Project description:This SuperSeries is composed of the following subset Series: GSE27967: ChIP-seq analysis reveals distinct H3K27me3 profiles associated with gene regulation [ChIP-seq] GSE27969: ChIP-seq analysis reveals distinct H3K27me3 profiles associated with gene regulation [mRNA profiling] Refer to individual Series
Project description:H3K27me3 is a histone modification associated with transcriptional repression that plays a pivotal role in differentiation and development in plants and animals. H2A.Z, a histone variant of H2A, is often colocalized with H3K27me3 in Arabidopsis. Previous genome-wide studies have raised the possibility that H2A.Z contributes to H3K27me3 homeostasis in plants. To examine the contribution of H2A.Z to H3K27me3, we utilized hta9 hta11, a plant line which is defective in two of three genes that code for H2A.Z and has been previously characterized as an H2A.Z-depletion mutant. Surprisingly, ChIP-seq analysis of H2A.Z enrichment revealed that hta9 hta11 plants exhibit a nearly indistinguishable genic H2A.Z enrichment pattern relative to wild type with few genes that are enriched or depleted for H2A.Z. Mass spectrometry measurement of histone protein abundance in hta9 hta11 plants in conjunction with our ChIP-seq analysis indicates that the chromatin of hta9 hta11 plants exhibits altered relative abundance of H2A.Z variants rather than a global depletion of H2A.Z. In contrast, ChIP-seq analysis of H3K27me3 reveals that hta9 hta11 plants exhibit a robust global reduction in H3K27me3 enrichment, and numerous genes are identified that exhibit altered levels for H3K27me3. In addition, hta9 hta11 plants exhibit differential expression of thermoresponsive genes that have previously been shown to be dependent on H2A.Z. Our combined analyses indicate that specific H2A.Z isoforms play distinct roles in chromatin composition and gene expression in Arabidopsis, particularly with regards to H3K27me3 homeostasis.
Project description:H3K27me3 is a histone modification associated with transcriptional repression that plays a pivotal role in differentiation and development in plants and animals. H2A.Z, a histone variant of H2A, is often colocalized with H3K27me3 in Arabidopsis. Previous genome-wide studies have raised the possibility that H2A.Z contributes to H3K27me3 homeostasis in plants. To examine the contribution of H2A.Z to H3K27me3, we utilized hta9 hta11, a plant line which is defective in two of three genes that code for H2A.Z and has been previously characterized as an H2A.Z-depletion mutant. Surprisingly, ChIP-seq analysis of H2A.Z enrichment revealed that hta9 hta11 plants exhibit a nearly indistinguishable genic H2A.Z enrichment pattern relative to wild type with few genes that are enriched or depleted for H2A.Z. Mass spectrometry measurement of histone protein abundance in hta9 hta11 plants in conjunction with our ChIP-seq analysis indicates that the chromatin of hta9 hta11 plants exhibits altered relative abundance of H2A.Z variants rather than a global depletion of H2A.Z. In contrast, ChIP-seq analysis of H3K27me3 reveals that hta9 hta11 plants exhibit a robust global reduction in H3K27me3 enrichment, and numerous genes are identified that exhibit altered levels for H3K27me3. In addition, hta9 hta11 plants exhibit differential expression of thermoresponsive genes that have previously been shown to be dependent on H2A.Z. Our combined analyses indicate that specific H2A.Z isoforms play distinct roles in chromatin composition and gene expression in Arabidopsis, particularly with regards to H3K27me3 homeostasis.
Project description:NONO deficiency in hiPSCs results in a distinct defect in early cardiomyocyte differentiation. Mechanistically, NONO interacts with HOXA1 and regulates the dynamic expression of key genes during early cardiomyocyte differentiation. ChIP-seq analysis reveals that NONO loss reduces HOXA1 occupancy at target genes, compromising its transcriptional regulation. Additionally, NONO and HOXA1 cooperatively activate the Wnt signaling.
Project description:Determining the genomic localization of chromatin features is an essential aspect of investigating gene expression control, and ChIP-Seq has long been the gold standard technique for interrogating chromatin landscapes. Recently, the development of alternative methods, such as CUT&Tag, have provided researchers with alternative strategies that eliminate the need for chromatin purification, and allow for in situ investigation of histone modifications and chromatin bound factors. Mindful of technical differences, we set out to investigate whether distinct chromatin modifications were equally compatible with these different chromatin interrogation techniques. We found that ChIP-Seq and CUT&Tag performed similarly for modifications known to reside at gene regulatory regions, such as promoters and enhancers, but major differences were observed when we assessed enrichment over heterochromatin-associated loci. Unlike ChIP-Seq, CUT&Tag detects robust levels of H3K9me3 at a substantial number of repetitive elements, with especially high sensitivity over evolutionarily young retrotransposons. IAPEz-int elements for example, exhibited underrepresentation in mouse ChIP-Seq datasets but strong enrichment using CUT&Tag. Additionally, we identified several euchromatin-associated proteins that co-purify with repetitive loci and are similarly depleted when applying ChIP-based methods. This study reveals that our current knowledge of chromatin states across the heterochromatin portions of the mammalian genome is extensively incomplete, largely due to36 limitations of ChIP-Seq. We also demonstrate that newer in situ chromatin fragmentation-based techniques, such as CUT&Tag and CUT&RUN, are more suitable for studying chromatin modifications over repetitive elements and retrotransposons.
Project description:Transcriptional control is dependent on a vast network of epigenetic modifications. One epigenetic mark of particular interest is tri-methylation of lysine 27 on histone H3 (H3K27me3), which is catalyzed and maintained by the Polycomb Repressor Complex (PRC2). Although this histone mark is studied widely, the precise relationship between its local pattern of enrichment and regulation of gene expression is currently unclear. We have used ChIP-seq to generate genome wide maps of H3K27me3 enrichment, and have identified three enrichment profiles with distinct regulatory consequences. First, a broad domain of H3K27me3 enrichment across the body of genes corresponds to the canonical view of H3K27me3 as inhibitory to transcription. Second, a peak of enrichment around the transcription start site is commonly associated with â??bivalentâ?? genes, where H3K4me3 also marks the TSS. Finally and most surprisingly, we identified an enrichment profile with a peak in the promoter of genes that is associated with active transcription. Genes with each of these three profiles were found in different proportions in each of the cell types studied. The data analysis techniques developed here will be useful for the identification of common enrichment profiles for other histone modifications that have important consequences for transcriptional regulation. Genomic DNA was extracted from ES cells and G1ME cells in mouse. ChIP-seq with antibodies for H3K27me3, RNApol-II were run for both cell types. As a control, whole cell extract or Input DNA was also sequenced for both cell types without the inclusion of an antibody.
Project description:This dataset contains data-independent acquisition (DIA) proteomics data generated from K562 human leukemia cells treated with coffee extract or vehicle control. Quantitative proteomic analysis was performed to investigate molecular mechanisms underlying coffee-induced epigenetic remodeling. The proteomics dataset was integrated with histone modification profiling, ChIP-seq and RNA-seq analyses to characterize pathways associated with histone acetylation and MYC transcriptional regulation.
Project description:Transcriptional control is dependent on a vast network of epigenetic modifications. One epigenetic mark of particular interest is tri-methylation of lysine 27 on histone H3 (H3K27me3), which is catalyzed and maintained by the Polycomb Repressor Complex (PRC2). Although this histone mark is studied widely, the precise relationship between its local pattern of enrichment and regulation of gene expression is currently unclear. We have used ChIP-seq to generate genome wide maps of H3K27me3 enrichment, and have identified three enrichment profiles with distinct regulatory consequences. First, a broad domain of H3K27me3 enrichment across the body of genes corresponds to the canonical view of H3K27me3 as inhibitory to transcription. Second, a peak of enrichment around the transcription start site is commonly associated with “bivalent” genes, where H3K4me3 also marks the TSS. Finally and most surprisingly, we identified an enrichment profile with a peak in the promoter of genes that is associated with active transcription. Genes with each of these three profiles were found in different proportions in each of the cell types studied. The data analysis techniques developed here will be useful for the identification of common enrichment profiles for other histone modifications that have important consequences for transcriptional regulation. Expression profiling of Gata1 null Megakaryocyte Erythroid cells (G1ME cells) Supplementary file: Comprehensive matrix representing the entire gene expression dataset (i.e., GSM691834 and GSM691835, plus the re-analyzed Samples from Series GSE8024).