Histone acetylation: a gateway to transcriptional activation

1996 ◽  
Vol 21 (10) ◽  
pp. 357-358 ◽  
Author(s):  
R STERNGLANZ
Keyword(s):  
Histone Acetylation ◽  
Transcriptional Activation

Abstract 15978: Acetyl-coa Catalysis by Atp-citrate Lyase is Essential for Myofibroblast Differentiation and Persistence

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Michael P Lazaropoulos ◽  
Andrew A Gibb ◽  
Anh Huynh ◽  
Kathryn Wellen ◽  
John W Elrod
Keyword(s):  
Histone Acetylation ◽  
Transcriptional Activation ◽  
Cardiac Fibrosis ◽  
Transforming Growth Factor ◽  
Metabolic Reprogramming ◽  
Myofibroblast Differentiation ◽  
Atp Citrate Lyase ◽  
Acetyl Coa ◽  
Matrix Deposition ◽  
Citrate Lyase

A feature of heart failure (HF) is excessive extracellular matrix deposition and cardiac remodeling by a differentiated fibroblast population known as myofibroblasts. Identifying mechanisms of myofibroblast differentiation in cardiac fibrosis could yield novel therapeutic targets to delay or reverse HF. Recent evidence suggests that myofibroblast differentiation requires metabolic reprogramming for transcriptional activation of the myofibroblast gene program by chromatin-dependent mechanisms. We previously reported that inhibition of histone demethylation blocks myofibroblast formation, however, whether histone acetylation (e.g., H3K27ac, a prominent mark associated with gene transcription) is involved in fibroblast reprogramming remains unclear. ATP-citrate lyase (ACLY) synthesizes acetyl-CoA and therein supplies acetyl-CoA to the nucleus, where it is used as a substrate by histone acetyltransferases (HATs). To define the role of acetyl-CoA metabolism in myofibroblast differentiation, we stimulated differentiation in mouse embryonic fibroblasts (MEFs) and adult mouse cardiac fibroblasts (ACFs) with the pro-fibrotic agonist transforming growth factor β (TGFβ) and treated cells with a pharmacological inhibitor of ACLY. ACLY inhibition decreased myofibroblast gene expression in ACF and MEFs in TGFβ-stimulated myofibroblast differentiation, in addition to decreasing the population of αSMA positive MEFs. Genetic deletion of ACLY in MEFs recapitulated the results observed with pharmacological inhibition. Encouragingly, the ACLY inhibitor was sufficient to revert fully differentiated myofibroblasts under continuous TGFβ stimulation to a quiescent, non-fibrotic phenotype. Altogether, our data indicate that ACLY activity is necessary for myofibroblast differentiation and persistence. We hypothesize that ACLY-dependent acetyl-CoA synthesis is necessary for histone acetylation and transcriptional activation of the myofibroblast gene program. Currently, we are examining mechanisms of ACLY-dependent chromatin remodeling in fibroblasts and the in vivo relevance of this mechanism in mutant mice. In summary, ACLY is a potential target to reverse cardiac fibrosis and lessen HF.

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 Potentiation of androgen receptor transcriptional activity by inhibition of histone deacetylation--rescue of transcriptionally compromised mutants

2004 ◽  
Vol 182 (3) ◽  
pp. 377-389 ◽  
Author(s):  
CG Korkmaz ◽  
K Fronsdal ◽  
Y Zhang ◽  
PI Lorenzo ◽  
F Saatcioglu
Keyword(s):  
Androgen Receptor ◽  
Histone Acetylation ◽  
Nuclear Receptor ◽  
Transcriptional Activation ◽  
Transcriptional Activity ◽  
Trichostatin A ◽  
Specific Antigen ◽  
Histone Deacetylation ◽  
Lncap Cells ◽  
Viral Oncoprotein

Androgens are critical in the development and maintenance of the male reproductive system and important in the progression of prostate cancer. The effects of androgens are mediated by the androgen receptor (AR), which is a ligand-modulated transcription factor that belongs to the nuclear receptor superfamily. We and others have previously shown that CREB-binding protein (CBP) can function as a coactivator for AR. Similar to some other nuclear receptor coactivators and/or the proteins that they interact with, CBP has histone acetyl transferase (HAT) activity that is thought to contribute to transcriptional activation by nuclear receptors. We have therefore assessed whether an increase in the histone acetylation status in the cell can influence AR transcriptional activity, by using the histone deacetylase (HDAC) inhibitors (HDACIs) trichostatin A (TSA), sodium butyrate (Na-But) and depsipeptide (FR901228). We found that inhibition of HDAC activity significantly increased the ability of endogenous AR in LNCaP cells, or ectopically expressed AR in HeLa cells, to activate transcription from AR-dependent reporter constructs. In addition, HDACIs increased the androgen-dependent activation of the prostate-specific antigen (PSA) gene in LNCaP cells, an increase that was not due to an increase in nuclear AR protein levels. Moreover, the viral oncoprotein E1A that inhibits CBP HAT activity fully repressed the ability of HDACIs to stimulate AR-mediated transcription, indicating that CBP is involved in this process. Deletional mutagenesis of AR indicated that whereas the AF-2 domain in the C-terminus is dispensable, the AF-1 domain in the N-terminus is required for augmentation of AR action by HDACIs, an observation which is in concordance with the reduced ability of CBP to activate AR N-terminal deletion mutants. Furthermore, HDACI treatment rescued the deficiency in the transactivation potential of AF-2 mutants. Taken together, our findings suggest that a change in the level of histone acetylation of target genes is an important determinant of AR action, possibly mediated by CBP.

scholarly journals PfGCN5-Mediated Histone H3 Acetylation Plays a Key Role in Gene Expression in Plasmodium falciparum

2007 ◽  
Vol 6 (7) ◽  
pp. 1219-1227 ◽  
Author(s):  
Long Cui ◽  
Jun Miao ◽  
Tetsuya Furuya ◽  
Xinyi Li ◽  
Xin-zhuan Su ◽  
...  
Keyword(s):  
Gene Expression ◽  
Plasmodium Falciparum ◽  
Histone Acetylation ◽  
Transcriptional Activation ◽  
Histone H3 ◽  
Epigenetic Mechanism ◽  
Promoter Regions ◽  
Specific Expression ◽  
Transcriptional Initiation ◽  
Translational Start

ABSTRACT Histone acetylation, regulated by the opposing actions of histone acetyltransferases (HATs) and deacetylases, is an important epigenetic mechanism in eukaryotic transcription. Although an acetyltransferase (PfGCN5) has been shown to preferentially acetylate histone H3 at K9 and K14 in Plasmodium falciparum, the scale of histone acetylation in the parasite genome and its role in transcriptional activation are essentially unknown. Using chromatin immunoprecipitation (ChIP) and DNA microarray, we mapped the global distribution of PfGCN5, histone H3K9 acetylation (H3K9ac) and trimethylation (H3K9m3) in the P. falciparum genome. While the chromosomal distributions of H3K9ac and PfGCN5 were similar, they are radically different from that of H3K9m3. In addition, there was a positive, though weak correlation between relative occupancy of H3K9ac on individual genes and the levels of gene expression, which was inversely proportional to the distance of array elements from the putative translational start codons. In contrast, H3K9m3 was negatively correlated with gene expression. Furthermore, detailed mapping of H3K9ac for selected genes using ChIP and real-time PCR in three erythrocytic stages detected stage-specific peak H3K9ac enrichment at the putative transcriptional initiation sites, corresponding to stage-specific expression of these genes. These data are consistent with H3K9ac and H3K9m3 as epigenetic markers of active and silent genes, respectively. We also showed that treatment with a PfGCN5 inhibitor led to reduced promoter H3K9ac and gene expression. Collectively, these results suggest that PfGCN5 is recruited to the promoter regions of genes to mediate histone acetylation and activate gene expression in P. falciparum.

scholarly journals 134INCOMPLETE HISTONE ACETYLATION OF SOMATIC CHROMATIN IN BOVINE OOCYTES

2004 ◽  
Vol 16 (2) ◽  
pp. 189
Author(s):  
G. Wee ◽  
S.-H. Kim ◽  
K.P. Kim ◽  
S. Yeo ◽  
D.-B. Koo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Somatic Cell ◽  
Histone Acetylation ◽  
Transcriptional Activation ◽  
Linear Models ◽  
Trichostatin A ◽  
Specific Inhibitor ◽  
Early Embryo ◽  
Image Analyzer ◽  
Cell Nuclei

Histone acetylation as an important regulatory mechanism of chromatin structure preceeding zygotic gene expression in early embryo development. After fertilization, transcriptional activation of the embryo begins during the S/G2 phase of the first cell cycle. However, the precise mechanism underlying activation of zygotic transcription remains to be understood, especially in bovine nuclear transfer (NT) embryos. It is known that acetylation of histone H4 lysine 5 (H4K5) represents hyperacetylation state, which is correlated with gene expression. In this study, the acetylation of H4K5 was observed during pronuclear formation by using immunofluorescence analysis with anti-AcH4K5. Our data were analyzed by the general linear models (GLM) procedure of the SAS. In IVF embryos, acetylation of H4K5 occurred on the paternal chromatin at 8h after fertilization but did not occur on the maternal chromatin until 10h after fertilization. Reconstructed oocytes with deactylated somatic cell nuclei began to show signs of acetylation on chromatin at 3h after fusion. When acetylation intensity was calculated using an image analyzer, IVF embryos presented a higher acetylation signal than NT embryos (P<0.05). To induce hyperacetylation in NT embryos, somatic cells were exposed to trichostatin A (TSA, 1μM for 60h), a specific inhibitor of histone deacetylase (HDAC), prior to NT. Acetylated signals of H4K5 increased significantly in TSA-treated cells as compared with non-treated cells (P<0.05). The reconstructed embryos with TSA-treated cells showed a higher fluorescence intensity than the oocytes with non-treated cells (P<0.05), but weak signals compared to IVF embryos. Thus, the results demonstrated low histone acetylation level of somatic cell nuclei after NT during the zygotic progress. Our findings suggest that developmental failures of NT embryos may be due to incomplete chromatin remodeling of somatic cell nuclei during early embryonic development.

scholarly journals FOXC2 Autoregulates Its Expression in the Pulmonary Endothelium After Endotoxin Stimulation in a Histone Acetylation-Dependent Manner

2021 ◽  
Vol 9 ◽  
Author(s):  
Sheng Xia ◽  
Wei Yu ◽  
Heather Menden ◽  
Scott T. Younger ◽  
Venkatesh Sampath
Keyword(s):  
Histone Acetylation ◽  
Cell Fate ◽  
Transcriptional Activation ◽  
Bioinformatic Analysis ◽  
Dependent Manner ◽  
Toll Like Receptor 4 ◽  
Pulmonary Endothelium ◽  
Pulmonary Endothelial Cells ◽  
Forkhead Box ◽  
Fate Decision

The innate immune response of pulmonary endothelial cells (EC) to lipopolysaccharide (LPS) induces Forkhead box protein C2 (FOXC2) activation through Toll Like Receptor 4 (TLR4). The mechanisms by which FOXC2 expression is regulated in lung EC under LPS stimulation remain unclear. We postulated that FOXC2 regulates its own expression in sepsis, and its transcriptional autoregulation directs lymphatic EC cell-fate decision. Bioinformatic analysis identified potential FOXC2 binding sites in the FOXC2 promoter. In human lung EC, we verified using chromatin immunoprecipitation (ChIP) and luciferase assays that FOXC2 bound to its own promoter and stimulated its expression after LPS stimulation. Chemical inhibition of histone acetylation by garcinol repressed LPS-induced histone acetylation in the FOXC2 promoter region, and disrupted LPS-mediated FOXC2 binding and transcriptional activation. CRISPR/dCas9/gRNA directed against FOXC2-binding-element (FBE) suppressed LPS-stimulated FOXC2 binding and autoregulation by blocking FBEs in the FOXC2 promoter, and repressed expression of lymphatic EC markers. In a neonatal mouse model of sterile sepsis, LPS-induced FOXC2 binding to FBE and FOXC2 expression in lung EC was attenuated with garcinol treatment. These data reveal a new mechanism of LPS-induced histone acetylation-dependent FOXC2 autoregulation.

Gcn5- and Elp3-induced histone H3 acetylation regulates hsp70 gene transcription in yeast

2008 ◽  
Vol 409 (3) ◽  
pp. 779-788 ◽  
Author(s):  
Qiuju Han ◽  
Jun Lu ◽  
Jizhou Duan ◽  
Dongmei Su ◽  
Xiaozhe Hou ◽  
...  
Keyword(s):  
Heat Shock ◽  
Histone Acetylation ◽  
Rna Polymerase Ii ◽  
Gene Transcription ◽  
Transcriptional Activation ◽  
Histone H3 ◽  
Hsp70 Gene ◽  
Transcriptional Initiation ◽  
Hsp Genes ◽  
H3 Acetylation

The purpose of this study was to elucidate the mechanisms by which histone acetylation participates in transcriptional regulation of hsp70 (heat-shock protein 70) genes SSA3 and SSA4 in yeast. Our results indicated that histone acetylation was required for the transcriptional activation of SSA3 and SSA4. The HATs (histone acetyltransferases) Gcn5 (general control non-derepressible 5) and Elp3 (elongation protein 3) modulated hsp70 gene transcription by affecting the acetylation status of histone H3. Although the two HATs possessed overlapping function regarding the acetylation of histone H3, they affected hsp70 gene transcription in different ways. The recruitment of Gcn5 was Swi/Snf-dependent and was required for HSF (heat-shock factor) binding and affected RNAPII (RNA polymerase II) recruitment, whereas Elp3 exerted its roles mainly through affecting RNAPII elongation. These results provide insights into the effects of Gcn5 and Elp3 in hsp70 gene transcription and underscore the importance of histone acetylation for transcriptional initiation and elongation in hsp genes.

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