the direct binding of NFAT at five sites of the GHRH promoter, among which the relative importance of three distal sites (−417/−403, −402/−387, −317/−301) was suggested. Finally, elimination of all five sites completely abolished the NFAT-induced GHRH gene up-regulation. Altogether, our results suggest that the transcription factor NFAT is involved in the depolarization-induced transcriptional activation of GHRH gene in the neuronal cells.

scholarly journals RNA polymerase II progression through H3K27me3-enriched gene bodies requires JMJD3 histone demethylase

2013 ◽  
Vol 24 (3) ◽  
pp. 351-360 ◽  
Author(s):  
Conchi Estarás ◽  
Raquel Fueyo ◽  
Naiara Akizu ◽  
Sergi Beltrán ◽  
Marian A. Martínez-Balbás
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Transcriptional Activation ◽  
Chromatin Immunoprecipitation ◽  
Target Genes ◽  
Transforming Growth Factor ◽  
Transcriptional Response ◽  
Transforming Growth Factor Β ◽  
Genome Wide ◽  
Pathway Activation

JMJD3 H3K27me3 demethylase plays an important role in the transcriptional response to different signaling pathways; however, the mechanism by which it facilitates transcription has been unclear. Here we show that JMJD3 regulates transcription of transforming growth factor β (TGFβ)–responsive genes by promoting RNA polymerase II (RNAPII) progression along the gene bodies. Using chromatin immunoprecipitation followed by sequencing experiments, we show that, upon TGFβ treatment, JMJD3 and elongating RNAPII colocalize extensively along the intragenic regions of TGFβ target genes. According to these data, genome-wide analysis shows that JMJD3-dependent TGFβ target genes are enriched in H3K27me3 before TGFβ signaling pathway activation. Further molecular analyses demonstrate that JMJD3 demethylates H3K27me3 along the gene bodies, paving the way for the RNAPII progression. Overall these findings uncover the mechanism by which JMJD3 facilitates transcriptional activation.

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