Drosophila melanogaster
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA118401 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR038616.fastq.gz | Fastqsanger.gz | |||
| SRR038617.fastq.gz | Fastqsanger.gz | |||
| SRR038618.fastq.gz | Fastqsanger.gz | |||
| SRR038619.fastq.gz | Fastqsanger.gz |
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Project description:Full title: Complex patterns of genome accessibility discriminate sites of PcG repression, H4K16 acetylation and replication initiation Histone modifications have been proposed to regulate gene expression in part by modulating DNA accessibility and higher-order chromatin structure. However, there is limited direct evidence to support structural differences between euchromatic and heterochromatic fibers in the nucleus. To ask how histone modifications relate to chromatin compaction, we measured DNA accessibility throughout the genome by combining M.SssI methylase footprinting with methylated DNA immunoprecipitation (MeDIP-footprint). In the Drosophila genome, we find that accessibility to DNA methylase is variable in a manner that relates to the differential distribution of active and repressive histone modifications. Active promoters are highly permissive to M.SssI activity, yet inactive chromosomal domains decorated with H3 lysine 27 trimethylation are least accessible providing in vivo evidence for Polycomb-mediated chromatin compaction. Conversely, DNA accessibility is increased at active chromosomal regions marked with H4 lysine 16 acetylation and at the dosage-compensated male X chromosome suggesting that Drosophila transcriptional dosage compensation is facilitated by more permissive chromatin structure. Interestingly early replicating chromosomal regions and sites of replication initiation show also higher accessibility linking temporal and spatial control of genome duplication to the structural organization of chromatin. In conclusion, using a novel protocol we generated a comprehensive view of DNA accessibility and uncover different levels of chromatin organization, which are delineated by distinct patterns of posttranslational histone modifications and replication. Keywords: cell type comparison, ChIP-chip, MeDIP-footprint, RNA-seq, ChIP-seq MeDIP-footprint and ChIP-chip: ChIP-chip was performed for H3K4me3, H3K36me2, H3K36me3, H3K27me3, and H3K9me2 in Kc cells. We measured DNA accessibility throughout the genome by combining M.SssI methylase footprinting with methylated DNA immunoprecipitation (MeDIP-footprint) in Kc and S2 cells. RNA-seq: cDNA from RNA from Drosophila Kc cells was sequenced using Illumina deep sequencing. Reads were mapped and the abundance of all transcripts was determined. ChIP-seq: PSC ChIP from Drosophila Kc cells was sequenced using Illumina deep sequencing in three lanes. Reads were mapped and the binding profile of PSC was determined.
2010-03-16 | E-GEOD-17697 | biostudies-arrayexpress
Project description:Full title: Complex patterns of genome accessibility discriminate sites of PcG repression, H4K16 acetylation and replication initiation Histone modifications have been proposed to regulate gene expression in part by modulating DNA accessibility and higher-order chromatin structure. However, there is limited direct evidence to support structural differences between euchromatic and heterochromatic fibers in the nucleus. To ask how histone modifications relate to chromatin compaction, we measured DNA accessibility throughout the genome by combining M.SssI methylase footprinting with methylated DNA immunoprecipitation (MeDIP-footprint). In the Drosophila genome, we find that accessibility to DNA methylase is variable in a manner that relates to the differential distribution of active and repressive histone modifications. Active promoters are highly permissive to M.SssI activity, yet inactive chromosomal domains decorated with H3 lysine 27 trimethylation are least accessible providing in vivo evidence for Polycomb-mediated chromatin compaction. Conversely, DNA accessibility is increased at active chromosomal regions marked with H4 lysine 16 acetylation and at the dosage-compensated male X chromosome suggesting that Drosophila transcriptional dosage compensation is facilitated by more permissive chromatin structure. Interestingly early replicating chromosomal regions and sites of replication initiation show also higher accessibility linking temporal and spatial control of genome duplication to the structural organization of chromatin. In conclusion, using a novel protocol we generated a comprehensive view of DNA accessibility and uncover different levels of chromatin organization, which are delineated by distinct patterns of posttranslational histone modifications and replication. Keywords: cell type comparison, ChIP-chip, MeDIP-footprint, RNA-seq, ChIP-seq
2010-03-16 | GSE17697 | GEO
Project description:DNA replication initiation is made possible by the assembly of pre- replication complexes (Pre-RCs) at genomic locations called DNA replication initiation sites (origins) during G1-phase. Although there are no conserved characteristics of metazoan origins on which Pre-RCs form, previous findings suggest that origins are strongly associated with open, active chromatin regions of the genome such as promoters, enhancers, and active histone marks. However, over a third of transcriptionally silent genes associate with DNA replication initiation activity in mESC cells, and most of these genes are bound and repressed by the Polycomb repressive complex 2 (PRC2) through the repressive H3K27me3 mark. This is the strongest observed association of an epigenetic regulator element with replication origin activity. Thus, I wished to ask whether Polycomb-mediated gene repression plays a direct role in the recruitment of DNA replication origins activity to silent genes. I comprehensively characterized the consequences of PRC2 catalytic activity (EZH2 subunit) depletion on the activity of DNA replication origins in mESC through a genome-wide evaluation. My findings suggest that absence of EZH2 results in increased DNA replication initiation activity at EZH2-bound sites. Interestingly, the increase in DNA replication initiation activity does not correlate with transcriptional de-repression or acquisition of the activating marks H3K4me3 and H3K27ac but loss of the repressive H3K27me3 mark leading to increased accessibility of chromatin.
2023-04-19 | GSE205756 | GEO
Project description:Histone acetylation is associated with open chromatin and transcriptionally active genes. Specifically, acetylation of lysine 16 on histone H4 (H4K16ac) has been shown to prevent the assembly of nucleosomal arrays in vitro. This modification is catalyzed by the MYST-family histone acetyltransferase KAT8 (also known as MOF and MYST1), which is part of two distinct chromatin-associated complexes: NSL and MSL. While extensively studied in Drosophila, the functions of H4K16ac and the two KAT8-containing complexes in mammalian cells are not well understood. Here, we demonstrate a surprising complex-dependent activity of KAT8. We found that KAT8 catalyzes H4K5 and H4K8 acetylation as part of the NSL complex, whereas it catalyzes the bulk of H4K16 acetylation as part of the MSL complex. Furthermore, we show that the core proteins of the MSL complex and H4K16ac are not required for cell proliferation and global chromatin accessibility, whereas the NSL complex is essential for cell survival, as it is enriched at the promoters of housekeeping genes and is required for their transcription initiation. In summary, we show that KAT8 switches catalytic activity and function depending on its associated proteins, and that, as part of the NSL complex, it catalyzes H4K5 and H4K8 acetylation required for the expression of genes essential for cell survival
2021-06-29 | PXD022267 | Pride
Project description:Histone acetylation is associated with open chromatin and transcriptionally active genes. Specifically, acetylation of lysine 16 on histone H4 (H4K16ac) has been shown to prevent the assembly of nucleosomal arrays in vitro. This modification is catalyzed by the MYST-family histone acetyltransferase KAT8 (also known as MOF and MYST1), which is part of two distinct chromatin-associated complexes: NSL and MSL. While extensively studied in Drosophila, the functions of H4K16ac and the two KAT8-containing complexes in mammalian cells are not well understood. Here, we demonstrate a surprising complex-dependent activity of KAT8. We found that KAT8 catalyzes H4K5 and H4K8 acetylation as part of the NSL complex, whereas it catalyzes the bulk of H4K16 acetylation as part of the MSL complex. Furthermore, we show that the core proteins of the MSL complex and H4K16ac are not required for cell proliferation and global chromatin accessibility, whereas the NSL complex is essential for cell survival, as it is enriched at the promoters of housekeeping genes and is required for their transcription initiation. In summary, we show that KAT8 switches catalytic activity and function depending on its associated proteins, and that, as part of the NSL complex, it catalyzes H4K5 and H4K8 acetylation required for the expression of genes essential for cell survival
2021-06-29 | PXD021943 | Pride
Project description:Histone acetylation is associated with open chromatin and transcriptionally active genes. Specifically, acetylation of lysine 16 on histone H4 (H4K16ac) has been shown to prevent the assembly of nucleosomal arrays in vitro. This modification is catalyzed by the MYST-family histone acetyltransferase KAT8 (also known as MOF and MYST1), which is part of two distinct chromatin-associated complexes: NSL and MSL. While extensively studied in Drosophila, the functions of H4K16ac and the two KAT8-containing complexes in mammalian cells are not well understood. Here, we demonstrate a surprising complex-dependent activity of KAT8. We found that KAT8 catalyzes H4K5 and H4K8 acetylation as part of the NSL complex, whereas it catalyzes the bulk of H4K16 acetylation as part of the MSL complex. Furthermore, we show that the core proteins of the MSL complex and H4K16ac are not required for cell proliferation and global chromatin accessibility, whereas the NSL complex is essential for cell survival, as it is enriched at the promoters of housekeeping genes and is required for their transcription initiation. In summary, we show that KAT8 switches catalytic activity and function depending on its associated proteins, and that, as part of the NSL complex, it catalyzes H4K5 and H4K8 acetylation required for the expression of genes essential for cell survival
2021-06-29 | PXD023865 | Pride
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:The Drosophila MSL complex mediates dosage compensation by increasing transcription of the single X chromosome in males approximately two-fold. This is accomplished through recognition of the X chromosome and subsequent acetylation of histone H4K16 on X-linked genes. Initial binding to the X is thought to occur at a subset of sites. However, the consensus sequence motif of entry sites (M-bM-^@M-^\MSL recognition elementM-bM-^@M-^] or MRE) is only slightly enriched on the X (~2 fold), and only a fraction of them is utilized by the MSL complex. Here we ask whether chromatin context could distinguish between utilized and non-utilized copies of the motif, by comparing their relative enrichment for histone modifications and chromosomal proteins mapped in the NHGRI modENCODE project. Through a comparative analysis of the chromatin features in male S2 cells, which contain MSL complex, and female Kc cells, which lack the complex, we find that the presence of active chromatin modifications, together with an elevated local GC content in surrounding sequence, has strong predictive value for functional MSL entry sites, independent of MSL binding. We tested these sites for function in Kc cells by RNAi knockdown of Sxl, resulting in induction of MSL complex. We show that ectopic MSL expression in Kc cells leads to H4K16 acetylation around these sites, and a relative increase in X chromosome transcription. Collectively, our results support a model in which a pre-existing active chromatin environment, coincident with H3K36me3, contributes to MSL entry site selection. The consequences of MSL targeting of the male X chromosome include increase in nucleosome lability, enrichment for H4K16 acetylation and JIL-1 kinase, and depletion of linker histone H1 on active X-linked genes. Our finding serves as a model to understand how chromatin and local sequence features are involved in the selection of functional protein binding sites in the genome. The key Drosophila female sex determinant protein, SXL, represses dosage compensation by inhibiting MSL2 translation. Loss of SXL results in the expression, stabilization, and targetting of the MSL complex in female cells. Therefore, depletion of SXL by RNA interference (RNAi) in female Kc cells will lead to a MSL2-dependent increase in transcription from the female X chromosomes, consistent with the induction of dosage compensation. In this experiment, we generated ChIP-chip profiles of H4K16 acetylation (H4K16ac) in Kc cells of control (GFP) and Sxl RNAi. For ChIP, we used Upstate (now Millipore) anti-H4K16ac antibody, catalog # 07-329, lot #JBC1355376.
2012-03-19 | E-GEOD-34857 | biostudies-arrayexpress
Project description:We report that acetylation of H4K16 is a new marker of active enhancers and that some enhancers are marked by H3K4me1, MOF and H4K16ac but not by acetylated H3K27 or p300, suggesting that they are novel p300-independent regulatory elements. ChIP-seq for H4K16 acetylation in undifferentiated ES cells, and cells after 3 days of retinoic acid differentiation, along with MNase digested input for both samples
2013-08-23 | E-GEOD-43102 | biostudies-arrayexpress