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Farag M, Mouawad L. Comprehensive analysis of intramolecular G-quadruplex structures: furthering the understanding of their formalism. Nucleic Acids Res 2024; 52:3522-3546. [PMID: 38512075 DOI: 10.1093/nar/gkae182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 02/16/2024] [Accepted: 03/01/2024] [Indexed: 03/22/2024] Open
Abstract
G-quadruplexes (G4) are helical structures found in guanine-rich DNA or RNA sequences. Generally, their formalism is based on a few dozen structures, which can produce some inconsistencies or incompleteness. Using the website ASC-G4, we analyzed the structures of 333 intramolecular G4s, of all types, which allowed us to clarify some key concepts and present new information. To each of the eight distinguishable topologies corresponds a groove-width signature and a predominant glycosidic configuration (gc) pattern governed by the directions of the strands. The relative orientations of the stacking guanines within the strands, which we quantified and related to their vertical gc successions, determine the twist and tilt of the helices. The latter impact the minimum groove widths, which represent the space available for lateral ligand binding. The G4 four helices have similar twists, even when these twists are irregular, meaning that they have various angles along the strands. Despite its importance, the vertical gc succession has no strict one-to-one relationship with the topology, which explains the discrepancy between some topologies and their corresponding circular dichroism spectra. This study allowed us to introduce the new concept of platypus G4s, which are structures with properties corresponding to several topologies.
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Affiliation(s)
- Marc Farag
- Chemistry and Modeling for the Biology of Cancer, CNRS UMR9187, INSERM U1196, Institut Curie, PSL Research University, Université Paris-Saclay, CS 90030, 91401 ORSAYCedex, France
| | - Liliane Mouawad
- Chemistry and Modeling for the Biology of Cancer, CNRS UMR9187, INSERM U1196, Institut Curie, PSL Research University, Université Paris-Saclay, CS 90030, 91401 ORSAYCedex, France
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2
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Gajarsky M, Stadlbauer P, Sponer J, Cucchiarini A, Dobrovolna M, Brazda V, Mergny JL, Trantirek L, Lenarcic Zivkovic M. DNA Quadruplex Structure with a Unique Cation Dependency. Angew Chem Int Ed Engl 2024; 63:e202313226. [PMID: 38143239 DOI: 10.1002/anie.202313226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 12/11/2023] [Accepted: 12/22/2023] [Indexed: 12/26/2023]
Abstract
DNA quadruplex structures provide an additional layer of regulatory control in genome maintenance and gene expression and are widely used in nanotechnology. We report the discovery of an unprecedented tetrastranded structure formed from a native G-rich DNA sequence originating from the telomeric region of Caenorhabditis elegans. The structure is defined by multiple properties that distinguish it from all other known DNA quadruplexes. Most notably, the formation of a stable so-called KNa-quadruplex (KNaQ) requires concurrent coordination of K+ and Na+ ions at two distinct binding sites. This structure provides novel insight into G-rich DNA folding under ionic conditions relevant to eukaryotic cell physiology and the structural evolution of telomeric DNA. It highlights the differences between the structural organization of human and nematode telomeric DNA, which should be considered when using C. elegans as a model in telomere biology, particularly in drug screening applications. Additionally, the absence/presence of KNaQ motifs in the host/parasite introduces an intriguing possibility of exploiting the KNaQ fold as a plausible antiparasitic drug target. The structure's unique shape and ion dependency and the possibility of controlling its folding by using low-molecular-weight ligands can be used for the design or discovery of novel recognition DNA elements and sensors.
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Affiliation(s)
- Martin Gajarsky
- Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 753/5, 62500, Brno, Czech Republic
- Current address: Center for Molecular Medicine Cologne, University of Cologne, 50931, Cologne, Germany
| | - Petr Stadlbauer
- Institute of Biophysics, Czech Academy of Sciences, Kralovopolska 135, 61265, Brno, Czech Republic
| | - Jiri Sponer
- Institute of Biophysics, Czech Academy of Sciences, Kralovopolska 135, 61265, Brno, Czech Republic
| | - Anne Cucchiarini
- Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 753/5, 62500, Brno, Czech Republic
- Laboratoire d'Optique et Biosciences, Ecole Polytechnique, CNRS, Inserm, Institut Polytechnique de Paris, 91120, Palaiseau, France
| | - Michaela Dobrovolna
- Institute of Biophysics, Czech Academy of Sciences, Kralovopolska 135, 61265, Brno, Czech Republic
- Faculty of Chemistry, Brno University of Technology, Purkynova 464, 61200, Brno, Czech Republic
| | - Vaclav Brazda
- Institute of Biophysics, Czech Academy of Sciences, Kralovopolska 135, 61265, Brno, Czech Republic
- Faculty of Chemistry, Brno University of Technology, Purkynova 464, 61200, Brno, Czech Republic
| | - Jean-Louis Mergny
- Institute of Biophysics, Czech Academy of Sciences, Kralovopolska 135, 61265, Brno, Czech Republic
- Laboratoire d'Optique et Biosciences, Ecole Polytechnique, CNRS, Inserm, Institut Polytechnique de Paris, 91120, Palaiseau, France
| | - Lukas Trantirek
- Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 753/5, 62500, Brno, Czech Republic
| | - Martina Lenarcic Zivkovic
- Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 753/5, 62500, Brno, Czech Republic
- Slovenian NMR Centre, National Institute of Chemistry, Hajdrihova 19, 1000, Ljubljana, Slovenia
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3
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Luo Y, Živković ML, Wang J, Ryneš J, Foldynová-Trantírková S, Trantírek L, Verga D, Mergny JL. A sodium/potassium switch for G4-prone G/C-rich sequences. Nucleic Acids Res 2024; 52:448-461. [PMID: 37986223 PMCID: PMC10783510 DOI: 10.1093/nar/gkad1073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Revised: 10/19/2023] [Accepted: 11/03/2023] [Indexed: 11/22/2023] Open
Abstract
Metal ions are essential components for the survival of living organisms. For most species, intracellular and extracellular ionic conditions differ significantly. As G-quadruplexes (G4s) are ion-dependent structures, changes in the [Na+]/[K+] ratio may affect the folding of genomic G4s. More than 11000 putative G4 sequences in the human genome (hg19) contain at least two runs of three continuous cytosines, and these mixed G/C-rich sequences may form a quadruplex or a competing hairpin structure based on G-C base pairing. In this study, we examine how the [Na+]/[K+] ratio influences the structures of G/C-rich sequences. The natural G4 structure with a 9-nt long central loop, CEBwt, was chosen as a model sequence, and the loop bases were gradually replaced by cytosines. The series of CEB mutations revealed that the presence of cytosines in G4 loops does not prevent G4 folding or decrease G4 stability but increases the probability of forming a competing structure, either a hairpin or an intermolecular duplex. Slow conversion to the quadruplex in vitro (in a potassium-rich buffer) and cells was demonstrated by NMR. 'Shape-shifting' sequences may respond to [Na+]/[K+] changes with delayed kinetics.
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Affiliation(s)
- Yu Luo
- Laboratoire d’Optique et Biosciences, Ecole Polytechnique, CNRS, Inserm, Institut Polytechnique de Paris, 91128 Palaiseau, France
- CNRS UMR9187, INSERM U1196, Université Paris-Saclay, F-91405 Orsay, France
| | - Martina Lenarčič Živković
- Central European Institute of Technology, Masaryk University, 625 00 Brno, Czech Republic
- Slovenian NMR Centre, National Institute of Chemistry, SI-1000 Ljubljana, Slovenia
| | - Jiawei Wang
- Laboratoire d’Optique et Biosciences, Ecole Polytechnique, CNRS, Inserm, Institut Polytechnique de Paris, 91128 Palaiseau, France
| | - Jan Ryneš
- Central European Institute of Technology, Masaryk University, 625 00 Brno, Czech Republic
| | | | - Lukáš Trantírek
- Central European Institute of Technology, Masaryk University, 625 00 Brno, Czech Republic
| | - Daniela Verga
- CNRS UMR9187, INSERM U1196, Université Paris-Saclay, F-91405 Orsay, France
- CNRS UMR9187, INSERM U1196, Institut Curie, PSL Research University, F-91405 Orsay, France
| | - Jean-Louis Mergny
- Laboratoire d’Optique et Biosciences, Ecole Polytechnique, CNRS, Inserm, Institut Polytechnique de Paris, 91128 Palaiseau, France
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4
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Luo Y, Granzhan A, Marquevielle J, Cucchiarini A, Lacroix L, Amrane S, Verga D, Mergny JL. Guidelines for G-quadruplexes: I. In vitro characterization. Biochimie 2023; 214:5-23. [PMID: 36596406 DOI: 10.1016/j.biochi.2022.12.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 12/19/2022] [Accepted: 12/28/2022] [Indexed: 01/02/2023]
Abstract
Besides the well-known DNA double-helix, non-canonical nucleic acid structures regulate crucial biological activities. Among these oddities, guanine-rich DNA sequences can form unusual four-stranded secondary structures called G-quadruplexes (G4s). G4-prone sequences have been found in the genomes of most species, and G4s play important roles in essential processes such as transcription, replication, genome integrity and epigenetic regulation. Here, we present a short overview of G-quadruplexes followed by a detailed description of the biophysical and biochemical methods used to characterize G4s in vitro. The principles, experimental details and possible shortcomings of each method are discussed to provide a comprehensive view of the techniques used to study these structures. We aim to provide a set of guidelines for standardizing research on G-quadruplexes; these guidelines are not meant to be a dogmatic set of rules, but should rather provide useful information on the methods currently used to study these fascinating motifs.
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Affiliation(s)
- Yu Luo
- Laboratoire D'Optique et Biosciences, Ecole Polytechnique, CNRS, Inserm, Institut Polytechnique de Paris, 91120, Palaiseau, France; CNRS UMR9187, INSERM U1196, Université Paris-Saclay, F-91405, Orsay, France
| | - Anton Granzhan
- CNRS UMR9187, INSERM U1196, Université Paris-Saclay, F-91405, Orsay, France; CNRS UMR9187, INSERM U1196, Institut Curie, PSL Research University, F-91405, Orsay, France
| | - Julien Marquevielle
- Université de Bordeaux, ARNA Laboratory, INSERM U1212, CNRS UMR 5320, IECB, 33076, Bordeaux, France
| | - Anne Cucchiarini
- Laboratoire D'Optique et Biosciences, Ecole Polytechnique, CNRS, Inserm, Institut Polytechnique de Paris, 91120, Palaiseau, France
| | - Laurent Lacroix
- Institut de Biologie de L'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Samir Amrane
- Université de Bordeaux, ARNA Laboratory, INSERM U1212, CNRS UMR 5320, IECB, 33076, Bordeaux, France
| | - Daniela Verga
- CNRS UMR9187, INSERM U1196, Université Paris-Saclay, F-91405, Orsay, France; CNRS UMR9187, INSERM U1196, Institut Curie, PSL Research University, F-91405, Orsay, France.
| | - Jean-Louis Mergny
- Laboratoire D'Optique et Biosciences, Ecole Polytechnique, CNRS, Inserm, Institut Polytechnique de Paris, 91120, Palaiseau, France; Institute of Biophysics of the Czech Academy of Sciences, Brno, Czech Republic.
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5
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Yu X, Gray S, Ferreira H. POT-3 preferentially binds the terminal DNA-repeat on the telomeric G-overhang. Nucleic Acids Res 2023; 51:610-618. [PMID: 36583365 PMCID: PMC9881156 DOI: 10.1093/nar/gkac1203] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 12/01/2022] [Accepted: 12/06/2022] [Indexed: 12/31/2022] Open
Abstract
Eukaryotic chromosomes typically end in 3' telomeric overhangs. The safeguarding of telomeric single-stranded DNA overhangs is carried out by factors related to the protection of telomeres 1 (POT1) protein in humans. Of the three POT1-like proteins in Caenorhabditis elegans, POT-3 was the only member thought to not play a role at telomeres. Here, we provide evidence that POT-3 is a bona fide telomere-binding protein. Using a new loss-of-function mutant, we show that the absence of POT-3 causes telomere lengthening and increased levels of telomeric C-circles. We find that POT-3 directly binds the telomeric G-strand in vitro and map its minimal DNA binding site to the six-nucleotide motif, GCTTAG. We further show that the closely related POT-2 protein binds the same motif, but that POT-3 shows higher sequence selectivity. Crucially, in contrast to POT-2, POT-3 prefers binding sites immediately adjacent to the 3' end of DNA. These differences are significant as genetic analyses reveal that pot-2 and pot-3 do not function redundantly with each other in vivo. Our work highlights the rapid evolution and specialisation of telomere binding proteins and places POT-3 in a unique position to influence activities that control telomere length.
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Affiliation(s)
- Xupeng Yu
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, North Haugh, St Andrews, UK
| | - Sean Gray
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, North Haugh, St Andrews, UK
| | - Helder C Ferreira
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, North Haugh, St Andrews, UK
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Amrane S, Jaubert C, Bedrat A, Rundstadler T, Recordon-Pinson P, Aknin C, Guédin A, De Rache A, Bartolucci L, Diene I, Lemoine F, Gascuel O, Pratviel G, Mergny JL, Andreola ML. Deciphering RNA G-quadruplex function during the early steps of HIV-1 infection. Nucleic Acids Res 2022; 50:12328-12343. [PMID: 36453997 PMCID: PMC9757044 DOI: 10.1093/nar/gkac1030] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 09/27/2022] [Accepted: 10/29/2022] [Indexed: 12/02/2022] Open
Abstract
G-quadruplexes (G4s) are four-stranded nucleic acid structures formed by the stacking of G-tetrads. Here we investigated their formation and function during HIV-1 infection. Using bioinformatics and biophysics analyses we first searched for evolutionary conserved G4-forming sequences in HIV-1 genome. We identified 10 G4s with conservation rates higher than those of HIV-1 regulatory sequences such as RRE and TAR. We then used porphyrin-based G4-binders to probe the formation of the G4s during infection of human cells by native HIV-1. The G4-binders efficiently inhibited HIV-1 infectivity, which is attributed to the formation of G4 structures during HIV-1 replication. Using a qRT-PCR approach, we showed that the formation of viral G4s occurs during the first 2 h post-infection and their stabilization by the G4-binders prevents initiation of reverse transcription. We also used a G4-RNA pull-down approach, based on a G4-specific biotinylated probe, to allow the direct detection and identification of viral G4-RNA in infected cells. Most of the detected G4-RNAs contain crucial regulatory elements such as the PPT and cPPT sequences as well as the U3 region. Hence, these G4s would function in the early stages of infection when the viral RNA genome is being processed for the reverse transcription step.
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Affiliation(s)
- Samir Amrane
- To whom correspondence should be addressed. Tel : +33 5 4000 2224;
| | - Chloé Jaubert
- Université de Bordeaux, Bordeaux, France,ARNA Laboratory, INSERM U1212, CNRS UMR 5320, IECB, Bordeaux, France
| | - Amina Bedrat
- Université de Bordeaux, Bordeaux, France,ARNA Laboratory, INSERM U1212, CNRS UMR 5320, IECB, Bordeaux, France
| | - Tiffany Rundstadler
- Université de Toulouse, UPS, INPT, Toulouse, France,Laboratoire de Chimie de Coordination, CNRS UPR 8241, Toulouse, France
| | | | - Cindy Aknin
- Université de Bordeaux, Bordeaux, France,MFP laboratory, UMR5234, CNRS, Bordeaux, France
| | - Aurore Guédin
- Université de Bordeaux, Bordeaux, France,ARNA Laboratory, INSERM U1212, CNRS UMR 5320, IECB, Bordeaux, France
| | - Aurore De Rache
- Université de Bordeaux, Bordeaux, France,ARNA Laboratory, INSERM U1212, CNRS UMR 5320, IECB, Bordeaux, France
| | - Laura Bartolucci
- Université de Bordeaux, Bordeaux, France,ARNA Laboratory, INSERM U1212, CNRS UMR 5320, IECB, Bordeaux, France
| | - Ibra Diene
- Université de Bordeaux, Bordeaux, France,ARNA Laboratory, INSERM U1212, CNRS UMR 5320, IECB, Bordeaux, France
| | - Frédéric Lemoine
- Institut Pasteur, Université de Paris, Unité de Bioinformatique Évolutive, F-75015 Paris, France,Institut Pasteur, Université de Paris, Hub de bioinformatique et biostatistiques, F-75015 Paris, France
| | - Olivier Gascuel
- Institut Pasteur, Université de Paris, Unité de Bioinformatique Évolutive, F-75015 Paris, France,Institut de Systématique, Évolution, Biodiversité (ISYEB, UMR 7205 - CNRS, Muséum National d’Histoire Naturelle, SU, EPHE UA), F-75005 Paris, France
| | - Geneviève Pratviel
- Université de Toulouse, UPS, INPT, Toulouse, France,Laboratoire de Chimie de Coordination, CNRS UPR 8241, Toulouse, France
| | - Jean-Louis Mergny
- Université de Bordeaux, Bordeaux, France,ARNA Laboratory, INSERM U1212, CNRS UMR 5320, IECB, Bordeaux, France,Laboratoire d’Optique & Biosciences, Ecole Polytechnique, CNRS, Inserm, Institut Polytechnique de Paris, Palaiseau, France
| | - Marie-Line Andreola
- Université de Bordeaux, Bordeaux, France,MFP laboratory, UMR5234, CNRS, Bordeaux, France
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