scholarly journals A Histone H2A Deubiquitinase Complex Coordinating Histone Acetylation and H1 Dissociation in Transcriptional Regulation

2007 ◽  
Vol 27 (4) ◽  
pp. 609-621 ◽  
Author(s):  
Ping Zhu ◽  
Wenlai Zhou ◽  
Jianxun Wang ◽  
Janusz Puc ◽  
Kenneth A. Ohgi ◽  
...  
Keyword(s):  
Transcriptional Regulation ◽  
Histone Acetylation ◽  
Histone H2a

scholarly journals The histone variant H2A.Z and chromatin remodeler BRAHMA act coordinately and antagonistically to regulate transcription and nucleosome dynamics in Arabidopsis

2018 ◽  
Author(s):  
E. Shannon Torres ◽  
Roger B. Deal
Keyword(s):  
Transcriptional Regulation ◽  
Transcription Factors ◽  
Binding Sites ◽  
Transcriptional Repression ◽  
Nucleosome Positioning ◽  
Chromatin Organization ◽  
Histone H2a ◽  
Nucleosome Dynamics ◽  
Environmentally Responsive ◽  
Context Specific

ABSTRACTPlants adapt to changes in their environment by regulating transcription and chromatin organization. The histone H2A variant H2A.Z and the SWI2/SNF2 ATPase BRAHMA have overlapping roles in positively and negatively regulating environmentally responsive genes in Arabidopsis, but the extent of this overlap was uncharacterized. Both have been associated with various changes in nucleosome positioning and stability in different contexts, but their specific roles in transcriptional regulation and chromatin organization need further characterization. We show that H2A.Z and BRM act both cooperatively and antagonistically to contribute directly to transcriptional repression and activation of genes involved in development and response to environmental stimuli. We identified 8 classes of genes that show distinct relationships between H2A.Z and BRM and their roles in transcription. We found that H2A.Z contributes to a range of different nucleosome properties, while BRM stabilizes nucleosomes where it binds and destabilizes and/or repositions flanking nucleosomes. H2A.Z and BRM contribute to +1 nucleosome destabilization, especially where they coordinately regulate transcription. We also found that at genes regulated by both BRM and H2A.Z, both factors overlap with the binding sites of light-regulated transcription factors PIF4, PIF5, and FRS9, and that some of the FRS9 binding sites are dependent on H2A.Z and BRM for accessibility. Collectively, we comprehensively characterized the antagonistic and cooperative contributions of H2A.Z and BRM to transcriptional regulation, and illuminated their interrelated roles in chromatin organization. The variability observed in their individual functions implies that both BRM and H2A.Z have more context-specific roles within diverse chromatin environments than previously assumed.

Effect of histone acetylation on transcriptional regulation of amyloid precursor protein activity

2010 ◽  
Vol 34 (8) ◽  
pp. S27-S27
Author(s):  
Jianqi Cui ◽  
Xiuying Pei ◽  
Qian Zhang ◽  
Bassel E. Sawaya ◽  
Xiaohong Lu ◽  
...  
Keyword(s):  
Transcriptional Regulation ◽  
Amyloid Precursor Protein ◽  
Histone Acetylation ◽  
Precursor Protein ◽  
Protein Activity

Kinetic analysis of histone acetylation turnover and Trichostatin A induced hyper- and hypoacetylation in alfalfa

2002 ◽  
Vol 80 (3) ◽  
pp. 279-293 ◽  
Author(s):  
Jakob H Waterborg ◽  
Tamás Kapros
Keyword(s):  
Gene Expression ◽  
Steady State ◽  
Histone Acetylation ◽  
Histone Deacetylases ◽  
Trichostatin A ◽  
Similar Rate ◽  
Lysine Methylation ◽  
Histone H2a ◽  
Turnover Rates

Dynamic histone acetylation is a characteristic of chromatin transcription. The first estimates for the rate of acetylation turnover of plants are reported, measured in alfalfa cells by pulse, pulse-chase, and steady-state acetylation labeling. Acetylation turnover half-lives of about 0.5 h were observed by all methods used for histones H3, H4, and H2B. This is consistent with the rate at which changes in gene expression occur in plants. Treatment with histone deacetylase inhibitor Trichostatin A (TSA) induced hyperacetylation at a similar rate. Replacement histone variant H3.2, preferentially localized in highly acetylated chromatin, displayed faster acetyl turnover. Histone H2A with a low level of acetylation was not subject to rapid turnover or hyperacetylation. Patterns of acetate labeling revealed fundamental differences between histone H3 versus histones H4 and H2B. In H3, acetylation of all molecules, limited by lysine methylation, had similar rates, independent of the level of lysine acetylation. Acetylation of histones H4 and H2B was seen in only a fraction of all molecules and involved multiacetylation. Acetylation turnover rates increased from mono- to penta- and hexaacetylated forms, respectively. TSA was an effective inhibitor of alfalfa histone deacetylases in vivo and caused a doubling in steady-state acetylation levels by 4–6 h after addition. However, hyperacetylation was transient due to loss of TSA inhibition. TSA-induced overexpression of cellular deacetylase activity produced hypoacetylation by 18 h treatment with enhanced acetate turnover labeling of alfalfa histones. Thus, application of TSA to change gene expression in vivo in plants may have unexpected consequences.

scholarly journals Reversible Histone Acetylation Involved in Transcriptional Regulation of WT1 Gene

2007 ◽  
Vol 39 (12) ◽  
pp. 931-938 ◽  
Author(s):  
Y. Shao ◽  
J. Lu ◽  
C. Cheng ◽  
L. Cui ◽  
G. Zhang ◽  
...  
Keyword(s):  
Transcriptional Regulation ◽  
Histone Acetylation ◽  
Wt1 Gene

Epigenetic effects of dietary butyrate on hepatic histone acetylation and enzymes of biotransformation in chicken

2013 ◽  
Vol 61 (4) ◽  
pp. 477-490 ◽  
Author(s):  
Gábor Mátis ◽  
Zsuzsanna Neogrády ◽  
György Csikó ◽  
Péter Gálfi ◽  
Hedvig Fébel ◽  
...  
Keyword(s):  
Histone Acetylation ◽  
Broiler Chickens ◽  
Cell Function ◽  
Enzyme Assays ◽  
Histone H2a ◽  
Epigenetic Effects ◽  
Acetylation State ◽  
Core Histones ◽  
Microsomal Cytochrome P450

The aim of the study was to investigate the in vivo epigenetic influences of dietary butyrate supplementation on the acetylation state of core histones and the activity of drug-metabolising microsomal cytochrome P450 (CYP) enzymes in the liver of broiler chickens in the starter period. One-day-old Ross 308 broilers were fed a starter diet without or with sodium butyrate (1.5 g/kg feed) for 21 days. After slaughtering, nucleus and microsome fractions were isolated from the exsanguinated liver by multi-step differential centrifugation. Histone acetylation level was detected from hepatocyte nuclei by Western blotting, while microsomal CYP activity was examined by specific enzyme assays. Hyperacetylation of hepatic histone H2A at lysine 5 was observed after butyrate supplementation, providing modifications in the epigenetic regulation of cell function. No significant changes could be found in the acetylation state of the other core histones at the acetylation sites examined. Furthermore, butyrate did not cause any changes in the drugmetabolising activity of hepatic microsomal CYP2H and CYP3A37 enzymes, which are mainly involved in the biotransformation of most xenobiotics in chicken. These data indicate that supplementation of the diet with butyrate probably does not have any pharmacokinetic interactions with simultaneously applied xenobiotics.

scholarly journals A novel SNF2 ATPase complex in Trypanosoma brucei with a role in H2A.Z-mediated chromatin remodelling

2021 ◽  
Author(s):  
Tim Vellmer ◽  
Laura Hartleb ◽  
Albert Fradera Sola ◽  
Susanne Kramer ◽  
Elisabeth Meyer-Natus ◽  
...  
Keyword(s):  
Transcriptional Regulation ◽  
Trypanosoma Brucei ◽  
Chromatin Condensation ◽  
Chromatin Remodelling ◽  
Model Organisms ◽  
Mrna Levels ◽  
Histone H2a ◽  
Atpase Subunit ◽  
Chromatin Remodelling Complex ◽  
Pol Ii

A cascade of histone acetylation events with subsequent incorporation of a histone H2A variant plays an essential part in transcription regulation in various model organisms. A key player in this cascade is the chromatin remodelling complex SWR1, which replaces the canonical histone H2A with its variant H2A.Z. Transcriptional regulation of polycistronic transcription units in the unicellular parasite Trypanosoma brucei has been shown to be highly dependent on acetylation of H2A.Z, which is mediated by the histone-acetyltransferase HAT2. The chromatin remodelling complex which mediates H2A.Z incorporation is not known and an SWR1 orthologue in trypanosomes has not yet been reported. In this study, we identified and characterised an SWR1-like remodeller complex in T. brucei that is responsible for Pol II-dependent transcriptional regulation. Bioinformatic analysis of potential SNF2 DEAD/Box helicases, the key component of SWR1 complexes, identified a 1211 amino acids-long protein that exhibits key structural characteristics of the SWR1 subfamily. Systematic protein-protein interaction analysis revealed the existence of a novel complex exhibiting key features of an SWR1-like chromatin remodeller. RNAi-mediated depletion of the ATPase subunit of this complex resulted in a significant reduction of H2A.Z incorporation at transcription start sites and a subsequent decrease of steady-state mRNA levels. Furthermore, depletion of SWR1 and RNA-polymerase II (Pol II) caused massive chromatin condensation. The potential function of several proteins associated with the SWR1-like complex and with HAT2, the key factor of H2A.Z incorporation, is discussed.

Promoter-associated histone acetylation is involved in the osmotic stress-induced transcriptional regulation of the maizeZmDREB2Agene

2013 ◽  
Vol 151 (4) ◽  
pp. 459-467 ◽  
Author(s):  
Lin Zhao ◽  
Pu Wang ◽  
Shihan Yan ◽  
Fei Gao ◽  
Hui Li ◽  
...  
Keyword(s):  
Transcriptional Regulation ◽  
Osmotic Stress ◽  
Histone Acetylation
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