scholarly journals Genome-wide prediction of topoisomerase IIβ binding by architectural factors and chromatin accessibility

2021 ◽  
Vol 17 (1) ◽  
pp. e1007814
Author(s):  
Pedro Manuel Martínez-García ◽  
Miguel García-Torres ◽  
Federico Divina ◽  
José Terrón-Bautista ◽  
Irene Delgado-Sainz ◽  
...  

DNA topoisomerase II-β (TOP2B) is fundamental to remove topological problems linked to DNA metabolism and 3D chromatin architecture, but its cut-and-reseal catalytic mechanism can accidentally cause DNA double-strand breaks (DSBs) that can seriously compromise genome integrity. Understanding the factors that determine the genome-wide distribution of TOP2B is therefore not only essential for a complete knowledge of genome dynamics and organization, but also for the implications of TOP2-induced DSBs in the origin of oncogenic translocations and other types of chromosomal rearrangements. Here, we conduct a machine-learning approach for the prediction of TOP2B binding using publicly available sequencing data. We achieve highly accurate predictions, with accessible chromatin and architectural factors being the most informative features. Strikingly, TOP2B is sufficiently explained by only three features: DNase I hypersensitivity, CTCF and cohesin binding, for which genome-wide data are widely available. Based on this, we develop a predictive model for TOP2B genome-wide binding that can be used across cell lines and species, and generate virtual probability tracks that accurately mirror experimental ChIP-seq data. Our results deepen our knowledge on how the accessibility and 3D organization of chromatin determine TOP2B function, and constitute a proof of principle regarding the in silico prediction of sequence-independent chromatin-binding factors.

2020 ◽  
Author(s):  
Pedro Manuel Martínez-García ◽  
Miguel García-Torres ◽  
Federico Divina ◽  
José Terrón-Bautista ◽  
Irene Delgado-Sainz ◽  
...  

AbstractDNA topoisomerase II-β (TOP2B) is fundamental to remove topological problems linked to DNA metabolism and 3D chromatin architecture, but its cut-and-reseal catalytic mechanism can accidentally cause DNA double-strand breaks (DSBs) that can seriously compromise genome integrity. Understanding the factors that determine the genome-wide distribution of TOP2B is therefore not only essential for a complete knowledge of genome dynamics and organization, but also for the implications of TOP2-induced DSBs in the origin of oncogenic translocations and other types of chromosomal rearrangements. Here, we conduct a machine-learning approach for the prediction of TOP2B binding sites using publicly available sequencing data. We achieve highly accurate predictions, with accessible chromatin and architectural factors being the most informative features. Strikingly, TOP2B is sufficiently explained by only three features: DNase I hypersensitivity, CTCF and cohesin binding, for which genome-wide data are widely available. Based on this, we develop a predictive model for TOP2B genome-wide binding that can be used across cell lines and species, and generate virtual probability tracks that accurately mirror experimental ChIP-seq data. Our results deepen our knowledge on how the accessibility and 3D organization of chromatin determine TOP2B function, and constitute a proof of principle regarding the in silico prediction of sequence-independent chromatin-binding factors.Author summaryType II DNA topoisomerases (TOP2) are a double-edged sword. They solve topological problems in the form of supercoiling, knots and tangles that inevitably accompany genome metabolism, but they do so at the cost of transiently cleaving DNA, with the risk that this entails for genome integrity, and the serious consequences for human health, such as neurodegeneration, developmental disorders or predisposition to cancer. A comprehensive analysis of TOP2 distribution throughout the genome is therefore essential for a deep understanding of its function and regulation, and how this can affect genome dynamics and stability. Here, we use machine learning to thoroughly explore genome-wide binding of TOP2B, a vertebrate TOP2 paralog that has been linked to genome organization and cancer-associated translocations. Our analysis shows that TOP2B-DNA binding can be accurately predicted exclusively using information on DNA accessibility and binding of genome-architecture factors. We show that such information is enough to generate virtual maps of TOP2B binding along the genome, which we validate with de novo experimental data. Our results highlight the importance of TOP2B for accessibility and 3D organization of chromatin, and show that computationally predicted TOP2 maps can be accurately obtained using minimal publicly available datasets, opening the door for their use in different organisms, cell types and conditions with experimental and/or clinical relevance.


2018 ◽  
Vol 156 (4) ◽  
pp. 215-222 ◽  
Author(s):  
Lucas A.M. Rosolen ◽  
Marcelo R. Vicari ◽  
Mara C. Almeida

Coleoptera is the most diverse order among insects, and comparative molecular cytogenetic studies in this group are lacking. The species of Omophoita (Oedionychina) possess a karyotype of 2n = 22 = 10II+X+Y. They are interesting models for evolutionary cytogenetic studies due to giant sex chromosomes which are asynaptic during meiosis. Transposable elements (TEs) confer plasticity and mobility to genomes and are considered hotspots for DNA double-strand breaks and chromosomal rearrangements. The objective of the present study was to verify the role of TEs in the karyotype and in the size expansion of the giant sex chromosomes in Omophoita. Thus, different TEs were characterized in the Omophoita genome and localized in the chromosomes by fluorescence in situ hybridization (FISH). The DNA sequencing data revealed identity with TE families Tc1/Mariner and RTE/L1-56_XT. FISH showed signals of all TEs in the karyotypes and a high accumulation in the sex chromosomes of the 3 Omophoita species analyzed. These data suggest that the genome size expansion and the origin of the giant sex chromosomes of Omophoita are due to an intensive genomic invasion of TEs, as those characterized here as Tc1/Mariner-Ooc and RTE-Ooc. Differences in the chromosomal location of the TEs among the 3 species indicate that they have participated in the karyotype differentiation in Omophoita.


Author(s):  
Abhishek Mitra ◽  
Norbert Dojer ◽  
Bernard Fongang ◽  
Jules Nde ◽  
Yingjie Zhu ◽  
...  

AbstractDNA double-strand breaks (DSBs), are a major threat to genomic stability and may lead to cancer. Several technologies to accurately detect DSBs genome-wide have been developed recently, but still lacking publicly available tools for analysis of the resulting data. Here, we present a step-by-step iSeq package (http://breakome.utmb.edu/software.html), custom designed for analysis and interpretation of DSB-sequencing data. iSeq performs barcode trimming and read counting, and identifies DSB-enriched regions by statistical test and annotate them to the desired genomic features. Applying this package, users can identify and annotate DSB-enriched regions from base pair (eg. Cas9 cleavage sites) up to megabase (eg. DNA replication stress-induced) resolution, and if possible quantify DSB frequencies per cell genome-wide by combining with qDSB-Seq. iSeq can be used for any sequencing-based DSB detection techniques. The analysis for Steps 1-19 can be performed within ~4 hours.


2021 ◽  
Vol 2 (2) ◽  
pp. 100554
Author(s):  
Ishita Joshi ◽  
Jenna DeRycke ◽  
Megan Palmowski ◽  
Robert LeSuer ◽  
Wenyi Feng

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Anna Biernacka ◽  
Yingjie Zhu ◽  
Magdalena Skrzypczak ◽  
Romain Forey ◽  
Benjamin Pardo ◽  
...  

AbstractMaintenance of genome stability is a key issue for cell fate that could be compromised by chromosome deletions and translocations caused by DNA double-strand breaks (DSBs). Thus development of precise and sensitive tools for DSBs labeling is of great importance for understanding mechanisms of DSB formation, their sensing and repair. Until now there has been no high resolution and specific DSB detection technique that would be applicable to any cells regardless of their size. Here, we present i-BLESS, a universal method for direct genome-wide DNA double-strand break labeling in cells immobilized in agarose beads. i-BLESS has three key advantages: it is the only unbiased method applicable to yeast, achieves a sensitivity of one break at a given position in 100,000 cells, and eliminates background noise while still allowing for fixation of samples. The method allows detection of ultra-rare breaks such as those forming spontaneously at G-quadruplexes.


2021 ◽  
Author(s):  
Supawat Thongthip ◽  
Annika Carlson ◽  
Madzia P. Crossley ◽  
Bjoern Schwer

ABSTRACTRecent work has revealed classes of recurrent DNA double-strand breaks (DSBs) in neural stem/progenitor cells, including transcription-associated, promoter-proximal breaks and recurrent DSB clusters in late-replicating, long neural genes. However, the mechanistic factors promoting these different classes of DSBs in neural stem/progenitor cells are not understood. Here, we elucidated the genome-wide landscape of DNA:RNA hybrid structures called “R-loops” in primary neural stem/progenitor cells in order to assess their contribution to the different classes of DNA break “hotspots”. We report that R-loops in neural stem/progenitor cells are associated primarily with transcribed regions that replicate early and genes that show GC skew in their promoter region. Surprisingly, the majority of genes with recurrent DSB clusters in long, neural genes does not show substantial R-loop accumulation. We implicate R-loops in promoter-proximal DNA break formation in highly transcribed, early replicating regions and conclude that R-loops are not a driver of recurrent double-strand break cluster formation in most long, neural genes. Together, our study provides an understanding of how R-loops may contribute to DNA break hotspots and affect lineage-specific processes in neural stem/progenitor cells.


2021 ◽  
Vol 11 ◽  
Author(s):  
Matthew J. Rybin ◽  
Melina Ramic ◽  
Natalie R. Ricciardi ◽  
Philipp Kapranov ◽  
Claes Wahlestedt ◽  
...  

Genome instability is associated with myriad human diseases and is a well-known feature of both cancer and neurodegenerative disease. Until recently, the ability to assess DNA damage—the principal driver of genome instability—was limited to relatively imprecise methods or restricted to studying predefined genomic regions. Recently, new techniques for detecting DNA double strand breaks (DSBs) and single strand breaks (SSBs) with next-generation sequencing on a genome-wide scale with single nucleotide resolution have emerged. With these new tools, efforts are underway to define the “breakome” in normal aging and disease. Here, we compare the relative strengths and weaknesses of these technologies and their potential application to studying neurodegenerative diseases.


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