101
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Herbert A. The Simple Biology of Flipons and Condensates Enhances the Evolution of Complexity. Molecules 2021; 26:molecules26164881. [PMID: 34443469 PMCID: PMC8400190 DOI: 10.3390/molecules26164881] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 08/10/2021] [Accepted: 08/10/2021] [Indexed: 01/09/2023] Open
Abstract
The classical genetic code maps nucleotide triplets to amino acids. The associated sequence composition is complex, representing many elaborations during evolution of form and function. Other genomic elements code for the expression and processing of RNA transcripts. However, over 50% of the human genome consists of widely dispersed repetitive sequences. Among these are simple sequence repeats (SSRs), representing a class of flipons, that under physiological conditions, form alternative nucleic acid conformations such as Z-DNA, G4 quartets, I-motifs, and triplexes. Proteins that bind in a structure-specific manner enable the seeding of condensates with the potential to regulate a wide range of biological processes. SSRs also encode the low complexity peptide repeats to patch condensates together, increasing the number of combinations possible. In situations where SSRs are transcribed, SSR-specific, single-stranded binding proteins may further impact condensate formation. Jointly, flipons and patches speed evolution by enhancing the functionality of condensates. Here, the focus is on the selection of SSR flipons and peptide patches that solve for survival under a wide range of environmental contexts, generating complexity with simple parts.
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Affiliation(s)
- Alan Herbert
- Unit 3412, Discovery, InsideOutBio 42 8th Street, Charlestown, MA 02129, USA
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102
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Rocher V, Genais M, Nassereddine E, Mourad R. DeepG4: A deep learning approach to predict cell-type specific active G-quadruplex regions. PLoS Comput Biol 2021; 17:e1009308. [PMID: 34383754 PMCID: PMC8384162 DOI: 10.1371/journal.pcbi.1009308] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 08/24/2021] [Accepted: 07/26/2021] [Indexed: 12/04/2022] Open
Abstract
DNA is a complex molecule carrying the instructions an organism needs to develop, live and reproduce. In 1953, Watson and Crick discovered that DNA is composed of two chains forming a double-helix. Later on, other structures of DNA were discovered and shown to play important roles in the cell, in particular G-quadruplex (G4). Following genome sequencing, several bioinformatic algorithms were developed to map G4s in vitro based on a canonical sequence motif, G-richness and G-skewness or alternatively sequence features including k-mers, and more recently machine/deep learning. Recently, new sequencing techniques were developed to map G4s in vitro (G4-seq) and G4s in vivo (G4 ChIP-seq) at few hundred base resolution. Here, we propose a novel convolutional neural network (DeepG4) to map cell-type specific active G4 regions (e.g. regions within which G4s form both in vitro and in vivo). DeepG4 is very accurate to predict active G4 regions in different cell types. Moreover, DeepG4 identifies key DNA motifs that are predictive of G4 region activity. We found that such motifs do not follow a very flexible sequence pattern as current algorithms seek for. Instead, active G4 regions are determined by numerous specific motifs. Moreover, among those motifs, we identified known transcription factors (TFs) which could play important roles in G4 activity by contributing either directly to G4 structures themselves or indirectly by participating in G4 formation in the vicinity. In addition, we used DeepG4 to predict active G4 regions in a large number of tissues and cancers, thereby providing a comprehensive resource for researchers. Availability: https://github.com/morphos30/DeepG4. DNA is a molecule carrying genetic information and found in all living cells. In 1953, Watson and Crick found that DNA has a double helix structure. However, other DNA structures were later identified, and most notably, G-quadruplex (G4). In 2000, the Human Genome Project revealed the widespread presence of G4s in the genome using algorithms. To date, all G4 mapping algorithms were developed to map G4s on naked DNA, without knowing if they could be formed in a given cell type. Here, we designed a novel artificial intelligence algorithm that could map G4 regions active in the cell from the DNA sequence and chromatin accessibility. Moreover, we identified key transcriptional factor motifs that could explain G4 activity depending on cell type. Lastly, we used our new algorithm to map active G4 regions in multiple tissues and cancers as a comprehensive resource for the G4 community.
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Affiliation(s)
- Vincent Rocher
- Molecular, Cellular and Developmental biology department (MCD), Centre de Biologie Intégrative (CBI), University of Toulouse, CNRS, UPS, Toulouse, France
| | - Matthieu Genais
- Centre de Recherches en Cancérologie de Toulouse (CRCT), INSERM U1037, Toulouse, France
| | - Elissar Nassereddine
- Molecular, Cellular and Developmental biology department (MCD), Centre de Biologie Intégrative (CBI), University of Toulouse, CNRS, UPS, Toulouse, France
| | - Raphael Mourad
- Molecular, Cellular and Developmental biology department (MCD), Centre de Biologie Intégrative (CBI), University of Toulouse, CNRS, UPS, Toulouse, France
- * E-mail:
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103
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Abstract
The world of long non-coding RNAs (lncRNAs) has opened up massive new prospects in understanding the regulation of gene expression. Not only are there seemingly almost infinite numbers of lncRNAs in the mammalian cell, but they have highly diverse mechanisms of action. In the nucleus, some are chromatin-associated, transcribed from transcriptional enhancers (eRNAs) and/or direct changes in the epigenetic landscape with profound effects on gene expression. The pituitary gonadotrope is responsible for activation of reproduction through production and secretion of appropriate levels of the gonadotropic hormones. As such, it exemplifies a cell whose function is defined through changes in developmental and temporal patterns of gene expression, including those that are hormonally induced. Roles for diverse distal regulatory elements and eRNAs in gonadotrope biology have only just begun to emerge. Here, we will present an overview of the different kinds of lncRNAs that alter gene expression, and what is known about their roles in regulating some of the key gonadotrope genes. We will also review various screens that have detected differentially expressed pituitary lncRNAs associated with changes in reproductive state and those whose expression is found to play a role in gonadotrope-derived nonfunctioning pituitary adenomas. We hope to shed light on this exciting new field, emphasize the open questions, and encourage research to illuminate the roles of lncRNAs in various endocrine systems.
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Affiliation(s)
- Tal Refael
- Faculty of Biology, Technion Israel Institute of Technology, Haifa 32000, Israel
| | - Philippa Melamed
- Faculty of Biology, Technion Israel Institute of Technology, Haifa 32000, Israel
- Correspondence: Philippa Melamed, PhD, Faculty of Biology, Technion - Israel Institute of Technology, Haifa 32000, Israel.
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104
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Guiblet WM, DeGiorgio M, Cheng X, Chiaromonte F, Eckert KA, Huang YF, Makova KD. Selection and thermostability suggest G-quadruplexes are novel functional elements of the human genome. Genome Res 2021; 31:1136-1149. [PMID: 34187812 PMCID: PMC8256861 DOI: 10.1101/gr.269589.120] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 05/24/2021] [Indexed: 12/11/2022]
Abstract
Approximately 1% of the human genome has the ability to fold into G-quadruplexes (G4s)-noncanonical strand-specific DNA structures forming at G-rich motifs. G4s regulate several key cellular processes (e.g., transcription) and have been hypothesized to participate in others (e.g., firing of replication origins). Moreover, G4s differ in their thermostability, and this may affect their function. Yet, G4s may also hinder replication, transcription, and translation and may increase genome instability and mutation rates. Therefore, depending on their genomic location, thermostability, and functionality, G4 loci might evolve under different selective pressures, which has never been investigated. Here we conducted the first genome-wide analysis of G4 distribution, thermostability, and selection. We found an overrepresentation, high thermostability, and purifying selection for G4s within genic components in which they are expected to be functional-promoters, CpG islands, and 5' and 3' UTRs. A similar pattern was observed for G4s within replication origins, enhancers, eQTLs, and TAD boundary regions, strongly suggesting their functionality. In contrast, G4s on the nontranscribed strand of exons were underrepresented, were unstable, and evolved neutrally. In general, G4s on the nontranscribed strand of genic components had lower density and were less stable than those on the transcribed strand, suggesting that the former are avoided at the RNA level. Across the genome, purifying selection was stronger at stable G4s. Our results suggest that purifying selection preserves the sequences of functional G4s, whereas nonfunctional G4s are too costly to be tolerated in the genome. Thus, G4s are emerging as fundamental, functional genomic elements.
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Affiliation(s)
- Wilfried M Guiblet
- Bioinformatics and Genomics Graduate Program, Penn State University, University Park, Pennsylvania 16802, USA
| | - Michael DeGiorgio
- Department of Computer and Electrical Engineering and Computer Science, Florida Atlantic University, Boca Raton, Florida 33431, USA
| | - Xiaoheng Cheng
- Department of Biology, Penn State University, University Park, Pennsylvania 16802, USA
| | - Francesca Chiaromonte
- Department of Statistics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
- Center for Medical Genomics, Penn State University, University Park and Hershey, Pennsylvania 16802, USA
- Sant'Anna School of Advanced Studies, 56127 Pisa, Italy
| | - Kristin A Eckert
- Center for Medical Genomics, Penn State University, University Park and Hershey, Pennsylvania 16802, USA
- Department of Pathology, Penn State University, College of Medicine, Hershey, Pennsylvania 17033, USA
| | - Yi-Fei Huang
- Department of Biology, Penn State University, University Park, Pennsylvania 16802, USA
- Center for Medical Genomics, Penn State University, University Park and Hershey, Pennsylvania 16802, USA
| | - Kateryna D Makova
- Department of Biology, Penn State University, University Park, Pennsylvania 16802, USA
- Center for Medical Genomics, Penn State University, University Park and Hershey, Pennsylvania 16802, USA
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105
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Zhang X, Spiegel J, Martínez Cuesta S, Adhikari S, Balasubramanian S. Chemical profiling of DNA G-quadruplex-interacting proteins in live cells. Nat Chem 2021; 13:626-633. [PMID: 34183817 PMCID: PMC8245323 DOI: 10.1038/s41557-021-00736-9] [Citation(s) in RCA: 74] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 05/18/2021] [Indexed: 12/17/2022]
Abstract
DNA-protein interactions regulate critical biological processes. Identifying proteins that bind to specific, functional genomic loci is essential to understand the underlying regulatory mechanisms on a molecular level. Here we describe a co-binding-mediated protein profiling (CMPP) strategy to investigate the interactome of DNA G-quadruplexes (G4s) in native chromatin. CMPP involves cell-permeable, functionalized G4-ligand probes that bind endogenous G4s and subsequently crosslink to co-binding G4-interacting proteins in situ. We first showed the robustness of CMPP by proximity labelling of a G4 binding protein in vitro. Employing this approach in live cells, we then identified hundreds of putative G4-interacting proteins from various functional classes. Next, we confirmed a high G4-binding affinity and selectivity for several newly discovered G4 interactors in vitro, and we validated direct G4 interactions for a functionally important candidate in cellular chromatin using an independent approach. Our studies provide a chemical strategy to map protein interactions of specific nucleic acid features in living cells.
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Affiliation(s)
- Xiaoyun Zhang
- Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Jochen Spiegel
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Cambridge, UK
| | - Sergio Martínez Cuesta
- Department of Chemistry, University of Cambridge, Cambridge, UK
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Cambridge, UK
- Data Sciences and Quantitative Biology, Discovery Sciences, AstraZeneca, Cambridge, UK
| | | | - Shankar Balasubramanian
- Department of Chemistry, University of Cambridge, Cambridge, UK.
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Cambridge, UK.
- School of Clinical Medicine, University of Cambridge, Cambridge, UK.
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106
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DNA G-Quadruplexes Contribute to CTCF Recruitment. Int J Mol Sci 2021; 22:ijms22137090. [PMID: 34209337 PMCID: PMC8269367 DOI: 10.3390/ijms22137090] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 06/25/2021] [Accepted: 06/25/2021] [Indexed: 12/12/2022] Open
Abstract
G-quadruplex (G4) sites in the human genome frequently colocalize with CCCTC-binding factor (CTCF)-bound sites in CpG islands (CGIs). We aimed to clarify the role of G4s in CTCF positioning. Molecular modeling data suggested direct interactions, so we performed in vitro binding assays with quadruplex-forming sequences from CGIs in the human genome. G4s bound CTCF with Kd values similar to that of the control duplex, while respective i-motifs exhibited no affinity for CTCF. Using ChIP-qPCR assays, we showed that G4-stabilizing ligands enhance CTCF occupancy at a G4-prone site in STAT3 gene. In view of the reportedly increased CTCF affinity for hypomethylated DNA, we next questioned whether G4s also facilitate CTCF recruitment to CGIs via protecting CpG sites from methylation. Bioinformatics analysis of previously published data argued against such a possibility. Finally, we questioned whether G4s facilitate CTCF recruitment by affecting chromatin structure. We showed that three architectural chromatin proteins of the high mobility group colocalize with G4s in the genome and recognize parallel-stranded or mixed-topology G4s in vitro. One of such proteins, HMGN3, contributes to the association between G4s and CTCF according to our bioinformatics analysis. These findings support both direct and indirect roles of G4s in CTCF recruitment.
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107
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Angeloni A, Bogdanovic O. Sequence determinants, function, and evolution of CpG islands. Biochem Soc Trans 2021; 49:1109-1119. [PMID: 34156435 PMCID: PMC8286816 DOI: 10.1042/bst20200695] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 05/25/2021] [Accepted: 05/26/2021] [Indexed: 12/25/2022]
Abstract
In vertebrates, cytosine-guanine (CpG) dinucleotides are predominantly methylated, with ∼80% of all CpG sites containing 5-methylcytosine (5mC), a repressive mark associated with long-term gene silencing. The exceptions to such a globally hypermethylated state are CpG-rich DNA sequences called CpG islands (CGIs), which are mostly hypomethylated relative to the bulk genome. CGIs overlap promoters from the earliest vertebrates to humans, indicating a concerted evolutionary drive compatible with CGI retention. CGIs are characterised by DNA sequence features that include DNA hypomethylation, elevated CpG and GC content and the presence of transcription factor binding sites. These sequence characteristics are congruous with the recruitment of transcription factors and chromatin modifying enzymes, and transcriptional activation in general. CGIs colocalize with sites of transcriptional initiation in hypermethylated vertebrate genomes, however, a growing body of evidence indicates that CGIs might exert their gene regulatory function in other genomic contexts. In this review, we discuss the diverse regulatory features of CGIs, their functional readout, and the evolutionary implications associated with CGI retention in vertebrates and possibly in invertebrates.
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Affiliation(s)
- Allegra Angeloni
- Genomics and Epigenetics Division, Garvan Institute of Medical Research, Sydney, Australia
- School of Biotechnology and Biomolecular Sciences, Faculty of Science, UNSW, Sydney, Australia
| | - Ozren Bogdanovic
- Genomics and Epigenetics Division, Garvan Institute of Medical Research, Sydney, Australia
- School of Biotechnology and Biomolecular Sciences, Faculty of Science, UNSW, Sydney, Australia
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108
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Lago S, Nadai M, Cernilogar FM, Kazerani M, Domíniguez Moreno H, Schotta G, Richter SN. Promoter G-quadruplexes and transcription factors cooperate to shape the cell type-specific transcriptome. Nat Commun 2021; 12:3885. [PMID: 34162892 PMCID: PMC8222265 DOI: 10.1038/s41467-021-24198-2] [Citation(s) in RCA: 113] [Impact Index Per Article: 37.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 06/07/2021] [Indexed: 02/07/2023] Open
Abstract
Cell identity is maintained by activation of cell-specific gene programs, regulated by epigenetic marks, transcription factors and chromatin organization. DNA G-quadruplex (G4)-folded regions in cells were reported to be associated with either increased or decreased transcriptional activity. By G4-ChIP-seq/RNA-seq analysis on liposarcoma cells we confirmed that G4s in promoters are invariably associated with high transcription levels in open chromatin. Comparing G4 presence, location and transcript levels in liposarcoma cells to available data on keratinocytes, we showed that the same promoter sequences of the same genes in the two cell lines had different G4-folding state: high transcript levels consistently associated with G4-folding. Transcription factors AP-1 and SP1, whose binding sites were the most significantly represented in G4-folded sequences, coimmunoprecipitated with their G4-folded promoters. Thus, G4s and their associated transcription factors cooperate to determine cell-specific transcriptional programs, making G4s to strongly emerge as new epigenetic regulators of the transcription machinery.
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Affiliation(s)
- Sara Lago
- Department of Molecular Medicine, University of Padua, Padua, Italy.
| | - Matteo Nadai
- Department of Molecular Medicine, University of Padua, Padua, Italy
| | - Filippo M Cernilogar
- Division of Molecular Biology, Biomedical Center, Faculty of Medicine, LMU Munich, Martinsried, Germany
| | - Maryam Kazerani
- Division of Molecular Biology, Biomedical Center, Faculty of Medicine, LMU Munich, Martinsried, Germany
| | - Helena Domíniguez Moreno
- Division of Molecular Biology, Biomedical Center, Faculty of Medicine, LMU Munich, Martinsried, Germany
| | - Gunnar Schotta
- Division of Molecular Biology, Biomedical Center, Faculty of Medicine, LMU Munich, Martinsried, Germany.
| | - Sara N Richter
- Department of Molecular Medicine, University of Padua, Padua, Italy.
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109
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Mishra S, Kota S, Chaudhary R, Misra HS. Guanine quadruplexes and their roles in molecular processes. Crit Rev Biochem Mol Biol 2021; 56:482-499. [PMID: 34162300 DOI: 10.1080/10409238.2021.1926417] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The role of guanine quadruplexes (G4) in fundamental biological processes like DNA replication, transcription, translation and telomere maintenance is recognized. G4 structure dynamics is regulated by G4 structure binding proteins and is thought to be crucial for the maintenance of genome integrity in both prokaryotic and eukaryotic cells. Growing research over the last decade has expanded the existing knowledge of the functional diversity of G4 (DNA and RNA) structures across the working models. The control of G4 structure dynamics using G4 binding drugs has been suggested as the putative targets in the control of cancer and bacterial pathogenesis. This review has brought forth the collections of recent information that indicate G4 (mostly G4 DNA) roles in microbial pathogenesis, DNA damaging stress response in bacteria and mammalian cells. Studies in mitochondrial gene function regulation by G4s have also been underscored. Finally, the interdependence of G4s and epigenetic modifications and their speculated medical implications through G4 interacting proteins has been discussed.
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Affiliation(s)
- Shruti Mishra
- Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai, India.,Life Sciences, Homi Bhabha National Institute (DAE Deemed to be University), Mumbai, India
| | - Swathi Kota
- Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai, India.,Life Sciences, Homi Bhabha National Institute (DAE Deemed to be University), Mumbai, India
| | - Reema Chaudhary
- Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai, India.,Life Sciences, Homi Bhabha National Institute (DAE Deemed to be University), Mumbai, India
| | - H S Misra
- Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai, India.,Life Sciences, Homi Bhabha National Institute (DAE Deemed to be University), Mumbai, India
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110
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Alavi S, Ghadiri H, Dabirmanesh B, Moriyama K, Khajeh K, Masai H. G-quadruplex binding protein Rif1, a key regulator of replication timing. J Biochem 2021; 169:1-14. [PMID: 33169133 DOI: 10.1093/jb/mvaa128] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 10/18/2020] [Indexed: 12/19/2022] Open
Abstract
DNA replication is spatially and temporally regulated during S phase to execute efficient and coordinated duplication of entire genome. Various epigenomic mechanisms operate to regulate the timing and locations of replication. Among them, Rif1 plays a major role to shape the 'replication domains' that dictate which segments of the genome are replicated when and where in the nuclei. Rif1 achieves this task by generating higher-order chromatin architecture near nuclear membrane and by recruiting a protein phosphatase. Rif1 is a G4 binding protein, and G4 binding activity of Rif1 is essential for replication timing regulation in fission yeast. In this article, we first summarize strategies by which cells regulate their replication timing and then describe how Rif1 and its interaction with G4 contribute to regulation of chromatin architecture and replication timing.
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Affiliation(s)
| | - Hamed Ghadiri
- Department of Biochemistry, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Bahareh Dabirmanesh
- Department of Biochemistry, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Kenji Moriyama
- Genome Dynamics Project, Department of Basic Medical Sciences, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, Japan
| | - Khosro Khajeh
- Department of Nanobiotechnology.,Department of Biochemistry, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Hisao Masai
- Genome Dynamics Project, Department of Basic Medical Sciences, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, Japan
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111
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Liu Y, Ai C, Gan T, Wu J, Jiang Y, Liu X, Lu R, Gao N, Li Q, Ji X, Hu J. Transcription shapes DNA replication initiation to preserve genome integrity. Genome Biol 2021; 22:176. [PMID: 34108027 PMCID: PMC8188667 DOI: 10.1186/s13059-021-02390-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 05/26/2021] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Early DNA replication occurs within actively transcribed chromatin compartments in mammalian cells, raising the immediate question of how early DNA replication coordinates with transcription to avoid collisions and DNA damage. RESULTS We develop a high-throughput nucleoside analog incorporation sequencing assay and identify thousands of early replication initiation zones in both mouse and human cells. The identified early replication initiation zones fall in open chromatin compartments and are mutually exclusive with transcription elongation. Of note, early replication initiation zones are mainly located in non-transcribed regions adjacent to transcribed regions. Mechanistically, we find that RNA polymerase II actively redistributes the chromatin-bound mini-chromosome maintenance complex (MCM), but not the origin recognition complex (ORC), to actively restrict early DNA replication initiation outside of transcribed regions. In support of this finding, we detect apparent MCM accumulation and DNA replication initiation in transcribed regions due to anchoring of nuclease-dead Cas9 at transcribed genes, which stalls RNA polymerase II. Finally, we find that the orchestration of early DNA replication initiation by transcription efficiently prevents gross DNA damage. CONCLUSION RNA polymerase II redistributes MCM complexes, but not the ORC, to prevent early DNA replication from initiating within transcribed regions. This RNA polymerase II-driven MCM redistribution spatially separates transcription and early DNA replication events and avoids the transcription-replication initiation collision, thereby providing a critical regulatory mechanism to preserve genome stability.
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Affiliation(s)
- Yang Liu
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University, Beijing, 100871, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Chen Ai
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University, Beijing, 100871, China
| | - Tingting Gan
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University, Beijing, 100871, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Jinchun Wu
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University, Beijing, 100871, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Yongpeng Jiang
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University, Beijing, 100871, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Xuhao Liu
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University, Beijing, 100871, China
| | - Rusen Lu
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University, Beijing, 100871, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Ning Gao
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
- State Key Laboratory of Membrane Biology, School of Life Sciences, Peking University, Beijing, 100871, China
| | - Qing Li
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, 100871, China
| | - Xiong Ji
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University, Beijing, 100871, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Jiazhi Hu
- The MOE Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Genome Editing Research Center, Peking University, Beijing, 100871, China.
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China.
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112
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Making it or breaking it: DNA methylation and genome integrity. Essays Biochem 2021; 64:687-703. [PMID: 32808652 DOI: 10.1042/ebc20200009] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 07/22/2020] [Accepted: 07/29/2020] [Indexed: 12/11/2022]
Abstract
Cells encounter a multitude of external and internal stress-causing agents that can ultimately lead to DNA damage, mutations and disease. A cascade of signaling events counters these challenges to DNA, which is termed as the DNA damage response (DDR). The DDR preserves genome integrity by engaging appropriate repair pathways, while also coordinating cell cycle and/or apoptotic responses. Although many of the protein components in the DDR are identified, how chemical modifications to DNA impact the DDR is poorly understood. This review focuses on our current understanding of DNA methylation in maintaining genome integrity in mammalian cells. DNA methylation is a reversible epigenetic mark, which has been implicated in DNA damage signaling, repair and replication. Sites of DNA methylation can trigger mutations, which are drivers of human diseases including cancer. Indeed, alterations in DNA methylation are associated with increased susceptibility to tumorigenesis but whether this occurs through effects on the DDR, transcriptional responses or both is not entirely clear. Here, we also highlight epigenetic drugs currently in use as therapeutics that target DNA methylation pathways and discuss their effects in the context of the DDR. Finally, we pose unanswered questions regarding the interplay between DNA methylation, transcription and the DDR, positing the potential coordinated efforts of these pathways in genome integrity. While the impact of DNA methylation on gene regulation is widely understood, how this modification contributes to genome instability and mutations, either directly or indirectly, and the potential therapeutic opportunities in targeting DNA methylation pathways in cancer remain active areas of investigation.
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113
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Abiri A, Lavigne M, Rezaei M, Nikzad S, Zare P, Mergny JL, Rahimi HR. Unlocking G-Quadruplexes as Antiviral Targets. Pharmacol Rev 2021; 73:897-923. [PMID: 34045305 DOI: 10.1124/pharmrev.120.000230] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Guanine-rich DNA and RNA sequences can fold into noncanonical nucleic acid structures called G-quadruplexes (G4s). Since the discovery that these structures may act as scaffolds for the binding of specific ligands, G4s aroused the attention of a growing number of scientists. The versatile roles of G4 structures in viral replication, transcription, and translation suggest direct applications in therapy or diagnostics. G4-interacting molecules (proteins or small molecules) may also affect the balance between latent and lytic phases, and increasing evidence reveals that G4s are implicated in generally suppressing viral processes, such as replication, transcription, translation, or reverse transcription. In this review, we focus on the discovery of G4s in viruses and the role of G4 ligands in the antiviral drug discovery process. After assessing the role of viral G4s, we argue that host G4s participate in immune modulation, viral tumorigenesis, cellular pathways involved in virus maturation, and DNA integration of viral genomes, which can be potentially employed for antiviral therapeutics. Furthermore, we scrutinize the impediments and shortcomings in the process of studying G4 ligands and drug discovery. Finally, some unanswered questions regarding viral G4s are highlighted for prospective future projects. SIGNIFICANCE STATEMENT: G-quadruplexes (G4s) are noncanonical nucleic acid structures that have gained increasing recognition during the last few decades. First identified as relevant targets in oncology, their importance in virology is now increasingly clear. A number of G-quadruplex ligands are known: viral transcription and replication are the main targets of these ligands. Both viral and cellular G4s may be targeted; this review embraces the different aspects of G-quadruplexes in both host and viral contexts.
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Affiliation(s)
- Ardavan Abiri
- Department of Medicinal Chemistry, Faculty of Pharmacy, Kerman University of Medical Sciences, Kerman, Iran (A.A., S.N.); Institut Pasteur, Department of Virology, UMR 3569 CNRS, Paris, France (M.L.); Faculty of Medicine, Kerman University of Medical Sciences, Kerman, Iran (M.R.); Dioscuri Center of Chromatin Biology and Epigenomics, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland (P.Z.); Faculty of Medicine, Cardinal Stefan Wyszyński University in Warsaw, Warsaw, Poland (P.Z.); Laboratoire d'Optique et Biosciences, Ecole Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, Palaiseau cedex, France (J.-L.M.); Pharmaceutics Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran (H.-R.R.); and Department of Pharmacology and Toxicology, Faculty of Pharmacy, Kerman University of Medical Sciences, Kerman, Iran (H.-R.R.)
| | - Marc Lavigne
- Department of Medicinal Chemistry, Faculty of Pharmacy, Kerman University of Medical Sciences, Kerman, Iran (A.A., S.N.); Institut Pasteur, Department of Virology, UMR 3569 CNRS, Paris, France (M.L.); Faculty of Medicine, Kerman University of Medical Sciences, Kerman, Iran (M.R.); Dioscuri Center of Chromatin Biology and Epigenomics, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland (P.Z.); Faculty of Medicine, Cardinal Stefan Wyszyński University in Warsaw, Warsaw, Poland (P.Z.); Laboratoire d'Optique et Biosciences, Ecole Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, Palaiseau cedex, France (J.-L.M.); Pharmaceutics Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran (H.-R.R.); and Department of Pharmacology and Toxicology, Faculty of Pharmacy, Kerman University of Medical Sciences, Kerman, Iran (H.-R.R.)
| | - Masoud Rezaei
- Department of Medicinal Chemistry, Faculty of Pharmacy, Kerman University of Medical Sciences, Kerman, Iran (A.A., S.N.); Institut Pasteur, Department of Virology, UMR 3569 CNRS, Paris, France (M.L.); Faculty of Medicine, Kerman University of Medical Sciences, Kerman, Iran (M.R.); Dioscuri Center of Chromatin Biology and Epigenomics, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland (P.Z.); Faculty of Medicine, Cardinal Stefan Wyszyński University in Warsaw, Warsaw, Poland (P.Z.); Laboratoire d'Optique et Biosciences, Ecole Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, Palaiseau cedex, France (J.-L.M.); Pharmaceutics Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran (H.-R.R.); and Department of Pharmacology and Toxicology, Faculty of Pharmacy, Kerman University of Medical Sciences, Kerman, Iran (H.-R.R.)
| | - Sanaz Nikzad
- Department of Medicinal Chemistry, Faculty of Pharmacy, Kerman University of Medical Sciences, Kerman, Iran (A.A., S.N.); Institut Pasteur, Department of Virology, UMR 3569 CNRS, Paris, France (M.L.); Faculty of Medicine, Kerman University of Medical Sciences, Kerman, Iran (M.R.); Dioscuri Center of Chromatin Biology and Epigenomics, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland (P.Z.); Faculty of Medicine, Cardinal Stefan Wyszyński University in Warsaw, Warsaw, Poland (P.Z.); Laboratoire d'Optique et Biosciences, Ecole Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, Palaiseau cedex, France (J.-L.M.); Pharmaceutics Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran (H.-R.R.); and Department of Pharmacology and Toxicology, Faculty of Pharmacy, Kerman University of Medical Sciences, Kerman, Iran (H.-R.R.)
| | - Peyman Zare
- Department of Medicinal Chemistry, Faculty of Pharmacy, Kerman University of Medical Sciences, Kerman, Iran (A.A., S.N.); Institut Pasteur, Department of Virology, UMR 3569 CNRS, Paris, France (M.L.); Faculty of Medicine, Kerman University of Medical Sciences, Kerman, Iran (M.R.); Dioscuri Center of Chromatin Biology and Epigenomics, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland (P.Z.); Faculty of Medicine, Cardinal Stefan Wyszyński University in Warsaw, Warsaw, Poland (P.Z.); Laboratoire d'Optique et Biosciences, Ecole Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, Palaiseau cedex, France (J.-L.M.); Pharmaceutics Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran (H.-R.R.); and Department of Pharmacology and Toxicology, Faculty of Pharmacy, Kerman University of Medical Sciences, Kerman, Iran (H.-R.R.)
| | - Jean-Louis Mergny
- Department of Medicinal Chemistry, Faculty of Pharmacy, Kerman University of Medical Sciences, Kerman, Iran (A.A., S.N.); Institut Pasteur, Department of Virology, UMR 3569 CNRS, Paris, France (M.L.); Faculty of Medicine, Kerman University of Medical Sciences, Kerman, Iran (M.R.); Dioscuri Center of Chromatin Biology and Epigenomics, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland (P.Z.); Faculty of Medicine, Cardinal Stefan Wyszyński University in Warsaw, Warsaw, Poland (P.Z.); Laboratoire d'Optique et Biosciences, Ecole Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, Palaiseau cedex, France (J.-L.M.); Pharmaceutics Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran (H.-R.R.); and Department of Pharmacology and Toxicology, Faculty of Pharmacy, Kerman University of Medical Sciences, Kerman, Iran (H.-R.R.)
| | - Hamid-Reza Rahimi
- Department of Medicinal Chemistry, Faculty of Pharmacy, Kerman University of Medical Sciences, Kerman, Iran (A.A., S.N.); Institut Pasteur, Department of Virology, UMR 3569 CNRS, Paris, France (M.L.); Faculty of Medicine, Kerman University of Medical Sciences, Kerman, Iran (M.R.); Dioscuri Center of Chromatin Biology and Epigenomics, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland (P.Z.); Faculty of Medicine, Cardinal Stefan Wyszyński University in Warsaw, Warsaw, Poland (P.Z.); Laboratoire d'Optique et Biosciences, Ecole Polytechnique, CNRS, INSERM, Institut Polytechnique de Paris, Palaiseau cedex, France (J.-L.M.); Pharmaceutics Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran (H.-R.R.); and Department of Pharmacology and Toxicology, Faculty of Pharmacy, Kerman University of Medical Sciences, Kerman, Iran (H.-R.R.)
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Tran P, Rieu M, Hodeib S, Joubert A, Ouellet J, Alberti P, Bugaut A, Allemand JF, Boulé JB, Croquette V. Folding and persistence times of intramolecular G-quadruplexes transiently embedded in a DNA duplex. Nucleic Acids Res 2021; 49:5189-5201. [PMID: 34009328 PMCID: PMC8136832 DOI: 10.1093/nar/gkab306] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 04/09/2021] [Accepted: 04/14/2021] [Indexed: 12/19/2022] Open
Abstract
G-quadruplex (G4) DNA structures have emerged as important regulatory elements during DNA metabolic transactions. While many in vitro studies have focused on the kinetics of G4 formation within DNA single-strands, G4 are found in vivo in double-stranded DNA regions, where their formation is challenged by the complementary strand. Since the energy of hybridization of Watson-Crick structures dominates the energy of G4 folding, this competition should play a critical role on G4 persistence. To address this, we designed a single-molecule assay allowing to measure G4 folding and persistence times in the presence of the complementary strand. We quantified both folding and unfolding rates of biologically relevant G4 sequences, such as the cMYC and cKIT oncogene promoters, human telomeres and an avian replication origin. We confirmed that G4s are found much more stable in tested replication origin and promoters than in human telomere repeats. In addition, we characterized how G4 dynamics was affected by G4 ligands and showed that both folding rate and persistence time increased. Our assay opens new perspectives for the measurement of G4 dynamics in double-stranded DNA mimicking a replication fork, which is important to understand their role in DNA replication and gene regulation at a mechanistic level.
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Affiliation(s)
- Phong Lan Thao Tran
- Structure et Instabilité des Génomes, Museum National d’Histoire Naturelle, INSERM, CNRS, Alliance Sorbonne Université, 75005 Paris, France
| | - Martin Rieu
- Laboratoire de physique de L’École Normale Supérieure de Paris, CNRS, ENS, Université PSL, Sorbonne Université, Université de Paris, 75005 Paris, France
- Institut de Biologie de l’École Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France
| | - Samar Hodeib
- Laboratoire de physique de L’École Normale Supérieure de Paris, CNRS, ENS, Université PSL, Sorbonne Université, Université de Paris, 75005 Paris, France
- Institut de Biologie de l’École Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France
| | - Alexandra Joubert
- Structure et Instabilité des Génomes, Museum National d’Histoire Naturelle, INSERM, CNRS, Alliance Sorbonne Université, 75005 Paris, France
| | - Jimmy Ouellet
- Depixus SAS, 3-5 Impasse Reille, 75014 Paris, France
| | - Patrizia Alberti
- Structure et Instabilité des Génomes, Museum National d’Histoire Naturelle, INSERM, CNRS, Alliance Sorbonne Université, 75005 Paris, France
| | - Anthony Bugaut
- Structure et Instabilité des Génomes, Museum National d’Histoire Naturelle, INSERM, CNRS, Alliance Sorbonne Université, 75005 Paris, France
| | - Jean-François Allemand
- Laboratoire de physique de L’École Normale Supérieure de Paris, CNRS, ENS, Université PSL, Sorbonne Université, Université de Paris, 75005 Paris, France
- Institut de Biologie de l’École Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France
| | - Jean-Baptiste Boulé
- Structure et Instabilité des Génomes, Museum National d’Histoire Naturelle, INSERM, CNRS, Alliance Sorbonne Université, 75005 Paris, France
| | - Vincent Croquette
- Laboratoire de physique de L’École Normale Supérieure de Paris, CNRS, ENS, Université PSL, Sorbonne Université, Université de Paris, 75005 Paris, France
- Institut de Biologie de l’École Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, Université PSL, 75005 Paris, France
- ESPCI Paris, Université PSL, 75005 Paris, France
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115
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Costa-Silva HM, Resende BC, Umaki ACS, Prado W, da Silva MS, Virgílio S, Macedo AM, Pena SDJ, Tahara EB, Tosi LRO, Elias MC, Andrade LO, Reis-Cunha JL, Franco GR, Fragoso SP, Machado CR. DNA Topoisomerase 3α Is Involved in Homologous Recombination Repair and Replication Stress Response in Trypanosoma cruzi. Front Cell Dev Biol 2021; 9:633195w. [PMID: 34055812 PMCID: PMC8155511 DOI: 10.3389/fcell.2021.633195] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 03/19/2021] [Indexed: 12/30/2022] Open
Abstract
DNA topoisomerases are enzymes that modulate DNA topology. Among them, topoisomerase 3α is engaged in genomic maintenance acting in DNA replication termination, sister chromatid separation, and dissolution of recombination intermediates. To evaluate the role of this enzyme in Trypanosoma cruzi, the etiologic agent of Chagas disease, a topoisomerase 3α knockout parasite (TcTopo3α KO) was generated, and the parasite growth, as well as its response to several DNA damage agents, were evaluated. There was no growth alteration caused by the TcTopo3α knockout in epimastigote forms, but a higher dormancy rate was observed. TcTopo3α KO trypomastigote forms displayed reduced invasion rates in LLC-MK2 cells when compared with the wild-type lineage. Amastigote proliferation was also compromised in the TcTopo3α KO, and a higher number of dormant cells was observed. Additionally, TcTopo3α KO epimastigotes were not able to recover cell growth after gamma radiation exposure, suggesting the involvement of topoisomerase 3α in homologous recombination. These parasites were also sensitive to drugs that generate replication stress, such as cisplatin (Cis), hydroxyurea (HU), and methyl methanesulfonate (MMS). In response to HU and Cis treatments, TcTopo3α KO parasites showed a slower cell growth and was not able to efficiently repair the DNA damage induced by these genotoxic agents. The cell growth phenotype observed after MMS treatment was similar to that observed after gamma radiation, although there were fewer dormant cells after MMS exposure. TcTopo3α KO parasites showed a population with sub-G1 DNA content and strong γH2A signal 48 h after MMS treatment. So, it is possible that DNA-damaged cell proliferation due to the absence of TcTopo3α leads to cell death. Whole genome sequencing of MMS-treated parasites showed a significant reduction in the content of the multigene families DFG-1 and RHS, and also a possible erosion of the sub-telomeric region from chromosome 22, relative to non-treated knockout parasites. Southern blot experiments suggest telomere shortening, which could indicate genomic instability in TcTopo3α KO cells owing to MMS treatment. Thus, topoisomerase 3α is important for homologous recombination repair and replication stress in T. cruzi, even though all the pathways in which this enzyme participates during the replication stress response remains elusive.
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Affiliation(s)
- Héllida Marina Costa-Silva
- Laboratório de Genética Bioquímica, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Bruno Carvalho Resende
- Laboratório de Genética Bioquímica, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Adriana Castilhos Souza Umaki
- Laboratório de Biologia Molecular e Sistêmica de Tripanossomatídeos, Instituto Carlos Chagas, Fundação Oswaldo Cruz (FIOCRUZ), Curitiba, Brazil
| | - Willian Prado
- Laboratório de Genética Bioquímica, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Marcelo Santos da Silva
- Laboratório de Ciclo Celular, Centro de Toxinas, Resposta Imune e Sinalização Celular, Instituto Butantan, São Paulo, Brazil
| | - Stela Virgílio
- Laboratório de Biologia Molecular de Leishmanias, Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo (USP), Ribeirão Preto, Brazil
| | - Andrea Mara Macedo
- Laboratório de Genética Bioquímica, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Sérgio Danilo Junho Pena
- Laboratório de Genética Bioquímica, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Erich Birelli Tahara
- Laboratório de Genética Bioquímica, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Luiz Ricardo Orsini Tosi
- Laboratório de Biologia Molecular de Leishmanias, Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo (USP), Ribeirão Preto, Brazil
| | - Maria Carolina Elias
- Laboratório de Ciclo Celular, Centro de Toxinas, Resposta Imune e Sinalização Celular, Instituto Butantan, São Paulo, Brazil
| | - Luciana Oliveira Andrade
- Laboratório de Biologia Celular e Molecular, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - João Luís Reis-Cunha
- Departamento de Medicina Veterinária Preventiva, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Glória Regina Franco
- Laboratório de Genética Bioquímica, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Stenio Perdigão Fragoso
- Laboratório de Biologia Molecular e Sistêmica de Tripanossomatídeos, Instituto Carlos Chagas, Fundação Oswaldo Cruz (FIOCRUZ), Curitiba, Brazil
| | - Carlos Renato Machado
- Laboratório de Genética Bioquímica, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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Costa Dos Santos G, Renovato-Martins M, de Brito NM. The remodel of the "central dogma": a metabolomics interaction perspective. Metabolomics 2021; 17:48. [PMID: 33969452 PMCID: PMC8106972 DOI: 10.1007/s11306-021-01800-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 04/30/2021] [Indexed: 12/30/2022]
Abstract
BACKGROUND In 1957, Francis Crick drew a linear diagram on a blackboard. This diagram is often called the "central dogma." Subsequently, the relationships between different steps of the "central dogma" have been shown to be considerably complex, mostly because of the emerging world of small molecules. It is noteworthy that metabolites can be generated from the diet through gut microbiome metabolism, serve as substrates for epigenetic modifications, destabilize DNA quadruplexes, and follow Lamarckian inheritance. Small molecules were once considered the missing link in the "central dogma"; however, recently they have acquired a central role, and their general perception as downstream products has become reductionist. Metabolomics is a large-scale analysis of metabolites, and this emerging field has been shown to be the closest omics associated with the phenotype and concomitantly, the basis for all omics. AIM OF REVIEW Herein, we propose a broad updated perspective for the flux of information diagram centered in metabolomics, including the influence of other factors, such as epigenomics, diet, nutrition, and the gut- microbiome. KEY SCIENTIFIC CONCEPTS OF REVIEW Metabolites are the beginning and the end of the flux of information.
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Affiliation(s)
- Gilson Costa Dos Santos
- Laboratory of NMR Metabolomics, IBRAG, Department of Genetics, State University of Rio de Janeiro, Rio de Janeiro, 20551-030, Brazil.
| | - Mariana Renovato-Martins
- Department of Cellular and Molecular Biology, IB, Federal Fluminense University, Niterói, 24210-200, Brazil
| | - Natália Mesquita de Brito
- Laboratory of Cellular and Molecular Pharmacology, IBRAG, Department of Cell Biology, State University of Rio de Janeiro, Rio de Janeiro, 20551-030, Brazil.
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117
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Pinter S, Knodel F, Choudalakis M, Schnee P, Kroll C, Fuchs M, Broehm A, Weirich S, Roth M, Eisler SA, Zuber J, Jeltsch A, Rathert P. A functional LSD1 coregulator screen reveals a novel transcriptional regulatory cascade connecting R-loop homeostasis with epigenetic regulation. Nucleic Acids Res 2021; 49:4350-4370. [PMID: 33823549 PMCID: PMC8096265 DOI: 10.1093/nar/gkab180] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 03/04/2021] [Indexed: 12/30/2022] Open
Abstract
The lysine specific demethylase 1 (LSD1) plays a pivotal role in cellular differentiation by regulating the expression of key developmental genes in concert with different coregulatory proteins. This process is impaired in different cancer types and incompletely understood. To comprehensively identify functional coregulators of LSD1, we established a novel tractable fluorescent reporter system to monitor LSD1 activity in living cells. Combining this reporter system with a state-of-the-art multiplexed RNAi screen, we identify the DEAD-box helicase 19A (DDX19A) as a novel coregulator and demonstrate that suppression of Ddx19a results in an increase of R-loops and reduced LSD1-mediated gene silencing. We further show that DDX19A binds to tri-methylated lysine 27 of histone 3 (H3K27me3) and it regulates gene expression through the removal of transcription promoting R-loops. Our results uncover a novel transcriptional regulatory cascade where the downregulation of genes is dependent on the LSD1 mediated demethylation of histone H3 lysine 4 (H3K4). This allows the polycomb repressive complex 2 (PRC2) to methylate H3K27, which serves as a binding site for DDX19A. Finally, the binding of DDX19A leads to the efficient removal of R-loops at active promoters, which further de-represses LSD1 and PRC2, establishing a positive feedback loop leading to a robust repression of the target gene.
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Affiliation(s)
- Sabine Pinter
- Department of Biochemistry, Institute of Biochemistry and Technical Biochemistry, University of Stuttgart, 70569 Stuttgart, Germany
| | - Franziska Knodel
- Department of Biochemistry, Institute of Biochemistry and Technical Biochemistry, University of Stuttgart, 70569 Stuttgart, Germany
| | - Michel Choudalakis
- Department of Biochemistry, Institute of Biochemistry and Technical Biochemistry, University of Stuttgart, 70569 Stuttgart, Germany
| | - Philipp Schnee
- Department of Biochemistry, Institute of Biochemistry and Technical Biochemistry, University of Stuttgart, 70569 Stuttgart, Germany
| | - Carolin Kroll
- Department of Biochemistry, Institute of Biochemistry and Technical Biochemistry, University of Stuttgart, 70569 Stuttgart, Germany
| | - Marina Fuchs
- Department of Biochemistry, Institute of Biochemistry and Technical Biochemistry, University of Stuttgart, 70569 Stuttgart, Germany
| | - Alexander Broehm
- Department of Biochemistry, Institute of Biochemistry and Technical Biochemistry, University of Stuttgart, 70569 Stuttgart, Germany
| | - Sara Weirich
- Department of Biochemistry, Institute of Biochemistry and Technical Biochemistry, University of Stuttgart, 70569 Stuttgart, Germany
| | - Mareike Roth
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
| | - Stephan A Eisler
- Stuttgart Research Center Systems Biology (SRCSB), University of Stuttgart, 70569 Stuttgart, Germany
| | - Johannes Zuber
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
- Medical University of Vienna, Vienna BioCenter (VBC), Vienna, Austria
| | - Albert Jeltsch
- Department of Biochemistry, Institute of Biochemistry and Technical Biochemistry, University of Stuttgart, 70569 Stuttgart, Germany
| | - Philipp Rathert
- Department of Biochemistry, Institute of Biochemistry and Technical Biochemistry, University of Stuttgart, 70569 Stuttgart, Germany
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118
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Brázda V, Bartas M, Bowater RP. Evolution of Diverse Strategies for Promoter Regulation. Trends Genet 2021; 37:730-744. [PMID: 33931265 DOI: 10.1016/j.tig.2021.04.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/31/2021] [Accepted: 04/01/2021] [Indexed: 12/15/2022]
Abstract
DNA is fundamentally important for all cellular organisms due to its role as a store of hereditary genetic information. The precise and accurate regulation of gene transcription depends primarily on promoters, which vary significantly within and between genomes. Some promoters are rich in specific types of bases, while others have more varied, complex sequence characteristics. However, it is not only base sequence but also epigenetic modifications and altered DNA structure that regulate promoter activity. Significantly, many promoters across all organisms contain sequences that can form intrastrand hairpins (cruciforms) or four-stranded structures (G-quadruplex or i-motif). In this review we integrate recent studies on promoter regulation that highlight the importance of DNA structure in the evolutionary adaptation of promoter sequences.
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Affiliation(s)
- Václav Brázda
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
| | - Martin Bartas
- Department of Biology and Ecology/Institute of Environmental Technologies, Faculty of Science, University of Ostrava, 710 00 Ostrava, Czech Republic
| | - Richard P Bowater
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
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Guiblet WM, Cremona MA, Harris RS, Chen D, Eckert KA, Chiaromonte F, Huang YF, Makova KD. Non-B DNA: a major contributor to small- and large-scale variation in nucleotide substitution frequencies across the genome. Nucleic Acids Res 2021; 49:1497-1516. [PMID: 33450015 PMCID: PMC7897504 DOI: 10.1093/nar/gkaa1269] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 12/14/2020] [Accepted: 01/11/2021] [Indexed: 12/12/2022] Open
Abstract
Approximately 13% of the human genome can fold into non-canonical (non-B) DNA structures (e.g. G-quadruplexes, Z-DNA, etc.), which have been implicated in vital cellular processes. Non-B DNA also hinders replication, increasing errors and facilitating mutagenesis, yet its contribution to genome-wide variation in mutation rates remains unexplored. Here, we conducted a comprehensive analysis of nucleotide substitution frequencies at non-B DNA loci within noncoding, non-repetitive genome regions, their ±2 kb flanking regions, and 1-Megabase windows, using human-orangutan divergence and human single-nucleotide polymorphisms. Functional data analysis at single-base resolution demonstrated that substitution frequencies are usually elevated at non-B DNA, with patterns specific to each non-B DNA type. Mirror, direct and inverted repeats have higher substitution frequencies in spacers than in repeat arms, whereas G-quadruplexes, particularly stable ones, have higher substitution frequencies in loops than in stems. Several non-B DNA types also affect substitution frequencies in their flanking regions. Finally, non-B DNA explains more variation than any other predictor in multiple regression models for diversity or divergence at 1-Megabase scale. Thus, non-B DNA substantially contributes to variation in substitution frequencies at small and large scales. Our results highlight the role of non-B DNA in germline mutagenesis with implications to evolution and genetic diseases.
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Affiliation(s)
- Wilfried M Guiblet
- Bioinformatics and Genomics Graduate Program, Penn State University, UniversityPark, PA 16802, USA
| | - Marzia A Cremona
- Department of Statistics, The Pennsylvania State University, University Park, PA 16802, USA
- Department of Operations and Decision Systems, Université Laval, Canada
- CHU de Québec – Université Laval Research Center, Canada
| | - Robert S Harris
- Department of Biology, Penn State University, University Park, PA 16802, USA
| | - Di Chen
- Intercollege Graduate Degree Program in Genetics, Huck Institutes of the Life Sciences, Penn State University, UniversityPark, PA 16802, USA
| | - Kristin A Eckert
- Department of Pathology, Penn State University, College of Medicine, Hershey, PA 17033, USA
- Center for Medical Genomics, Penn State University, University Park and Hershey, PA, USA
| | - Francesca Chiaromonte
- Department of Statistics, The Pennsylvania State University, University Park, PA 16802, USA
- Center for Medical Genomics, Penn State University, University Park and Hershey, PA, USA
- EMbeDS, Sant’Anna School of Advanced Studies, 56127 Pisa, Italy
| | - Yi-Fei Huang
- Department of Biology, Penn State University, University Park, PA 16802, USA
- Center for Medical Genomics, Penn State University, University Park and Hershey, PA, USA
| | - Kateryna D Makova
- Department of Biology, Penn State University, University Park, PA 16802, USA
- Center for Medical Genomics, Penn State University, University Park and Hershey, PA, USA
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Komůrková D, Svobodová Kovaříková A, Bártová E. G-Quadruplex Structures Colocalize with Transcription Factories and Nuclear Speckles Surrounded by Acetylated and Dimethylated Histones H3. Int J Mol Sci 2021; 22:1995. [PMID: 33671470 PMCID: PMC7922289 DOI: 10.3390/ijms22041995] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 02/11/2021] [Accepted: 02/15/2021] [Indexed: 12/26/2022] Open
Abstract
G-quadruplexes (G4s) are four-stranded helical structures that regulate several nuclear processes, including gene expression and telomere maintenance. We observed that G4s are located in GC-rich (euchromatin) regions and outside the fibrillarin-positive compartment of nucleoli. Genomic regions around G4s were preferentially H3K9 acetylated and H3K9 dimethylated, but H3K9me3 rarely decorated G4 structures. We additionally observed the variability in the number of G4s in selected human and mouse cell lines. We found the highest number of G4s in human embryonic stem cells. We observed the highest degree of colocalization between G4s and transcription factories, positive on the phosphorylated form of RNA polymerase II (RNAP II). Similarly, a high colocalization rate was between G4s and nuclear speckles, enriched in pre-mRNA splicing factor SC-35. PML bodies, the replication protein SMD1, and Cajal bodies colocalized with G4s to a lesser extent. Thus, G4 structures seem to appear mainly in nuclear compartments transcribed via RNAP II, and pre-mRNA is spliced via the SC-35 protein. However, α-amanitin, an inhibitor of RNAP II, did not affect colocalization between G4s and transcription factories as well as G4s and SC-35-positive domains. In addition, irradiation by γ-rays did not change a mutual link between G4s and DNA repair proteins (G4s/γH2AX, G4s/53BP1, and G4s/MDC1), accumulated into DNA damage foci. Described characteristics of G4s seem to be the manifestation of pronounced G4s stability that is likely maintained not only via a high-order organization of these structures but also by a specific histone signature, including H3K9me2, responsible for chromatin compaction.
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Affiliation(s)
| | | | - Eva Bártová
- Institute of Biophysics of the Czech Academy of Sciences, Department of Molecular Cytology and Cytometry, Královopolská 135, 612 65 Brno, Czech Republic; (D.K.); (A.S.K.)
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Sengupta P, Bose D, Chatterjee S. The Molecular Tête-à-Tête between G-Quadruplexes and the i-motif in the Human Genome. Chembiochem 2021; 22:1517-1537. [PMID: 33355980 DOI: 10.1002/cbic.202000703] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 12/16/2020] [Indexed: 12/22/2022]
Abstract
G-Quadruplex (GQ) and i-motif structures are the paradigmatic examples of nonclassical tetrastranded nucleic acids having multifarious biological functions and widespread applications in therapeutics and material science. Recently, tetraplexes emerged as promising anticancer targets due to their structural robustness, gene-regulatory roles, and predominant distribution at specific loci of oncogenes. However, it is arguable whether the i-motif evolves in the complementary single-stranded region after GQ formation in its opposite strand and vice versa. In this review, we address the prerequisites and significance of the simultaneous and/or mutually exclusive formation of GQ and i-motif structures at complementary and sequential positions in duplexes in the cellular milieu. We discussed how their dynamic interplay Sets up cellular homeostasis and exacerbates carcinogenesis. The review gives insights into the spatiotemporal formation of GQ and i-motifs that could be harnessed to design different types of reporter systems and diagnostic platforms for potential bioanalytical and therapeutic intervention.
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Affiliation(s)
- Pallabi Sengupta
- Department of Biophysics, Bose Institute, Centenary Campus, P-1/12, C.I.T. Scheme VIIM, Kankurgachi, Kolkata, 700054, West Bengal, India
| | - Debopriya Bose
- Department of Biophysics, Bose Institute, Centenary Campus, P-1/12, C.I.T. Scheme VIIM, Kankurgachi, Kolkata, 700054, West Bengal, India
| | - Subhrangsu Chatterjee
- Department of Biophysics, Bose Institute, Centenary Campus, P-1/12, C.I.T. Scheme VIIM, Kankurgachi, Kolkata, 700054, West Bengal, India
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122
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YY1 interacts with guanine quadruplexes to regulate DNA looping and gene expression. Nat Chem Biol 2021; 17:161-168. [PMID: 33199912 PMCID: PMC7854983 DOI: 10.1038/s41589-020-00695-1] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 08/30/2020] [Accepted: 10/14/2020] [Indexed: 01/28/2023]
Abstract
The DNA guanine quadruplexes (G4) play important roles in multiple cellular processes, including DNA replication, transcription and maintenance of genome stability. Here, we showed that Yin and Yang 1 (YY1) can bind directly to G4 structures. ChIP-seq results revealed that YY1-binding sites overlap extensively with G4 structure loci in chromatin. We also observed that the dimerization of YY1 and its binding with G4 structures contribute to YY1-mediated long-range DNA looping. Displacement of YY1 from G4 structure sites disrupts substantially the YY1-mediated DNA looping. Moreover, treatment with G4-stabilizing ligands modulates the expression of not only those genes with G4 structures in their promoters, but also those associated with distal G4 structures that are brought to close proximity via YY1-mediated DNA looping. Together, we identified YY1 as a DNA G4-binding protein, and revealed that YY1-mediated long-range DNA looping requires its dimerization and occurs, in part, through its recognition of G4 structure.
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123
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Kumari N, Raghavan SC. G-quadruplex DNA structures and their relevance in radioprotection. Biochim Biophys Acta Gen Subj 2021; 1865:129857. [PMID: 33508382 DOI: 10.1016/j.bbagen.2021.129857] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 01/21/2021] [Accepted: 01/22/2021] [Indexed: 12/14/2022]
Abstract
BACKGROUND DNA, the genetic material of most of the organisms, is the crucial element of life. Integrity of DNA needs to be maintained for transmission of genetic material from one generation to another. All organisms are constantly challenged by the environmental conditions which can lead to the induction of DNA damage. Ionizing radiation (IR) has been known to induce DNA damage and IR sensitivity varies among different organisms. The causes for differential radiosensitivity among various organisms have not been studied in great detail. SCOPE OF REVIEW We discuss DNA secondary structure formation, GC content of the genome, role of G-quadruplex formation, and its relationship with radiosensitivity of the genome. MAJOR CONCLUSION In Deinococcus radiodurans, the bacterium that exhibits maximum radio resistance, multiple G-quadruplex forming motifs are reported. In human cells, G-quadruplex formation led to differential radiosensitivity. In this article, we have discussed, the role of secondary DNA structure formation like G-quadruplex in shielding the genome from radiation and its implications in understanding evolution of radio protective effect of an organism. We also discuss role of GC content and its correlation with radio resistance. GENERAL SIGNIFICANCE This review provides an insight into the role of G-quadruplexes in providing differential radiosensitivity at different site of the genome and in different organisms. It further discusses the possibility of higher GC content contributing towards reduced radiosensitivity in different organisms, evolution of radiosensitivity, and regulation of multiple cellular processes.
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Affiliation(s)
- Nitu Kumari
- Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India
| | - Sathees C Raghavan
- Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India.
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124
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Wang M, Ngo V, Wang W. Deciphering the genetic code of DNA methylation. Brief Bioinform 2021; 22:6082840. [PMID: 33432324 DOI: 10.1093/bib/bbaa424] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 12/03/2020] [Accepted: 12/22/2020] [Indexed: 12/17/2022] Open
Abstract
DNA methylation plays crucial roles in many biological processes and abnormal DNA methylation patterns are often observed in diseases. Recent studies have shed light on cis-acting DNA elements that regulate locus-specific DNA methylation, which involves transcription factors, histone modification and DNA secondary structures. In addition, several recent studies have surveyed DNA motifs that regulate DNA methylation and suggest potential applications in diagnosis and prognosis. Here, we discuss the current biological foundation for the cis-acting genetic code that regulates DNA methylation. We review the computational models that predict DNA methylation with genetic features and discuss the biological insights revealed from these models. We also provide an in-depth discussion on how to leverage such knowledge in clinical applications, particularly in the context of liquid biopsy for early cancer diagnosis and treatment.
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Affiliation(s)
- Mengchi Wang
- Bioinformatics and Systems Biology at University of California, USA
| | - Vu Ngo
- Bioinformatics and Systems Biology at University of California, USA
| | - Wei Wang
- Bioinformatics and Systems Biology, Department of Chemistry and Biochemistry, and Department of Cellular and Molecular Medicine at University of California, USA
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125
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Sengupta A, Roy SS, Chowdhury S. Non-duplex G-Quadruplex DNA Structure: A Developing Story from Predicted Sequences to DNA Structure-Dependent Epigenetics and Beyond. Acc Chem Res 2021; 54:46-56. [PMID: 33347280 DOI: 10.1021/acs.accounts.0c00431] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The story of the non-duplex DNA form known as the G-quadruplex (G4) has traversed a winding path. From initial skepticism followed by debate to a surge in interest, the G4 story intertwines many threads. Starting with computational predictions of a gene regulatory role, which now include epigenetic functions, our group was involved in many of these advances along with many other laboratories. Following a brief background, set in the latter half of the last century when the concept of the G4 as a structure took ground, here we account the developments. This is through a lens that though focused on our groups' research presents work from many other groups that played significant roles. Together these provide a broad perspective to the G4 story. Initially we were intrigued on seeing potential G4 (pG4)-forming sequences, then known to be found primarily at the telomeres and immunoglobin switch regions, occurring throughout the genome and being particularly prevalent in promoters of bacteria. We further observed that pG4s were not only prevalent but also conserved through evolution in promoters of human, chimpanzee, mouse and rat genomes. This was between 2005 and 2007. Encouraged by these partly and partly in response to the view held by many that genome-wide presence of G4s were genomic "accidents", the focus shifted to seeking experimental evidence.In the next year, 2008, two independent findings showed promise. First, on treating human cancer cells with G4-binding ligands, we observed widespread change in gene expression. Second, our search for the missing G4-specific transcription factor, without which, importantly, G4s in promoters posed only half the story, yielded results. We determined how NM23-H2 (also known as NME2 or NDPK-B) interacts with G4s and how interaction of NM23-H2 with a G4 in the promoter of the oncogene c-myc was important for regulation of c-myc transcription. NM23-H2, and subsequently many other similar factors discovered by multiple groups, is possibly giving shape to what might be the "G4-transcriptome". Later, a close look at NM23-H2-G4 interaction in regulation of the human reverse transcriptase gene (hTERT) revealed the role of G4s in local epigenetic modifications. Meanwhile work from others showed how G4s impact histone modifications following replication. Together these show the intrinsic role of DNA sequence, through formation of DNA structure, in epigenetics.More recent work, however, was waiting to reveal aspects that tend to bring forth a completely new understanding of G4s. We observed that the telomere-repeat-binding-factor-2 (TRF2), known canonically to be telomere-associated, binds extensively outside telomeres throughout the genome. Moreover, a large fraction of the non-telomeric TRF2 sites comprise G4s. Second, the extent of non-telomeric TRF2 binding at promoters was dependent on telomere length. Thereby TRF2-induced epigenetic gene regulation was telomere-dependent. Together these implicate underlying connections that show signs of addressing an intriguing unanswered question that takes us back to the beginning: Why are G4s prevalent in two distinct regions, the telomeres and gene promoters?
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Affiliation(s)
- Antara Sengupta
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Shuvra Shekhar Roy
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Shantanu Chowdhury
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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126
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Li L, Williams P, Gao Z, Wang Y. VEZF1-guanine quadruplex DNA interaction regulates alternative polyadenylation and detyrosinase activity of VASH1. Nucleic Acids Res 2020; 48:11994-12003. [PMID: 33231681 PMCID: PMC7708047 DOI: 10.1093/nar/gkaa1092] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 10/22/2020] [Accepted: 11/20/2020] [Indexed: 11/14/2022] Open
Abstract
Vascular endothelial zinc finger 1 (VEZF1) plays important roles in endothelial lineage definition and angiogenesis. Vasohibins 1 and 2 (VASH1 and VASH2) can form heterodimers with small vasohibin-binding protein (SVBP) and were recently shown to regulate angiogenesis by acting as tubulin detyrosinases. Here, we showed that VEZF1 binds directly with DNA guanine quadruplex (G quadruplex, G4) structures in vitro and in cells, which modulates the levels of the two isoforms of VASH1 mRNA. Disruption of this interaction, through genetic depletion of VEZF1 or treatment of cells with G4-stabilizing small molecules, led to increased production of the long over short isoform of VASH1 (i.e. VASH1A and VASH1B, respectively) mRNA and elevated tubulin detyrosinase activity in cells. Moreover, disruption of VEZF1-G4 interactions in human umbilical vein endothelial cells resulted in diminished angiogenesis. These results suggest that the interaction between VEZF1 and G4 structures assumes a crucial role in angiogenesis, which occurs through regulating the relative levels of the two isoforms of VASH1 mRNA and the detyrosinase activity of the VASH1-SVBP complex. Together, our work revealed VEZF1 as a G4-binding protein, identified a novel regulatory mechanism for tubulin detyrosinase, and illustrated that the VEZF1- and VASH1-mediated angiogenesis pathways are functionally connected.
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Affiliation(s)
- Lin Li
- Department of Chemistry, University of California, Riverside, CA 92521, USA
| | - Preston Williams
- Department of Chemistry, University of California, Riverside, CA 92521, USA
| | - Zi Gao
- Department of Chemistry, University of California, Riverside, CA 92521, USA
| | - Yinsheng Wang
- Department of Chemistry, University of California, Riverside, CA 92521, USA
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Su K, Lin N, Xie S, Han Y, Yang Z, Zhang H, He H, Zhou SA, Ma W, Zhang T, Wang N. DNMT3A inhibits E2F1-induced arterial marker expression and impairs angiogenesis in human umbilical artery endothelial cells. Acta Biochim Biophys Sin (Shanghai) 2020; 52:1236-1246. [PMID: 33079978 DOI: 10.1093/abbs/gmaa109] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 06/05/2020] [Accepted: 08/18/2020] [Indexed: 12/13/2022] Open
Abstract
Arterial marker genes EphrinB2 and HEY2 are essential for cardiovascular development and postnatal neovascularization. Our previous study confirmed that E2F1 could activate the transcription of EphrinB2 and HEY2 in human mesenchymal stem cells; however, the detailed mechanism has not been resolved yet. In this study, we focused on the interaction between E2F1 and DNMT3A, a de novo DNA methyltransferase, on regulating the expression of EphrinB2 and HEY2, and explored the potential mechanisms. Gain- and loss-of-function experiments implicated the positive effect of E2F1 on the expression of EphrinB2 and HEY2 and tube formation in human umbilical artery endothelial cells. Accumulation of DNMT3A decreased the levels of EphrinB2 and HEY2, and impaired tube formation induced by E2F1, while inhibiting DNMT3A by RNA interference augmented their expression and angiogenesis in E2F1-trasfected cells. We then asked whether the low expressions of EphrinB2 and HEY2 induced by DNMT3A are related to the methylation status of their promoters. Surprisingly, the methylation status of the CpG islands in the promoter region was not significantly affected by overexpression of exogenous DNMT3A. Furthermore, the interaction between E2F1 and DNMT3A was confirmed by co-immunoprecipitation. DNMT3A could inhibit the transcription of EphrinB2 and HEY2 promoters by affecting the binding of E2F1 to its recognition sequences as revealed by luciferase reporter assay and chromatin immunoprecipitation. These results identified a novel mechanism underlying the cooperation of DNMT3A with E2F1 on regulating target gene expression, and revealed their roles in the angiogenic process.
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Affiliation(s)
- Kaiyue Su
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin 300457, China
| | - Ningning Lin
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin 300457, China
| | - Shouqiang Xie
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin 300457, China
| | - Yabo Han
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin 300457, China
| | - Zaiming Yang
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin 300457, China
| | - Hongmin Zhang
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin 300457, China
| | - Hongpeng He
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin 300457, China
| | - S a Zhou
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin 300457, China
| | - Wenjian Ma
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin 300457, China
| | - Tongcun Zhang
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin 300457, China
| | - Nan Wang
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin 300457, China
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Kuznetsova AA, Fedorova OS, Kuznetsov NA. Lesion Recognition and Cleavage of Damage-Containing Quadruplexes and Bulged Structures by DNA Glycosylases. Front Cell Dev Biol 2020; 8:595687. [PMID: 33330484 PMCID: PMC7734321 DOI: 10.3389/fcell.2020.595687] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 11/10/2020] [Indexed: 12/22/2022] Open
Abstract
Human telomeres as well as more than 40% of human genes near the promoter regions have been found to contain the sequence that may form a G-quadruplex structure. Other non-canonical DNA structures comprising bulges, hairpins, or bubbles may have a functionally important role during transcription, replication, or recombination. The guanine-rich regions of DNA are hotspots of oxidation that forms 7,8-dihydro-8-oxoguanine, thymine glycol, and abasic sites: the lesions that are handled by the base excision repair pathway. Nonetheless, the features of DNA repair processes in non-canonical DNA structures are still poorly understood. Therefore, in this work, a comparative analysis of the efficiency of the removal of a damaged nucleotide from various G-quadruplexes and bulged structures was performed using endonuclease VIII-like 1 (NEIL1), human 8-oxoguanine-DNA glycosylase (OGG1), endonuclease III (NTH1), and prokaryotic formamidopyrimidine-DNA glycosylase (Fpg), and endonuclease VIII (Nei). All the tested enzymes were able to cleave damage-containing bulged DNA structures, indicating their important role in the repair process when single-stranded DNA and intermediate non–B-form structures such as bubbles and bulges are formed. Nevertheless, our results suggest that the ability to cleave damaged quadruplexes is an intrinsic feature of members of the H2tH structural family, suggesting that these enzymes can participate in the modulation of processes controlled by the formation of quadruplex structures in genomic DNA.
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Affiliation(s)
| | - Olga S Fedorova
- Institute of Chemical Biology and Fundamental Medicine of SB RAS, Novosibirsk, Russia.,Department of Natural Sciences, Novosibirsk State University, Novosibirsk, Russia
| | - Nikita A Kuznetsov
- Institute of Chemical Biology and Fundamental Medicine of SB RAS, Novosibirsk, Russia.,Department of Natural Sciences, Novosibirsk State University, Novosibirsk, Russia
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129
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Pavlova II, Tsvetkov VB, Isaakova EA, Severov VV, Khomyakova EA, Lacis IA, Lazarev VN, Lagarkova MA, Pozmogova GE, Varizhuk AM. Transcription-facilitating histone chaperons interact with genomic and synthetic G4 structures. Int J Biol Macromol 2020; 160:1144-1157. [PMID: 32454109 DOI: 10.1016/j.ijbiomac.2020.05.173] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 05/11/2020] [Accepted: 05/21/2020] [Indexed: 01/26/2023]
Abstract
Affinity for G-quadruplex (G4) structures may be a common feature of transcription-facilitating histone chaperons (HCs). This assumption is based on previous unmatched studies of HCs FACT, nucleolin (NCL), BRD3, and ATRX. We verified this assumption and considered its implications for the therapeutic applications of synthetic (exogenous) G4s and the biological significance of genomic G4s. First, we questioned whether exogenous G4s that recognize cell-surface NCL and could trap other HCs in the nucleus are usable as anticancer agents. We performed in vitro binding assays and selected leading multi-targeted G4s. They exhibited minor effects on cell viability. The presumed NCL-regulated intracellular transport of G4s was inefficient or insufficient for tumor-specific G4 delivery. Next, to clarify whether G4s in the human genome could recruit HCs, we compared available HC ChIP-seq data with G4-seq/G4-ChIP-seq data. Several G4s, including the well-known c-Myc quadruplex structure, were found to be colocalized with HC occupancy sites in cancer cell lines. As evidenced by our molecular modeling data, c-Myc G4 might interfere with the HC function of BRD3 but is unlikely to prevent the BRD3-driven assembly of the chromatin remodeling complex. The c-Myc case illustrates the intricate role of genomic G4s in chromatin remodeling, nucleosome remodeling, and transcription.
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Affiliation(s)
- Iulia I Pavlova
- Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Malaya Pirogovskaya str. 1a, Moscow 119435, Russia.; Moscow Institute of Physics and Technology, Dolgoprudny 141700, Russia
| | - Vladimir B Tsvetkov
- Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Malaya Pirogovskaya str. 1a, Moscow 119435, Russia.; Computational Oncology Group, I.M. Sechenov First Moscow State Medical University, Trubetskaya str, 8/2, Moscow 119146, Russia; A.V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Leninsky prospect str. 29, Moscow 119991, Russia
| | - Ekaterina A Isaakova
- Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Malaya Pirogovskaya str. 1a, Moscow 119435, Russia.; Moscow Institute of Physics and Technology, Dolgoprudny 141700, Russia
| | - Vyacheslav V Severov
- Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Malaya Pirogovskaya str. 1a, Moscow 119435, Russia
| | - Ekaterina A Khomyakova
- Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Malaya Pirogovskaya str. 1a, Moscow 119435, Russia
| | - Ivan A Lacis
- Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Malaya Pirogovskaya str. 1a, Moscow 119435, Russia
| | - Vassilii N Lazarev
- Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Malaya Pirogovskaya str. 1a, Moscow 119435, Russia.; Moscow Institute of Physics and Technology, Dolgoprudny 141700, Russia; Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Malaya Pirogovskaya str. 1a, Moscow 119435, Russia
| | - Maria A Lagarkova
- Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Malaya Pirogovskaya str. 1a, Moscow 119435, Russia.; Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Malaya Pirogovskaya str. 1a, Moscow 119435, Russia
| | - Galina E Pozmogova
- Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Malaya Pirogovskaya str. 1a, Moscow 119435, Russia.; Moscow Institute of Physics and Technology, Dolgoprudny 141700, Russia; Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Malaya Pirogovskaya str. 1a, Moscow 119435, Russia
| | - Anna M Varizhuk
- Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Malaya Pirogovskaya str. 1a, Moscow 119435, Russia.; Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Malaya Pirogovskaya str. 1a, Moscow 119435, Russia; Engelhardt Institute of Molecular Biology, Vavilova str. 32, Moscow 119991, Russia.
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130
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Masai H, Kanoh Y, Kakusho N, Fukatsu R. Detection of cellular G-quadruplex by using a loop structure as a structural determinant. Biochem Biophys Res Commun 2020; 531:75-83. [DOI: 10.1016/j.bbrc.2020.05.191] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 05/22/2020] [Accepted: 05/25/2020] [Indexed: 12/23/2022]
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131
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Fukunaga J, Nomura Y, Tanaka Y, Torigoe H, Nakamura Y, Sakamoto T, Kozu T. A G-quadruplex-forming RNA aptamer binds to the MTG8 TAFH domain and dissociates the leukemic AML1-MTG8 fusion protein from DNA. FEBS Lett 2020; 594:3477-3489. [PMID: 32870501 DOI: 10.1002/1873-3468.13914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 08/10/2020] [Accepted: 08/12/2020] [Indexed: 11/11/2022]
Abstract
MTG8 (RUNX1T1) is a fusion partner of AML1 (RUNX1) in the leukemic chromosome translocation t(8;21). The AML1-MTG8 fusion gene encodes a chimeric transcription factor. One of the highly conserved domains of MTG8 is TAFH which possesses homology with human TAF4 [TATA-box binding protein-associated factor]. To obtain specific inhibitors of the AML1-MTG8 fusion protein, we isolated RNA aptamers against the MTG8 TAFH domain using systematic evolution of ligands by exponential enrichment. All TAF aptamers contained guanine-rich sequences. Analyses of a TAF aptamer by NMR, CD, and mutagenesis revealed that it forms a parallel G-quadruplex structure in the presence of K+ . Furthermore, the aptamer could bind to the AML1-MTG8 fusion protein and dissociate the AML1-MTG8/DNA complex, suggesting that it can inhibit the dominant negative effects of AML1-MTG8 against normal AML1 function and serve as a potential therapeutic agent for leukemia.
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Affiliation(s)
- Junichi Fukunaga
- Research Institute for Clinical Oncology, Saitama Cancer Center, Ina, Japan
| | - Yusuke Nomura
- Department of Life and Environmental Sciences, Faculty of Engineering, Chiba Institute of Technology, Narashino, Japan.,Department of Applied Chemistry, Faculty of Science, Tokyo University of Science, Shinjuku-ku, Japan
| | - Yoichiro Tanaka
- Research Institute for Clinical Oncology, Saitama Cancer Center, Ina, Japan.,Facility for RI Research and Education, Instrumental Analysis Center, Research Initiatives and Promotion Organization, Yokohama National University, Hodogaya-ku, Japan
| | - Hidetaka Torigoe
- Department of Applied Chemistry, Faculty of Science, Tokyo University of Science, Shinjuku-ku, Japan
| | - Yoshikazu Nakamura
- Department of Basic Medical Sciences, Institute of Medical Science, University of Tokyo, Minato-ku, Japan.,Ribomic Inc., Minato-ku, Japan
| | - Taiichi Sakamoto
- Department of Life and Environmental Sciences, Faculty of Engineering, Chiba Institute of Technology, Narashino, Japan
| | - Tomoko Kozu
- Research Institute for Clinical Oncology, Saitama Cancer Center, Ina, Japan
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132
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Malousi A, Andreou AZ, Kouidou S. In silico structural analysis of sequences containing 5-hydroxymethylcytosine reveals its potential as binding regulator for development, ageing and cancer-related transcription factors. Epigenetics 2020; 16:503-518. [PMID: 32752914 DOI: 10.1080/15592294.2020.1805693] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The presence of 5-hydroxymethyl cytosine in DNA has been previously associated with ageing. Using in silico analysis of normal liver samples we presently observed that in 5-hydroxymethyl cytosine sequences, DNA methylation is dependent on the co-presence of G-quadruplexes and palindromes. This association exhibits discrete patterns depending on G-quadruplex and palindrome densities. DNase-Seq data show that 5-hydroxymethyl cytosine sequences are common among liver nucleosomes (p < 2.2x10-16) and threefold more frequent than nucleosome sequences. Nucleosomes lacking palindromes and potential G-quadruplexes are rare in vivo (1%) and nucleosome occupancy potential decreases with increasing G-quadruplexes. Palindrome distribution is similar to that previously reported in nucleosomes. In low and mixed complexity sequences 5-hydroxymethyl cytosine is frequently located next to three elements: G-quadruplexes or imperfect G-quadruplexes with CpGs, or unstable hairpin loops (TCCCAY6TGGGA) mostly located in antisense strands or finally A-/T-rich segments near these motifs. The high frequencies and selective distribution of pentamer sequences (including TCCCA, TGGGA) probably indicate the positive contribution of 5-hydroxymethyl cytosine to stabilize the formation of structures unstable in the absence of this cytosine modification. Common motifs identified in all total 5-hydroxymethyl cytosine-containing sequences exhibit high homology to recognition sites of several transcription factor families: homeobox, factors involved in growth, mortality/ageing, cancer, neuronal function, vision, and reproduction. We conclude that cytosine hydroxymethylation could play a role in the recognition of sequences with G-quadruplexes/palindromes by forming epigenetically regulated DNA 'springs' and governing expansions or compressions recognized by different transcription factors or stabilizing nucleosomes. The balance of these epigenetic elements is lost in hepatocellular carcinoma.
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Affiliation(s)
- Andigoni Malousi
- Lab. of Biological Chemistry, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | | | - Sofia Kouidou
- Lab. of Biological Chemistry, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
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133
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Hänsel-Hertsch R, Simeone A, Shea A, Hui WWI, Zyner KG, Marsico G, Rueda OM, Bruna A, Martin A, Zhang X, Adhikari S, Tannahill D, Caldas C, Balasubramanian S. Landscape of G-quadruplex DNA structural regions in breast cancer. Nat Genet 2020; 52:878-883. [PMID: 32747825 DOI: 10.1038/s41588-020-0672-8] [Citation(s) in RCA: 108] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 06/25/2020] [Indexed: 12/25/2022]
Abstract
Response and resistance to anticancer therapies vary due to intertumor and intratumor heterogeneity1. Here, we map differentially enriched G-quadruplex (G4) DNA structure-forming regions (∆G4Rs) in 22 breast cancer patient-derived tumor xenograft (PDTX) models. ∆G4Rs are associated with the promoters of highly amplified genes showing high expression, and with somatic single-nucleotide variants. Differences in ΔG4R landscapes reveal seven transcription factor programs across PDTXs. ∆G4R abundance and locations stratify PDTXs into at least three G4-based subtypes. ∆G4Rs in most PDTXs (14 of 22) were found to associate with more than one breast cancer subtype, which we also call an integrative cluster (IC)2. This suggests the frequent coexistence of multiple breast cancer states within a PDTX model, the majority of which display aggressive triple-negative IC10 gene activity. Short-term cultures of PDTX models with increased ∆G4R levels are more sensitive to small molecules targeting G4 DNA. Thus, G4 landscapes reveal additional IC-related intratumor heterogeneity in PDTX biopsies, improving breast cancer stratification and potentially identifying new treatment strategies.
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Affiliation(s)
- Robert Hänsel-Hertsch
- Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne and University Hospital Cologne, Cologne, Germany
- Institute of Human Genetics, University Hospital Cologne, Cologne, Germany
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Cambridge, UK
| | - Angela Simeone
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Cambridge, UK
| | - Abigail Shea
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Cambridge, UK
| | - Winnie W I Hui
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Cambridge, UK
| | - Katherine G Zyner
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Cambridge, UK
| | - Giovanni Marsico
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Cambridge, UK
- Inivata, Babraham Research Campus, Cambridge, UK
| | - Oscar M Rueda
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Cambridge, UK
| | - Alejandra Bruna
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Cambridge, UK
- The Institute of Cancer Research, London, UK
| | - Alistair Martin
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Cambridge, UK
| | - Xiaoyun Zhang
- Department of Chemistry, University of Cambridge, Cambridge, UK
| | | | - David Tannahill
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Cambridge, UK
| | - Carlos Caldas
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Cambridge, UK
- Cambridge Breast Cancer Research Unit, Cambridge University Hospital NHS Foundation Trust, Cambridge, UK
- Cancer Research UK Cambridge Centre, NIHR Cambridge Biomedical Research Centre and Cambridge Experimental Cancer Medicine Centre, Cambridge University Hospital NHS Foundation Trust, Cambridge, UK
| | - Shankar Balasubramanian
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Cambridge, UK.
- Department of Chemistry, University of Cambridge, Cambridge, UK.
- School of Clinical Medicine, University of Cambridge, Cambridge, UK.
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134
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Masai H, Tanaka T. G-quadruplex DNA and RNA: Their roles in regulation of DNA replication and other biological functions. Biochem Biophys Res Commun 2020; 531:25-38. [PMID: 32826060 DOI: 10.1016/j.bbrc.2020.05.132] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 05/15/2020] [Accepted: 05/18/2020] [Indexed: 12/19/2022]
Abstract
G-quadruplex is one of the best-studied non-B type DNA that is now known to be prevalently present in the genomes of almost all the biological species. Recent studies reveal roles of G-quadruplex (G4) structures in various nucleic acids and chromosome transactions. In this short article, we will first describe recent findings on the roles of G4 in regulation of DNA replication. G4 is involved in regulation of spatio-temporal regulation of DNA replication through interaction with a specific binding protein, Rif1. This regulation is at least partially mediated by generation of specific chromatin architecture through Rif1-G4 interactions. We will also describe recent studies showing the potential roles of G4 in initiation of DNA replication. Next, we will present showcases of highly diversified roles of DNA G4 and RNA G4 in regulation of nucleic acid and chromosome functions. Finally, we will discuss how the formation of cellular G4 could be regulated.
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Affiliation(s)
- Hisao Masai
- Department of Basic Medical Sciences, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506, Japan.
| | - Taku Tanaka
- Department of Basic Medical Sciences, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506, Japan
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135
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Varshney D, Spiegel J, Zyner K, Tannahill D, Balasubramanian S. The regulation and functions of DNA and RNA G-quadruplexes. Nat Rev Mol Cell Biol 2020; 21:459-474. [PMID: 32313204 PMCID: PMC7115845 DOI: 10.1038/s41580-020-0236-x] [Citation(s) in RCA: 632] [Impact Index Per Article: 158.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/11/2020] [Indexed: 02/06/2023]
Abstract
DNA and RNA can adopt various secondary structures. Four-stranded G-quadruplex (G4) structures form through self-recognition of guanines into stacked tetrads, and considerable biophysical and structural evidence exists for G4 formation in vitro. Computational studies and sequencing methods have revealed the prevalence of G4 sequence motifs at gene regulatory regions in various genomes, including in humans. Experiments using chemical, molecular and cell biology methods have demonstrated that G4s exist in chromatin DNA and in RNA, and have linked G4 formation with key biological processes ranging from transcription and translation to genome instability and cancer. In this Review, we first discuss the identification of G4s and evidence for their formation in cells using chemical biology, imaging and genomic technologies. We then discuss possible functions of DNA G4s and their interacting proteins, particularly in transcription, telomere biology and genome instability. Roles of RNA G4s in RNA biology, especially in translation, are also discussed. Furthermore, we consider the emerging relationships of G4s with chromatin and with RNA modifications. Finally, we discuss the connection between G4 formation and synthetic lethality in cancer cells, and recent progress towards considering G4s as therapeutic targets in human diseases.
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Affiliation(s)
- Dhaval Varshney
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, Cambridge, UK
| | - Jochen Spiegel
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, Cambridge, UK
| | - Katherine Zyner
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, Cambridge, UK
| | - David Tannahill
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, Cambridge, UK
| | - Shankar Balasubramanian
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, Cambridge, UK.
- Department of Chemistry, University of Cambridge, Cambridge, UK.
- School of Clinical Medicine, University of Cambridge, Cambridge, UK.
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136
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Yuan DH, Xing JF, Luan MW, Ji KK, Guo J, Xie SQ, Zhang YM. DNA N6-Methyladenine Modification in Wild and Cultivated Soybeans Reveals Different Patterns in Nucleus and Cytoplasm. Front Genet 2020; 11:736. [PMID: 32849778 PMCID: PMC7398112 DOI: 10.3389/fgene.2020.00736] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Accepted: 06/18/2020] [Indexed: 01/16/2023] Open
Abstract
DNA 6mA modification, an important newly discovered epigenetic mark, plays a crucial role in organisms and has been attracting more and more attention in recent years. The soybean is economically the most important bean in the world, providing vegetable protein for millions of people. However, the distribution pattern and function of 6mA in soybean are still unknown. In this study, we decoded 6mA modification to single-nucleotide resolution in wild and cultivated soybeans, and compared the 6mA differences between cytoplasmic and nuclear genomes and between wild and cultivated soybeans. The motif of 6mA in the nuclear genome was conserved across the two kinds of soybeans, and ANHGA was the most dominant motif in wild and cultivated soybeans. Genes with 6mA modification in the nucleus had higher expression than those without modification. Interestingly, 6mA distribution patterns in cytoplasm for each soybean were significantly different from those in nucleus, which was reported for the first time in soybean. Our research provides a new insight in the deep analysis of cytoplasmic genomic DNA modification in plants.
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Affiliation(s)
- De-Hui Yuan
- Crop Information Center, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Jian-Feng Xing
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants (Ministry of Education), Hainan Key Laboratory for Biology of Tropical Ornamental Plant Germplasm, College of Forestry, Hainan University, Haikou, China
| | - Mei-Wei Luan
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants (Ministry of Education), Hainan Key Laboratory for Biology of Tropical Ornamental Plant Germplasm, College of Forestry, Hainan University, Haikou, China
| | - Kai-Kai Ji
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants (Ministry of Education), Hainan Key Laboratory for Biology of Tropical Ornamental Plant Germplasm, College of Forestry, Hainan University, Haikou, China
| | - Jun Guo
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants (Ministry of Education), Hainan Key Laboratory for Biology of Tropical Ornamental Plant Germplasm, College of Forestry, Hainan University, Haikou, China
| | - Shang-Qian Xie
- Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants (Ministry of Education), Hainan Key Laboratory for Biology of Tropical Ornamental Plant Germplasm, College of Forestry, Hainan University, Haikou, China
| | - Yuan-Ming Zhang
- Crop Information Center, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
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137
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Li M, Alsager JS, Wang Z, Cheng L, Shan B. Epigenetic upregulation of HOXC10 in non-small lung cancer cells. Aging (Albany NY) 2020; 12:16921-16935. [PMID: 32687064 PMCID: PMC7521540 DOI: 10.18632/aging.103597] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 06/13/2020] [Indexed: 01/24/2023]
Abstract
The homeobox genes (HOX) have emerged as a new family of master regulators of development and cancer. In the current study, we examined the expression and function of HOXC10 in human non-small cell lung cancer (NSCLC). We observed increased expression of HOXC10 in the more aggressive human NSCLC cell line NCI-H23 over the well differentiated A549 cells. To elucidate the expression and function of HOXC10 in NSCLC cells, we employed RT-PCR, immunoblotting, methylation-specific PCR, apoptosis assays, and xenograft model. Overexpression of HOXC10 in A549 cells conveyed increased proliferation, reduced apoptosis, and accelerated tumor growth when transplanted into nude mice. In contrast, siRNA-mediated knockdown of HOXC10 in NCI-H23 cells reduced proliferation and increased apoptosis. Our results further indicated that hypomethylation of the CpG island in the HOXC10 promoter was critical to elevated expression of HOXC10 in NSCLC cells. Lastly, we identified a G-quadruplex in the HOXC10 promoter and its G-quadruplex formation was required for elevated expression of HOXC10 in NSCLC cells. Moreover our results suggest that disruption of G-quadruplex formation can silence HOXC10 expression in NSCLC cells. In summary, we report HOXC10 as a novel tumor promoting oncogene in NSCLC cells.
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Affiliation(s)
- Miao Li
- Department of Microbiology and Parasitology, College of Basic Medical Sciences, China Medical University, Shenyang, China
| | - John Simon Alsager
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA 99202, USA
| | - Zhaokai Wang
- The First Clinical Department of China Medical University, Shenyang, China
| | - Lin Cheng
- The First Clinical Department of China Medical University, Shenyang, China
| | - Bin Shan
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA 99202, USA
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138
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Herbert A. Simple Repeats as Building Blocks for Genetic Computers. Trends Genet 2020; 36:739-750. [PMID: 32690316 DOI: 10.1016/j.tig.2020.06.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 06/17/2020] [Accepted: 06/22/2020] [Indexed: 11/15/2022]
Abstract
Processing of RNA involves heterogeneous nuclear ribonucleoproteins. The simple sequence repeats (SSRs) they bind can also adopt alternative DNA structures, like Z DNA, triplexes, G quadruplexes, and I motifs. Those SSRs capable of switching conformation under physiological conditions (called flipons) are genetic elements that can encode alternative RNA processing by their effects on RNA processivity, most likely as DNA:RNA hybrids. Flipons are elements of a binary, instructive genetic code directing how genomic sequences are compiled into transcripts. The combinatorial nature of this code provides a rich set of options for creating genetic computers able to reproduce themselves and use a heritable and evolvable code to optimize survival. The underlying computational logic potentiates a diverse set of genetic programs that modify cis-mediated heritability and disease risk.
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Affiliation(s)
- Alan Herbert
- Discovery, InsideOutBio, 42 8th Street, Charlestown, MA 02129, USA.
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139
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Mao SQ, Cuesta SM, Tannahill D, Balasubramanian S. Genome-wide DNA Methylation Signatures Are Determined by DNMT3A/B Sequence Preferences. Biochemistry 2020; 59:2541-2550. [PMID: 32543182 PMCID: PMC7364778 DOI: 10.1021/acs.biochem.0c00339] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 06/16/2020] [Indexed: 12/24/2022]
Abstract
Cytosine methylation is an important epigenetic mark, but how the distinctive patterns of DNA methylation arise remains elusive. For the first time, we systematically investigated how these patterns can be imparted by the inherent enzymatic preferences of mammalian de novo DNA methyltransferases in vitro and the extent to which this applies in cells. In a biochemical experiment, we subjected a wide variety of DNA sequences to methylation by DNMT3A or DNMT3B and then applied deep bisulfite sequencing to quantitatively determine the sequence preferences for methylation. The data show that DNMT3A prefers CpG and non-CpG sites followed by a 3'-pyrimidine, whereas DNMT3B favors a 3'-purine. Overall, we show that DNMT3A has a sequence preference for a TNC[G/A]CC context, while DNMT3B prefers TAC[G/A]GC. We extended our finding using publicly available data from mouse Dnmt1/3a/3b triple-knockout cells in which reintroduction of either DNMT3A or DNMT3B expression results in the acquisition of the same enzyme specific signature sequences observed in vitro. Furthermore, loss of DNMT3A or DNMT3B in human embryonic stem cells leads to a loss of methylation at the corresponding enzyme specific signatures. Therefore, the global DNA methylation landscape of the mammalian genome can be fundamentally determined by the inherent sequence preference of de novo methyltransferases.
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Affiliation(s)
- Shi-Qing Mao
- Cancer
Research UK Cambridge Institute, Li Ka Shing Centre, Cambridge CB2 0RE, U.K.
| | - Sergio Martínez Cuesta
- Cancer
Research UK Cambridge Institute, Li Ka Shing Centre, Cambridge CB2 0RE, U.K.
- Department
of Chemistry, University of Cambridge, Cambridge CB2 1EW, U.K.
| | - David Tannahill
- Cancer
Research UK Cambridge Institute, Li Ka Shing Centre, Cambridge CB2 0RE, U.K.
| | - Shankar Balasubramanian
- Cancer
Research UK Cambridge Institute, Li Ka Shing Centre, Cambridge CB2 0RE, U.K.
- Department
of Chemistry, University of Cambridge, Cambridge CB2 1EW, U.K.
- School
of Clinical Medicine, University of Cambridge, Cambridge CB2 0SP, U.K.
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140
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Reversible N6-methyladenosine of RNA: The regulatory mechanisms on gene expression and implications in physiology and pathology. Genes Dis 2020; 7:585-597. [PMID: 33335958 PMCID: PMC7729110 DOI: 10.1016/j.gendis.2020.06.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 06/21/2020] [Accepted: 06/30/2020] [Indexed: 12/21/2022] Open
Abstract
N6-methyladenosine (m6A) is the most abundant inner RNA modification in eukaryotes. Due to the development of RNA sequencing technology, the distribution pattern of m6A in the transcriptome has been uncovered. Dynamically, the reversible N6-methylation is mediated by two types of proteins, which are classified as "writers" and "erasers". Under the association of specific co-factors, writers show spatiotemporal N6-methyltransferase activity. Mechanically, m6A can be recognized by "reader" proteins or can directly modify RNA conformation, and it widely affects gene expression by mediating RNA stability, translation, splicing and export. m6A is involved in a series of physiology processes. Dysregulation of m6A is gradually defined as the pathogenesis of some diseases, e.g., cancer and cardiovascular disease. Therefore, a good understanding of m6A is essential for molecular biology and pathology research. In this article we systemically present an overview of the functions and mechanisms of identified m6A regulators. The discovered biological and pathological processes affected by m6A are also summarized. We hope that readers with related research interests benefit from our review.
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141
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Williams JD, Houserova D, Johnson BR, Dyniewski B, Berroyer A, French H, Barchie AA, Bilbrey DD, Demeis JD, Ghee KR, Hughes AG, Kreitz NW, McInnis CH, Pudner SC, Reeves MN, Stahly AN, Turcu A, Watters BC, Daly GT, Langley RJ, Gillespie MN, Prakash A, Larson ED, Kasukurthi MV, Huang J, Jinks-Robertson S, Borchert GM. Characterization of long G4-rich enhancer-associated genomic regions engaging in a novel loop:loop 'G4 Kissing' interaction. Nucleic Acids Res 2020; 48:5907-5925. [PMID: 32383760 PMCID: PMC7293029 DOI: 10.1093/nar/gkaa357] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 04/22/2020] [Accepted: 04/27/2020] [Indexed: 12/27/2022] Open
Abstract
Mammalian antibody switch regions (∼1500 bp) are composed of a series of closely neighboring G4-capable sequences. Whereas numerous structural and genome-wide analyses of roles for minimal G4s in transcriptional regulation have been reported, Long G4-capable regions (LG4s)-like those at antibody switch regions-remain virtually unexplored. Using a novel computational approach we have identified 301 LG4s in the human genome and find LG4s prone to mutation and significantly associated with chromosomal rearrangements in malignancy. Strikingly, 217 LG4s overlap annotated enhancers, and we find the promoters regulated by these enhancers markedly enriched in G4-capable sequences suggesting G4s facilitate promoter-enhancer interactions. Finally, and much to our surprise, we also find single-stranded loops of minimal G4s within individual LG4 loci are frequently highly complementary to one another with 178 LG4 loci averaging >35 internal loop:loop complements of >8 bp. As such, we hypothesized (then experimentally confirmed) that G4 loops within individual LG4 loci directly basepair with one another (similar to characterized stem-loop kissing interactions) forming a hitherto undescribed, higher-order, G4-based secondary structure we term a 'G4 Kiss or G4K'. In conclusion, LG4s adopt novel, higher-order, composite G4 structures directly contributing to the inherent instability, regulatory capacity, and maintenance of these conspicuous genomic regions.
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Affiliation(s)
- Jonathan D Williams
- Department of Molecular Genetics and Microbiology, Duke University, Durham, NC 27708, USA
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | - Dominika Houserova
- Department of Pharmacology, University of South Alabama, Mobile, AL 36688, USA
| | - Bradley R Johnson
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | - Brad Dyniewski
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | - Alexandra Berroyer
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | - Hannah French
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | - Addison A Barchie
- Department of Biology, University of South Alabama, Mobile, AL 36688, USA
| | - Dakota D Bilbrey
- Department of Biology, University of South Alabama, Mobile, AL 36688, USA
| | - Jeffrey D Demeis
- Department of Biology, University of South Alabama, Mobile, AL 36688, USA
| | - Kanesha R Ghee
- Department of Biology, University of South Alabama, Mobile, AL 36688, USA
| | - Alexandra G Hughes
- Department of Biology, University of South Alabama, Mobile, AL 36688, USA
| | - Naden W Kreitz
- Department of Biology, University of South Alabama, Mobile, AL 36688, USA
| | - Cameron H McInnis
- Department of Biology, University of South Alabama, Mobile, AL 36688, USA
| | - Susanna C Pudner
- Department of Biology, University of South Alabama, Mobile, AL 36688, USA
| | - Monica N Reeves
- Department of Biology, University of South Alabama, Mobile, AL 36688, USA
| | - Ashlyn N Stahly
- Department of Biology, University of South Alabama, Mobile, AL 36688, USA
| | - Ana Turcu
- Department of Biology, University of South Alabama, Mobile, AL 36688, USA
| | - Brianna C Watters
- Department of Biology, University of South Alabama, Mobile, AL 36688, USA
| | - Grant T Daly
- Department of Pharmacology, University of South Alabama, Mobile, AL 36688, USA
| | - Raymond J Langley
- Department of Pharmacology, University of South Alabama, Mobile, AL 36688, USA
| | - Mark N Gillespie
- Department of Pharmacology, University of South Alabama, Mobile, AL 36688, USA
| | - Aishwarya Prakash
- Department of Pharmacology, University of South Alabama, Mobile, AL 36688, USA
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mitchell Cancer Institute, Mobile, AL 36688, USA
| | - Erik D Larson
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
- Department of Biomedical Sciences, Western Michigan University Homer Stryker MD School of Medicine, Kalamazoo, MI 49007, USA
| | | | - Jingshan Huang
- School of Computing, University of South Alabama, Mobile, AL 36688, USA
| | - Sue Jinks-Robertson
- Department of Molecular Genetics and Microbiology, Duke University, Durham, NC 27708, USA
| | - Glen M Borchert
- Department of Pharmacology, University of South Alabama, Mobile, AL 36688, USA
- Department of Biology, University of South Alabama, Mobile, AL 36688, USA
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142
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Reina C, Cavalieri V. Epigenetic Modulation of Chromatin States and Gene Expression by G-Quadruplex Structures. Int J Mol Sci 2020; 21:E4172. [PMID: 32545267 PMCID: PMC7312119 DOI: 10.3390/ijms21114172] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 06/07/2020] [Accepted: 06/10/2020] [Indexed: 02/07/2023] Open
Abstract
G-quadruplexes are four-stranded helical nucleic acid structures formed by guanine-rich sequences. A considerable number of studies have revealed that these noncanonical structural motifs are widespread throughout the genome and transcriptome of numerous organisms, including humans. In particular, G-quadruplexes occupy strategic locations in genomic DNA and both coding and noncoding RNA molecules, being involved in many essential cellular and organismal functions. In this review, we first outline the fundamental structural features of G-quadruplexes and then focus on the concept that these DNA and RNA structures convey a distinctive layer of epigenetic information that is critical for the complex regulation, either positive or negative, of biological activities in different contexts. In this framework, we summarize and discuss the proposed mechanisms underlying the functions of G-quadruplexes and their interacting factors. Furthermore, we give special emphasis to the interplay between G-quadruplex formation/disruption and other epigenetic marks, including biochemical modifications of DNA bases and histones, nucleosome positioning, and three-dimensional organization of chromatin. Finally, epigenetic roles of RNA G-quadruplexes in post-transcriptional regulation of gene expression are also discussed. Undoubtedly, the issues addressed in this review take on particular importance in the field of comparative epigenetics, as well as in translational research.
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Affiliation(s)
- Chiara Reina
- Department of Health Promotion, Mother and Child Care, Internal Medicine and Medical Specialties (PROMISE), University of Palermo, 90127 Palermo, Italy;
| | - Vincenzo Cavalieri
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, 90128 Palermo, Italy
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143
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Islam B, Stadlbauer P, Vorlíčková M, Mergny JL, Otyepka M, Šponer J. Stability of Two-Quartet G-Quadruplexes and Their Dimers in Atomistic Simulations. J Chem Theory Comput 2020; 16:3447-3463. [PMID: 32163706 DOI: 10.1021/acs.jctc.9b01068] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
G-quadruplexes (GQs) are four-stranded noncanonical DNA and RNA architectures that can be formed by guanine-rich sequences. The stability of GQs increases with the number of G-quartets, and three G-quartets generally form stable GQs. However, the stability of two-quartet GQs is an open issue. To understand the intrinsic stability of two-quartet GQ stems, we have carried out a series of unbiased molecular dynamics (MD) simulations (505 μs in total) of two- and four-quartet DNA and RNA GQs, with attention paid mainly to parallel-stranded arrangements. We used AMBER DNA parmOL15 and RNA parmOL3 force fields and tested different ion and water models. Two-quartet parallel-stranded DNA GQs unfolded in all the simulations, while the equivalent RNA GQ was stable in most of the simulations. GQs composed of two stacked units of two-quartet GQs were stable for both DNA and RNA. The simulations suggest that a minimum of three quartets are needed to form an intrinsically stable all-anti parallel-stranded DNA GQ. Parallel two-quartet DNA GQ may exist if substantially stabilized by another molecule or structural element, including multimerization. On the other hand, we predict that isolated RNA two-quartet parallel GQs may form, albeit being weakly stable. We also show that ionic parameters and water models should be chosen with caution because some parameter combinations can cause spurious instability of GQ stems. Some in-so-far unnoticed limitations of force-field description of multiple ions inside the GQs are discussed, which compromise the capability of simulations to fully capture the effect of increase in the number of quartets on the GQ stability.
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Affiliation(s)
- Barira Islam
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
| | - Petr Stadlbauer
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic.,Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacký University, tř. 17 listopadu 12, 771 46 Olomouc, Czech Republic
| | - Michaela Vorlíčková
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
| | - Jean-Louis Mergny
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
| | - Michal Otyepka
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic.,Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacký University, tř. 17 listopadu 12, 771 46 Olomouc, Czech Republic.,Department of Physical Chemistry, Faculty of Science, Palacký University, tř. 17 listopadu 12, 771 46 Olomouc, Czech Republic
| | - Jiří Šponer
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
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144
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Nakanishi C, Seimiya H. G-quadruplex in cancer biology and drug discovery. Biochem Biophys Res Commun 2020; 531:45-50. [PMID: 32312519 DOI: 10.1016/j.bbrc.2020.03.178] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 03/30/2020] [Indexed: 12/19/2022]
Abstract
G-quadruplex (G4) is a non-canonical nucleic acid structure formed in guanine-rich DNA or RNA. G4s are formed not only in vitro but also in vivo and are attracting considerable interest owing to their potential involvement in biological processes, including replication, transcription, mRNA splicing, translation and epigenetic regulation of the genome. In this review, we outline the functions of G4 in cellular biology and their implication in human pathogenesis, especially in cancer. Furthermore, we describe the properties of G4-stabilizing chemical compounds, G4 ligands, and their application for cancer therapeutics.
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Affiliation(s)
- Chuya Nakanishi
- Division of Molecular Biotherapy, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, 3-8-31 Ariake, Koto-ku, Tokyo, 135-8550, Japan; Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Tokyo, Japan
| | - Hiroyuki Seimiya
- Division of Molecular Biotherapy, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, 3-8-31 Ariake, Koto-ku, Tokyo, 135-8550, Japan; Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Tokyo, Japan.
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145
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Ray S, Tillo D, Boer RE, Assad N, Barshai M, Wu G, Orenstein Y, Yang D, Schneekloth JS, Vinson C. Custom DNA Microarrays Reveal Diverse Binding Preferences of Proteins and Small Molecules to Thousands of G-Quadruplexes. ACS Chem Biol 2020; 15:925-935. [PMID: 32216326 PMCID: PMC7263473 DOI: 10.1021/acschembio.9b00934] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Single-stranded DNA (ssDNA) containing four guanine repeats can form G-quadruplex (G4) structures. While cellular proteins and small molecules can bind G4s, it has been difficult to broadly assess their DNA-binding specificity. Here, we use custom DNA microarrays to examine the binding specificities of proteins, small molecules, and antibodies across ∼15,000 potential G4 structures. Molecules used include fluorescently labeled pyridostatin (Cy5-PDS, a small molecule), BG4 (Cy5-BG4, a G4-specific antibody), and eight proteins (GST-tagged nucleolin, IGF2, CNBP, FANCJ, PIF1, BLM, DHX36, and WRN). Cy5-PDS and Cy5-BG4 selectively bind sequences known to form G4s, confirming their formation on the microarrays. Cy5-PDS binding decreased when G4 formation was inhibited using lithium or when ssDNA features on the microarray were made double-stranded. Similar conditions inhibited the binding of all other molecules except for CNBP and PIF1. We report that proteins have different G4-binding preferences suggesting unique cellular functions. Finally, competition experiments are used to assess the binding specificity of an unlabeled small molecule, revealing the structural features in the G4 required to achieve selectivity. These data demonstrate that the microarray platform can be used to assess the binding preferences of molecules to G4s on a broad scale, helping to understand the properties that govern molecular recognition.
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Affiliation(s)
| | | | - Robert E. Boer
- Chemical Biology Laboratory, National Cancer Institute-Frederick, Frederick, Maryland 21702, United States
| | - Nima Assad
- Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Mira Barshai
- School of Electrical and Computer Engineering, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Guanhui Wu
- Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, Indiana 47907, United States
| | - Yaron Orenstein
- School of Electrical and Computer Engineering, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Danzhou Yang
- Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, Indiana 47907, United States
| | - John S. Schneekloth
- Chemical Biology Laboratory, National Cancer Institute-Frederick, Frederick, Maryland 21702, United States
| | - Charles Vinson
- Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
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146
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Tan J, Lan L. The DNA secondary structures at telomeres and genome instability. Cell Biosci 2020; 10:47. [PMID: 32257105 PMCID: PMC7104500 DOI: 10.1186/s13578-020-00409-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 03/14/2020] [Indexed: 01/09/2023] Open
Abstract
Telomeric DNA are TTAGGG tandem repeats, which are susceptible for oxidative DNA damage and hotspot regions for formation of DNA secondary structures such as t-loop, D-loop, G-quadruplexes (G4), and R-loop. In the past two decades, unique DNA or RNA secondary structures at telomeres or some specific regions of genome have become promising therapeutic targets. G-quadruplex and R-loops at telomeres or transcribed regions of genome have been considered as the potential targets for cancer therapy. Here we discuss the potentials to target the secondary structures (G4s and R-loops) in genome as therapy approaches.
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Affiliation(s)
- Jun Tan
- Harvard Medical School, Massachusetts General Hospital Cancer Center, Charlestown, MA 02129 USA
- Department of Radiation Oncology, Harvard Medical School, Massachusetts General Hospital, Boston, MA 02115 USA
| | - Li Lan
- Harvard Medical School, Massachusetts General Hospital Cancer Center, Charlestown, MA 02129 USA
- Department of Radiation Oncology, Harvard Medical School, Massachusetts General Hospital, Boston, MA 02115 USA
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147
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From R-Loops to G-Quadruplexes: Emerging New Threats for the Replication Fork. Int J Mol Sci 2020; 21:ijms21041506. [PMID: 32098397 PMCID: PMC7073102 DOI: 10.3390/ijms21041506] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 02/14/2020] [Accepted: 02/20/2020] [Indexed: 12/12/2022] Open
Abstract
Replicating the entire genome is one of the most complex tasks for all organisms. Research carried out in the last few years has provided us with a clearer picture on how cells preserve genomic information from the numerous insults that may endanger its stability. Different DNA repair pathways, coping with exogenous or endogenous threat, have been dissected at the molecular level. More recently, there has been an increasing interest towards intrinsic obstacles to genome replication, paving the way to a novel view on genomic stability. Indeed, in some cases, the movement of the replication fork can be hindered by the presence of stable DNA: RNA hybrids (R-loops), the folding of G-rich sequences into G-quadruplex structures (G4s) or repetitive elements present at Common Fragile Sites (CFS). Although differing in their nature and in the way they affect the replication fork, all of these obstacles are a source of replication stress. Replication stress is one of the main hallmarks of cancer and its prevention is becoming increasingly important as a target for future chemotherapeutics. Here we will try to summarize how these three obstacles are generated and how the cells handle replication stress upon their encounter. Finally, we will consider their role in cancer and their exploitation in current chemotherapeutic approaches.
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148
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Abstract
Guanine-rich DNA sequences can fold into four-stranded, noncanonical secondary structures called G-quadruplexes (G4s). G4s were initially considered a structural curiosity, but recent evidence suggests their involvement in key genome functions such as transcription, replication, genome stability, and epigenetic regulation, together with numerous connections to cancer biology. Collectively, these advances have stimulated research probing G4 mechanisms and consequent opportunities for therapeutic intervention. Here, we provide a perspective on the structure and function of G4s with an emphasis on key molecules and methodological advances that enable the study of G4 structures in human cells. We also critically examine recent mechanistic insights into G4 biology and protein interaction partners and highlight opportunities for drug discovery.
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Affiliation(s)
- Jochen Spiegel
- Cancer Research UK, Cambridge Institute, Li Ka Shing Centre, Cambridge CB2 0RE, UK
| | - Santosh Adhikari
- Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK
| | - Shankar Balasubramanian
- Cancer Research UK, Cambridge Institute, Li Ka Shing Centre, Cambridge CB2 0RE, UK
- Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK
- School of Clinical Medicine, University of Cambridge, Cambridge CB2 0SP, UK
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149
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Yan T, Zhao B, Wu Q, Wang W, Shi J, Li D, Stovall DB, Sui G. Characterization of G-quadruplex formation in the ARID1A promoter. Int J Biol Macromol 2020; 147:750-761. [PMID: 31982538 DOI: 10.1016/j.ijbiomac.2020.01.210] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 01/21/2020] [Accepted: 01/21/2020] [Indexed: 12/22/2022]
Abstract
As a member of the SWI/SNF family, ARID1A plays an essential role in modulating chromatin structure and gene expression. The tumor suppressive function of ARID1A has been well-defined and its downregulation in cancers is attributed to genomic deletion, DNA methylation and microRNA-mediated inhibition. In this study, we demonstrated that the negative strand of a C-rich region in the upstream vicinity of the human ARID1A transcription start site could form G-quadruplexes. Synthesized oligonucleotides based on the sequence of this region exhibited molar ellipticity at specific wavelengths characteristic of G-quadruplex structures in circular dichroism analyses. The formation of G-quadruplexes by these oligonucleotides were also proved by native polyacrylamide gel electrophoresis, DNA synthesis block assays, immunofluorescent staining and dimethyl sulfate footprinting studies. In reporter assays, mutations of the G-quadruplex forming sequence reduced ARID1A promoter-mediated transcription. Transfection of the oligonucleotide with the full length of G-quadruplex motif region, but not its partial sequences or the mutants, could both promote endogenous ARID1A expression and reduce cell proliferation.
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Affiliation(s)
- Ting Yan
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Science, Northeast Forestry University, Harbin 150040, China
| | - Bo Zhao
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Science, Northeast Forestry University, Harbin 150040, China
| | - Qiong Wu
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Science, Northeast Forestry University, Harbin 150040, China
| | - Wenmeng Wang
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Science, Northeast Forestry University, Harbin 150040, China
| | - Jinming Shi
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Science, Northeast Forestry University, Harbin 150040, China
| | - Dangdang Li
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Science, Northeast Forestry University, Harbin 150040, China
| | - Daniel B Stovall
- College of Arts and Sciences, Winthrop University, Rock Hill, SC 29733, United States
| | - Guangchao Sui
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Science, Northeast Forestry University, Harbin 150040, China.
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150
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Fleming AM, Burrows CJ. Interplay of Guanine Oxidation and G-Quadruplex Folding in Gene Promoters. J Am Chem Soc 2020; 142:1115-1136. [PMID: 31880930 PMCID: PMC6988379 DOI: 10.1021/jacs.9b11050] [Citation(s) in RCA: 91] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Living in an oxygen atmosphere demands an ability to thrive in the presence of reactive oxygen species (ROS). Aerobic organisms have successfully found solutions to the oxidative threats imposed by ROS by evolving an elaborate detoxification system, upregulating ROS during inflammation, and utilizing ROS as messenger molecules. In this Perspective, recent studies are discussed that demonstrate ROS as signaling molecules for gene regulation by combining two emergent properties of the guanine (G) heterocycle in DNA, namely, oxidation sensitivity and a propensity for G-quadruplex (G4) folding, both of which depend upon sequence context. In human gene promoters, this results from an elevated 5'-GG-3' dinucleotide frequency and GC enrichment near transcription start sites. Oxidation of DNA by ROS drives conversion of G to 8-oxo-7,8-dihydroguanine (OG) to mark target promoters for base excision repair initiated by OG-glycosylase I (OGG1). Sequence-dependent mechanisms for gene activation are available to OGG1 to induce transcription. Either OGG1 releases OG to yield an abasic site driving formation of a non-canonical fold, such as a G4, to be displayed to apurinic/apyrimidinic 1 (APE1) and stalling on the fold to recruit activating factors, or OGG1 binds OG and facilitates activator protein recruitment. The mechanisms described drive induction of stress response, DNA repair, or estrogen-induced genes, and these pathways are novel potential anticancer targets for therapeutic intervention. Chemical concepts provide a framework to discuss the regulatory or possible epigenetic potential of the OG modification in DNA, in which DNA "damage" and non-canonical folds collaborate to turn on or off gene expression. The next steps for scientific discovery in this growing field are discussed.
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Affiliation(s)
- Aaron M. Fleming
- 315 South 1400 East, Dept. of Chemistry, University of Utah, Salt Lake City, UT 84112-0850, USA
| | - Cynthia J. Burrows
- 315 South 1400 East, Dept. of Chemistry, University of Utah, Salt Lake City, UT 84112-0850, USA
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