DNase I–hypersensitive exons colocalize with promoters and distal regulatory elements
ABSTRACT: Native-ChIP was performed to determine whether cross-linked ChIP-Seq enrichments observed at DHS exons result from co-precipitation with proximal promoter. Native ChIP-Seq was performed on H3K4me3 and H3K27me3 histone modifications in human cells
Project description:Symmetrical dimethylation on arginine-3 of histone H4 (H4R3me2s) has been reported to occur at several repressed genes, but its specific regulation and genomic distribution remained unclear. Here, we show that the type-II protein arginine methyltransferase PRMT5 controls H4R3me2s in mouse embryonic fibroblasts (MEFs). In these differentiated cells, we find that the genome-wide pattern of H4R3me2s is highly similar to that in embryonic stem cells. In both the cell types, H4R3me2s peaks are detected predominantly at G + C-rich regions. Promoters are consistently marked by H4R3me2s, independently of transcriptional activity. Remarkably, H4R3me2s is mono-allelic at imprinting control regions (ICRs), at which it marks the same parental allele as H3K9me3, H4K20me3 and DNA methylation. These repressive chromatin modifications are regulated independently, however, since PRMT5-depletion in MEFs resulted in loss of H4R3me2s, without affecting H3K9me3, H4K20me3 or DNA methylation. Conversely, depletion of ESET (KMT1E) or SUV420H1/H2 (KMT5B/C) affected H3K9me3 and H4K20me3, respectively, without altering H4R3me2s at ICRs. Combined, our data indicate that PRMT5-mediated H4R3me2s uniquely marks the mammalian genome, mostly at G + C-rich regions, and independently from transcriptional activity or chromatin repression. Furthermore, comparative bioinformatics analyses suggest a putative role of PRMT5-mediated H4R3me2s in chromatin configuration in the nucleus. High throughput sequencing data from H4R3me2s native ChIP samples from mouse embryonic stem cells and fibroblasts were generated using Illumina Hi-seq 2000.
Project description:JmjC domain containing protein 14 (JMJ14) is an H3K4-specific histone demethylase that plays important roles in RNA-mediated gene silencing and flowering time regulation in Arabidopsis. However, how JMJ14 is recruited to their target genes remains unclear. Here, we show that the C-terminal FYRN and FYRC domains of JMJ14 are required for RNA silencing and flowering time regulation. Chromatin binding of JMJ14 is lost upon deletion of its FYRN and FYRC domains, along with increased H3K4me3. FYRN and FYRC domains interact with a pair of NAC domain containing transcription factors, NAC050 and NAC052. Genome-wide analysis revealed that JMJ14 and NAC050/052 share a set of common target genes with CTTGNNNNNCAAG consensus sequences. Mutations in either NAC052 or NAC050 impair RNA-mediated gene silencing. Thus, our findings demonstrate an important role of FYRN and FYRC in targeting JMJ14 through direct interaction with NAC050/052 transcription factors, which reveals a novel mechanism of recruiting a histone demethylases to its target loci in higher plants. anti-HA ChIP-seq were performed with six samples: Col, NAC050-HA, NAC052-HA, jmj14-1, JMJ14-HA and JMJ14-FYR-HA. Anti-H3K4me3 ChIP were performed with four samples: Col, jmj14-1, JMJ14-HA and JMJ14-FYR-HA. (NAC050-HA indicates PNAC050::NAC050-HA nac050-1, NAC052-HA indicates PNAC052::NAC052-HA nac052-2, JMJ14-HA indicates PJMJ14::JMJ14-HA jmj14-1, JMJ14-FYR-HA indicates PJMJ14::JMJ14-FYR-HA jmj14-1)
Project description:This experiment characterizes the localisation of H2A.Z, H3K9ac and H3K4me3 in the epigenome of the human malaria parasite, P. falciparum at 4 different stages of intraerythrocytic development. Examination of H2A.Z, H3K9ac, H3K4me3 and mono-nucleosomal input in 3D7 strain at 4 different stages and H2A in 3D7 strain at 1 stage using native ChIP-seq
Project description:Polycomb repressive complex 2 (PRC2) regulates gene expression during lineage specification through trimethylation of lysine 27 on histone H3 (H3K27me3). In Drosophila, polycomb binding sites are dynamic chromatin regions coupled to incorporation of the histone variant H3.3. Here we show in mouse embryonic stem cells (ESCs) that H3.3 is required for proper establishment of H3K27me3 at the promoters of developmentally regulated genes. These promoters show reduced dynamics as determined by deposition of de novo synthesized histones, associated with reduced PRC2 occupancy. H3.3-depleted ESCs show upregulation of extraembryonic trophectoderm, as well as misregulation of other developmental genes upon differentiation. Our data demonstrate the importance of H3.3 incorporation in ESCs and suggest that changes in chromatin dynamics in its absence lead to misregulation of gene expression during differentiation. Moreover, our findings lend support to the emerging notion that H3.3 has multiple functions in distinct genomic locations that are not always correlated with an “active” chromatin state. Native ChIP analysis of three histone post-translational modifications (H3K4me3, H3K27me3, H3K27ac) in two mouse embryonic stem cell (ESC) lines (control and H3.3-depleted). Inputs sequenced as control. Native ChIP analysis of H3.3B-HA in control and Suz12-/- ESCs. Crosslinking ChIP analysis of histone H3 using a general H3 antibody in two ESC lines (control and H3.3-depleted). Crosslinking ChIP analysis Hira, UTX, and Jmjd3 in wild type and H3.3 KO ESCs.
Project description:Reward-related memory is an important factor in cocaine seeking. One necessary signaling mechanism for long-term memory formation is the activation of poly(ADP-ribose) polymerase-1 (PARP-1), via poly(ADP-ribosyl)ation. We demonstrate herein that auto-poly(ADP-ribosyl)ation of activated PARP-1 was significantly pronounced during retrieval of cocaine-associated contextual memory, in the central amygdala (CeA) of rats expressing cocaine-conditioned place preference (CPP). Intra-CeA pharmacological and shRNA depletion of PARP-1 activity during cocaine-associated memory retrieval abolished CPP. In contrast, PARP-1 inhibition after memory retrieval did not affect CPP reconsolidation process and subsequent retrievals. Chromatin Immuoprecipitation (ChIP) sequencing revealed that PARP-1 binding in the CeA is highly enriched in genes involved in neuronal signaling. We identified amongst PARP targets in CeA a single gene, yet uncharacterized and encoding a putative transposase inhibitor, at which PARP-1 enrichment dramatically increases during cocaine-associated memory retrieval and positively correlates with CPP. Our findings have important implications for understanding drug-related behaviors, and suggest possible future therapeutic targets for drug abuse. 4 samples, each is pooled central amygdalae tissues collected from 2 rats. Rats were trained for cocaine-conditioned place-preference (CPP), tissues were harvested immediately following cocaine-CPP retrieval. Three groups of rats were used: high cocaine CPP, low cocaine CPP and control saline only trained rats.
Project description:Using DNaseI hypersensitivity (HS) assays (Dnase-seq), high resolution DNaseI digestion profiles were generated genome-wide in diverse human cell types. We showed that within general regions of DNaseI HS that are known to identify locations of gene regulatory elements, DNaseI digestion patterns allowed us to identify locations of individual transcription factor binding sites that protected against the bound DNA against digestion. To measure the accuracy of these footprints, we also generated ChIP-seq data for the CTCF DNA binding factor in the same cell growths. We found that DNaseI footprints containing the CTCF canonical binding motif show significant ChIP-seq signal while CTCF binding motifs not in footprints show almost no signal providing one measure of valdation of the DNaseI footprints. For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf Five cell lines representing cervica carcinoma, chronic myeloid leukemia, embryonic stem cells, epidermal keratinocytes, and umbilical vein endothelial cells were analyzed using ChIP-seq.
Project description:This SuperSeries is composed of the following subset Series: GSE25344: High-resolution genome-wide in vivo footprinting of diverse transcription factors in human cells (Dnase-seq) GSE25416: High-resolution genome-wide in vivo footprinting of diverse transcription factors in human cells (ChIP-seq) For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf Refer to individual Series
Project description:Adipogenesis is tightly controlled by a complex network of transcription factors acting at different stages of differentiation. Peroxisome proliferator-activated receptor gamma (PPAR gamma) and CCAAT/enhancer binding protein (C/EBP) family members are key regulators of this process. We have employed DNase I hypersensitive site analysis to investigate the genome-wide changes in chromatin structure that accompany the binding of adipogenic transcription factors. These analyses revealed a dramatic and dynamic modulation of the chromatin landscape during the first hours of adipocyte differentiation that coincides with cooperative binding of multiple early transcription factors (including glucocorticoid receptor, retinoid X receptor, Stat5a, C/EBPbeta and -delta) to transcription factor 'hotspots'. Our results demonstrate that C/EBPbeta marks a large number of these transcription factor 'hotspots' prior to induction of differentiation and chromatin remodeling and is required for their establishment. Furthermore, a subset of early remodeled C/EBP binding sites persists throughout differentiation and is later occupied by PPAR gamma , indicating that early C/EBP family members, in addition to their well established role in activation of PPAR gamma transcription, may act as pioneering factors for PPAR gamma binding. DNase I hypersensitive chromatin regions and transcription factor binding sites were identified at various time points of 3T3-L1 differentiation using DHS-seq and ChIP-seq, respectively.
Project description:Despite serving as a central experimental technique in epigenetics research, chromatin immunoprecipitation (ChIP) suffers from several serious drawbacks: it is a relative measurement untethered to any external scale that obviates fair comparison amongst experiments; it employs antibody reagents that have differing affinity and specificity for target epitopes, which are in turn variable in abundance; and it is frequently not reproducible. To address these problems, we developed internal standard calibrated ChIP (ICeChIP), a method of spiking a native chromatin sample with nucleosomes reconstituted from recombinant and semisynthetic histones on barcoded DNA prior to immunoprecipitation. ICeChIP measures local histone modification densities on a biologically meaningful scale, enabling unbiased trans-experimental comparisons and revealing a correlation between the apparent symmetry of H3K4me3 in promoter nucleosomes and gene expression. Direct in situ assessment of immunoprecipitation accommodates for a number of experimental pitfalls, and provides a critical examination of untested assumptions inherent in conventional ChIP. Examination of spiked-in semi-synthetic nucleosomes in ICeChIP-seq experiments performed for HEK293, mESC E14 and DM S2 cell line