Drosophila melanogaster S2 cells nucleosome occupancy data after simulation by heat killed Salmonella typhimurium
Ontology highlight
ABSTRACT:
ORGANISM(S): Drosophila melanogaster
PROVIDER: GSE64507 | GEO | 2014/12/24
SECONDARY ACCESSION(S): PRJNA271150
REPOSITORIES: GEO
Similar Datasets
Project description:In eukaryotes, nucleosomes participate in all DNA-templated events by regulating access to the underlying DNA sequence. However, the dynamics of nucleosomes during a genome response has not been well characterized . We stimulated DrosophilaM-BM- S2 cells with heat-killed Gram-negative bacteria Salmonella typhimurium, and mapped genome-wide nucleosome occupancy at high temporal resolution by MNase-seq using Illumina HiSeq 2500. We show widespread nucleosome occupancy change in S2 cells during the immune response, with the biggest nucleosomal loss occurring at 4hr post stimulation. Drsophila S2 cells at 0hr, 30minutes, 1hr and 4hr post heat-killed Salmonella typhimuriumstimulation
2014-12-24 | E-GEOD-64507 | biostudies-arrayexpress
Project description:The innate immune response is among the strongest genomic responses and is conserved across all metazoa. Although transcription during the innate immune response has been well studied, the associated chromatin reorganizations are largely uncharacterized. Here we show that Drosophila S2 cells stimulated with Staphylococcus aureus display a dynamic change in genome-wide nucleosome occupancy and sensitivity. We found a widespread and transient nucleosomal loss peaking at 30 minutes post stimulation, and we demonstrated that the regulatory potentials of nucleosomes differ following stimulation. In addition, we identified differentially sensitive nucleosomes with response-specific potentials. Our results provide high-resolution nucleosome-distribution maps of the fly genome, revealing chromatin's role in: the innate immune response to Gram-positive bacteria, response-specific regulatory-factor binding, and nucleosome sensitivity. We identify functional chromatin regulatory features associated with immune response, and lay a foundation for a framework linking general and locus-specific roles for nucleosomes in immune regulation. Drsophila S2 cells at 0hr, 30minutes, 1hr and 4hr post heat-killed Staphylococcus aureus stimulation
2015-02-28 | E-GEOD-66367 | biostudies-arrayexpress
Project description:The innate immune response is among the strongest genomic responses and is conserved across all metazoa. Although transcription during the innate immune response has been well studied, the associated chromatin reorganizations are largely uncharacterized. Here we show that Drosophila S2 cells stimulated with Staphylococcus aureus display a dynamic change in genome-wide nucleosome occupancy and sensitivity. We found a widespread and transient nucleosomal loss peaking at 30 minutes post stimulation, and we demonstrated that the regulatory potentials of nucleosomes differ following stimulation. In addition, we identified differentially sensitive nucleosomes with response-specific potentials. Our results provide high-resolution nucleosome-distribution maps of the fly genome, revealing chromatin's role in: the innate immune response to Gram-positive bacteria, response-specific regulatory-factor binding, and nucleosome sensitivity. We identify functional chromatin regulatory features associated with immune response, and lay a foundation for a framework linking general and locus-specific roles for nucleosomes in immune regulation.
2015-02-28 | GSE66367 | GEO
Project description:Nucleosome remodeling factors regulate the occupancy and positioning of nucleosomes genome-wide through ATP-driven DNA translocation. While many nucleosomes are well- and consistently positioned, some nucleosomes and nucleosome-like structures are more sensitive to nuclease digestion or transitory in nature. To better understand the role of nucleosome remodeling factors in generating and clearing these alternative nucleosome structures, we depleted murine embryonic stem cells of the remodeler ATPases BRG1 and SNF2H then performed MNase-seq in murine embryonic stem cells. We performed MNase-seq under high- and low-MNase conditions to assess the effects of nucleosome remodeling factors on nuclease-sensitive or “fragile” nucleosome occupancy. In parallel, we gel-extracted MNase-digested fragments to enrich for another alternative nucleosome structure, the overlapping dinucleosome. Overlapping dinucleosomes are composed of two canonical nucleosomes, asymmetrically lacking one H2A:H2B dimer and wrapped by ~250 bp of DNA. In vitro studies of nucleosome remodeling have suggested that the collision of adjacent nucleosomes by nucleosome sliding can stimulate formation of overlapping dinucleosomes. Using these methods, we were able to identify fragile nucleosomes and overlapping dinucleosomes near transcription start sites and gene-distal DNaseI hypersensitive sites in mouse embryonic stem cells, among other loci. We find that BRG1 consistently stimulates occupancy of fragile nucleosomes but represses occupancy of overlapping dinucleosomes through its nucleosome remodeling function, while SNF2H expression slightly increases fragile nucleosome occupancy.
2023-03-14 | GSE216057 | GEO
Project description:Nuclear proteins bind chromatin to execute and regulate genome-templated processes. While structural and biochemical studies of individual nucleosome interactions have suggested that an acidic patch on the nucleosome disk surface may be a common site for recruitment to chromatin, the pervasiveness of acidic patch binding and whether other nucleosome surface binding hot-spots exist remains unclear. Here, we use nucleosome affinity proteomics with a library of nucleosomes that collectively disrupts all exposed histone surfaces to establish the universal principles of nucleosome binding. We find that the acidic patch and two adjacent surfaces are the primary hot-spots for nucleosome disk binding and are critical for the majority of nucleosome-protein interactions. In contrast, nearly half of the nucleosome disk surface participates only minimally in protein binding. In addition to establishing the fundamental principles of chromatin binding, our screen defines nucleosome surface requirements of nearly 300 nucleosome interacting proteins implicated in diverse nuclear processes including transcription, DNA damage repair, cell cycle regulation, and nuclear architecture. Building from our screen, we demonstrate that the Anaphase-Promoting Complex/Cyclosome directly binds the acidic patch and elucidate a redundant charge-based mechanism of acidic patch binding by nuclear pore protein ELYS. Overall, our interactome screen illuminates a highly competitive nucleosome binding hub for chromatin-targeted activities and curates a list of nucleosome interacting proteins that will enable mechanistic exploration of many unexpected chromatin-templated nuclear processes.
2020-06-24 | PXD018690 | Pride
Project description:We employed an MNase-Transcription Start Site Sequence Capture method to map and determine the accessibility of all nucleosomes during immune stimulus, at high coverage for all human Pol II promoters. We uncovered features of nucleosomal organization and sensitivity to MNase digestion in B-lymphoblastoid cells. We also find that transcription factor binding is associated with sensitive nucleosomes.
2020-01-01 | GSE139224 | GEO
Project description:Nucleosome organization is critical for gene regulation. In living cells, this organization is determined by multiple factors, including the action of chromatin remodelers, competition with site-specific DNA-binding proteins, and the DNA sequence preferences of the nucleosomes themselves. However, it has been difficult to estimate the relative importance of each of these mechanisms in vivo, because in vivo nucleosome maps reflect the combined action of all influencing factors. Here, we determine the importance of DNA sequence preferences experimentally by measuring the genome-wide occupancy of nucleosomes assembled on purified yeast genomic DNA. The resulting map, in which nucleosome occupancy is governed only by the intrinsic sequence preferences of nucleosomes, is remarkably similar to in vivo nucleosome maps generated in three different growth conditions. In vitro, nucleosome depletion is evident at many transcription factor binding sites and around gene start and end sites, suggesting that nucleosome depletion at these sites in vivo is partially encoded in the genome. We confirm these results with a micrococcal nuclease-independent experiment that measures the relative affinity of nucleosomes for ~40,000 double-stranded 150bp oligonucleotides. Using our in vitro data, we devise a computational model of nucleosome sequence preferences that is significantly correlated with in vivo nucleosome occupancy in C. elegans. Our results indicate that the intrinsic DNA sequence preferences of nucleosomes play a central role in determining the organization of nucleosomes in vivo.
2008-12-18 | GSE13622 | GEO
Project description:MNase-sequencing analysis led to identification of 56,637 to 71,823 nucleosomes under RPMI-growth or macrophage-internalized conditions. Mapping of dynamic nucleosomes revealed that 12 to 24% of total nucleosomes were altered in their position, occupancy or fuzziness. Notably, while the nucleosome position shift was the most common dynamic event, the nucleosome fuzziness was the least observed change. Promoter regions were found to be nucleosome-depleted.
2024-04-16 | GSE234671 | GEO
Project description:Mapping of nucleosomes, the basic DNA packaging unit in eukaryotes, is fundamental for understanding genome regulation as nucleosomes modulate DNA access by their positioning along the genome. A cell population nucleosome map requires two observables: nucleosome positions along the DNA (“Where?”) and nucleosome occupancies across the population (“In how many cells?”). All available genome-wide nucleosome mapping techniques are yield methods as they score either nucleosomal (e.g., MNase-seq, chemical cleavage-seq) or non-nucleosomal (e.g., ATAC-seq) DNA but lose track of the total DNA population for each genomic region. Therefore, they only provide nucleosome positions and maybe compare relative occupancies between positions but cannot measure absolute nucleosome occupancy, which is the fraction of all DNA molecules occupied at a given position and time by a nucleosome. Here, we established two orthogonal and thereby crossvalidating approaches to measure absolute nucleosome occupancy across the Saccharomyces cerevisiae genome via restriction enzymes and DNA methyltransferases. The resulting high-resolution (9 bp) map shows uniform absolute occupancies. Most nucleosome positions are occupied in most cells: 97% of all nucleosomes called by chemical cleavage-seq have a mean absolute occupancy of 90 ± 6% (± SD). Depending on nucleosome position calling procedures, there are 57-60,000 nucleosomes per yeast cell. The few low absolute occupancy nucleosomes do not correlate with highly transcribed gene bodies, but with increased presence of the nucleosome-evicting RSC chromatin remodeling complex there and are enriched upstream of highly transcribed or regulated genes. Our work provides a quantitative method and reference frame in absolute terms for future chromatin studies.
2019-11-27 | GSE141051 | GEO
Project description:Mapping of nucleosomes, the basic DNA packaging unit in eukaryotes, is fundamental for understanding genome regulation as nucleosomes modulate DNA access by their positioning along the genome. A cell population nucleosome map requires two observables: nucleosome positions along the DNA (“Where?”) and nucleosome occupancies across the population (“In how many cells?”). All available genome-wide nucleosome mapping techniques are yield methods as they score either nucleosomal (e.g., MNase-seq, chemical cleavage-seq) or non-nucleosomal (e.g., ATAC-seq) DNA but lose track of the total DNA population for each genomic region. Therefore, they only provide nucleosome positions and maybe compare relative occupancies between positions but cannot measure absolute nucleosome occupancy, which is the fraction of all DNA molecules occupied at a given position and time by a nucleosome. Here, we established two orthogonal and thereby crossvalidating approaches to measure absolute nucleosome occupancy across the Saccharomyces cerevisiae genome via restriction enzymes and DNA methyltransferases. The resulting high-resolution (9 bp) map shows uniform absolute occupancies. Most nucleosome positions are occupied in most cells: 97% of all nucleosomes called by chemical cleavage-seq have a mean absolute occupancy of 90 ± 6% (± SD). Depending on nucleosome position calling procedures, there are 57-60,000 nucleosomes per yeast cell. The few low absolute occupancy nucleosomes do not correlate with highly transcribed gene bodies, but with increased presence of the nucleosome-evicting RSC chromatin remodeling complex there and are enriched upstream of highly transcribed or regulated genes. Our work provides a quantitative method and reference frame in absolute terms for future chromatin studies.
2019-11-27 | GSE141056 | GEO