scholarly journals RedChIP identifies noncoding RNAs associated with genomic sites occupied by Polycomb and CTCF proteins

2021 ◽  
Vol 119 (1) ◽  
pp. e2116222119
Author(s):  
Alexey A. Gavrilov ◽  
Rinat I. Sultanov ◽  
Mikhail D. Magnitov ◽  
Aleksandra A. Galitsyna ◽  
Erdem B. Dashinimaev ◽  
...  

Nuclear noncoding RNAs (ncRNAs) are key regulators of gene expression and chromatin organization. The progress in studying nuclear ncRNAs depends on the ability to identify the genome-wide spectrum of contacts of ncRNAs with chromatin. To address this question, a panel of RNA–DNA proximity ligation techniques has been developed. However, neither of these techniques examines proteins involved in RNA–chromatin interactions. Here, we introduce RedChIP, a technique combining RNA–DNA proximity ligation and chromatin immunoprecipitation for identifying RNA–chromatin interactions mediated by a particular protein. Using antibodies against architectural protein CTCF and the EZH2 subunit of the Polycomb repressive complex 2, we identify a spectrum of cis- and trans-acting ncRNAs enriched at Polycomb- and CTCF-binding sites in human cells, which may be involved in Polycomb-mediated gene repression and CTCF-dependent chromatin looping. By providing a protein-centric view of RNA–DNA interactions, RedChIP represents an important tool for studies of nuclear ncRNAs.

2016 ◽  
Author(s):  
Rongxin Fang ◽  
Miao Yu ◽  
Guoqiang Li ◽  
Sora Chee ◽  
Tristin Liu ◽  
...  

AbstractWe report a highly sensitive and cost-effective method for genome-wide identification of chromatin interactions in eukaryotic cells. Combining proximity ligation with chromatin immunoprecipitation and sequencing, the method outperforms the state of art approach in sensitivity, accuracy and ease of operation. Application of the method to mouse embryonic stem cells improves mapping of enhancer-promoter interactions.


2020 ◽  
Vol 48 (17) ◽  
pp. 9606-9620
Author(s):  
Gongcheng Hu ◽  
Xiaotao Dong ◽  
Shixin Gong ◽  
Yawei Song ◽  
Andrew P Hutchins ◽  
...  

Abstract CTCF plays a pivotal role in mediating chromatin interactions, but it does not do so alone. A number of factors have been reported to co-localize with CTCF and regulate CTCF loops, but no comprehensive analysis of binding partners has been performed. This prompted us to identify CTCF loop participants and regulators by co-localization analysis with CTCF. We screened all factors that had ChIP-seq data in humans by co-localization analysis with human super conserved CTCF (hscCTCF) binding sites, and identified many new factors that overlapped with hscCTCF binding sites. Combined with CTCF loop information, we observed that clustered factors could promote CTCF loops. After in-depth mining of each factor, we found that many factors might have the potential to promote CTCF loops. Our data further demonstrated that BHLHE40 affected CTCF loops by regulating CTCF binding. Together, this study revealed that many factors have the potential to participate in or regulate CTCF loops, and discovered a new role for BHLHE40 in modulating CTCF loop formation.


RNA Biology ◽  
2018 ◽  
Vol 15 (12) ◽  
pp. 1468-1476 ◽  
Author(s):  
Fan Wang ◽  
Pranik Chainani ◽  
Tommy White ◽  
Jin Yang ◽  
Yu Liu ◽  
...  

2021 ◽  
Vol 12 ◽  
Author(s):  
Weizhi Ouyang ◽  
Xiwen Zhang ◽  
Yong Peng ◽  
Qing Zhang ◽  
Zhilin Cao ◽  
...  

Characterizing genome-wide histone posttranscriptional modifications and transcriptional factor occupancy is crucial for deciphering their biological functions. Chromatin immunoprecipitation followed by sequencing (ChIP-seq) is a powerful method for genome-wide profiling of histone modifications and transcriptional factor-binding sites. However, the current ChIP-seq experimental procedure in plants requires significant material and several days for completion. CUT&Tag is an alternative method of ChIP-seq for low-sample and single-cell epigenomic profiling using protein A-Tn5 transposase fusion proteins (PAT). In this study, we developed a nucleus CUT&Tag (nCUT&Tag) protocol based on the live-cell CUT&Tag technology. Our results indicate that nCUT&Tag could be used for histone modifications profiling in both monocot rice and dicot rapeseed using crosslinked or fresh tissues. In addition, both active and repressive histone marks such as H3K4me3 and H3K9me2 can be identified using our nCUT&Tag. More importantly, all the steps in nCUT&Tag can be finished in only 1 day, and the assay can be performed with as little as 0.01 g of plant tissue as starting materials. Therefore, our results demonstrate that nCUT&Tag is an efficient alternative strategy for plant epigenomic studies.


F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 76
Author(s):  
Ivan Antonov ◽  
Yulia A. Medvedeva

Many long noncoding RNAs are bound to chromatin. MEG3 binds to multiple different genomic locations, containing GA-rich motifs, and form RNA-DNA triplex structures. In this work, we test whether the MEG3 binding sites are specific enough to be regulated by a particular lncRNA. We show that at least in the case of MEG3, a subset of the triplex target sites (TTS) is able to hybridize with various different RNAs almost irrespectively of their sequences. Nowadays, the role of chromatin bound RNAs in the formation of 3D chromatin structure is actively discussed. We speculate that such universal TTSs may contribute to establishing long-distance chromosomal contacts.


2018 ◽  
Author(s):  
Kyster K. Nanan ◽  
David M. Sturgill ◽  
Maria F. Prigge ◽  
Morgan Thenoz ◽  
Allissa A. Dillman ◽  
...  

SummaryThe mechanisms supporting dynamic regulation of CTCF binding sites remain poorly understood. Here we describe the TET-catalyzed 5-methylcytosine derivative, 5-carboxylcytosine (5caC) as a factor driving new CTCF binding within genomic DNA. Through a combination of in vivo and in vitro approaches, we reveal that 5caC generally strengthens CTCF association with DNA and facilitates binding to suboptimal sequences. Dramatically, profiling of CTCF binding in a cellular model that accumulates genomic 5caC identified ∼13,000 new CTCF sites. The new sites were enriched for overlapping 5caC and were marked by an overall reduction in CTCF motif strength. As CTCF has multiple roles in gene expression, these findings have wide-reaching implications and point to induced 5caC as a potential mechanism to achieve differential CTCF binding in cells.


2015 ◽  
Vol 112 (27) ◽  
pp. E3535-E3544 ◽  
Author(s):  
Kelan Chen ◽  
Jiang Hu ◽  
Darcy L. Moore ◽  
Ruijie Liu ◽  
Sarah A. Kessans ◽  
...  

Structural maintenance of chromosomes flexible hinge domain containing 1 (Smchd1) is an epigenetic repressor with described roles in X inactivation and genomic imprinting, but Smchd1 is also critically involved in the pathogenesis of facioscapulohumeral dystrophy. The underlying molecular mechanism by which Smchd1 functions in these instances remains unknown. Our genome-wide transcriptional and epigenetic analyses show that Smchd1 binds cis-regulatory elements, many of which coincide with CCCTC-binding factor (Ctcf) binding sites, for example, the clustered protocadherin (Pcdh) genes, where we show Smchd1 and Ctcf act in opposing ways. We provide biochemical and biophysical evidence that Smchd1–chromatin interactions are established through the homodimeric hinge domain of Smchd1 and, intriguingly, that the hinge domain also has the capacity to bind DNA and RNA. Our results suggest Smchd1 imparts epigenetic regulation via physical association with chromatin, which may antagonize Ctcf-facilitated chromatin interactions, resulting in coordinated transcriptional control.


2005 ◽  
Vol 187 (17) ◽  
pp. 6166-6174 ◽  
Author(s):  
Christopher D. Herring ◽  
Marni Raffaelle ◽  
Timothy E. Allen ◽  
Elenita I. Kanin ◽  
Robert Landick ◽  
...  

ABSTRACT The genome-wide location of RNA polymerase binding sites was determined in Escherichia coli using chromatin immunoprecipitation and microarrays (chIP-chip). Cross-linked chromatin was isolated in triplicate from rifampin-treated cells, and DNA bound to RNA polymerase was precipitated with an antibody specific for the β′ subunit. The DNA was amplified and hybridized to “tiled” oligonucleotide microarrays representing the whole genome at 25-bp resolution. A total of 1,139 binding sites were detected and evaluated by comparison to gene expression data from identical conditions and to 961 promoters previously identified by established methods. Of the detected binding sites, 418 were located within 1,000 bp of a known promoter, leaving 721 previously unknown RNA polymerase binding sites. Within 200 bp, we were able to detect 51% (189/368) of the known σ70-specific promoters occurring upstream of an expressed open reading frame and 74% (273/368) within 1,000 bp. Conversely, many known promoters were not detected by chIP-chip, leading to an estimated 26% negative-detection rate. Most of the detected binding sites could be associated with expressed transcription units, but 299 binding sites occurred near inactive transcription units. This map of RNA polymerase binding sites represents a foundation for studies of transcription factors in E. coli and an important evaluation of the chIP-chip technique.


2016 ◽  
Author(s):  
Ivana Jerković ◽  
Daniel M. Ibrahim ◽  
Guillaume Andrey ◽  
Stefan Haas ◽  
Peter Hansen ◽  
...  

AbstractHomeotic genes code for key transcription factors (HOX-TFs) that pattern the animal body plan. During embryonic development, Hox genes are expressed in overlapping patterns and function in a partially redundant manner. In vitro biochemical screens probing the HOX-TF sequence specificity revealed largely overlapping sequence preferences, indicating that co-factors might modulate the biological function of HOX-TFs. However, due to their overlapping expression pattern, high protein homology, and insufficiently specific antibodies, little is known about their genome-wide binding preferences. In order to overcome this problem, we virally expressed tagged versions of limb-expressed posterior Hox genes (Hoxa9-13, and Hoxd9-13) in primary mesenchymal limb progenitor cells (micromass). We determined the effect of each HOX-TF on cellular differentiation (chondrogenesis) and gene expression and found that groups of HOX-TFs induce distinct regulatory programs. We used ChIP-seq to determine their individual genome-wide binding profiles and identified between 12,540 and 27,466 binding sites for each of the nine HOX-TFs. Principal Component Analysis (PCA) of binding profiles revealed that the HOX-TFs are clustered in two subgroups (Group 1: HOXA/D9, HOXA/D10, HOXD12, and HOXA13 and Group 2: HOXA/D11 and HOXD13), which are characterized by differences in their sequence specificity and by the presence of cofactor motifs. Specifically, we identified CTCF binding sites in Group 1, indicating that this subgroup of HOX-proteins cooperates with CTcf. We confirmed this interaction by an independent biological assay (proximity ligation assay) and showed that CTCF is a novel HOX cofactor that specifically associates with Group 1 HOX-TFs, pointing towards a possible interplay between HOX-TFs and chromatin architecture.


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