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Yi C, Liu Q, Huang Y, Liu C, Guo X, Fan C, Zhang K, Liu Y, Han F. Non-B-form DNA is associated with centromere stability in newly-formed polyploid wheat. SCIENCE CHINA. LIFE SCIENCES 2024; 67:1479-1488. [PMID: 38639838 DOI: 10.1007/s11427-023-2513-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Accepted: 12/18/2023] [Indexed: 04/20/2024]
Abstract
Non-B-form DNA differs from the classic B-DNA double helix structure and plays a crucial regulatory role in replication and transcription. However, the role of non-B-form DNA in centromeres, especially in polyploid wheat, remains elusive. Here, we systematically analyzed seven non-B-form DNA motif profiles (A-phased DNA repeat, direct repeat, G-quadruplex, inverted repeat, mirror repeat, short tandem repeat, and Z-DNA) in hexaploid wheat. We found that three of these non-B-form DNA motifs were enriched at centromeric regions, especially at the CENH3-binding sites, suggesting that non-B-form DNA may create a favorable loading environment for the CENH3 nucleosome. To investigate the dynamics of centromeric non-B form DNA during the alloploidization process, we analyzed DNA secondary structure using CENH3 ChIP-seq data from newly formed allotetraploid wheat and its two diploid ancestors. We found that newly formed allotetraploid wheat formed more non-B-form DNA in centromeric regions compared with their parents, suggesting that non-B-form DNA is related to the localization of the centromeric regions in newly formed wheat. Furthermore, non-B-form DNA enriched in the centromeric regions was found to preferentially form on young LTR retrotransposons, explaining CENH3's tendency to bind to younger LTR. Collectively, our study describes the landscape of non-B-form DNA in the wheat genome, and sheds light on its potential role in the evolution of polyploid centromeres.
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Affiliation(s)
- Congyang Yi
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Qian Liu
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yuhong Huang
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chang Liu
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xianrui Guo
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chaolan Fan
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Kaibiao Zhang
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yang Liu
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Fangpu Han
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
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Shi X, Teng H, Sun Z. An updated overview of experimental and computational approaches to identify non-canonical DNA/RNA structures with emphasis on G-quadruplexes and R-loops. Brief Bioinform 2022; 23:6751149. [PMID: 36208174 PMCID: PMC9677470 DOI: 10.1093/bib/bbac441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 08/22/2022] [Accepted: 09/13/2022] [Indexed: 12/14/2022] Open
Abstract
Multiple types of non-canonical nucleic acid structures play essential roles in DNA recombination and replication, transcription, and genomic instability and have been associated with several human diseases. Thus, an increasing number of experimental and bioinformatics methods have been developed to identify these structures. To date, most reviews have focused on the features of non-canonical DNA/RNA structure formation, experimental approaches to mapping these structures, and the association of these structures with diseases. In addition, two reviews of computational algorithms for the prediction of non-canonical nucleic acid structures have been published. One of these reviews focused only on computational approaches for G4 detection until 2020. The other mainly summarized the computational tools for predicting cruciform, H-DNA and Z-DNA, in which the algorithms discussed were published before 2012. Since then, several experimental and computational methods have been developed. However, a systematic review including the conformation, sequencing mapping methods and computational prediction strategies for these structures has not yet been published. The purpose of this review is to provide an updated overview of conformation, current sequencing technologies and computational identification methods for non-canonical nucleic acid structures, as well as their strengths and weaknesses. We expect that this review will aid in understanding how these structures are characterised and how they contribute to related biological processes and diseases.
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Affiliation(s)
- Xiaohui Shi
- Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The first Affiliated Hospital of WMU; Beijing Institutes of Life Science, Chinese Academy of Sciences; University of Chinese Academy of Sciences, Ouhai District, Wenzhou 325000, China
| | - Huajing Teng
- Department of Radiation Oncology, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education) at Peking University Cancer Hospital and Institute, Ouhai District, Wenzhou 325000, China
| | - Zhongsheng Sun
- Corresponding author: Zhongsheng Sun, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The 1st Affiliated Hospital of WMU, Nanbaixiang Wenyi Yiyuan Xinyuan District, Ouhai District, Wenzhou 325000, China. E-mail:
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R-Loop Tracker: Web Access-Based Tool for R-Loop Detection and Analysis in Genomic DNA Sequences. Int J Mol Sci 2021; 22:ijms222312857. [PMID: 34884661 PMCID: PMC8657672 DOI: 10.3390/ijms222312857] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 11/19/2021] [Accepted: 11/25/2021] [Indexed: 12/02/2022] Open
Abstract
R-loops are common non-B nucleic acid structures formed by a three-stranded nucleic acid composed of an RNA–DNA hybrid and a displaced single-stranded DNA (ssDNA) loop. Because the aberrant R-loop formation leads to increased mutagenesis, hyper-recombination, rearrangements, and transcription-replication collisions, it is regarded as important in human diseases. Therefore, its prevalence and distribution in genomes are studied intensively. However, in silico tools for R-loop prediction are limited, and therefore, we have developed the R-loop tracker tool, which was implemented as a part of the DNA Analyser web server. This new tool is focused upon (1) prediction of R-loops in genomic DNA without length and sequence limitations; (2) integration of R-loop tracker results with other tools for nucleic acids analyses, including Genome Browser; (3) internal cross-evaluation of in silico results with experimental data, where available; (4) easy export and correlation analyses with other genome features and markers; and (5) enhanced visualization outputs. Our new R-loop tracker tool is freely accessible on the web pages of DNA Analyser tools, and its implementation on the web-based server allows effective analyses not only for DNA segments but also for full chromosomes and genomes.
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Karageorgiou C, Tarrío R, Rodríguez-Trelles F. The Cyclically Seasonal Drosophila subobscura Inversion O 7 Originated From Fragile Genomic Sites and Relocated Immunity and Metabolic Genes. Front Genet 2020; 11:565836. [PMID: 33193649 PMCID: PMC7584159 DOI: 10.3389/fgene.2020.565836] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 09/09/2020] [Indexed: 11/28/2022] Open
Abstract
Chromosome inversions are important contributors to standing genetic variation in Drosophila subobscura. Presently, the species is experiencing a rapid replacement of high-latitude by low-latitude inversions associated with global warming. Yet not all low-latitude inversions are correlated with the ongoing warming trend. This is particularly unexpected in the case of O7 because it shows a regular seasonal cycle that peaks in summer and rose with a heatwave. The inconsistent behavior of O7 across components of the ambient temperature suggests that is causally more complex than simply due to temperature alone. In order to understand the dynamics of O7, high-quality genomic data are needed to determine both the breakpoints and the genetic content. To fill this gap, here we generated a PacBio long read-based chromosome-scale genome assembly, from a highly homozygous line made isogenic for an O3 + 4 + 7 chromosome. Then we isolated the complete continuous sequence of O7 by conserved synteny analysis with the available reference genome. Main findings include the following: (i) the assembled O7 inversion stretches 9.936 Mb, containing > 1,000 annotated genes; (ii) O7 had a complex origin, involving multiple breaks associated with non-B DNA-forming motifs, formation of a microinversion, and ectopic repair in trans with the two homologous chromosomes; (iii) the O7 breakpoints carry a pre-inversion record of fragility, including a sequence insertion, and transposition with later inverted duplication of an Attacin immunity gene; and (iv) the O7 inversion relocated the major insulin signaling forkhead box subgroup O (foxo) gene in tight linkage with its antagonistic regulatory partner serine/threonine-protein kinase B (Akt1) and disrupted concerted evolution of the two inverted Attacin duplicates, reattaching them to dFOXO metabolic enhancers. Our findings suggest that O7 exerts antagonistic pleiotropic effects on reproduction and immunity, setting a framework to understand its relationship with climate change. Furthermore, they are relevant for fragility in genome rearrangement evolution and for current views on the contribution of breakage versus repair in shaping inversion-breakpoint junctions.
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Affiliation(s)
- Charikleia Karageorgiou
- Grup de Genòmica, Bioinformàtica i Biologia Evolutiva (GGBE), Departament de Genètica i de Microbiologia, Universitat Autonòma de Barcelona, Barcelona, Spain
| | - Rosa Tarrío
- Grup de Genòmica, Bioinformàtica i Biologia Evolutiva (GGBE), Departament de Genètica i de Microbiologia, Universitat Autonòma de Barcelona, Barcelona, Spain
| | - Francisco Rodríguez-Trelles
- Grup de Genòmica, Bioinformàtica i Biologia Evolutiva (GGBE), Departament de Genètica i de Microbiologia, Universitat Autonòma de Barcelona, Barcelona, Spain
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Deciphering the complexity of simple chromosomal insertions by genome sequencing. Hum Genet 2020; 140:361-380. [PMID: 32728808 DOI: 10.1007/s00439-020-02210-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 07/22/2020] [Indexed: 10/23/2022]
Abstract
Chromosomal insertions are thought to be rare structural rearrangements. The current understanding of the underlying mechanisms of their origin is still limited. In this study, we sequenced 16 cases with apparent simple insertions previously identified by karyotyping and/or chromosomal microarray analysis. Using mate-pair genome sequencing (GS), we identified all 16 insertions and revised previously designated karyotypes in 75.0% (12/16) of the cases. Additional cryptic rearrangements were identified in 68.8% of the cases (11/16). The incidence of additional cryptic rearrangements in chromosomal insertions was significantly higher compared to balanced translocations and inversions reported in other studies by GS. We characterized and classified the cryptic insertion rearrangements into four groups, which were not mutually exclusive: (1) insertion segments were fragmented and their subsegments rearranged and clustered at the insertion site (10/16, 62.5%); (2) one or more cryptic subsegments were not inserted into the insertion site (5/16, 31.3%); (3) segments of the acceptor chromosome were scattered and rejoined with the insertion segments (2/16, 12.5%); and (4) copy number gains were identified in the flanking regions of the insertion site (2/16, 12.5%). In addition to the observation of these chromothripsis- or chromoanasynthesis-like events, breakpoint sequence analysis revealed microhomology to be the predominant feature. However, no significant correlation was found between the number of cryptic rearrangements and the size of the insertion. Overall, our study provide molecular characterization of karyotypically apparent simple insertions, demonstrate previously underappreciated complexities, and evidence that chromosomal insertions are likely formed by nonhomologous end joining and/or microhomology-mediated replication-based DNA repair.
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Beauclair L, Ramé C, Arensburger P, Piégu B, Guillou F, Dupont J, Bigot Y. Sequence properties of certain GC rich avian genes, their origins and absence from genome assemblies: case studies. BMC Genomics 2019; 20:734. [PMID: 31610792 PMCID: PMC6792250 DOI: 10.1186/s12864-019-6131-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 09/23/2019] [Indexed: 12/14/2022] Open
Abstract
Background More and more eukaryotic genomes are sequenced and assembled, most of them presented as a complete model in which missing chromosomal regions are filled by Ns and where a few chromosomes may be lacking. Avian genomes often contain sequences with high GC content, which has been hypothesized to be at the origin of many missing sequences in these genomes. We investigated features of these missing sequences to discover why some may not have been integrated into genomic libraries and/or sequenced. Results The sequences of five red jungle fowl cDNA models with high GC content were used as queries to search publicly available datasets of Illumina and Pacbio sequencing reads. These were used to reconstruct the leptin, TNFα, MRPL52, PCP2 and PET100 genes, all of which are absent from the red jungle fowl genome model. These gene sequences displayed elevated GC contents, had intron sizes that were sometimes larger than non-avian orthologues, and had non-coding regions that contained numerous tandem and inverted repeat sequences with motifs able to assemble into stable G-quadruplexes and intrastrand dyadic structures. Our results suggest that Illumina technology was unable to sequence the non-coding regions of these genes. On the other hand, PacBio technology was able to sequence these regions, but with dramatically lower efficiency than would typically be expected. Conclusions High GC content was not the principal reason why numerous GC-rich regions of avian genomes are missing from genome assembly models. Instead, it is the presence of tandem repeats containing motifs capable of assembling into very stable secondary structures that is likely responsible.
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Affiliation(s)
- Linda Beauclair
- PRC, UMR INRA0085, CNRS 7247, Centre INRA Val de Loire, 37380, Nouzilly, France
| | - Christelle Ramé
- PRC, UMR INRA0085, CNRS 7247, Centre INRA Val de Loire, 37380, Nouzilly, France
| | - Peter Arensburger
- Biological Sciences Department, California State Polytechnic University, Pomona, CA, 91768, USA
| | - Benoît Piégu
- PRC, UMR INRA0085, CNRS 7247, Centre INRA Val de Loire, 37380, Nouzilly, France
| | - Florian Guillou
- PRC, UMR INRA0085, CNRS 7247, Centre INRA Val de Loire, 37380, Nouzilly, France
| | - Joëlle Dupont
- PRC, UMR INRA0085, CNRS 7247, Centre INRA Val de Loire, 37380, Nouzilly, France
| | - Yves Bigot
- PRC, UMR INRA0085, CNRS 7247, Centre INRA Val de Loire, 37380, Nouzilly, France.
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Cechová J, Lýsek J, Bartas M, Brázda V. Complex analyses of inverted repeats in mitochondrial genomes revealed their importance and variability. Bioinformatics 2019; 34:1081-1085. [PMID: 29126205 PMCID: PMC6030915 DOI: 10.1093/bioinformatics/btx729] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 11/07/2017] [Indexed: 01/08/2023] Open
Abstract
Motivation The NCBI database contains mitochondrial DNA (mtDNA) genomes from numerous species. We investigated the presence and locations of inverted repeat sequences (IRs) in these mtDNA sequences, which are known to be important for regulating nuclear genomes. Results IRs were identified in mtDNA in all species. IR lengths and frequencies correlate with evolutionary age and the greatest variability was detected in subgroups of plants and fungi and the lowest variability in mammals. IR presence is non-random and evolutionary favoured. The frequency of IRs generally decreased with IR length, but not for IRs 24 or 30 bp long, which are 1.5 times more abundant. IRs are enriched in sequences from the replication origin, followed by D-loop, stem-loop and miscellaneous sequences, pointing to the importance of IRs in regulatory regions of mitochondrial DNA. Availability and implementation Data were produced using Palindrome analyser, freely available on the web at http://bioinformatics.ibp.cz. Supplementary information Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Jana Cechová
- Department of Biophysical Chemistry and Molecular Oncology, Institute of Biophysics, The Czech Academy of Sciences, 612 65 Brno, Czech Republic
| | - Jirí Lýsek
- Department of Informatics, Mendel University in Brno, 613 00 Brno, Czech Republic
| | - Martin Bartas
- Department of Biophysical Chemistry and Molecular Oncology, Institute of Biophysics, The Czech Academy of Sciences, 612 65 Brno, Czech Republic.,Department of Biology and Ecology/Institute of Environmental Technologies, Faculty of Science, University of Ostrava, 701 03 Ostrava, Czech Republic
| | - Václav Brázda
- Department of Biophysical Chemistry and Molecular Oncology, Institute of Biophysics, The Czech Academy of Sciences, 612 65 Brno, Czech Republic
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Brázda V, Červeň J, Bartas M, Mikysková N, Coufal J, Pečinka P. The Amino Acid Composition of Quadruplex Binding Proteins Reveals a Shared Motif and Predicts New Potential Quadruplex Interactors. Molecules 2018; 23:E2341. [PMID: 30216987 PMCID: PMC6225207 DOI: 10.3390/molecules23092341] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 09/09/2018] [Accepted: 09/12/2018] [Indexed: 12/27/2022] Open
Abstract
The importance of local DNA structures in the regulation of basic cellular processes is an emerging field of research. Amongst local non-B DNA structures, G-quadruplexes are perhaps the most well-characterized to date, and their presence has been demonstrated in many genomes, including that of humans. G-quadruplexes are selectively bound by many regulatory proteins. In this paper, we have analyzed the amino acid composition of all seventy-seven described G-quadruplex binding proteins of Homo sapiens. Our comparison with amino acid frequencies in all human proteins and specific protein subsets (e.g., all nucleic acid binding) revealed unique features of quadruplex binding proteins, with prominent enrichment for glycine (G) and arginine (R). Cluster analysis with bootstrap resampling shows similarities and differences in amino acid composition of particular quadruplex binding proteins. Interestingly, we found that all characterized G-quadruplex binding proteins share a 20 amino acid long motif/domain (RGRGR GRGGG SGGSG GRGRG) which is similar to the previously described RG-rich domain (RRGDG RRRGG GGRGQ GGRGR GGGFKG) of the FRM1 G-quadruplex binding protein. Based on this protein fingerprint, we have predicted a new set of potential G-quadruplex binding proteins sharing this interesting domain rich in glycine and arginine residues.
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Affiliation(s)
- Václav Brázda
- Institute of Biophysics, Academy of Sciences of the Czech Republic v.v.i., Královopolská 135, 612 65 Brno, Czech Republic.
| | - Jiří Červeň
- Department of Biology and Ecology/Institute of Environmental Technologies, Faculty of Science, University of Ostrava, 710 00 Ostrava, Czech Republic.
| | - Martin Bartas
- Department of Biology and Ecology/Institute of Environmental Technologies, Faculty of Science, University of Ostrava, 710 00 Ostrava, Czech Republic.
| | - Nikol Mikysková
- Department of Biology and Ecology/Institute of Environmental Technologies, Faculty of Science, University of Ostrava, 710 00 Ostrava, Czech Republic.
| | - Jan Coufal
- Institute of Biophysics, Academy of Sciences of the Czech Republic v.v.i., Královopolská 135, 612 65 Brno, Czech Republic.
| | - Petr Pečinka
- Department of Biology and Ecology/Institute of Environmental Technologies, Faculty of Science, University of Ostrava, 710 00 Ostrava, Czech Republic.
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Antipova VN, Reveguk ZV, Kraynyukov ES, Zyrina NV. Structure of DNA obtained during the ab initio synthesis by Bst DNA polymerase in the presence of the nicking endonuclease from Bacillus stearothermophilus (Nt.BstNBI). J Biomol Struct Dyn 2018; 37:3314-3321. [PMID: 30146945 DOI: 10.1080/07391102.2018.1515662] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Valeriya N Antipova
- a Laboratory of Biophysics of Active Media , Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences , Pushchino , Moscow , Russia
| | - Zakhar V Reveguk
- b Centre for Diagnostics of Functional Materials for Medicine, Pharmacology and Nanoelectronics , St. Petersburg State University , St. Petersburg , Russia
| | - Evgeny S Kraynyukov
- b Centre for Diagnostics of Functional Materials for Medicine, Pharmacology and Nanoelectronics , St. Petersburg State University , St. Petersburg , Russia
| | - Nadezhda V Zyrina
- c Laboratory of Crystallophysics and X-ray Research , Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences , Pushchino , Moscow , Russia
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Brázda V, Coufal J. Recognition of Local DNA Structures by p53 Protein. Int J Mol Sci 2017; 18:ijms18020375. [PMID: 28208646 PMCID: PMC5343910 DOI: 10.3390/ijms18020375] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 02/03/2017] [Indexed: 02/06/2023] Open
Abstract
p53 plays critical roles in regulating cell cycle, apoptosis, senescence and metabolism and is commonly mutated in human cancer. These roles are achieved by interaction with other proteins, but particularly by interaction with DNA. As a transcription factor, p53 is well known to bind consensus target sequences in linear B-DNA. Recent findings indicate that p53 binds with higher affinity to target sequences that form cruciform DNA structure. Moreover, p53 binds very tightly to non-B DNA structures and local DNA structures are increasingly recognized to influence the activity of wild-type and mutant p53. Apart from cruciform structures, p53 binds to quadruplex DNA, triplex DNA, DNA loops, bulged DNA and hemicatenane DNA. In this review, we describe local DNA structures and summarize information about interactions of p53 with these structural DNA motifs. These recent data provide important insights into the complexity of the p53 pathway and the functional consequences of wild-type and mutant p53 activation in normal and tumor cells.
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Affiliation(s)
- Václav Brázda
- Institute of Biophysics, Academy of Sciences of the Czech Republic v.v.i., Královopolská 135, 612 65 Brno, Czech Republic.
| | - Jan Coufal
- Institute of Biophysics, Academy of Sciences of the Czech Republic v.v.i., Královopolská 135, 612 65 Brno, Czech Republic.
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11
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Singh HN, Rajeswari MR. Gene regulation by long purine tracks in brain related diseases. Data Brief 2015; 5:218-25. [PMID: 26543885 PMCID: PMC4589756 DOI: 10.1016/j.dib.2015.08.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2015] [Revised: 08/15/2015] [Accepted: 08/24/2015] [Indexed: 11/26/2022] Open
Abstract
Purine repeats are randomly distributed in the human genome, however, they show potential role in the transcriptional deregulation of genes. Presence of long tracks of purine repeats in the genome can disturb its integrity and interfere with the cellular behavior by introducing mutations and/or triple stranded structure formation in DNA. Our data revealed interesting finding that a majority of genes carrying purine repeats, of length n≥200, were down regulated and found to be linked with several brain related diseases [1]. The unique feature of the purine repeats found in the present study clearly manifests their significant application in developing therapeutics for neurological diseases.
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Coppieters F, Todeschini AL, Fujimaki T, Baert A, De Bruyne M, Van Cauwenbergh C, Verdin H, Bauwens M, Ongenaert M, Kondo M, Meire F, Murakami A, Veitia RA, Leroy BP, De Baere E. Hidden Genetic Variation in LCA9-Associated Congenital Blindness Explained by 5'UTR Mutations and Copy-Number Variations of NMNAT1. Hum Mutat 2015; 36:1188-96. [PMID: 26316326 PMCID: PMC5054839 DOI: 10.1002/humu.22899] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 08/19/2015] [Indexed: 11/28/2022]
Abstract
Leber congenital amaurosis (LCA) is a severe autosomal‐recessive retinal dystrophy leading to congenital blindness. A recently identified LCA gene is NMNAT1, located in the LCA9 locus. Although most mutations in blindness genes are coding variations, there is accumulating evidence for hidden noncoding defects or structural variations (SVs). The starting point of this study was an LCA9‐associated consanguineous family in which no coding mutations were found in the LCA9 region. Exploring the untranslated regions of NMNAT1 revealed a novel homozygous 5′UTR variant, c.‐70A>T. Moreover, an adjacent 5′UTR variant, c.‐69C>T, was identified in a second consanguineous family displaying a similar phenotype. Both 5′UTR variants resulted in decreased NMNAT1 mRNA abundance in patients’ lymphocytes, and caused decreased luciferase activity in human retinal pigment epithelial RPE‐1 cells. Second, we unraveled pseudohomozygosity of a coding NMNAT1 mutation in two unrelated LCA patients by the identification of two distinct heterozygous partial NMNAT1 deletions. Molecular characterization of the breakpoint junctions revealed a complex Alu‐rich genomic architecture. Our study uncovered hidden genetic variation in NMNAT1‐associated LCA and emphasized a shift from coding to noncoding regulatory mutations and repeat‐mediated SVs in the molecular pathogenesis of heterogeneous recessive disorders such as hereditary blindness.
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Affiliation(s)
| | | | - Takuro Fujimaki
- Department of Ophthalmology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Annelot Baert
- Center for Medical Genetics Ghent, Ghent University, Ghent, Belgium
| | | | | | - Hannah Verdin
- Center for Medical Genetics Ghent, Ghent University, Ghent, Belgium
| | - Miriam Bauwens
- Center for Medical Genetics Ghent, Ghent University, Ghent, Belgium
| | - Maté Ongenaert
- Center for Medical Genetics Ghent, Ghent University, Ghent, Belgium
| | - Mineo Kondo
- Department of Ophthalmology, Mie University Graduate School of Medicine, Mie, Japan
| | - Françoise Meire
- Department of Ophthalmology, Queen Fabiola Children's University Hospital, Brussels, Belgium
| | - Akira Murakami
- Department of Ophthalmology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Reiner A Veitia
- Institut Jacques Monod, UMR 7592 CNRS-Université Paris Diderot, Paris, France
| | - Bart P Leroy
- Center for Medical Genetics Ghent, Ghent University, Ghent, Belgium.,Department of Ophthalmology, Ghent University Hospital, Ghent, Belgium.,Division of Ophthalmology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Elfride De Baere
- Center for Medical Genetics Ghent, Ghent University, Ghent, Belgium
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Singh HN, Rajeswari MR. Identification of genes containing expanded purine repeats in the human genome and their apparent protective role against cancer. J Biomol Struct Dyn 2015; 34:689-704. [PMID: 25990537 DOI: 10.1080/07391102.2015.1049553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Purine repeat sequences present in a gene are unique as they have high propensity to form unusual DNA-triple helix structures. Friedreich's ataxia is the only human disease that is well known to be associated with DNA-triplexes formed by purine repeats. The purpose of this study was to recognize the expanded purine repeats (EPRs) in human genome and find their correlation with cancer pathogenesis. We developed "PuRepeatFinder.pl" algorithm to identify non-overlapping EPRs without pyrimidine interruptions in the human genome and customized for searching repeat lengths, n ≥ 200. A total of 1158 EPRs were identified in the genome which followed Wakeby distribution. Two hundred and ninety-six EPRs were found in geneic regions of 282 genes (EPR-genes). Gene clustering of EPR-genes was done based on their cellular function and a large number of EPR-genes were found to be enzymes/enzyme modulators. Meta-analysis of 282 EPR-genes identified only 63 EPR-genes in association with cancer, mostly in breast, lung, and blood cancers. Protein-protein interaction network analysis of all 282 EPR-genes identified proteins including those in cadherins and VEGF. The two observations, that EPRs can induce mutations under malignant conditions and that identification of some EPR-gene products in vital cell signaling-mediated pathways, together suggest the crucial role of EPRs in carcinogenesis. The new link between EPR-genes and their functionally interacting proteins throws a new dimension in the present understanding of cancer pathogenesis and can help in planning therapeutic strategies. Validation of present results using techniques like NGS is required to establish the role of the EPR genes in cancer pathology.
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Affiliation(s)
- Himanshu Narayan Singh
- a Department of Biochemistry , All India Institute of Medical Sciences , Room No: 3005A, New Delhi 110029 , India
| | - Moganty R Rajeswari
- a Department of Biochemistry , All India Institute of Medical Sciences , Room No: 3005A, New Delhi 110029 , India
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DNA and RNA quadruplex-binding proteins. Int J Mol Sci 2014; 15:17493-517. [PMID: 25268620 PMCID: PMC4227175 DOI: 10.3390/ijms151017493] [Citation(s) in RCA: 191] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Revised: 09/15/2014] [Accepted: 09/22/2014] [Indexed: 02/01/2023] Open
Abstract
Four-stranded DNA structures were structurally characterized in vitro by NMR, X-ray and Circular Dichroism spectroscopy in detail. Among the different types of quadruplexes (i-Motifs, minor groove quadruplexes, G-quadruplexes, etc.), the best described are G-quadruplexes which are featured by Hoogsteen base-paring. Sequences with the potential to form quadruplexes are widely present in genome of all organisms. They are found often in repetitive sequences such as telomeric ones, and also in promoter regions and 5' non-coding sequences. Recently, many proteins with binding affinity to G-quadruplexes have been identified. One of the initially portrayed G-rich regions, the human telomeric sequence (TTAGGG)n, is recognized by many proteins which can modulate telomerase activity. Sequences with the potential to form G-quadruplexes are often located in promoter regions of various oncogenes. The NHE III1 region of the c-MYC promoter has been shown to interact with nucleolin protein as well as other G-quadruplex-binding proteins. A number of G-rich sequences are also present in promoter region of estrogen receptor alpha. In addition to DNA quadruplexes, RNA quadruplexes, which are critical in translational regulation, have also been predicted and observed. For example, the RNA quadruplex formation in telomere-repeat-containing RNA is involved in interaction with TRF2 (telomere repeat binding factor 2) and plays key role in telomere regulation. All these fundamental examples suggest the importance of quadruplex structures in cell processes and their understanding may provide better insight into aging and disease development.
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Abstract
Repetitive genomic sequences can adopt a number of alternative DNA structures that differ from the canonical B-form duplex (i.e. non-B DNA). These non-B DNA-forming sequences have been shown to have many important biological functions related to DNA metabolic processes; for example, they may have regulatory roles in DNA transcription and replication. In addition to these regulatory functions, non-B DNA can stimulate genetic instability in the presence or absence of DNA damage, via replication-dependent and/or replication-independent pathways. This review focuses on the interactions of non-B DNA conformations with DNA repair proteins and how these interactions impact genetic instability.
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Affiliation(s)
- Guliang Wang
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Dell Pediatric Research Institute, 1400 Barbara Jordan Blvd. R1800, Austin, TX 78723, United States
| | - Karen M Vasquez
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Dell Pediatric Research Institute, 1400 Barbara Jordan Blvd. R1800, Austin, TX 78723, United States.
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Luke JM, Carnes AE, Williams JA. Development of antibiotic-free selection system for safer DNA vaccination. Methods Mol Biol 2014; 1143:91-111. [PMID: 24715283 DOI: 10.1007/978-1-4939-0410-5_6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The use of antibiotic-resistance markers in DNA vaccines is discouraged by regulatory agencies due to various theoretical safety concerns. This chapter presents methodologies for the design and cloning of synthetic antigen genes into RNA-OUT encoding antibiotic-free DNA vaccine vectors that are additionally optimized to improve protein expression, and immunogenicity, compared to alternative kanamycin-resistant vectors. First, antigen targeting considerations are discussed in the context of immune response customization through MHC class I or class II directed antigen presentation; the example NTC868 series RNA-OUT vector system allows simultaneous cloning into multiple vectors that feature various transgene intracellular targeting destinations. Then a detailed flowchart for codon optimization and synthetic transgene design is presented. Finally in-depth methodologies for cloning transgenes into the NTC868 series RNA-OUT vector system are presented. The resultant antibiotic-free DNA vaccine vectors are a more potent, safer alternative to existing kanamycin resistance marker encoding vectors.
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Affiliation(s)
- Jeremy M Luke
- Nature Technology Corporation, 4701 Innovation Drive, Lincoln, NE, 68521, USA
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Hon J, Martínek T, Rajdl K, Lexa M. Triplex: an R/Bioconductor package for identification and visualization of potential intramolecular triplex patterns in DNA sequences. ACTA ACUST UNITED AC 2013; 29:1900-1. [PMID: 23709494 DOI: 10.1093/bioinformatics/btt299] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
MOTIVATION Upgrade and integration of triplex software into the R/Bioconductor framework. RESULTS We combined a previously published implementation of a triplex DNA search algorithm with visualization to create a versatile R/Bioconductor package 'triplex'. The new package provides functions that can be used to search Bioconductor genomes and other DNA sequence data for occurrence of nucleotide patterns capable of forming intramolecular triplexes (H-DNA). Functions producing 2D and 3D diagrams of the identified triplexes allow instant visualization of the search results. Leveraging the power of Biostrings and GRanges classes, the results get fully integrated into the existing Bioconductor framework, allowing their passage to other Genome visualization and annotation packages, such as GenomeGraphs, rtracklayer or Gviz. AVAILABILITY R package 'triplex' is available from Bioconductor (bioconductor.org). CONTACT lexa@fi.muni.cz SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Jiří Hon
- Department of Computer Systems, Faculty of Information Technology, Brno Technical University, Božetěchova 2, 61266 Brno, Czech Republic
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Cer RZ, Donohue DE, Mudunuri US, Temiz NA, Loss MA, Starner NJ, Halusa GN, Volfovsky N, Yi M, Luke BT, Bacolla A, Collins JR, Stephens RM. Non-B DB v2.0: a database of predicted non-B DNA-forming motifs and its associated tools. Nucleic Acids Res 2012; 41:D94-D100. [PMID: 23125372 PMCID: PMC3531222 DOI: 10.1093/nar/gks955] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The non-B DB, available at http://nonb.abcc.ncifcrf.gov, catalogs predicted non-B DNA-forming sequence motifs, including Z-DNA, G-quadruplex, A-phased repeats, inverted repeats, mirror repeats, direct repeats and their corresponding subsets: cruciforms, triplexes and slipped structures, in several genomes. Version 2.0 of the database revises and re-implements the motif discovery algorithms to better align with accepted definitions and thresholds for motifs, expands the non-B DNA-forming motifs coverage by including short tandem repeats and adds key visualization tools to compare motif locations relative to other genomic annotations. Non-B DB v2.0 extends the ability for comparative genomics by including re-annotation of the five organisms reported in non-B DB v1.0, human, chimpanzee, dog, macaque and mouse, and adds seven additional organisms: orangutan, rat, cow, pig, horse, platypus and Arabidopsis thaliana. Additionally, the non-B DB v2.0 provides an overall improved graphical user interface and faster query performance.
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Affiliation(s)
- Regina Z Cer
- Advanced Biomedical Computing Center, Information Systems Program, SAIC-Frederick, Inc., Frederick, MD 21702, USA
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