Project description:It is increasingly evident that various RNA molecules can bind chromatin to regulate gene expression and genome organization. Here we adapted a sequencing-based technique to profile RNA-chromatin interactions at a genome-wide scale in Arabidopsis seedlings. We identified more than ten thousand RNA-chromatin interactions mediated by protein-coding RNAs, long non-coding RNAs (ncRNAs) and small ncRNAs in Arabidopsis. These RNAs preferentially target genic regions, especially exonic regions. Protein-coding RNAs primarily engage in local and cis-chromosomal interactions, whereas long ncRNAs (lncRNAs) and small ncRNAs preferentially engage in trans-chromosomal interactions. RNA-chromatin interactions tend to positively correlate with DNA-DNA interactions, suggesting a role of DNA-DNA interactions in confining RNA-chromatin interactions and/or a role of RNA-chromatin interactions in shaping genome organization at a global level. We further show that some RNA-chromatin interactions undergo alterations in response to biotic and abiotic stresses. Our study provides a global view of RNA-chromatin interactions in Arabidopsis and a rich resource for future investigation of the regulatory roles of RNAs in gene expression and genome organization.
Project description:It is increasingly evident that various RNA molecules can bind chromatin to regulate gene expression and genome organization. Here we adapted a sequencing-based technique to profile RNA-chromatin interactions at a genome-wide scale in Arabidopsis seedlings. We identified more than ten thousand RNA-chromatin interactions mediated by protein-coding RNAs, long non-coding RNAs (ncRNAs) and small ncRNAs in Arabidopsis. These RNAs preferentially target genic regions, especially exonic regions. Protein-coding RNAs primarily engage in local and cis-chromosomal interactions, whereas long ncRNAs (lncRNAs) and small ncRNAs preferentially engage in trans-chromosomal interactions. RNA-chromatin interactions tend to positively correlate with DNA-DNA interactions, suggesting a role of DNA-DNA interactions in confining RNA-chromatin interactions and/or a role of RNA-chromatin interactions in shaping genome organization at a global level. We further show that some RNA-chromatin interactions undergo alterations in response to biotic and abiotic stresses. Our study provides a global view of RNA-chromatin interactions in Arabidopsis and a rich resource for future investigation of the regulatory roles of RNAs in gene expression and genome organization.
Project description:Millions of cis-regulatory sequences have recently been found in the human genome, but the function of most cis-elements are not yet clear, in part due to the difficulty in determining their regulatory targets, which are often located millions of base pairs away and separated by one or more unrelated genes. To address this problem, the Hi-C method has been developed to identify long-range looping interactions in a genome-wide, unbiased fashion. However, current data analysis of Hi-C datasets cannot fully resolve regulatory interactions between enhancers and promoters due to the low resolution. Here, we generated a high-depth Hi-C dataset and applied a new analysis method that offers improved resolution permitting genome-wide identification of nearly one million chromatin interactions. We demonstrated the use of Hi-C to identify target promoters of enhancers regulated by NF-M-NM-:B signaling and signal-dependent dynamic chromatin interaction at these enhancers in human cells. Surprisingly, our results showed that most NF-M-NM-:B binding sites are looped to their regulatory targets prior to activation of the signaling pathway, and appear to undergo little change during signaling. This observation suggests that the chromatin organization landscape, once established in a cell type, is rather stable and may influence the selection and activation of target genes by a transcription factor. We performed Hi-C analysis using a human fibroblast cell line IMR90 before and after NF-M-NM-:B activation. In the meantime, we also performed ChIP-seq experiments to map the location of NF-M-NM-:B p65 subunit, RNA polymerase II, p300, and several histone modifications (including H3K4me1, H3K4me3, H3K27ac and H3K36me3) in IMR90 cells before and after transient TNF-M-NM-1 stimulation. Additionally, to monitor the dynamic transcription profiles, we also performed Global Run-On sequencing (GRO-seq).
Project description:Transcriptional regulatory elements (TREs), including enhancers and promoters, determine the transcription levels of associated genes. We have recently shown that global run-on and sequencing (GRO-seq) with enrichment for 5'-capped RNAs reveals active TREs with high accuracy. Here, we demonstrate that active TREs can be identified by applying sensitive machine-learning methods to standard GRO-seq data. This approach allows TREs to be assayed together with gene expression levels and other transcriptional features in a single experiment. Our prediction method, called discriminative Regulatory Element detection from GRO-seq (dREG), summarizes GRO-seq read counts at multiple scales and uses support vector regression to identify active TREs. The predicted TREs are more strongly enriched for several marks of transcriptional activation, including eQTL, GWAS-associated SNPs, H3K27ac, and transcription factor binding than those identified by alternative functional assays. Using dREG, we survey TREs in eight human cell types and provide new insights into global patterns of TRE function. We analyzed GRO-seq or PRO-seq data from eight human cell lines. Please note that this study comprises new sample data plus reanalysis of old Sample data submitted by another user. Existing PRO-seq or GRO-seq data was combined as detailed in the GSE66031_readme.txt. See GSM1613181 and GSM1613182 Sample records for data processing information.
Project description:Identification of specific chromatin interactions of 53 selected genes with the Capture-C technique in Raji iBZLF1 cells prior to and 6 or 15 h after induction of EBV’s lytic cycle. The experiments were performed as triplicates.
Project description:Transcriptional regulatory elements (TREs), including enhancers and promoters, determine the transcription levels of associated genes. We have recently shown that global run-on and sequencing (GRO-seq) with enrichment for 5'-capped RNAs reveals active TREs with high accuracy. Here, we demonstrate that active TREs can be identified by applying sensitive machine-learning methods to standard GRO-seq data. This approach allows TREs to be assayed together with gene expression levels and other transcriptional features in a single experiment. Our prediction method, called discriminative Regulatory Element detection from GRO-seq (dREG), summarizes GRO-seq read counts at multiple scales and uses support vector regression to identify active TREs. The predicted TREs are more strongly enriched for several marks of transcriptional activation, including eQTL, GWAS-associated SNPs, H3K27ac, and transcription factor binding than those identified by alternative functional assays. Using dREG, we survey TREs in eight human cell types and provide new insights into global patterns of TRE function.
Project description:Identification of specific chromatin interactions of 49 selected genes with the Capture-C technique in DG75 iBZLF1 cells prior to and 15 h after expression of EBV's protein BZLF1. The experiments were performed as triplicates.
Project description:Millions of cis-regulatory sequences have recently been found in the human genome, but the function of most cis-elements are not yet clear, in part due to the difficulty in determining their regulatory targets, which are often located millions of base pairs away and separated by one or more unrelated genes. To address this problem, the Hi-C method has been developed to identify long-range looping interactions in a genome-wide, unbiased fashion. However, current data analysis of Hi-C datasets cannot fully resolve regulatory interactions between enhancers and promoters due to the low resolution. Here, we generated a high-depth Hi-C dataset and applied a new analysis method that offers improved resolution permitting genome-wide identification of nearly one million chromatin interactions. We demonstrated the use of Hi-C to identify target promoters of enhancers regulated by NF-κB signaling and signal-dependent dynamic chromatin interaction at these enhancers in human cells. Surprisingly, our results showed that most NF-κB binding sites are looped to their regulatory targets prior to activation of the signaling pathway, and appear to undergo little change during signaling. This observation suggests that the chromatin organization landscape, once established in a cell type, is rather stable and may influence the selection and activation of target genes by a transcription factor.