scholarly journals Genome-wide binding of posterior HOXA/D transcription factors reveals subgrouping and association with CTCF

2016 ◽  
Author(s):  
Ivana Jerković ◽  
Daniel M. Ibrahim ◽  
Guillaume Andrey ◽  
Stefan Haas ◽  
Peter Hansen ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Binding Sites ◽  
Hox Genes ◽  
Ctcf Binding ◽  
Proximity Ligation Assay ◽  
Homeotic Genes ◽  
Sequence Specificity ◽  
Individual Genome ◽  
Genome Wide ◽  
Group 1

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.

scholarly journals TFutils: Data structures for transcription factor bioinformatics

F1000Research ◽  
2019 ◽  
Vol 8 ◽  
pp. 152
Author(s):  
Benjamin J. Stubbs ◽  
Shweta Gopaulakrishnan ◽  
Kimberly Glass ◽  
Nathalie Pochet ◽  
Celine Everaert ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Data Structures ◽  
Binding Sites ◽  
Genome Wide Association Study ◽  
Genome Wide Association ◽  
Bioconductor Package ◽  
Genome Wide ◽  
Study Results ◽  
Integrative Analyses

DNA transcription is intrinsically complex. Bioinformatic work with transcription factors (TFs) is complicated by a multiplicity of data resources and annotations. The Bioconductor package TFutils includes data structures and functions to enhance the precision and utility of integrative analyses that have components involving TFs. TFutils provides catalogs of human TFs from three reference sources (CISBP, HOCOMOCO, and GO), a catalog of TF targets derived from MSigDb, and multiple approaches to enumerating TF binding sites. Aspects of integration of TF binding patterns and genome-wide association study results are explored in examples.

scholarly journals Exploring the Changing Landscape of Cell-to-Cell Variation After CTCF Knockdown via Single Cell RNA-seq

2019 ◽  
Author(s):  
Wei Wang ◽  
Gang Ren ◽  
Ni Hong ◽  
Wenfei Jin
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Single Cell ◽  
Zinc Finger ◽  
Ctcf Binding ◽  
Rna Seq ◽  
Expression Noise ◽  
Genome Wide ◽  
Cell Variation ◽  
Variable Genes

Abstract Background: CCCTC-Binding Factor (CTCF), also known as 11-zinc finger protein, participates in many cellular processes, including insulator activity, transcriptional regulation and organization of chromatin architecture. Based on single cell flow cytometry and single cell RNA-FISH analyses, our previous study showed that deletion of CTCF binding site led to a significantly increase of cellular variation of its target gene. However, the effect of CTCF on genome-wide landscape of cell-to-cell variation is unclear. Results: We knocked down CTCF in EL4 cells using shRNA, and conducted single cell RNA-seq on both wild type (WT) cells and CTCF-Knockdown (CTCF-KD) cells using Fluidigm C1 system. Principal component analysis of single cell RNA-seq data showed that WT and CTCF-KD cells concentrated in two different clusters on PC1, indicating gene expression profiles of WT and CTCF-KD cells were systematically different. Interestingly, GO terms including regulation of transcription, DNA binding, Zinc finger and transcription factor binding were significantly enriched in CTCF-KD-specific highly variable genes, indicating tissue-specific genes such as transcription factors were highly sensitive to CTCF level. The dysregulation of transcription factors potentially explain why knockdown of CTCF lead to systematic change of gene expression. In contrast, housekeeping genes such as rRNA processing, DNA repair and tRNA processing were significantly enriched in WT-specific highly variable genes, potentially due to a higher cellular variation of cell activity in WT cells compared to CTCF-KD cells. We further found cellular variation-increased genes were significantly enriched in down-regulated genes, indicating CTCF knockdown simultaneously reduced the expression levels and increased the expression noise of its regulated genes. Conclusions: To our knowledge, this is the first attempt to explore genome-wide landscape of cellular variation after CTCF knockdown. Our study not only advances our understanding of CTCF function in maintaining gene expression and reducing expression noise, but also provides a framework for examining gene function.

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 ◽  
...  
Keyword(s):  
Chromatin Immunoprecipitation ◽  
Binding Sites ◽  
Wide Spectrum ◽  
Noncoding Rnas ◽  
Ctcf Binding ◽  
Polycomb Repressive Complex 2 ◽  
Proximity Ligation ◽  
Chromatin Interactions ◽  
Genome Wide ◽  
Architectural Protein

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.

scholarly journals Effects of DNA Methylation on TFs in Human Embryonic Stem Cells

2021 ◽  
Vol 12 ◽  
Author(s):  
Ximei Luo ◽  
Tianjiao Zhang ◽  
Yixiao Zhai ◽  
Fang Wang ◽  
Shumei Zhang ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Binding Sites ◽  
Embryonic Stem ◽  
Cell Types ◽  
Epigenetic Mechanism ◽  
Ctcf Binding ◽  
Sequence Specificity ◽  
Sequencing Data ◽  
Methylated Dna

DNA methylation is an important epigenetic mechanism for gene regulation. The conventional view of DNA methylation is that DNA methylation could disrupt protein-DNA interactions and repress gene expression. Several recent studies reported that DNA methylation could alter transcription factors (TFs) binding sequence specificity in vitro. Here, we took advantage of the large sets of ChIP-seq data for TFs and whole-genome bisulfite sequencing data in many cell types to perform a systematic analysis of the protein-DNA methylation in vivo. We observed that many TFs could bind methylated DNA regions, especially in H1-hESC cells. By locating binding sites, we confirmed that some TFs could bind to methylated CpGs directly. The different proportion of CpGs at TF binding specificity motifs in different methylation statuses shows that some TFs are sensitive to methylation and some could bind to the methylated DNA with different motifs, such as CEBPB and CTCF. At the same time, TF binding could interactively alter local DNA methylation. The TF hypermethylation binding sites extensively overlap with enhancers. And we also found that some DNase I hypersensitive sites were specifically hypermethylated in H1-hESC cells. At last, compared with TFs’ binding regions in multiple cell types, we observed that CTCF binding to high methylated regions in H1-hESC were not conservative. These pieces of evidence indicate that TFs that bind to hypermethylation DNA in H1-hESC cells may associate with enhancers to regulate special biological functions.

scholarly journals TET-catalyzed 5-carboxylcytosine promotes CTCF binding to suboptimal sequences genome-wide

2018 ◽  
Author(s):  
Kyster K. Nanan ◽  
David M. Sturgill ◽  
Maria F. Prigge ◽  
Morgan Thenoz ◽  
Allissa A. Dillman ◽  
...  
Keyword(s):  
Binding Sites ◽  
Genomic Dna ◽  
Multiple Roles ◽  
Ctcf Binding ◽  
Cellular Model ◽  
Potential Mechanism ◽  
Dynamic Regulation ◽  
Genome Wide

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.

scholarly journals CTCF: the protein, the binding partners, the binding sites and their chromatin loops

2013 ◽  
Vol 368 (1620) ◽  
pp. 20120369 ◽  
Author(s):  
Sjoerd Johannes Bastiaan Holwerda ◽  
Wouter de Laat
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Rna Polymerase Ii ◽  
Binding Sites ◽  
Ctcf Binding ◽  
Chromatin Domain ◽  
Gene Promoters ◽  
Tissue Specific ◽  
Chromatin Loops ◽  
Exact Function

CTCF has it all. The transcription factor binds to tens of thousands of genomic sites, some tissue-specific, others ultra-conserved. It can act as a transcriptional activator, repressor and insulator, and it can pause transcription. CTCF binds at chromatin domain boundaries, at enhancers and gene promoters, and inside gene bodies. It can attract many other transcription factors to chromatin, including tissue-specific transcriptional activators, repressors, cohesin and RNA polymerase II, and it forms chromatin loops. Yet, or perhaps therefore, CTCF's exact function at a given genomic site is unpredictable. It appears to be determined by the associated transcription factors, by the location of the binding site relative to the transcriptional start site of a gene, and by the site's engagement in chromatin loops with other CTCF-binding sites, enhancers or gene promoters. Here, we will discuss genome-wide features of CTCF binding events, as well as locus-specific functions of this remarkable transcription factor.

scholarly journals The cis-regulatory logic underlying abdominal Hox-mediated repression versus activation of regulatory elements in Drosophila

2018 ◽  
Author(s):  
Arya Zandvakili ◽  
Juli Uhl ◽  
Ian Campbell ◽  
Yuntao Charlie Song ◽  
Brian Gebelein
Keyword(s):  
Transcription Factors ◽  
Dna Binding ◽  
Dna Sequences ◽  
Binding Sites ◽  
Target Genes ◽  
Hox Genes ◽  
Regulatory Elements ◽  
Protease Gene ◽  
Precise Integration

AbstractHox genes encode a family of transcription factors that, despite having similar in vitro DNA binding preferences, regulate distinct genetic programs along the metazoan anterior-posterior axis. To better define mechanisms of Hox specificity, we compared and contrasted the ability of abdominal Hox factors to regulate two cis-regulatory elements within the Drosophila embryo. Both the Ultrabithorax (Ubx) and Abdominal-A (Abd-A) Hox factors form cooperative complexes with the Extradenticle (Exd) and Homothorax (Hth) transcription factors to repress the distal-less leg selector gene via the DCRE, whereas only Abd-A interacts with Exd and Hth on the RhoA element to activate a rhomboid serine protease gene that stimulates Epidermal Growth Factor secretion. By swapping binding sites between these elements, we found that the RhoA Exd/Hth/Hox site configuration that mediates Abd-A specific activation can also convey transcriptional repression by both Ubx and Abd-A when placed into the DCRE, but only in one orientation. We further show that the orientation and spacing of Hox sites relative to additional transcription factor binding sites within the RhoA and DCRE elements is critical to mediate appropriate cell- and segment-specific output. These results indicate that the interaction between Hox, Exd, and Hth neither determines activation vs repression specificity nor defines Ubx vs Abd-A specificity. Instead the precise integration of Hox sites with additional TF inputs is required for accurate transcriptional output. Taken together, these studies provide new insight into the mechanisms of Hox target and regulatory specificity as well as the constraints placed on regulatory elements to convey appropriate outputs.Author SummaryThe Hox genes encode a family of transcription factors that give cells within each region along the developing body plan a unique identity in animals from worms to mammals. Surprisingly, however, most of the Hox factors bind the same or highly similar DNA sequences. These findings raise a paradox: How can proteins that have highly similar DNA binding properties perform different functions in the animal by regulating different sets of target genes? In this study, we address this question by studying how two Hox factors regulate the expression of target genes that specify leg development and the making of liver-like cells in the developing fly. By comparing and contrasting how Hox target genes are activated and/or repressed, we found that the same Hox binding sites can mediate either activation or repression in a manner that depends upon context. In addition, we found that a Hox binding site that is normally regulated by only one Hox factor, can also be used by more than one Hox factor swapped into another target gene. These findings indicate that the specificity of a Hox factor to regulate target genes does not rely solely upon DNA binding specificity but also requires regulatory specificity.

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