scholarly journals Hdac3, Setdb1, and Kap1 mark H3K9me3/H3K14ac bivalent regions in young and aged liver

2019 ◽  
Author(s):  
Andrew J. Price ◽  
Mohan C. Manjegowda ◽  
Irina M. Bochkis
Keyword(s):  
Gene Expression ◽  
Location Analysis ◽  
Histone Tails ◽  
Post Translational Modifications ◽  
The Core ◽  
Expression Of Genes ◽  
Genome Wide ◽  
Core Histones ◽  
Chromatin Profiling ◽  
Cholesterol Secretion

SummaryPost-translational modifications of histone tails play a crucial role in gene regulation. Here, we performed chromatin profiling by quantitative targeted mass spectrometry to assess all possible modifications of the core histones. We discovered a novel bivalent combination, a dually-marked H3K9me3/H3K14ac modification in the liver, that is significantly decreased in old hepatocytes. Subsequent genome-wide location analysis (ChIP-Seq) identified 1032 and 668 bivalent regions in young and old livers, respectively, with 280 in common. Histone H3K9 deacetylase Hdac3, as well as H3K9 methyltransferase Setdb1, found in complex Kap1, occupied bivalent regions in both young and old livers, correlating to presence of H3K9me3. Expression of genes associated with bivalent regions in young liver, including those regulating cholesterol secretion and triglyceride synthesis, is upregulated in old liver once the bivalency is lost. Hence, H3K9me3/H3K14ac dually-marked regions define a poised inactive state that is resolved with loss of one or both of the chromatin marks, which subsequently leads to change in gene expression.

scholarly journals Epigenomics of Plant’s Responses to Environmental Stress

2017 ◽  
Author(s):  
Suresh Kumar
Keyword(s):  
Gene Expression ◽  
Nuclear Dna ◽  
Environmental Stresses ◽  
Transcriptional Level ◽  
Epigenetic Changes ◽  
Post Translational Modifications ◽  
Genome Wide ◽  
A Cell ◽  
Non Coding Rnas ◽  
Function Activity

Genome-wide epigenetic changes in plants are being reported during the development and environmental stresses, which are often correlated with gene expression at the transcriptional level. Sum total of the biochemical changes in nuclear DNA, post-translational modifications in histone proteins and variations in the biogenesis of non-coding RNAs in a cell is known as epigenome. These changes are often responsible for variation in expression of the gene without any change in the underlying nucleotide sequence. The changes might also cause variation in chromatin structure resulting into the changes in function/activity of the genome. The epigenomic changes are dynamic with respect to the endogenous and/or environmental stimuli which affect phenotypic plasticity of the organism. Both, the epigenetic changes and variation in gene expression might return to the pre-stress state soon after withdrawal of the stress. However, a part of the epigenetic changes may be retained which is reported to play role in acclimatization, adaptation as well as in the evolutionary processes. Understanding epigenome-engineering for improved stress tolerance in plants has become essential for better utilization of the genetic factors. This review delineates the importance of epigenomics towards possible improvement of plant’s responses to environmental stresses for climate resilient agriculture.

scholarly journals Chromatin Profiling of the Repetitive and Nonrepetitive Genomes of the Human Fungal Pathogen Candida albicans

mBio ◽  
2019 ◽  
Vol 10 (4) ◽  
Author(s):  
Robert Jordan Price ◽  
Esther Weindling ◽  
Judith Berman ◽  
Alessia Buscaino
Keyword(s):  
Gene Expression ◽  
Candida Albicans ◽  
Histone Modifications ◽  
Chromatin Structure ◽  
Fungal Pathogen ◽  
Histone H3 ◽  
Content Type ◽  
Chromatin States ◽  
Genome Wide ◽  
Chromatin Profiling

ABSTRACT Eukaryotic genomes are packaged into chromatin structures that play pivotal roles in regulating all DNA-associated processes. Histone posttranslational modifications modulate chromatin structure and function, leading to rapid regulation of gene expression and genome stability, key steps in environmental adaptation. Candida albicans, a prevalent fungal pathogen in humans, can rapidly adapt and thrive in diverse host niches. The contribution of chromatin to C. albicans biology is largely unexplored. Here, we generated the first comprehensive chromatin profile of histone modifications (histone H3 trimethylated on lysine 4 [H3K4me3], histone H3 acetylated on lysine 9 [H3K9Ac], acetylated lysine 16 on histone H4 [H4K16Ac], and γH2A) across the C. albicans genome and investigated its relationship to gene expression by harnessing genome-wide sequencing approaches. We demonstrated that gene-rich nonrepetitive regions are packaged into canonical euchromatin in association with histone modifications that mirror their transcriptional activity. In contrast, repetitive regions are assembled into distinct chromatin states; subtelomeric regions and the ribosomal DNA (rDNA) locus are assembled into heterochromatin, while major repeat sequences and transposons are packaged in chromatin that bears features of euchromatin and heterochromatin. Genome-wide mapping of γH2A, a marker of genome instability, identified potential recombination-prone genomic loci. Finally, we present the first quantitative chromatin profiling in C. albicans to delineate the role of the chromatin modifiers Sir2 and Set1 in controlling chromatin structure and gene expression. This report presents the first genome-wide chromatin profiling of histone modifications associated with the C. albicans genome. These epigenomic maps provide an invaluable resource to understand the contribution of chromatin to C. albicans biology and identify aspects of C. albicans chromatin organization that differ from that of other yeasts. IMPORTANCE The fungus Candida albicans is an opportunistic pathogen that normally lives on the human body without causing any harm. However, C. albicans is also a dangerous pathogen responsible for millions of infections annually. C. albicans is such a successful pathogen because it can adapt to and thrive in different environments. Chemical modifications of chromatin, the structure that packages DNA into cells, can allow environmental adaptation by regulating gene expression and genome organization. Surprisingly, the contribution of chromatin modification to C. albicans biology is still largely unknown. For the first time, we analyzed C. albicans chromatin modifications on a genome-wide basis. We demonstrate that specific chromatin states are associated with distinct regions of the C. albicans genome and identify the roles of the chromatin modifiers Sir2 and Set1 in shaping C. albicans chromatin and gene expression.

scholarly journals Impact of Chromosome Fusions on 3D Genome Organization and Gene Expression in Budding Yeast

Genetics ◽  
2020 ◽  
Vol 214 (3) ◽  
pp. 651-667 ◽  
Author(s):  
Marco Di Stefano ◽  
Francesca Di Giovanni ◽  
Vasilisa Pozharskaia ◽  
Mercè Gomar-Alba ◽  
Davide Baù ◽  
...  
Keyword(s):  
Gene Expression ◽  
Budding Yeast ◽  
Nuclear Organization ◽  
Nuclear Periphery ◽  
Three Dimensional ◽  
Global Gene Expression ◽  
3D Genome ◽  
Expression Of Genes ◽  
Genome Wide ◽  
Chromosome Fusions

The three-dimensional (3D) organization of chromosomes can influence transcription. However, the frequency and magnitude of these effects remain debated. To determine how changes in chromosome positioning affect transcription across thousands of genes with minimal perturbation, we characterized nuclear organization and global gene expression in budding yeast containing chromosome fusions. We used computational modeling and single-cell imaging to determine chromosome positions, and integrated these data with genome-wide transcriptional profiles from RNA sequencing. We find that chromosome fusions dramatically alter 3D nuclear organization without leading to strong genome-wide changes in transcription. However, we observe a mild but significant and reproducible increase in the expression of genes displaced away from the periphery. The increase in transcription is inversely proportional to the propensity of a given locus to be at the nuclear periphery; for example, a 10% decrease in the propensity of a gene to reside at the nuclear envelope is accompanied by a 10% increase in gene expression. Modeling suggests that this is due to both deletion of telomeres and to displacement of genes relative to the nuclear periphery. These data suggest that basal transcriptional activity is sensitive to radial changes in gene position, and provide insight into the functional relevance of budding yeast chromosome-level 3D organization in gene expression.

scholarly journals Genome-Wide Analysis of the Relationship between Transcriptional Regulation by Rpd3p and the Histone H3 and H4 Amino Termini in Budding Yeast

2004 ◽  
Vol 24 (20) ◽  
pp. 8823-8833 ◽  
Author(s):  
Nevin Sabet ◽  
Sam Volo ◽  
Cailin Yu ◽  
James P. Madigan ◽  
Randall H. Morse
Keyword(s):  
Gene Expression ◽  
Budding Yeast ◽  
Histone H3 ◽  
Global Gene Expression ◽  
Amino Terminus ◽  
Histone H4 ◽  
Histone Tails ◽  
Genome Wide ◽  
Lysine Residues ◽  
The Relationship

ABSTRACT The histone amino termini have emerged as key targets for a variety of modifying enzymes that function as transcriptional coactivators and corepressors. However, an important question that has remained largely unexplored is the extent to which specific histone amino termini are required for the activating and repressive functions of these enzymes, Here we address this issue by focusing on the prototypical histone deacetylase, Rpd3p, in the budding yeast Saccharomyces cerevisiae. We show that targeting Rpd3p to a reporter gene in this yeast can partially repress transcription when either the histone H3 or the histone H4 amino terminus is deleted, indicating that the “tails” are individually dispensable for repression by Rpd3p. In contrast, we find that the effect of rpd3 gene disruption on global gene expression is considerably reduced in either a histone H3Δ1-28 (H3 lacking the amino-terminal 28 amino acids) or a histone H4(K5,8,12,16Q) (H4 with lysine residues 5, 8, 12, and 16 changed to glutamine residues) background compared to the wild-type background, indicating a requirement for one or both of these histone tails in Rpd3p-mediated regulation for many genes. These results suggest that acetylation of either the H3 or the H4 amino terminus could suffice to allow the activation of such genes. We also examine the relationship between H3 tails and H4 tails in global gene expression and find substantial overlap among the gene sets regulated by these histone tails. We also show that the effects on genome-wide expression of deleting the H3 or H4 amino terminus are similar but not identical to the effects of mutating the lysine residues in these same regions. These results indicate that the gene regulatory potential of the H3 and H4 amino termini is substantially but not entirely contained in these modifiable lysine residues.

scholarly journals Gene expression of settled and metamorphosed Orbicella faveolata during establishment of symbiosis

2017 ◽  
Author(s):  
Aubrie O'Rourke ◽  
Aki Ohdera ◽  
Shinichi Sunagawa ◽  
Erika M Diaz-Almeyda ◽  
Michael K DeSalvo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Nutrient Metabolism ◽  
Transcriptomic Response ◽  
Tropical Oceans ◽  
Expression Of Genes ◽  
Expression Studies ◽  
Genome Wide ◽  
Orbicella Faveolata ◽  
Algal Symbiosis ◽  
Differential Gene

Corals rely on a symbiosis with dinoflagellate algae (Symbiodinium spp.) to thrive in nutrient poor tropical oceans. However, the coral-algal symbiosis can break down during bleaching events, potentially leading to coral death. While genome-wide expression studies have shown the genes associated with the breakdown of this partnership, the full conglomerate of genes responsible for the establishment and maintenance of a healthy symbiosis remains unknown. Results from previous studies suggested little transcriptomic change associated with the establishment of symbiosis. We examined the transcriptomic response of the coral Orbicella faveolata in the presence (symbiotic) and absence (aposymbiotic) of Symbiodinium minutum, one of its associated symbionts. 9 days post-metamorphic aposymbiotic coral polyps of O. faveolata were compared to symbiotic coral polyps and the subsequent differential gene expression between control and treatment was quantified using cDNA microarray technology. Coral polyps exhibited differential expression of genes associated with nutrient metabolism and development, providing insight into control of pathways as a result of symbiosis driving early polyp growth. Furthermore, genes associated with lysosomal fusion were also upregulated, suggesting host regulation of symbiont densities soon after infection.

scholarly journals MiRNA-mediated Changes in DNA Methylation Affect the Expression of Genes Involved in the Thickness of Pod Canopy Trait in Brassica Napus

2021 ◽  
Author(s):  
Zhiyou Chen ◽  
Ledong Jia ◽  
Yuanyuan Wan ◽  
Jinqi Ma ◽  
Kun Lu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Brassica Napus ◽  
Flower Buds ◽  
Promoter Regions ◽  
Flower Bud ◽  
Stem Apex ◽  
Expression Of Genes ◽  
Genome Wide ◽  
Family Protein ◽  
Crop Development

Abstract Background: Methylation plays an important role in regulating crop development, but little is known about how methylation regulates plant architecture in rapeseed (Brassica napus). Here, we examined how methylation affects the TPC (thickness of pod canopy) trait in rapeseed by performing genome-wide methylation analysis of two extreme TPC lines. Results: We detected significant differences in overall methylation levels between the high- and low-TPC lines in the CG, CHG, and CHH contexts in the promoters of genes in the stem apex and flower bud. In flower buds, 26 genes had significantly higher methylation levels in the high-TPC samples compared to the low-TPC samples, resulting in significantly reduced gene expression. By contrast, in the stem apex samples, the promoter regions of 22 genes were hypermethylated in the high- vs. low-TPC samples. The promoters of 19 and 21 genes had significantly reduced methylation levels in the flower bud and stem apex, respectively, of the high- vs. low-TPC samples, resulting in significantly higher expression levels. Some of these differentially expressed genes are associated with TPC-related traits, such as BnaC03g53050D (UBC32), BnaA05g26660D (CYSB), BnaA10g07880D (TCP 1), BnaAnng09670D (SMP1), BnaA09g02000D (SDH2-2), BnaC01g12960D (NRT1.8), and BnaC09g30490D (TAF15b). In addition, 14 important genes related to growth and development were differentially regulated between the two groups due to miRNA-mediated differences in methylation levels in their promoters. For example, hypermethylation in the promoter region of BnaCnng64040D (Lipase family protein) mediated by miR159a led to significantly reduced gene expression in flower buds of high-TPC vs. low-TPC lines. Conclusions: These results, together with our previously generated RNA-seq and miRNA profiling data, indicate that both methylation and miRNAs are involved in regulating the expression of genes in nitrogen-related metabolic pathways, thereby affecting the TPC trait in B. napus, providing a reference for uncovering the molecular mechanism regulating this crucial trait.

scholarly journals Kynurenine, 3-OH-kynurenine, and anthranilate are nutrient metabolites that alter H3K4 trimethylation and H2AS40 O-GlcNAcylation at hypothalamus-related loci

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Koji Hayakawa ◽  
Kenta Nishitani ◽  
Satoshi Tanaka
Keyword(s):  
Gene Expression ◽  
Epigenetic Regulation ◽  
Epigenetic Modification ◽  
Neural Cells ◽  
Epigenetic Mechanisms ◽  
Post Translational Modifications ◽  
H3k4 Trimethylation ◽  
Expression Of Genes ◽  
Nutritional Conditions ◽  
Hypothalamic Function

AbstractEpigenetic mechanisms can establish and maintain mitotically stable patterns of gene expression while retaining the DNA sequence. These mechanisms can be affected by environmental factors such as nutrients. The importance of intracellular dosages of nutrient metabolites such as acetyl coenzyme A and S-adenosylmethionine, which are utilized as donors for post-translational modifications, is well-known in epigenetic regulation; however, the significance of indirect metabolites in epigenetic regulation is not clear. In this study, we screened for metabolites that function as epigenetic modulators. Because the expression of genes related to hypothalamic function is reportedly affected by nutritional conditions, we used a neural cell culture system and evaluated hypothalamic-linked loci. We supplemented the culture medium with 129 metabolites separately during induction of human-iPS-derived neural cells and used high-throughput ChIP-qPCR to determine the epigenetic status at 37 hypothalamus-linked loci. We found three metabolites (kynurenine, 3-OH-kynurenine, and anthranilate) from tryptophan pathways that increased H3K4 trimethylation and H2AS40 O-GlcNAcylation, resulting in upregulated gene expression at most loci, except those encoding pan-neural markers. Dietary supplementation of these three metabolites and the resulting epigenetic modification were important for stability in gene expression. In conclusion, our findings provide a better understanding of how nutrients play a role in epigenetic mechanisms.

scholarly journals Epigenomics of Plant’s Responses to Environmental Stress

2017 ◽  
Author(s):  
Suresh Kumar
Keyword(s):  
Gene Expression ◽  
Nuclear Dna ◽  
Environmental Stresses ◽  
Transcriptional Level ◽  
Epigenetic Changes ◽  
Post Translational Modifications ◽  
Genome Wide ◽  
A Cell ◽  
Non Coding Rnas ◽  
Function Activity

Genome-wide epigenetic changes in plants are being reported during the development and environmental stresses, which are often correlated with gene expression at the transcriptional level. Sum total of the biochemical changes in nuclear DNA, post-translational modifications in histone proteins and variations in the biogenesis of non-coding RNAs in a cell is known as epigenome. These changes are often responsible for variation in expression of the gene without any change in the underlying nucleotide sequence. The changes might also cause variation in chromatin structure resulting into the changes in function/activity of the genome. The epigenomic changes are dynamic with respect to the endogenous and/or environmental stimuli which affect phenotypic plasticity of the organism. Both, the epigenetic changes and variation in gene expression might return to the pre-stress state soon after withdrawal of the stress. However, a part of the epigenetic changes may be retained which is reported to play role in acclimatization, adaptation as well as in the evolutionary processes. Understanding epigenome-engineering for improved stress tolerance in plants has become essential for better utilization of the genetic factors. This review delineates the importance of epigenomics towards possible improvement of plant’s responses to environmental stresses for climate resilient agriculture.

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