scholarly journals SIRT6 promotes transcription of a subset of NRF2 targets by mono-ADP-ribosylating BAF170

2019 ◽  
Vol 47 (15) ◽  
pp. 7914-7928 ◽  
Author(s):  
Sarallah Rezazadeh ◽  
David Yang ◽  
Gregory Tombline ◽  
Matthew Simon ◽  
Sean P Regan ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Rna Polymerase Ii ◽  
Chromatin Remodeling ◽  
Transcriptional Activation ◽  
Heme Oxygenase 1 ◽  
Nuclear Factor ◽  
Active Chromatin ◽  
Adp Ribosylation ◽  
Chromatin Remodeling Complex ◽  
A Subunit

Abstract SIRT6 is critical for activating transcription of Nuclear factor (erythroid-derived 2)-like 2 (NRF2) responsive genes during oxidative stress. However, while the mechanism of SIRT6-mediated silencing is well understood, the mechanism of SIRT6-mediated transcriptional activation is unknown. Here, we employed SIRT6 separation of function mutants to reveal that SIRT6 mono-ADP-ribosylation activity is required for transcriptional activation. We demonstrate that SIRT6 mono-ADP-ribosylation of BAF170, a subunit of BAF chromatin remodeling complex, is critical for activation of a subset of NRF2 responsive genes upon oxidative stress. We show that SIRT6 recruits BAF170 to enhancer region of the Heme oxygenase-1 locus and promotes recruitment of RNA polymerase II. Furthermore, SIRT6 mediates the formation of the active chromatin 10-kb loop at the HO-1 locus, which is absent in SIRT6 deficient tissue. These results provide a novel mechanism for SIRT6-mediated transcriptional activation, where SIRT6 mono-ADP-ribosylates and recruits chromatin remodeling proteins to mediate the formation of active chromatin loop.

scholarly journals The Swi/Snf Chromatin Remodeling Complex Is Required for Ribosomal DNA and Telomeric Silencing in Saccharomyces cerevisiae

2004 ◽  
Vol 24 (18) ◽  
pp. 8227-8235 ◽  
Author(s):  
Vardit Dror ◽  
Fred Winston
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Chromatin Remodeling ◽  
Ribosomal Dna ◽  
Transcriptional Activation ◽  
Rdna Locus ◽  
Detectable Effect ◽  
Chromatin Remodeling Complex ◽  
Two Factors

ABSTRACT The Swi/Snf chromatin remodeling complex has been previously demonstrated to be required for transcriptional activation and repression of a subset of genes in Saccharomyces cerevisiae. In this work we demonstrate that Swi/Snf is also required for repression of RNA polymerase II-dependent transcription in the ribosomal DNA (rDNA) locus (rDNA silencing). This repression appears to be independent of both Sir2 and Set1, two factors known to be required for rDNA silencing. In contrast to many other rDNA silencing mutants that have elevated levels of rDNA recombination, snf2Δ mutants have a significantly decreased level of rDNA recombination. Additional studies have demonstrated that Swi/Snf is also required for silencing of genes near telomeres while having no detectable effect on silencing of HML or HMR.

scholarly journals Efg1-mediated Recruitment of NuA4 to Promoters Is Required for Hypha-specific Swi/Snf Binding and Activation inCandida albicans

2008 ◽  
Vol 19 (10) ◽  
pp. 4260-4272 ◽  
Author(s):  
Yang Lu ◽  
Chang Su ◽  
Xuming Mao ◽  
Prashna Pala Raniga ◽  
Haoping Liu ◽  
...  
Keyword(s):  
Chromatin Remodeling ◽  
Transcriptional Activation ◽  
Chromatin Immunoprecipitation ◽  
Pathogenic Fungus ◽  
Dependent Manner ◽  
Hyphal Development ◽  
Chromatin Remodeling Complex ◽  
A Subunit ◽  
Human Pathogenic Fungus ◽  
Incandida Albicans

Efg1 is essential for hyphal development and virulence in the human pathogenic fungus Candida albicans. How Efg1 regulates gene expression is unknown. Here, we show that Efg1 interacts with components of the nucleosome acetyltransferase of H4 (NuA4) histone acetyltransferase (HAT) complex in both yeast and hyphal cells. Deleting YNG2, a subunit of the NuA4 HAT module, results in a significant decrease in the acetylation level of nucleosomal H4 and a profound defect in hyphal development, as well as a defect in the expression of hypha-specific genes. Using chromatin immunoprecipitation, Efg1 and the NuA4 complex are found at the UAS regions of hypha-specific genes in both yeast and hyphal cells, and Efg1 is required for the recruitment of NuA4. Nucleosomal H4 acetylation at the promoters peaks during initial hyphal induction in an Efg1-dependent manner. We also find that Efg1 bound to the promoters of hypha-specific genes is critical for recruitment of the Swi/Snf chromatin remodeling complex during hyphal induction. Our data show that the recruitment of the NuA4 complex by Efg1 to the promoters of hypha-specific genes is required for nucleosomal H4 acetylation at the promoters during hyphal induction and for subsequent binding of Swi/Snf and transcriptional activation.

scholarly journals The DPF Domain As a Unique Structural Unit Participating in Transcriptional Activation, Cell Differentiation, and Malignant Transformation

Acta Naturae ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 57-65
Author(s):  
N. V. Soshnikova ◽  
A. A. Sheynov ◽  
Eu. V. Tatarskiy ◽  
S. G. Georgieva
Keyword(s):  
Malignant Transformation ◽  
Chromatin Remodeling ◽  
Transcriptional Activation ◽  
Mammalian Cells ◽  
Protein Complexes ◽  
Active Chromatin ◽  
Phd Finger ◽  
Chromatin Remodeling Complex ◽  
Single Structure ◽  
Chromatin Proteins

The DPF (double PHD finger) domain consists of two PHD fingers organized in tandem. The two PHD-finger domains within a DPF form a single structure that interacts with the modification of the N-terminal histone fragment in a way different from that for single PHD fingers. Several histone modifications interacting with the DPF domain have already been identified. They include acetylation of H3K14 and H3K9, as well as crotonylation of H3K14. These modifications are found predominantly in transcriptionally active chromatin. Proteins containing DPF belong to two classes of protein complexes, which are the transcriptional coactivators involved in the regulation of the chromatin structure. These are the histone acetyltransferase complex belonging to the MYST family and the SWI/SNF chromatin-remodeling complex. The DPF domain is responsible for the specificity of the interactions between these complexes and chromatin. Proteins containing DPF play a crucial role in the activation of the transcription of a number of genes expressed during the development of an organism. These genes are important in the differentiation and malignant transformation of mammalian cells.

scholarly journals (–)-Loliolide Isolated from Sargassum horneri Suppressed Oxidative Stress and Inflammation by Activating Nrf2/HO-1 Signaling in IFN-γ/TNF-α-Stimulated HaCaT Keratinocytes

Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 856
Author(s):  
Eui-Jeong Han ◽  
Ilekuttige Priyan Shanura Fernando ◽  
Hyun-Soo Kim ◽  
Dae-Sung Lee ◽  
Areum Kim ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nuclear Factor Κb ◽  
Sargassum Horneri ◽  
Mitogen Activated Protein Kinase ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Nuclear Factor ◽  
Hacat Keratinocytes ◽  
Tnf Α ◽  
Ifn Γ

The present study evaluated the effects of (–)-loliolide isolated from Sargassum horneri (S. horneri) against oxidative stress and inflammation, and its biological mechanism in interferon (IFN)-γ/tumor necrosis factor (TNF)-α-stimulated HaCaT keratinocytes. The results showed that (–)-loliolide improved the cell viability by reducing the production of intracellular reactive oxygen species (ROS) in IFN-γ/TNF-α-stimulated HaCaT keratinocytes. In addition, (–)-loliolide effectively decreased the expression of inflammatory cytokines (interleukin (IL)-4 IL-6, IL-13, IFN-γ and TNF-α) and chemokines (CCL11 (Eotaxin), macrophage-derived chemokine (MDC), regulated on activation, normal T cell expressed and secreted (RANTES), and thymus and activation-regulated chemokine (TARC)), by downregulating the expression of epidermal-derived initial cytokines (IL-25, IL-33 and thymic stromal lymphopoietin (TSLP)). Furthermore, (–)-loliolide suppressed the activation of mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) signaling, whereas it activated nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling. Interestingly, the cytoprotective effects of (–)-loliolide against IFN-γ/TNF-α stimulation were significantly blocked upon inhibition of HO-1. Taken together, these results suggest that (–)-loliolide effectively suppressed the oxidative stress and inflammation by activating the Nrf2/HO-1 signaling in IFN-γ/TNF-α-stimulated HaCaT keratinocytes.

Co-dependent recruitment of Ino80p and Snf2p is required for yeast CUP1 activation

2014 ◽  
Vol 92 (1) ◽  
pp. 69-75 ◽  
Author(s):  
Roshini N. Wimalarathna ◽  
Po Yun Pan ◽  
Chang-Hui Shen
Keyword(s):  
Rna Polymerase ◽  
Histone Acetylation ◽  
Rna Polymerase Ii ◽  
Chromatin Remodeling ◽  
Transcriptional Activation ◽  
Copper Toxicity ◽  
Yeast Cells ◽  
Chromatin Remodelers ◽  
Insight Into ◽  
Cup1 Promoter

In yeast, Ace1p-dependent induction of CUP1 is responsible for protecting cells from copper toxicity. Although the mechanism of yeast CUP1 induction has been studied intensively, it is still uncertain which chromatin remodelers are involved in CUP1 transcriptional activation. Here, we show that yeast cells are inviable in the presence of copper when either chromatin remodeler, Ino80p or Snf2p, is not present. This inviability is due to the lack of CUP1 expression in ino80Δ and snf2Δ cells. Subsequently, we observe that both Ino80p and Snf2p are present at the promoter and they are responsible for recruiting chromatin remodeling activity to the CUP1 promoter under induced conditions. These results suggest that they directly participate in CUP1 transcriptional activation. Furthermore, the codependent recruitment of both INO80 and SWI/SNF depends on the presence of the transcriptional activator, Ace1p. We also demonstrate that both remodelers are required to recruit RNA polymerase II and targeted histone acetylation, indicating that remodelers are recruited to the CUP1 promoter before RNA polymerase II and histone acetylases. These observations provide evidence for the mechanism of CUP1 induction. As such, we propose a model that describes novel insight into the order of events in CUP1 activation.

scholarly journals Schisandrin A protects intestinal epithelial cells from deoxynivalenol-induced cytotoxicity, oxidative damage and inflammation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Murphy L. Y. Wan ◽  
Paul C. Turner ◽  
Vanessa A. Co ◽  
M. F. Wang ◽  
Khaled M. A. Amiri ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Intestinal Inflammation ◽  
Health Concern ◽  
Heme Oxygenase 1 ◽  
Antioxidant Enzyme Activities ◽  
Transferase Activity ◽  
Nuclear Factor ◽  
Ht 29

AbstractExtensive research has revealed the association of continued oxidative stress with chronic inflammation, which could subsequently affect many different chronic diseases. The mycotoxin deoxynivalenol (DON) frequently contaminates cereals crops worldwide, and are a public health concern since DON ingestion may result in persistent intestinal inflammation. There has also been considerable attention over the potential of DON to provoke oxidative stress. In this study, the cytoprotective effect of Schisandrin A (Sch A), one of the most abundant active dibenzocyclooctadiene lignans in the fruit of Schisandra chinensis (Turcz.) Baill (also known as Chinese magnolia-vine), was investigated in HT-29 cells against DON-induced cytotoxicity, oxidative stress and inflammation. Sch A appeared to protect against DON-induced cytotoxicity in HT-29 cells, and significantly lessened the DON-stimulated intracellular reactive oxygen species and nitrogen oxidative species production. Furthermore, Sch A lowered DON-induced catalase, superoxide dismutase and glutathione peroxidase antioxidant enzyme activities but maintains glutathione S transferase activity and glutathione levels. Mechanistic studies suggest that Sch A reduced DON-induced oxidative stress by down-regulating heme oxygenase-1 expression via nuclear factor (erythroid-derived 2)-like 2 signalling pathway. In addition, Sch A decreased the DON-induced cyclooxygenase-2 expression and prostaglandin E2 production and pro-inflammatory cytokine interleukin 8 expression and secretion. This may be mediated by preventing DON-induced translocation of nuclear factor-κB, as well as activation of mitogen-activated protein kinases pathways. In the light of these findings, we concluded that Sch A exerted a cytoprotective role in DON-induced toxicity in vitro, and it would be valuable to examine in vivo effects.

Nuclear receptor coactivators: the key to unlock chromatin

2005 ◽  
Vol 83 (4) ◽  
pp. 418-428 ◽  
Author(s):  
Wei Xu
Keyword(s):  
Nuclear Receptors ◽  
Nuclear Receptor ◽  
Chromatin Remodeling ◽  
Transcriptional Activation ◽  
Transcriptional Control ◽  
Biological Effects ◽  
Gene Activation ◽  
Nuclear Hormone Receptor ◽  
Nuclear Receptor Coactivators ◽  
Chromatin Remodeling Complex

The biological effects of hormones, ranging from organogenesis, metabolism, and proliferation, are transduced through nuclear receptors (NRs). Over the last decade, NRs have been used as a model to study transcriptional control. The conformation of activated NRs is favorable for the recruitment of coactivators, which promote transcriptional activation by directly communicating with chromatin. This review will focus on the function of different classes of coactivators and associated complexes, and on progress in our understanding of gene activation by NRs through chromatin remodeling.Key words: nuclear hormone receptor, p160 family of coactivators, histone modification, chromatin remodeling complex.

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