ChIP-seq Identification of Weakly Conserved Heart Enhancers
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE22549 | GEO | 2010/08/22
SECONDARY ACCESSION(S): PRJNA128177
REPOSITORIES: GEO
Similar Datasets
Project description:Accurate control of tissue-specific gene expression plays a pivotal role in heart development. However, few cardiac transcriptional enhancers have thus far been identified. Extreme non-coding sequence conservation successfully predicts enhancers active in many tissues, but fails to identify substantial numbers of enhancers active in the heart. We used ChIP-seq with the enhancer-associated protein p300 from mouse embryonic heart tissue to identify over three thousand candidate heart enhancers genome-wide. In contrast to other studied tissues at this time-point, most candidate heart enhancers are not deeply conserved in vertebrate evolution. Nevertheless, the testing of 130 candidate regions in a transgenic mouse assay revealed that most of them reproducibly function as enhancers active in the heart, irrespective of their degree of evolutionary constraint. These results provide evidence for tissue-dependent differences in evolutionary constraint of enhancers acting through the transcriptional co-activator p300 at this time-point, and identify a large population of poorly conserved heart enhancers. Examination of p300 binding in embryonic stage 11.5 mouse heart and midbrain
2010-08-22 | E-GEOD-22549 | biostudies-arrayexpress
Project description:We report a method for high throughput mapping of transcriptional enhancers, genomic regulatory regions that activate lineage-specific transcription. Since tissue-specific enhancers are bound by the transcriptional co-activator p300, we developed murine knock-in alleles that permit Cre-dependent, lineage-specific p300 in vivo biotinylation and high affinity pulldown on immobilized streptavidin. Subsequent next generation sequencing of p300-bound genomic DNA identified lineage-specific enhancers. By driving this system with lineage-specific Cre transgenes, we mapped enhancers active in embryonic endothelial cells/blood or skeletal muscle. Analysis of these enhancer sequences identified new transcription factor heterodimer motifs that likely regulate transcription in these lineages. Furthermore, we identified candidate enhancers that regulate adult heart- or lung- specific endothelial cell specialization.
2017-01-24 | GSE88789 | GEO
Project description:Development and function of the human heart depend on the dynamic control of tissue-specific gene expression by distant-acting transcriptional enhancers. While large numbers of heart enhancers have been identified using the mouse as a model system, many of these regulatory sequences are poorly conserved in the human genome. To generate an accurate genome-wide map of human heart enhancers, we used an epigenomic enhancer discovery approach and identified ~6,200 candidate enhancer sequences directly from fetal and adult human heart tissue. Consistent with their predicted function, these elements were markedly enriched near genes implicated in heart development, function and disease. To further validate their in vivo enhancer activity, we tested 65 of these human sequences in a transgenic mouse enhancer assay and observed that 43 (66%) drove reproducible reporter gene expression in the heart. These results support the discovery of a genome-wide set of non-coding sequences highly enriched in human heart enhancers which is likely to facilitate down-stream studies of the role of enhancers in development and pathological conditions of the heart. Examination of AcCBP/p300 binding in human adult heart, human fetal (16wk) heart and mouse postnatal day 2 heart
2011-12-04 | E-GEOD-32587 | biostudies-arrayexpress
Project description:Chromatin features are widely used for genome-scale mapping of enhancers. However, discriminating active enhancers from other cis-regulatory elements, predicting enhancer strength, and identifying their target genes remains challenging. Here we establish histone H2B N-terminus multisite lysine acetylation (H2BNTac) as a genuine signature of active enhancers. H2BNTac prominently marks candidate active enhancers and a subset of promoters and discriminates them from ubiquitously active promoters. Two mechanisms afford the distinct H2BNTac specificity. (1) Unlike H3K27ac, H2BNTac is specifically catalyzed by CBP/p300. (2) H2A-H2B, but not H3-H4, are rapidly exchanged through transcription-induced nucleosome remodeling. H2BNTac-positive candidate enhancers show a high validation rate in orthogonal enhancer activity assays, and a vast majority of endogenously active enhancers are marked by H2BNTac and H3K27ac. Notably, H2BNTac intensity predicts enhancer strength and outperforms the current state-of-the-art models in predicting CBP/p300 target genes. These findings have broad implications for generating fine-grained enhancer maps and modeling CBP/p300-dependent gene regulation.
2023-02-23 | GSE186349 | GEO
Project description:Enhancers determine tissue-specific gene expression programs. Enhancers are marked by high histone H3 lysine 4 mono-methylation (H3K4me1) and by the acetyl-transferase p300, which has allowed genome-wide enhancer identification. However, the regulatory principles by which subsets of enhancers become active in specific developmental and/or environmental contexts are unknown. We exploited inducible p300 binding to chromatin to identify, and then mechanistically dissect, enhancers controlling endotoxin-stimulated gene expression in macrophages. In these enhancers, binding sites for the lineage-restricted and constitutive Ets protein PU.1 coexisted with those for ubiquitous stress-inducible transcription factors such as NF-kappaB, IRF, and AP-1. PU.1 was required for maintaining H3K4me1 at macrophage-specific enhancers. Reciprocally, ectopic expression of PU.1 reactivated these enhancers in fibroblasts. Thus, the combinatorial assembly of tissue- and signal-specific transcription factors determines the activity of a distinct group of enhancers. We suggest that this may represent a general paradigm in tissue-restricted and stimulus-responsive gene regulation. Chromatin immuno-precipitations of p300, PU.1 and mono-methylated H3 lysine 4 followed by multiparallel sequencing were performed in bone marrow-derived macrophages. Experiments for p300 and PU.1 were also carried out in cells treated for 2hrs with lipopolysaccharide (LPS). In case of p300, reads obtained from two different biological replicates were merged.
2010-03-05 | E-GEOD-19553 | biostudies-arrayexpress
Project description:The ability to measure epigenetic features, such as histone modifications and occupancy by transcription factors and co-activators, on a genome-wide scale is advancing the accuracy of CRM predictions. While integration of signals from multiple features is expected to improve predictions, the contribution of each feature to prediction accuracy is not known. We began with predictions of 4,915 erythroid enhancers based on genomic occupancy by TAL1, a key hematopoietic transcription factor that is strongly associated with gene induction in erythroid cells. Seventy of these DNA segments occupied by TAL1 (TAL1 OSs) were tested by transient transfections of cultured hematopoietic cells, and 56% of these were active as enhancers. Sixty-six TAL1 OSs were evaluated in transgenic mouse embryos, and 65% of these were active enhancers in various tissues. Inclusion of additional epigenetic features improved the prediction accuracy, with combinations of TAL1, GATA1, EP300, H3K4me1, and H3K27ac giving high accuracy of enhancer prediction (70%-75% success depending on method of clustering) while maintaining good sensitivity and specificity. Motifs that distinguish active from inactive TAL1 OSs implicate IRFs, STATs, and FOX protein families as candidate positive co-factors with TAL1, while REST (NRSF) and HOX family proteins are implicated in inactivity. While signals for evolutionary constraint were weak over the entire TAL1-bound DNA segments regardless of activity in either assay, phylogenetic preservation of a TF-binding site motif was associated with enhancer activity. The contribution of 8 epigenetic features including H3K27ac to identification of enhancers in 24h-induced G1E-ER4 cells.
2015-04-27 | E-GEOD-61349 | biostudies-arrayexpress
Project description:Signaling pathways are intimately involved in cellular differentiation, allowing cells to respond to their environment by regulating gene expression. While enhancers are recognized as key elements that regulate selective gene expression, the interplay between signaling pathways and actively used enhancer elements is not clear. Here, we use CD4+ T cells as a model of differentiation, mapping the acquisition of cell-type-specific enhancer elements in T-helper 1 (Th1) and Th2 cells. Our data establish that STAT proteins have a major impact on the acquisition of lineage-specific enhancers and the suppression of enhancers associated with alternative cell fates. Transcriptome analysis further supports a functional role for enhancers regulated by STATs. Importantly, expression of lineage-defining master regulators in STAT-deficient cells fails to fully recover the chromatin signature of STAT-dependent enhancers. Thus, these findings point to a critical role of STATs as environmental sensors in dynamically molding the specialized enhancer architecture of differentiating cells. Active enhancer elements were defined as p300-high/H3K4me1-high. Using ChIP-seq, we mapped active enhancer landscapes of two CD4+ T helper cells, Th1 and Th2. To investigate the effect of STAT proteins on this landscape, we profiled active enhancers in the absence of STATs. Overall, STATs deficiency had a major impact on recruitment of p300. In addition, ectopic expression of master regulators T-bet and GATA3 in STAT-deficient cells failed to recover most active enhancers.
2012-11-24 | E-GEOD-40463 | biostudies-arrayexpress
Project description:The contraction pattern of the heart relies on the activation and conduction of the electrical impulse. Perturbations of cardiac conduction have been associated with congenital and acquired arrhythmias as well as cardiac arrest. The pattern of conduction depends on the regulation of heterogeneous gene expression by key transcription factors and transcriptional enhancers. Here, we assessed the genome-wide occupation of conduction system–regulating transcription factors TBX3, NKX2-5, and GATA4 and of enhancer-associated coactivator p300 in the mouse heart, uncovering cardiac enhancers throughout the genome. Examination of 3 cardiac transcription factors and p300 in adult mouse heart
2012-06-22 | E-GEOD-35151 | biostudies-arrayexpress
Project description:Identification of cell-type specific enhancers is important for understanding the regulation of programs controlling cellular development and differentiation. Enhancers are typically marked by the co-transcriptional activator protein p300 or by groups of cell-expressed transcription factors. We hypothesized that a unique set of enhancers regulates gene expression in human erythroid cells, a highly specialized cell type evolved to provide adequate amounts of oxygen throughout the body. Using chromatin immunoprecipitation followed by massively parallel sequencing, genome-wide maps of candidate enhancers were constructed for p300 and four transcription factors, GATA1, NF-E2, KLF1, and SCL, using primary human erythroid cells. These data were combined with gene expression analyses and candidate enhancers identified. Consistent with their predicted function as candidate enhancers, there was statistically significant enrichment of p300 and combinations of co-localizing erythroid transcription factors within 1-50 kb of the TSS of genes highly expressed in erythroid cells. Candidate enhancers were also enriched near genes with known erythroid cell function or erythroid cell phenotypes. Candidate enhancers exhibited only moderate conservation with mouse and minimal conservation with nonplacental vertebrates. Candidate enhancers were mapped to a data set of erythroid-associated, biologically relevant, SNPs from the GWAS catalog of the NHGRI. Fourteen candidate enhancers, representing 10 genetic loci, mapped to sites associated with biologically relevant erythroid traits. Fragments from these loci directed statistically significant expression in reporter gene assays. Identification of enhancers in human erythroid cells will allow a better understanding of erythroid cell development, differentiation, structure, and function, and provide insights into inherited and acquired hematologic disease. CD34+-selected stem and progenitor cells were expanded for three days in the absence of EPO. The cells were further cultured in the presence of EPO, and formaldehyde crosslinked chromatin was isolated after cells differentiated into R3/R4 nucleated erythroid cells. Chromatin Immunoprecipitation followed by sequencing (chIP-seq) was performed using antibodies against GATA1, KLF1, NFE2, TAL1, p300, H3K4me2 and H3K4me3, along with a total input control. Raw data (fastq, SRA) is missing for the TAL1 chIP-seq dataset
2013-01-28 | E-GEOD-43625 | biostudies-arrayexpress
Project description:The shape of the human face is largely genetically determined, but the genetic drivers of craniofacial morphology remain poorly understood. In particular, little is known about the contributions of gene regulatory sequences active in the developing face to craniofacial morphology. Here we used a combination of epigenomic profiling, in vivo characterization of more than 200 craniofacial candidate enhancer sequences in transgenic mice, and targeted deletion experiments to examine the role of distant-acting enhancers in craniofacial development. We identified complex regulatory landscapes with thousands of enhancers genome-wide that drive a remarkable spatial complexity of in vivo expression patterns. The ChIP-seq experiments in this entry was the basis for the genome-wide analysis of craniofacial enhancers and served as the source for substantialin vivo characterization via transgenic reporter mice and for enhancer knockout experiments. p300 ChIP-seq experiment on mouse embryonic tissue (e11.5)
2013-11-06 | E-GEOD-49413 | biostudies-arrayexpress