Mapping of long-range chromatin interactions by proximity ligation-assisted ChIP-seq.
Ontology highlight
ABSTRACT:
SUBMITTER: Fang R
PROVIDER: S-EPMC5143423 | biostudies-literature | 2016 Dec
REPOSITORIES: biostudies-literature
Publications
Mapping of long-range chromatin interactions by proximity ligation-assisted ChIP-seq.
Fang Rongxin R Yu Miao M Li Guoqiang G Chee Sora S Liu Tristin T Schmitt Anthony D AD Ren Bing B
Cell research 20161125 12
Similar Datasets
Project description:We report Proximity Ligation Assisted ChIP-sequencing (PLAC-seq), a method for comprehensive detection of long-range interactions associated with proteins of interest. PLAC-seq requires up to 500-fold less starting material compared to ChIA-PET and using experimentally determined input as control precisely reveals protein associated interaction upto single-element resolution. Application of PLAC-seq to mouse embryonic stem cells revealed a comprehensive map of regulatory interactions.
2016-11-15 | GSE86150 | GEO
Project description:The nuclear lamina (NL) is a meshwork found beneath the inner nuclear membrane. The study of the NL is hindered by the insolubility of the meshwork and has driven the development of proximity ligation methods to identify the NL-associated/proximal proteins, RNA, and DNA. To simplify and improve temporal labeling, we fused APEX2 to the NL protein lamin-B1 to map proteins, RNA, and DNA. The identified NL-interacting/proximal RNAs show a long 3' UTR bias, a finding consistent with an observed bias toward longer 3' UTRs in genes deregulated in lamin-null cells. A C-rich motif was identified in these 3' UTR. Our APEX2-based proteomics identifies a C-rich motif binding regulatory protein that exhibits altered localization in lamin-null cells. Finally, we use APEX2 to map lamina-associated domains (LADs) during the cell cycle and uncover short, H3K27me3-rich variable LADs. Thus, the APEX2-based tools presented here permit identification of proteomes, transcriptomes, and genome elements associated with or proximal to the NL.
| S-EPMC7737704 | biostudies-literature
Project description:Hi-C and chromatin immunoprecipitation (ChIP) have been combined to identify long-range chromatin interactions genome-wide at reduced cost and enhanced resolution, but extracting information from the resulting datasets has been challenging. Here we describe a computational method, MAPS, Model-based Analysis of PLAC-seq and HiChIP, to process the data from such experiments and identify long-range chromatin interactions. MAPS adopts a zero-truncated Poisson regression framework to explicitly remove systematic biases in the PLAC-seq and HiChIP datasets, and then uses the normalized chromatin contact frequencies to identify significant chromatin interactions anchored at genomic regions bound by the protein of interest. MAPS shows superior performance over existing software tools in the analysis of chromatin interactions from multiple PLAC-seq and HiChIP datasets centered on different transcriptional factors and histone marks. MAPS is freely available at https://github.com/ijuric/MAPS.
| S-EPMC6483256 | biostudies-literature
Project description:BACKGROUND:The Estrogen Receptor alpha (ER?) is the key transcriptional regulator in luminal breast cancer and is therefore the main target for adjuvant treatment of this subtype. Luminal gene signatures are dictated by the transcriptional capacities of ER?, which are a direct consequence of the receptors binding preference at specific sites on the chromatin. The identification of ER? binding signatures on a genome-wide level has greatly enhanced our understanding of Estrogen Receptor biology in cell lines and tumours, but the technique has its limitations with respect to its applicability in limited amounts of tumour tissue. RESULTS:Here, we present a refinement of the ChIP-seq procedures to enable transcription factor mapping on limited amounts of tissue culture cells as well as from a limited amount of tumor tissue derived from core needle biopsies. Our approach uses a carrier that can be removed prior to DNA amplification and sequencing. CONCLUSION:We illustrate the applicability of this refined technology by mapping the ER? genome-wide chromatin binding landscape in core needle biopsy material from primary breast tumours. With this, our refined technology permits for a high-resolution transcription factor mapping even from clinical samples.
| S-EPMC3637562 | biostudies-literature
Project description:The human genome is non-randomly organized within the cell nucleus. Spatial mapping of genome folding by biochemical methods and imaging has revealed extensive variation in locus interaction frequencies between cells in a population and between homologs within an individual cell. Commonly used mapping approaches typically examine either the relative position of genomic sites to each other or the position of individual loci relative to nuclear landmarks. Whether the frequency of specific chromatin-chromatin interactions is affected by where in the nuclear space a locus is located is unknown. Here, we have simultaneously mapped at the single cell level the interaction frequencies and radial position of more than a hundred locus pairs using high-throughput imaging to ask whether the location within the nucleus affects interaction frequency. We find strong enrichment of many interactions at specific radial positions. Position-dependency of interactions was cell-type specific, correlated with local chromatin type, and cell-type-specific enriched associations were marked by increased variability, sometimes without a significant decrease in mean spatial distance. These observations demonstrate that the folding of the chromatin fiber, which brings genomically distant loci into proximity, and the position of that chromatin fiber relative to nuclear landmarks, are closely linked.
| S-EPMC9581366 | biostudies-literature
Project description:Chromatin modifiers and histone modifications are components of a chromatin-signaling network involved in transcription and its regulation. The interactions between chromatin modifiers and histone modifications are often unknown, are based on the analysis of few genes or are studied in vitro. Here, we apply computational methods to recover interactions between chromatin modifiers and histone modifications from genome-wide ChIP-Seq data. These interactions provide a high-confidence backbone of the chromatin-signaling network. Many recovered interactions have literature support; others provide hypotheses about yet unknown interactions. We experimentally verified two of these predicted interactions, leading to a link between H4K20me1 and members of the Polycomb Repressive Complexes 1 and 2. Our results suggest that our computationally derived interactions are likely to lead to novel biological insights required to establish the connectivity of the chromatin-signaling network involved in transcription and its regulation.
| S-EPMC4267652 | biostudies-literature
Project description:A large number of distal cis-regulatory elements (cREs) have been annotated in the human genome, which plays a central role in orchestrating spatiotemporal gene expression. Since many cREs regulate non-adjacent genes, long-range cRE-promoter interactions are an important factor in the functional characterization of the engaged cREs. In this regard, recent studies have demonstrated that identification of long-range target genes can decipher the effect of genetic mutations residing within cREs on abnormal gene expression. In addition, investigation of altered long-range cREs-promoter interactions induced by chromosomal rearrangements has revealed their critical roles in pathogenic gene expression. In this review, we briefly discuss how the analysis of 3D chromatin structure can help us understand the functional impact of cREs harboring disease-associated genetic variants and how chromosomal rearrangements disrupting topologically associating domains can lead to pathogenic gene expression.
| S-EPMC7714423 | biostudies-literature
Project description:Mapping open chromatin regions has emerged as a widely used tool for identifying active regulatory elements in eukaryotes. However, existing approaches, limited by reliance on DNA fragmentation and short-read sequencing, cannot provide information about large-scale chromatin states or reveal coordination between the states of distal regulatory elements. We have developed a method for profiling the accessibility of individual chromatin fibers, a single-molecule long-read accessible chromatin mapping sequencing assay (SMAC-seq), enabling the simultaneous, high-resolution, single-molecule assessment of chromatin states at multikilobase length scales. Our strategy is based on combining the preferential methylation of open chromatin regions by DNA methyltransferases with low sequence specificity, in this case EcoGII, an N6-methyladenosine (m6A) methyltransferase, and the ability of nanopore sequencing to directly read DNA modifications. We demonstrate that aggregate SMAC-seq signals match bulk-level accessibility measurements, observe single-molecule nucleosome and transcription factor protection footprints, and quantify the correlation between chromatin states of distal genomic elements.
| S-EPMC7968351 | biostudies-literature
Project description:Chromosome Conformation Capture, or 3C, is a pioneering method for investigating the three-dimensional structure of chromatin. 3C is used to analyze long-range looping interactions between any pair of selected genomic loci. Most 3C studies focus on defined genomic regions of interest that can be up to several hundred Kb in size. The method has become widely adopted and has been modified to increase throughput to allow unbiased genome-wide analysis. These large-scale adaptations are presented in other articles in this issue of Methods. Here we describe the 3C procedure in detail, including the appropriate use of the technology, the experimental set-up, an optimized protocol and troubleshooting guide, and considerations for data analysis. The protocol described here contains previously unpublished improvements, which save time and reduce labor. We pay special attention to primer design, appropriate controls and data analysis. We include notes and discussion based on our extensive experience to help researchers understand the principles of 3C-based techniques and to avoid common pitfalls and mistakes. This paper represents a complete resource and detailed guide for anyone who desires to perform 3C.
| S-EPMC3874837 | biostudies-literature
Project description:The pluripotent state of embryonic stem cells (ESCs) is produced by active transcription of cell identity genes and repression of genes encoding lineage-specifying developmental regulators. Here we use large ESC cohesin ChIA-PET datasets and other genomic data to identify the local chromosomal structures at both active and repressed genes across the genome. The results show that super-enhancer driven cell identity genes generally occur within large loops that are connected through CTCF-CTCF interaction sites occupied by cohesin. H3K27me3 ChIP-seq data from wild type murine embryonic stem cells V6.5 were generated by deep sequencing using Illumina Hi-Seq 2000.
2014-06-27 | E-GEOD-57912 | biostudies-arrayexpress