Search results for " Acetylation"

Transcription of genes in the biosynthetic pathway for fumonisin mycotoxins is epigenetically and differentially regulated in the fungal maize pathog…

2012

ABSTRACT When the fungal pathogen Gibberella moniliformis (anamorph, Fusarium verticillioides ) colonizes maize and maize-based products, it produces class B fumonisin (FB) mycotoxins, which are a significant threat to human and animal health. FB biosynthetic enzymes and accessory proteins are encoded by a set of clustered and cotranscribed genes collectively named FUM, whose molecular regulation is beginning to be unraveled by researchers. FB accumulation correlates with the amount of transcripts from the key FUM genes, FUM1 , FUM21 , and FUM8 . In fungi in general, gene expression is often partially controlled at the chromatin level in secondary metabolism; when this is the case, the deac…

'Up-regulation of histone acetylation induced by social defeat mediates the conditioned rewarding effects of cocaine

2016

Social defeat (SD) induces a long-lasting increase in the rewarding effects of psychostimulants measured using the self-administration and conditioned place procedures (CPP). However, little is known about the epigenetic changes induced by social stress and about their role in the increased response to the rewarding effects of psychostimulants. Considering that histone acetylation regulates transcriptional activity and contributes to drug-induced behavioral changes, we addressed the hypothesis that SD induces transcriptional changes by histone modifications associated with the acquisition of place conditioning. After a fourth defeat, H3(K9) acetylation was decreased in the hippocampus, whil…

Enzymes involved in the dynamic equilibrium of core histone acetylation ofPhysarum polycephalum

1992

DEAE-Scpharose chromatography of extracts from plasmodia of the myxomyccte PI~.~suru~~t ,~/.~crpl~~ho~~ revealed the presence of multiple histone acetyltransferases and histonc deacctylascs. A cyloplasmic histonc acctyltransferase B, specific for histonc H4, and two nuclear acetyltransferases Al and A2 were identilied; Al acetylates all core hislones with a preference for l-13 and H2A. whereas A2 is specific for H3 and also slightly for H2B. Two hislone deacetylases. HDI and HD2, could be discriminated. They differ with respect to subslralc speciliciiy and pH dependence. For the first time the substrate specificity of histonc deacetylascs was determined using HPLC-purilicd individual core h…

Promoter-Targeted Histone Acetylation of Chromatinized Parvoviral Genome Is Essential for the Progress of Infection

2015

ABSTRACT The association of host histones with parvoviral DNA is poorly understood. We analyzed the chromatinization and histone acetylation of canine parvovirus DNA during infection by confocal imaging and in situ proximity ligation assay combined with chromatin immunoprecipitation and high-throughput sequencing. We found that during late infection, parvovirus replication bodies were rich in histones bearing modifications characteristic of transcriptionally active chromatin, i.e., histone H3 lysine 27 acetylation (H3K27ac). H3K27ac, in particular, was located in close proximity to the viral DNA-binding protein NS1. Importantly, our results show for the first time that in the chromatinized …

Loss of the Sin3A/Rpd3 Histone De-Acetylase Complex Causes Polytene Chromosome Telomeric Fusions

2009

Supported Keggin heteropolyacid catalysts for glycerol acetylation

2017

Heteropolyacids (HPAs) are a class of molecular metal oxides called polyoxometalates, with a heteroatom in the cluster structure forming an oxo-metallic cluster with the addenda metal atoms. Due to the tunable acid-base and redox properties, HPAs have been used as catalysts both for homogeneous and heterogeneous reactions. Many efforts have been devoted to HPAs heterogeneization because, being soluble in polar solvents, their separation and recovery in liquid-solid regime reactors is a relevant practical application problem. Moreover, due to the low specific surface areas (1÷10 m2 g-1) their dispersion on supports with high surface area can increase the accessibility of the reacting species…

A conserved role for the mitochondrial citrate transporter Sea/SLC25A1 in the maintenance of chromosome integrity.

2009

Histone acetylation plays essential roles in cell cycle progression, DNA repair, gene expression and silencing. Although the knowledge regarding the roles of acetylation of histone lysine residues is rapidly growing, very little is known about the biochemical pathways providing the nucleus with metabolites necessary for physiological chromatin acetylation. Here, we show that mutations in the scheggia (sea)-encoded Sea protein, the Drosophila ortholog of the human mitochondrial citrate carrier Solute carrier 25 A1 (SLC25A1), impair citrate transport from mitochondria to the cytosol. Interestingly, inhibition of sea expression results in extensive chromosome breakage in mitotic cells and indu…

Histone deacetylase A key enzyme for the binding of regulatory proteins to chromatin

1993

AbstractCore histones can be modified by reversible, posttranslational acetylation of specific lysine residues within the N-terminal protein domains. The dynamic equilibrium of acetylation is maintained by two enzyme activities, histone acetyltransferase and histone deacetylase. Recent data on histone deacetylases and on anionic motifs in chromatin- or DNA-binding regulatory proteins (e.g. transcription factors, nuclear proto-oncogenes) are summarized and united into a hypothesis which attributes a key function to histone deacetylation for the binding of regulatory proteins to chromatin by a transient, specific local increase of the positive charge in the N-terminal domains of nucleosomal c…

Acetylated nucleosome assembly on telomeric DNAs

2003

Abstract The role of histone N-terminal domains on the thermodynamic stability of nucleosomes assembled on several different telomeric DNAs as well as on ‘average’ sequence DNA and on strong nucleosome positioning sequences, has been studied by competitive reconstitution. We find that histone tails hyperacetylation favors nucleosome formation, in a similar extent for all the examined sequences. On the contrary, removal of histone terminal domains by selective trypsinization causes a decrease of nucleosome stability which is smaller for telomeres compared to the other sequences examined, suggesting that telomeric sequences have only minor interactions with histone tails. Micrococcal nuclease…

Interactions between polyamines, acetylpolyamines and PCAF during histone acetylation.

2009

Polyamines are involved in several gene regulatory functions, as the transcription process. In order to clarify their effect, in an initial “in vitro” biochemical study, we considered their influence on the nuclear PCAF acetyltransferase (PCAF-HAT). In a model system, using both commercial histones and laboratory histone preparations from mammary epithelial cells, we evidenced the inhibitory effect played by 40-180 uM spermidine (Spd) versus PCAF, assayed on 250 nM histone and 40 uM acetyl-CoA. At the same concentrations N8-acetylspermidine (N8-Ac.Spd), the acetylated form of spermidine located in the nucleus, exerts a significant activating effect on the PCAF-HAT. In addition, N8-Ac.Spd se…