Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA227548 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:We use ChIP-Seq technology to profile the occupancy of histone H2A.Z and its chaperone in HeLa cells genome wide to check if they are co-colocalized. H2A.Z is ChIPed by antibody and its chaperone is tagged by Flag and ChIPed by M2 beads against Flag. ChIPed fragments are sequenced by Illumina HiSeq 2000 platform.
2014-03-01 | E-GEOD-52371 | biostudies-arrayexpress
Project description:We use ChIP-Seq technology to profile the occupancy of histone H2A.Z and its chaperone in HeLa cells genome wide to check if they are co-colocalized.
2014-03-01 | GSE52371 | GEO
Project description:In eukaryotes, DNA wraps around histones to form nucleosomes, which are compacted into chromatin. DNA-templated processes, including transcription, require chromatin disassembly and reassembly mediated by histone chaperones. Additionally, distinct histone variants can replace core histones to regulate chromatin structure and function. Although replacement of H2A with the evolutionarily conserved H2A.Z via the SWR1 histone chaperone complex has been extensively studied, in plants little is known about how a reduction of H2A.Z levels can be achieved. Here, we show that NRP proteins cause a decrease of H2A.Z-containing nucleosomes in Arabidopsis under standard growing conditions. nrp1-1 nrp2-2 double mutants show an over-accumulation of H2A.Z genome-wide, especially at heterochromatic regions normally H2A.Z-depleted in wild-type plants. Our work suggests that NRP proteins regulate gene expression by counteracting SWR1, thereby preventing excessive accumulation of H2A.Z.
2020-05-18 | PXD019248 | Pride
Project description:This SuperSeries is composed of the following subset Series: GSE29781: Expression data from 30do mouse spermatids [Affymetrix] GSE29913: Genome-wide distribution maps of histone variants H2A.Lap1 and H2A.Z in 30do mouse spermatids[ChIP_seq] Refer to individual Series
2012-01-20 | E-GEOD-29916 | biostudies-arrayexpress
Project description:In eukaryotes, DNA wraps around histones to form nucleosomes, which are compacted into chromatin. DNA-templated processes, including transcription, require chromatin disassembly and reassembly mediated by histone chaperones. Additionally, distinct histone variants can replace core histones to regulate chromatin structure and function. Although replacement of H2A with the evolutionarily conserved H2A.Z via the SWR1 histone chaperone complex has been extensively studied, in plants little is known about how a reduction of H2A.Z levels can be achieved in plants. Here, we show that NRP proteins cause a decrease of H2A.Z-containing nucleosomes in Arabidopsis under standard growing conditions. nrp1-1 nrp2-2 double mutants show an over-accumulation of H2A.Z genome-wide, especially at heterochromatic regions normally H2A.Z-depleted in wild-type plants. Our work suggests that NRP proteins regulate gene expression by counteracting SWR1, thereby preventing excessive accumulation of H2A.Z.
2020-04-29 | GSE127986 | GEO
Project description:Both, acetylation of histones and of histone variant H2A.Z are conserved features of eukaryotic transcription start sites (TSSs) and both features appear to be critical for correct transcription initiation. However, complex patterns of transcriptional regulation have complicated the establishment of functional links between histone acetylation, H2A.Z deposition and their importance in transcription regulation. To elucidate these links, we took advantage of the unusual genome organization in Trypanosoma brucei, a highly divergent eukaryote. In T. brucei genes are organized in long polycistronic transcription units, drastically reducing the sites of transcription initiation. Employing a highly sensitive and quantitative mass-spectrometry-based approach, we quantified the genome-wide histone acetylation and methylation pattern and identified various acetyl and methyl marks exclusively enriched at TSSs In addition, we show that deletion of histone acetyltransferase 2 results in a loss of H4 acetylation at TSSs, a loss of H2A.Z deposition at TSSs and a shift in the sites of transcription initiation. Combined, our findings demonstrate an evolutionary conserved link between histone H4 acetylation, H2A.Z deposition and RNA transcription initiation.
2020-03-24 | PXD014452 | Pride
Project description:Genome-wide maps of histone H3 K79 succinylation in U251 cells.
| PRJNA383587 | ENA
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.
| S-EPMC2531291 | biostudies-literature
Project description:In most eukaryotes, the centromere is epigenetically defined by nucleosomes that contain the histone H3 variant centromere protein A (CENP-A). Specific targeting of the CENP-A-loading chaperone to the centromere is vital for stable centromere propagation; however, the existence of ectopic centromeres (neocentromeres) indicates that this chaperone can function in different chromatin environments. The mechanism responsible for accommodating the CENP-A chaperone at novel chromatin regions is poorly understood. Here, we report the identification of transient, immature neocentromeres in Schizosaccharomyces pombe, which show reduced association with the CENP-A chaperone Scm3 attributable to persistence of the histone H2A variant H2A.Z. Following acquisition of adjacent heterochromatin or relocation of the immature neocentromeres to subtelomeric regions, H2A.Z was depleted and Scm3 was replenished, leading to subsequent stabilization of the neocentromeres. These findings provide novel insights into histone variant-mediated epigenetic control of neocentromere establishment. Comparison of chromosomal distributions of centromeric proteins and heterochromatin proteins between the NC survivors and their derivatives.
2013-11-03 | E-GEOD-37094 | biostudies-arrayexpress
Project description:Nucleosomes that contain the histone variant H2A.Z are enriched around transcriptional start sites in many organisms. A single octameric nucleosome can contain two H2A.Z histones (homotypic) or one H2A.Z and one canonical H2A (heterotype). We generated high-resolution maps of homotypic and heterotypic Drosophila H2A.Z (H2Av) nucleosomes. Although homotypic and heterotypic H2Av nucleosomes map throughout most of the genome, homotypic nucleosomes are enriched and heterotypic nucleosomes are depleted downstream of active promoters and intron/exon boundaries. The distribution of homotypic H2A.Z nucleosomes resembles that of salt-soluble nucleosomes and shows evidence of displacement during transcriptional elongation. Homotypic nucleosomes are also depleted downstream of paused polymerases, where salt-soluble nucleosomes are conspicuously depleted. Our results suggest a model whereby H2A.Z enrichment patterns result from different structural interactions within the core of heterotypic and homotypic nucleosomes following disruption during transcriptional elongation. We analyzed two replicates for input, heterotypic and homotypic purifications. We sequenced one library for each of the single H2Av pulldown and 80mM salt soluble samples.
2010-11-01 | E-GEOD-21615 | biostudies-arrayexpress