1
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Michael Sabo T, Trent JO, Chaires JB, Monsen RC. Strategy for modeling higher-order G-quadruplex structures recalcitrant to NMR determination. Methods 2024; 230:9-20. [PMID: 39032720 DOI: 10.1016/j.ymeth.2024.07.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Revised: 06/22/2024] [Accepted: 07/17/2024] [Indexed: 07/23/2024] Open
Abstract
Guanine-rich nucleic acids can form intramolecularly folded four-stranded structures known as G-quadruplexes (G4s). Traditionally, G4 research has focused on short, highly modified DNA or RNA sequences that form well-defined homogeneous compact structures. However, the existence of longer sequences with multiple G4 repeats, from proto-oncogene promoters to telomeres, suggests the potential for more complex higher-order structures with multiple G4 units that might offer selective drug-targeting sites for therapeutic development. These larger structures present significant challenges for structural characterization by traditional high-resolution methods like multi-dimensional NMR and X-ray crystallography due to their molecular complexity. To address this current challenge, we have developed an integrated structural biology (ISB) platform, combining experimental and computational methods to determine self-consistent molecular models of higher-order G4s (xG4s). Here we outline our ISB method using two recent examples from our lab, an extended c-Myc promoter and long human telomere G4 repeats, that highlights the utility and generality of our approach to characterizing biologically relevant xG4s.
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Affiliation(s)
- T Michael Sabo
- UofL Health Brown Cancer Center, University of Louisville, Louisville, KY, United States
| | - John O Trent
- UofL Health Brown Cancer Center, University of Louisville, Louisville, KY, United States
| | - Jonathan B Chaires
- UofL Health Brown Cancer Center, University of Louisville, Louisville, KY, United States
| | - Robert C Monsen
- UofL Health Brown Cancer Center, University of Louisville, Louisville, KY, United States.
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2
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Lacen A, Symasek A, Gunter A, Lee HT. Slow G-Quadruplex Conformation Rearrangement and Accessibility Change Induced by Potassium in Human Telomeric Single-Stranded DNA. J Phys Chem B 2024; 128:5950-5965. [PMID: 38875355 PMCID: PMC11216195 DOI: 10.1021/acs.jpcb.4c00719] [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: 02/01/2024] [Revised: 05/24/2024] [Accepted: 06/03/2024] [Indexed: 06/16/2024]
Abstract
The guanine-rich telomeric repeats can form G-quadruplexes (G4s) that alter the accessibility of the single-stranded telomeric overhang. In this study, we investigated the effects of Na+ and K+ on G4 folding and accessibility through cation introduction and exchange. We combined differential scanning calorimetry (DSC), circular dichroism (CD), and single molecule Förster resonance energy transfer (smFRET) to monitor the stability, conformational dynamics, and complementary strand binding accessibility of G4 formed by single-stranded telomeric DNA. Our data showed that G4 formed through heating and slow cooling in K+ solution exhibited fewer conformational dynamics than G4 formed in Na+ solution, which is consistent with the higher thermal stability of G4 in K+. Monitoring cation exchange with real time smFRET at room temperature shows that Na+ and K+ can replace each other in G4. When encountering high K+ at room or body temperature, G4 undergoes a slow conformational rearrangement process which is mostly complete by 2 h. The slow conformational rearrangement ends with a stable G4 that is unable to be unfolded by a complementary strand. This study provides new insights into the accessibility of G4 forming sequences at different time points after introduction to a high K+ environment in cells, which may affect how the nascent telomeric overhang interacts with proteins and telomerase.
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Affiliation(s)
- Arianna
N. Lacen
- Department of Chemistry, University
of Alabama at Birmingham, 901 14th Street South, Birmingham, Alabama 35294, United
States
| | - Andrew Symasek
- Department of Chemistry, University
of Alabama at Birmingham, 901 14th Street South, Birmingham, Alabama 35294, United
States
| | - Alan Gunter
- Department of Chemistry, University
of Alabama at Birmingham, 901 14th Street South, Birmingham, Alabama 35294, United
States
| | - Hui-Ting Lee
- Department of Chemistry, University
of Alabama at Birmingham, 901 14th Street South, Birmingham, Alabama 35294, United
States
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3
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Basu M, Mishra PP. G-quadruplex modulation by E. coli SSB: A comprehensive study on binding affinities and modes using single-molecule FRET. Int J Biol Macromol 2024; 266:131057. [PMID: 38522699 DOI: 10.1016/j.ijbiomac.2024.131057] [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: 12/07/2023] [Revised: 02/29/2024] [Accepted: 03/08/2024] [Indexed: 03/26/2024]
Abstract
G-quadruplexes (GQs) are essential guanine-rich secondary structures found in DNA and RNA, playing crucial roles in genomic maintenance and stability. Recent studies have unveiled GQs in the intergenic regions of the E. coli genome, suggesting their biological significance and potential as anti-microbial targets. Here, we investigated the interaction between homo-tetrameric E. coli SSB and GQ-forming single-stranded DNA (ssDNA) sequence with varying lengths. Combining Microscale Thermophoresis (MST) and conventional spectroscopic techniques, we explored E. coli SSB binding to ssDNA and the structural changes of these secondary DNA structures upon protein binding. Subsequently, we have utilized smFRET to probe the conformational changes of GQ-ssDNA structures upon SSB binding. Our results provide detailed insights into SSB's access to various GQ-ssDNA sequencies and the wrapping of this homo-tetrameric protein around GQ-ssDNA in multiple distinct binding modalities. This study sheds light on the intricate details of E. coli SSB's interaction with ssDNA and the resulting widespread conformational changes within these oligonucleotide structures after protein binding. It offers a thorough insight into SSB's accesses to various GQ-ssDNA architectures. The finding demonstrates the multifaceted binding methods through which this homo-tetrameric protein envelops GQ-ssDNA and could prove valuable in deciphering biological processes that involve DNA G-quadruplexes.
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Affiliation(s)
- Manali Basu
- Single Molecule Biophysics Lab, Chemical Sciences Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064, India; Homi Bhabha National Institute, Mumbai, India
| | - Padmaja Prasad Mishra
- Single Molecule Biophysics Lab, Chemical Sciences Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064, India; Homi Bhabha National Institute, Mumbai, India.
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4
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Wang C, Xu G, Liu X, Jiang L, Zhou X, Liu M, Li C. 19F Nuclear Magnetic Resonance Fingerprinting Technique for Identifying and Quantifying G-Quadruplex Topology in Human Telomeric Overhangs. J Am Chem Soc 2024; 146:4741-4751. [PMID: 38346932 DOI: 10.1021/jacs.3c12247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
G-quadruplexes (G4s) are noncanonical nucleic acid secondary structures with diverse topological features and biological roles. Human telomeric (Htelo) overhangs consisting of TTAGGG repeats can fold into G4s that adopt different topologies under physiological conditions. These G4s are potential targets for anticancer drugs. Despite intensive research, the existence and topology of G4s at Htelo overhangs in vivo are still unclear because there is no method to distinguish and quantify the topology of Htelo overhangs with native lengths that can form more than three tandem G4s in living cells. Herein, we present a novel 19F chemical shift fingerprinting technique to identify and quantify the topology of the Htelo overhangs up to five G-quadruplexes (G4s) and 120 nucleotides long both in vitro and in living cells. Our results show that longer overhang sequences tend to form stable G4s at the 5'- and 3'-ends, while the interior G4s are dynamic and "sliding" along the sequence, with TTA or 1-3 TTAGGG repeats as a linker. Each G4 in the longer overhang is conformationally heterogeneous, but the predominant ones are hybrid-2, two- or three-tetrad antiparallel, and hybrid-1 at the 5'-terminal, interior, and 3'-terminal, respectively. Additionally, we observed a distinct behavior of different lengths of telomeric sequences in living cells, suggesting that the overhang length and protein accessibility are related to its function. This technique provides a powerful tool for quickly identifying the folding topology and relative population of long Htelo overhangs, which may provide valuable insights into telomere functionality and be beneficial for structure-based anticancer drug development targeting G4s.
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Affiliation(s)
- Chen Wang
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan National Laboratory for Optoelectronics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Guohua Xu
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan National Laboratory for Optoelectronics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, P. R. China
| | - Xiaoli Liu
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan National Laboratory for Optoelectronics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, P. R. China
| | - Ling Jiang
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan National Laboratory for Optoelectronics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, P. R. China
| | - Xin Zhou
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan National Laboratory for Optoelectronics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, P. R. China
| | - Maili Liu
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan National Laboratory for Optoelectronics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, P. R. China
| | - Conggang Li
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan National Laboratory for Optoelectronics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, P. R. China
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5
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Shiekh S, Kodikara SG, Balci H. Structure, Topology, and Stability of Multiple G-quadruplexes in Long Telomeric Overhangs. J Mol Biol 2024; 436:168205. [PMID: 37481156 PMCID: PMC10799177 DOI: 10.1016/j.jmb.2023.168205] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 07/05/2023] [Accepted: 07/12/2023] [Indexed: 07/24/2023]
Abstract
Telomeres and their single stranded overhangs gradually shorten with successive cell divisions, as part of the natural aging process, but can be elongated by telomerase, a nucleoprotein complex which is activated in the majority of cancers. This prominent implication in cancer and aging has made the repetitive telomeric sequences (TTAGGG repeats) and the G-quadruplex structures that form in their overhangs the focus of intense research in the past several decades. However, until recently most in vitro efforts to understand the structure, stability, dynamics, and interactions of telomeric overhangs had been focused on short sequences that are not representative of longer sequences encountered in a physiological setting. In this review, we will provide a broad perspective about telomeres and associated factors, and introduce the agents and structural characteristics involved in organizing, maintaining, and protecting telomeric DNA. We will also present a summary of recent research performed on long telomeric sequences, nominally defined as those that can form two or more tandem G-quadruplexes, i.e., which contain eight or more TTAGGG repeats. Results of experimental studies using a broad array of experimental tools, in addition to recent computational efforts will be discussed, particularly in terms of their implications for the stability, folding topology, and compactness of the tandem G-quadruplexes that form in long telomeric overhangs.
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Affiliation(s)
- Sajad Shiekh
- Department of Physics, Kent State University, Kent, OH 44242, USA
| | | | - Hamza Balci
- Department of Physics, Kent State University, Kent, OH 44242, USA.
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6
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Riccardi C, Pérez de Carvasal K, Platella C, Meyer A, Smietana M, Morvan F, Montesarchio D. Probing naphthalene diimide and 3-hydroxypropylphosphate as end-conjugating moieties for improved thrombin binding aptamers: Structural and biological effects. Bioorg Chem 2023; 141:106917. [PMID: 37865055 DOI: 10.1016/j.bioorg.2023.106917] [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: 09/04/2023] [Revised: 09/27/2023] [Accepted: 10/09/2023] [Indexed: 10/23/2023]
Abstract
The limitations associated with the in vivo use of the thrombin binding aptamer (TBA or TBA15) have dramatically stimulated the search of suitable chemically modified analogues in order to discover effective and reversible inhibitors of thrombin activity. In this context, we previously proposed cyclic and pseudo-cyclic TBA analogues with improved stability that proved to be more active than the parent aptamer. Herein, we have investigated a novel library of TBA derivatives carrying naphthalene diimide (NDI) moieties at the 3'- or 5'-end. In a subset of the investigated oligonucleotides, additional 3-hydroxypropylphosphate (HPP) groups were introduced at one or both ends of the TBA sequence. Evaluation of the G-quadruplex thermal stability, serum nuclease resistance and in vitro anticoagulant activity of the new TBA analogues allowed rationalizing the effect of these appendages on the activity of the aptamer on the basis of their relative position. Notably, most of the different TBA analogues tested were more potent thrombin inhibitors than unmodified TBA. Particularly, the analogue carrying an NDI group at the 5'-end and an HPP group at the 3'-end, named N-TBA-p, exhibited enhanced G-quadruplex thermal stability (ΔTm + 14° C) and ca. 10-fold improved nuclease resistance in serum compared to the native aptamer. N-TBA-p also induced prolonged and dose-dependent clotting times, showing a ca. 11-fold higher anticoagulant activity compared to unmodified TBA, as determined by spectroscopic methods. Overall, N-TBA-p proved to be in vitro a more efficient thrombin inhibitor than all the best ones previously investigated in our group. Its interesting features, associated with its easy preparation, make it a very promising candidate for future in vivo studies.
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Affiliation(s)
- Claudia Riccardi
- Department of Chemical Sciences, University of Naples Federico II, 80126 Naples, Italy
| | - Kévan Pérez de Carvasal
- Institut des Biomolécules Max Mousseron, Université de Montpellier, CNRS, ENSCM, 34095 Montpellier, France
| | - Chiara Platella
- Department of Chemical Sciences, University of Naples Federico II, 80126 Naples, Italy
| | - Albert Meyer
- Institut des Biomolécules Max Mousseron, Université de Montpellier, CNRS, ENSCM, 34095 Montpellier, France
| | - Michael Smietana
- Institut des Biomolécules Max Mousseron, Université de Montpellier, CNRS, ENSCM, 34095 Montpellier, France
| | - François Morvan
- Institut des Biomolécules Max Mousseron, Université de Montpellier, CNRS, ENSCM, 34095 Montpellier, France.
| | - Daniela Montesarchio
- Department of Chemical Sciences, University of Naples Federico II, 80126 Naples, Italy.
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7
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De Piante E, D'Aria F, Napolitano LMR, Amato J, Pirrello S, Onesti S, Giancola C. Exploring the G-quadruplex binding and unwinding activity of the bacterial FeS helicase DinG. Sci Rep 2023; 13:12610. [PMID: 37537265 PMCID: PMC10400533 DOI: 10.1038/s41598-023-39675-5] [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: 04/26/2023] [Accepted: 07/28/2023] [Indexed: 08/05/2023] Open
Abstract
Despite numerous reports on the interactions of G-quadruplexes (G4s) with helicases, systematic analysis addressing the selectivity and specificity of each helicase towards a variety of G4 topologies are scarce. Among the helicases able to unwind G4s are those containing an iron-sulphur (FeS) cluster, including both the bacterial DinG (found in E. coli and several pathogenic bacteria) and the medically important eukaryotic homologues (XPD, FancJ, DDX11 and RTEL1). We carried out a detailed study of the interactions between the E. coli DinG and a variety of G4s, by employing physicochemical and biochemical methodologies. A series of G4-rich sequences from different genomic locations (promoter and telomeric regions), able to form unimolecular G4 structures with diverse topologies, were analyzed (c-KIT1, KRAS, c-MYC, BCL2, Tel23, T30695, Zic1). DinG binds to most of the investigated G4s with little discrimination, while it exhibits a clear degree of unwinding specificity towards different G4 topologies. Whereas previous reports suggested that DinG was active only on bimolecular G4s, here we show that it is also able to bind to and resolve the more physiologically relevant unimolecular G4s. In addition, when the G4 structures were stabilized by ligands (Pyridostatin, PhenDC3, BRACO-19 or Netropsin), the DinG unwinding activity decreased and in most cases was abolished, with a pattern that is not simply explained by a change in binding affinity. Overall, these results have important implications for the biochemistry of helicases, strongly suggesting that when analysing the G4 unwinding property of an enzyme, it is necessary to investigate a variety of G4 substrates.
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Affiliation(s)
- Elisa De Piante
- Structural Biology Laboratory, Elettra-Sincrotrone Trieste S.C.p.A, 34149, Trieste, Italy
- Department of Pharmacy, University of Naples Federico II, 80131, Naples, Italy
| | - Federica D'Aria
- Department of Pharmacy, University of Naples Federico II, 80131, Naples, Italy
| | - Luisa M R Napolitano
- Structural Biology Laboratory, Elettra-Sincrotrone Trieste S.C.p.A, 34149, Trieste, Italy
| | - Jussara Amato
- Department of Pharmacy, University of Naples Federico II, 80131, Naples, Italy
| | - Simone Pirrello
- Structural Biology Laboratory, Elettra-Sincrotrone Trieste S.C.p.A, 34149, Trieste, Italy
| | - Silvia Onesti
- Structural Biology Laboratory, Elettra-Sincrotrone Trieste S.C.p.A, 34149, Trieste, Italy.
| | - Concetta Giancola
- Department of Pharmacy, University of Naples Federico II, 80131, Naples, Italy.
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8
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Kench T, Rakers V, Bouzada D, Gomez-González J, Robinson J, Kuimova MK, Vázquez López M, Vázquez ME, Vilar R. Dimeric Metal-Salphen Complexes Which Target Multimeric G-Quadruplex DNA. Bioconjug Chem 2023; 34:911-921. [PMID: 37119235 DOI: 10.1021/acs.bioconjchem.3c00114] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
G-Quadruplex DNA structures have attracted increasing attention due to their biological roles and potential as targets for the development of new drugs. While most guanine-rich sequences in the genome have the potential to form monomeric G-quadruplexes, certain sequences have enough guanine-tracks to give rise to multimeric quadruplexes. One of these sequences is the human telomere where tandem repeats of TTAGGG can lead to the formation of two or more adjacent G-quadruplexes. Herein we report on the modular synthesis via click chemistry of dimeric metal-salphen complexes (with NiII and PtII) bridged by either polyether or peptide linkers. We show by circular dichroism (CD) spectroscopy that they generally have higher selectivity for dimeric vs monomeric G-quadruplexes. The emissive properties of the PtII-salphen dimeric complexes have been used to study their interactions with monomeric and dimeric G-quadruplexes in vitro as well as to study their cellular uptake and localization.
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Affiliation(s)
- Timothy Kench
- Department of Chemistry, Imperial College London, White City Campus, 82 Wood Lane, London W12 0BZ, United Kingdom
| | - Viktoria Rakers
- Department of Chemistry, Imperial College London, White City Campus, 82 Wood Lane, London W12 0BZ, United Kingdom
| | - David Bouzada
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS), Departamento de Química Orgánica, Universidade de Santiago de Compostela, Santiago de Compostela 15782, Spain
| | - Jacobo Gomez-González
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS), Departamento de Química Orgánica, Universidade de Santiago de Compostela, Santiago de Compostela 15782, Spain
| | - Jenna Robinson
- Department of Chemistry, Imperial College London, White City Campus, 82 Wood Lane, London W12 0BZ, United Kingdom
| | - Marina K Kuimova
- Department of Chemistry, Imperial College London, White City Campus, 82 Wood Lane, London W12 0BZ, United Kingdom
| | - Miguel Vázquez López
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS), Departamento de Química Inorgánica, Universidade de Santiago de Compostela, Santiago de Compostela 15782, Spain
| | - M Eugenio Vázquez
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS), Departamento de Química Orgánica, Universidade de Santiago de Compostela, Santiago de Compostela 15782, Spain
| | - Ramon Vilar
- Department of Chemistry, Imperial College London, White City Campus, 82 Wood Lane, London W12 0BZ, United Kingdom
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9
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Hu MH, Lin JH. New triazole-attached quinoxalines selectively recognize the telomeric multimeric G-quadruplexes and inhibit breast cancer cell growth. Int J Biol Macromol 2023; 241:124548. [PMID: 37094649 DOI: 10.1016/j.ijbiomac.2023.124548] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 04/10/2023] [Accepted: 04/12/2023] [Indexed: 04/26/2023]
Abstract
The telomeric 3'-overhang had potential to form into higher-order structures termed multimeric G-quadruplexes (G4s), which may mainly exist in telomeres, representing an attractive drug target for development of anticancer agents with few side effects. However, only a few molecules that selectively bind to multimeric G4s have been found by random screening, which means a lot of room for improvement. In this study, we raised a feasible strategy to design small-molecule ligands with possible selectivity to multimeric G4s, and then synthesized a focused library of multi-aryl compounds by attaching triazole rings to the quinoxaline skeleton. Among them, QTR-3 was identified as the most promising selective ligand that may bind at the G4-G4 interface, which accordingly stabilized multimeric G4s and induced DNA damage in telomeric region, thereby leading to cell cycle arrest and apoptosis. Notably, QTR-3 showed more significant inhibition on breast cancer cells against normal mammary cells.
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Affiliation(s)
- Ming-Hao Hu
- Nation-Regional Engineering Lab for Synthetic Biology of Medicine, International Cancer Center, School of Pharmacy, Shenzhen University Medical School, Shenzhen 518060, China; Shenzhen Key Laboratory for Nano-Biosensing Technology (ZDSYS20210112161400001), Shenzhen University Medical School, Shenzhen 518060, China.
| | - Jia-Hong Lin
- Nation-Regional Engineering Lab for Synthetic Biology of Medicine, International Cancer Center, School of Pharmacy, Shenzhen University Medical School, Shenzhen 518060, China
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10
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Kristoffersen E, Coletta A, Lund L, Schiøtt B, Birkedal V. Inhibited complete folding of consecutive human telomeric G-quadruplexes. Nucleic Acids Res 2023; 51:1571-1582. [PMID: 36715345 PMCID: PMC9976873 DOI: 10.1093/nar/gkad004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 12/24/2022] [Accepted: 01/04/2023] [Indexed: 01/31/2023] Open
Abstract
Noncanonical DNA structures, termed G-quadruplexes, are present in human genomic DNA and are important elements in many DNA metabolic processes. Multiple sites in the human genome have G-rich DNA stretches able to support formation of several consecutive G-quadruplexes. One of those sites is the telomeric overhang region that has multiple repeats of TTAGGG and is tightly associated with both cancer and aging. We investigated the folding of consecutive G-quadruplexes in both potassium- and sodium-containing solutions using single-molecule FRET spectroscopy, circular dichroism, thermal melting and molecular dynamics simulations. Our observations show coexistence of partially and fully folded DNA, the latter consisting of consecutive G-quadruplexes. Following the folding process over hours in sodium-containing buffers revealed fast G-quadruplex folding but slow establishment of thermodynamic equilibrium. We find that full consecutive G-quadruplex formation is inhibited by the many DNA structures randomly nucleating on the DNA, some of which are off-path conformations that need to unfold to allow full folding. Our study allows describing consecutive G-quadruplex formation in both nonequilibrium and equilibrium conditions by a unified picture, where, due to the many possible DNA conformations, full folding with consecutive G-quadruplexes as beads on a string is not necessarily achieved.
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Affiliation(s)
- Emil Laust Kristoffersen
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus, Denmark
| | - Andrea Coletta
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus, Denmark
| | - Line Mørkholt Lund
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus, Denmark
| | - Birgit Schiøtt
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus, Denmark,Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus, Denmark
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11
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Monsen RC, Trent JO, Chaires JB. G-quadruplex DNA: A Longer Story. Acc Chem Res 2022; 55:3242-3252. [PMID: 36282946 DOI: 10.1021/acs.accounts.2c00519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
G-quadruplexes (G4s) are distinctive four-stranded DNA or RNA structures found within cells that are thought to play functional roles in gene regulation and transcription, translation, recombination, and DNA damage/repair. While G4 structures can be uni-, bi-, or tetramolecular with respect to strands, folded unimolecular conformations are most significant in vivo. Unimolecular G4 can potentially form in sequences with runs of guanines interspersed with what will become loops in the folded structure: 5'GxLyGxLyGxLyGx, where x is typically 2-4 and y is highly variable. Such sequences are highly conserved and specifically located in genomes. In the folded structure, guanines from each run combine to form planar tetrads with four hydrogen-bonded guanine bases; these tetrads stack on one another to produce four strand segments aligned in specific parallel or antiparallel orientations, connected by the loop sequences. Three types of loops (lateral, diagonal, or "propeller") have been identified. The stacked tetrads form a central cavity that features strong coordination sites for monovalent cations that stabilize the G4 structure, with potassium or sodium preferred. A single monomeric G4 typically forms from a sequence containing roughly 20-30 nucleotides. Such short sequences have been the primary focus of X-ray crystallographic or NMR studies that have produced high-resolution structures of a variety of monomeric G4 conformations. These structures are often used as the basis for drug design efforts to modulate G4 function.We believe that the focus on monomeric G4 structures formed by such short sequences is perhaps myopic. Such short sequences for structural studies are often arbitrarily selected and removed from their native genomic sequence context, and then are often changed from their native sequences by base substitutions or deletions intended to optimize the formation of a homogeneous G4 conformation. We believe instead that G-quadruplexes prefer company and that in a longer natural sequence context multiple adjacent G4 units can form to combine into more complex multimeric G4 structures with richer topographies than simple monomeric forms. Bioinformatic searches of the human genome show that longer sequences with the potential for forming multiple G4 units are common. Telomeric DNA, for example, has a single-stranded overhang of hundreds of nucleotides with the requisite repetitive sequence with the potential for formation of multiple G4s. Numerous extended promoter sequences have similar potentials for multimeric G4 formation. X-ray crystallography and NMR methods are challenged by these longer sequences (>30 nt), so other tools are needed to explore the possible multimeric G4 landscape. We have implemented an integrated structural biology approach to address this challenge. This approach integrates experimental biophysical results with atomic-level molecular modeling and molecular dynamics simulations that provide quantitatively testable model structures. In every long sequence we have studied so far, we found that multimeric G4 structures readily form, with a surprising diversity of structures dependent on the exact native sequence used. In some cases, stable hairpin duplexes form along with G4 units to provide an even richer landscape. This Account provides an overview of our approach and recent progress and provides a new perspective on the G-quadruplex folding landscape.
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Affiliation(s)
- Robert C Monsen
- UofL Health Brown Cancer Center, University of Louisville, 505 S. Hancock St., Louisville, Kentucky 40202, United States
| | - John O Trent
- UofL Health Brown Cancer Center, University of Louisville, 505 S. Hancock St., Louisville, Kentucky 40202, United States.,Department of Medicine, University of Louisville, 505 S. Hancock St., Louisville, Kentucky 40202, United States.,Department of Biochemistry and Molecular Genetics, University of Louisville, 505 S. Hancock St., Louisville, Kentucky 40202, United States
| | - Jonathan B Chaires
- UofL Health Brown Cancer Center, University of Louisville, 505 S. Hancock St., Louisville, Kentucky 40202, United States.,Department of Medicine, University of Louisville, 505 S. Hancock St., Louisville, Kentucky 40202, United States.,Department of Biochemistry and Molecular Genetics, University of Louisville, 505 S. Hancock St., Louisville, Kentucky 40202, United States
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12
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Spiridonova VA, Naumova YO, Nikolaeva PA, Novikova TM, Kolomijtseva GY. Thermodynamics and Kinetics of Unfolding of Antiparallel G-Quadruplexes in Anti-Thrombin Aptamers. BIOCHEMISTRY. BIOKHIMIIA 2022; 87:1292-1300. [PMID: 36509716 DOI: 10.1134/s0006297922110086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The process of unfolding of G-quadruplex structure in the RE31 DNA-aptamer and in its complex with thrombin under the action of the fluorescently labeled complementary oligonucleotides of varying length with formation of double-helix structures has been studied. It has been suggested that G-quadruplex unfolding involves formation of an intermediate complex with an oligonucleotide. Thermodynamic parameters and kinetics of unfolding of the free aptamer and its complex with thrombin differ. Extension of the oligonucleotide sequence complementary to G-quadruplex by two nucleotides to cover the so-called "hinge region" had little impact on the conformational transition of G-quadruplex of the free aptamer. However, a pronounced effect has been observed for the aptamer-protein complex. Most likely these differences could be explained by the thrombin-induced conformational transition of the aptamer involving the hinge region.
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Affiliation(s)
- Vera A Spiridonova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Yulia O Naumova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Polina A Nikolaeva
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Tatiana M Novikova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Galina Ya Kolomijtseva
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.
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13
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Verma S, Patidar RK, Tiwari K, Tiwari R, Baranwal J, Velayutham R, Ranjan N. Preferential Recognition of Human Telomeric G-Quadruplex DNA by a Red-Emissive Molecular Rotor. J Phys Chem B 2022; 126:7298-7309. [DOI: 10.1021/acs.jpcb.2c04418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Smita Verma
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research-Raebareli, New Transit Campus, Lucknow 226002, Uttar Pradesh, India
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research, Kolkata, Maniktala Main Road, Kolkata 700054, India
| | - Rajesh K. Patidar
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research-Raebareli, New Transit Campus, Lucknow 226002, Uttar Pradesh, India
| | - Khushboo Tiwari
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research-Raebareli, New Transit Campus, Lucknow 226002, Uttar Pradesh, India
| | - Ratnesh Tiwari
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research-Raebareli, New Transit Campus, Lucknow 226002, Uttar Pradesh, India
| | - Jaya Baranwal
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research-Raebareli, New Transit Campus, Lucknow 226002, Uttar Pradesh, India
| | - Ravichandiran Velayutham
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research, Kolkata, Maniktala Main Road, Kolkata 700054, India
| | - Nihar Ranjan
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research-Raebareli, New Transit Campus, Lucknow 226002, Uttar Pradesh, India
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14
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Riccardi C, Piccolo M, Ferraro MG, Graziano R, Musumeci D, Trifuoggi M, Irace C, Montesarchio D. Bioengineered lipophilic Ru(III) complexes as potential anticancer agents. BIOMATERIALS ADVANCES 2022; 139:213016. [PMID: 35882162 DOI: 10.1016/j.bioadv.2022.213016] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 06/21/2022] [Accepted: 07/02/2022] [Indexed: 06/15/2023]
Abstract
Lipid-conjugated Ru(III) complexes - designed to obtain lipophilic analogues of the low molecular weight derivative AziRu, which is a NAMI-A-like anticancer agent - have been synthesized and fully characterized. A detailed biophysical investigation, including multiple, integrated techniques, allowed determining their molecular and self-assembling properties in aqueous solutions mimicking the extracellular environment, showing that our design produced a protective effect from hydrolysis of the Ru(III) complexes. In vitro biological experiments, carried out in comparison with AziRu, demonstrated that, among the novel lipophilic Ru(III) complexes synthesized, the compounds derivatized with palmitic and stearic acid, that we named PalmiPyRu and StePyRu respectively, showed attractive features and a promising antiproliferative activity, selective on specific breast cancer phenotypes. To get a deeper insight into their interactions with potential biomacromolecular targets, their ability to bind both bovine serum albumin (BSA), an abundant serum carrier protein, and some DNA model systems, including duplex and G-quadruplex structures, has been investigated by spectroscopic techniques. Inductively coupled plasma-mass spectrometry (ICP-MS) analysis of the ruthenium amount incorporated in human MCF-7 and MDA-MB-231 breast cancer cells, after incubation in parallel experiments with PalmiPyRu and AziRu, showed a markedly higher cell uptake of the lipophilic Ru(III) complex with respect to AziRu. These data confirmed that the proper lipidic tail decorating the metal complex not only favoured the formation of aggregates in the extracellular media but also improved their cell membrane penetration, thus leading to higher antiproliferative activity selective on breast cancer cells.
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Affiliation(s)
- Claudia Riccardi
- Department of Chemical Sciences, University of Naples "Federico II", Via Cintia 21, 80126 Naples, Italy
| | - Marialuisa Piccolo
- Department of Pharmacy, School of Medicine and Surgery, University of Naples "Federico II", Via D. Montesano 49, 80131 Naples, Italy
| | - Maria Grazia Ferraro
- Department of Pharmacy, School of Medicine and Surgery, University of Naples "Federico II", Via D. Montesano 49, 80131 Naples, Italy
| | - Raffaele Graziano
- Department of Chemical Sciences, University of Naples "Federico II", Via Cintia 21, 80126 Naples, Italy; Department of Pharmacy, School of Medicine and Surgery, University of Naples "Federico II", Via D. Montesano 49, 80131 Naples, Italy
| | - Domenica Musumeci
- Department of Chemical Sciences, University of Naples "Federico II", Via Cintia 21, 80126 Naples, Italy; Institute of Biostructures and Bioimages, CNR, Naples, Italy
| | - Marco Trifuoggi
- Department of Chemical Sciences, University of Naples "Federico II", Via Cintia 21, 80126 Naples, Italy
| | - Carlo Irace
- Department of Pharmacy, School of Medicine and Surgery, University of Naples "Federico II", Via D. Montesano 49, 80131 Naples, Italy
| | - Daniela Montesarchio
- Department of Chemical Sciences, University of Naples "Federico II", Via Cintia 21, 80126 Naples, Italy.
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15
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Abstract
We present single-molecule experimental and computational modeling studies investigating the accessibility of human telomeric overhangs of physiologically relevant lengths. We studied 25 different overhangs that contain 4-28 repeats of GGGTTA (G-Tract) sequence and accommodate one to seven tandem G-quadruplex (GQ) structures. Using the FRET-PAINT method, we probed the distribution of accessible sites via a short imager strand, which is complementary to a G-Tract and transiently binds to available sites. We report accessibility patterns that periodically change with overhang length and interpret these patterns in terms of the underlying folding landscape and folding frustration. Overhangs that have [4n]G-Tracts, (12, 16, 20…) demonstrate the broadest accessibility patterns where the peptide nucleic acid probe accesses G-Tracts throughout the overhang. On the other hand, constructs with [4n+2]G-Tracts, (14, 18, 22…) have narrower patterns where the neighborhood of the junction between single- and double-stranded telomeres is most accessible. We interpret these results as the folding frustration being higher in [4n]G-Tract constructs compared to [4n+2]G-Tract constructs. We also developed a computational model that tests the consistency of different folding stabilities and cooperativities between neighboring GQs with the observed accessibility patterns. Our experimental and computational studies suggest the neighborhood of the junction between single- and double-stranded telomeres is least stable and most accessible, which is significant as this is a potential site where the connection between POT1/TPP1 (bound to single-stranded telomere) and other shelterin proteins (localized on double-stranded telomere) is established.
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16
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Platella C, Napolitano E, Riccardi C, Musumeci D, Montesarchio D. Affinity Chromatography-Based Assays for the Screening of Potential Ligands Selective for G-Quadruplex Structures. Chemistry 2022; 11:e202200090. [PMID: 35608081 PMCID: PMC9127747 DOI: 10.1002/open.202200090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 04/22/2022] [Indexed: 12/27/2022]
Abstract
DNA G‐quadruplexes (G4s) are key structures for the development of targeted anticancer therapies. In this context, ligands selectively interacting with G4s can represent valuable anticancer drugs. Aiming at speeding up the identification of G4‐targeting synthetic or natural compounds, we developed an affinity chromatography‐based assay, named G‐quadruplex on Oligo Affinity Support (G4‐OAS), by synthesizing G4‐forming sequences on commercially available polystyrene OAS. Then, due to unspecific binding of several hydrophobic ligands on nude OAS, we moved to Controlled Pore Glass (CPG). We thus conceived an ad hoc functionalized, universal support on which both the on‐support elongation and deprotection of the G4‐forming oligonucleotides can be performed, along with the successive affinity chromatography‐based assay, renamed as G‐quadruplex on Controlled Pore Glass (G4‐CPG) assay. Here we describe these assays and their applications to the screening of several libraries of chemically different putative G4 ligands. Finally, ongoing studies and outlook of our G4‐CPG assay are reported.
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Affiliation(s)
- Chiara Platella
- Department of Chemical Sciences, University of Naples Federico II, via Cintia 21, 80126, Naples, Italy
| | - Ettore Napolitano
- Department of Chemical Sciences, University of Naples Federico II, via Cintia 21, 80126, Naples, Italy
| | - Claudia Riccardi
- Department of Chemical Sciences, University of Naples Federico II, via Cintia 21, 80126, Naples, Italy
| | - Domenica Musumeci
- Department of Chemical Sciences, University of Naples Federico II, via Cintia 21, 80126, Naples, Italy.,Institute of Biostructures and Bioimages, CNR, Via Tommaso De Amicis, 95, 80145, Naples, Italy
| | - Daniela Montesarchio
- Department of Chemical Sciences, University of Naples Federico II, via Cintia 21, 80126, Naples, Italy
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17
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Frasson I, Pirota V, Richter SN, Doria F. Multimeric G-quadruplexes: A review on their biological roles and targeting. Int J Biol Macromol 2022; 204:89-102. [PMID: 35124022 DOI: 10.1016/j.ijbiomac.2022.01.197] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 01/20/2022] [Accepted: 01/31/2022] [Indexed: 12/12/2022]
Abstract
In human cells, nucleic acids adopt several non-canonical structures that regulate key cellular processes. Among them, G-quadruplexes (G4s) are stable structures that form in guanine-rich regions in vitro and in cells. G4 folded/unfolded state shapes numerous cellular processes, including genome replication, transcription, and translation. Moreover, G4 folding is involved in genomic instability. G4s have been described to multimerize, forming high-order structures in both DNA and/or RNA strands. Multimeric G4s can be formed by adjacent intramolecular G4s joined by stacking interactions or connected by short loops. Multimeric G4s can also originate from the assembly of guanines embedded on independent DNA or RNA strands. Notably, crucial regions of the human genome, such as the 3'-terminal overhang of the telomeric DNA as well as the open reading frame of genes involved in the preservation of neuron viability in the human central and peripheral nervous system are prone to form multimeric G4s. The biological importance of such structures has been recently described, with multimeric G4s playing potentially protective or deleterious effects in the pathogenic cascade of various diseases. Here, we portray the multifaceted scenario of multimeric G4s, in terms of structural properties, biological roles, and targeting strategies.
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Affiliation(s)
- Ilaria Frasson
- Department of Molecular Medicine, University of Padova, via A. Gabelli 63, 35121 Padova, Italy
| | - Valentina Pirota
- Department of Chemistry, University of Pavia, v. le Taramelli 10, 27100 Pavia, Italy; G4-INTERACT, USERN, v. le Taramelli 10, 27100 Pavia, Italy
| | - Sara N Richter
- Department of Molecular Medicine, University of Padova, via A. Gabelli 63, 35121 Padova, Italy.
| | - Filippo Doria
- Department of Chemistry, University of Pavia, v. le Taramelli 10, 27100 Pavia, Italy.
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18
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Ceschi S, Berselli M, Cozzaglio M, Giantin M, Toppo S, Spolaore B, Sissi C. Vimentin binds to G-quadruplex repeats found at telomeres and gene promoters. Nucleic Acids Res 2022; 50:1370-1381. [PMID: 35100428 PMCID: PMC8860586 DOI: 10.1093/nar/gkab1274] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 11/22/2021] [Accepted: 01/24/2022] [Indexed: 11/15/2022] Open
Abstract
G-quadruplex (G4) structures that can form at guanine-rich genomic sites, including telomeres and gene promoters, are actively involved in genome maintenance, replication, and transcription, through finely tuned interactions with protein networks. In the present study, we identified the intermediate filament protein Vimentin as a binder with nanomolar affinity for those G-rich sequences that give rise to at least two adjacent G4 units, named G4 repeats. This interaction is supported by the N-terminal domains of soluble Vimentin tetramers. The selectivity of Vimentin for G4 repeats versus individual G4s provides an unprecedented result. Based on GO enrichment analysis performed on genes having putative G4 repeats within their core promoters, we suggest that Vimentin recruitment at these sites may contribute to the regulation of gene expression during cell development and migration, possibly by reshaping the local higher-order genome topology, as already reported for lamin B.
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Affiliation(s)
- Silvia Ceschi
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova 35131, Italy
| | - Michele Berselli
- Department of Molecular Medicine, University of Padova, Padova 35131, Italy
| | - Marta Cozzaglio
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova 35131, Italy
| | - Mery Giantin
- Department of Comparative Biomedicine and Food Science, University of Padova, Legnaro 35020, Italy
| | - Stefano Toppo
- CRIBI Biotechnology Center (Centro di Ricerca Interdipartimentale per le Biotecnologie Innovative), University of Padova, Padova 35131, Italy
- Department of Molecular Medicine, University of Padova, Padova 35131, Italy
| | - Barbara Spolaore
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova 35131, Italy
- CRIBI Biotechnology Center (Centro di Ricerca Interdipartimentale per le Biotecnologie Innovative), University of Padova, Padova 35131, Italy
| | - Claudia Sissi
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova 35131, Italy
- CRIBI Biotechnology Center (Centro di Ricerca Interdipartimentale per le Biotecnologie Innovative), University of Padova, Padova 35131, Italy
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19
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Chatain J, Hatem G, Delagoutte E, Riou JF, Alberti P, Saintomé C. Multiple hPOT1-TPP1 cooperatively unfold contiguous telomeric G-quadruplexes proceeding from 3' toward 5', a feature due to a 3'-end binding preference and to structuring of telomeric DNA. Nucleic Acids Res 2021; 49:10735-10746. [PMID: 34534331 PMCID: PMC8501996 DOI: 10.1093/nar/gkab768] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 08/04/2021] [Accepted: 09/15/2021] [Indexed: 02/07/2023] Open
Abstract
Telomeres are DNA repeated sequences that associate with shelterin proteins and protect the ends of eukaryotic chromosomes. Human telomeres are composed of 5'TTAGGG repeats and ends with a 3' single-stranded tail, called G-overhang, that can be specifically bound by the shelterin protein hPOT1 (human Protection of Telomeres 1). In vitro studies have shown that the telomeric G-strand can fold into stable contiguous G-quadruplexes (G4). In the present study we investigated how hPOT1, in complex with its shelterin partner TPP1, binds to telomeric sequences structured into contiguous G4 in potassium solutions. We observed that binding of multiple hPOT1-TPP1 preferentially proceeds from 3' toward 5'. We explain this directionality in terms of two factors: (i) the preference of hPOT1-TPP1 for the binding site situated at the 3' end of a telomeric sequence and (ii) the cooperative binding displayed by hPOT1-TPP1 in potassium. By comparing binding in K+ and in Li+, we demonstrate that this cooperative behaviour does not stem from protein-protein interactions, but from structuring of the telomeric DNA substrate into contiguous G4 in potassium. Our study suggests that POT1-TPP1, in physiological conditions, might preferentially cover the telomeric G-overhang starting from the 3'-end and proceeding toward 5'.
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Affiliation(s)
- Jean Chatain
- Structure et Instabilité des Génomes, Muséum national d'Histoire naturelle, CNRS, INSERM, 43 rue Cuvier, F-75005 Paris, France
| | - Georges Hatem
- Structure et Instabilité des Génomes, Muséum national d'Histoire naturelle, CNRS, INSERM, 43 rue Cuvier, F-75005 Paris, France
| | - Emmanuelle Delagoutte
- Structure et Instabilité des Génomes, Muséum national d'Histoire naturelle, CNRS, INSERM, 43 rue Cuvier, F-75005 Paris, France
| | - Jean-François Riou
- Structure et Instabilité des Génomes, Muséum national d'Histoire naturelle, CNRS, INSERM, 43 rue Cuvier, F-75005 Paris, France
| | - Patrizia Alberti
- Structure et Instabilité des Génomes, Muséum national d'Histoire naturelle, CNRS, INSERM, 43 rue Cuvier, F-75005 Paris, France
| | - Carole Saintomé
- Structure et Instabilité des Génomes, Muséum national d'Histoire naturelle, CNRS, INSERM, 43 rue Cuvier, F-75005 Paris, France.,Sorbonne Université, UFR927, F-75005 Paris, France
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20
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Pérez de Carvasal K, Riccardi C, Russo Krauss I, Cavasso D, Vasseur JJ, Smietana M, Morvan F, Montesarchio D. Charge-Transfer Interactions Stabilize G-Quadruplex-Forming Thrombin Binding Aptamers and Can Improve Their Anticoagulant Activity. Int J Mol Sci 2021; 22:9510. [PMID: 34502432 PMCID: PMC8430690 DOI: 10.3390/ijms22179510] [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: 07/29/2021] [Revised: 08/24/2021] [Accepted: 08/27/2021] [Indexed: 02/07/2023] Open
Abstract
In the search for optimized thrombin binding aptamers (TBAs), we herein describe the synthesis of a library of TBA analogues obtained by end-functionalization with the electron-rich 1,5-dialkoxy naphthalene (DAN) and the electron-deficient 1,8,4,5-naphthalenetetra-carboxylic diimide (NDI) moieties. Indeed, when these G-rich oligonucleotides were folded into the peculiar TBA G-quadruplex (G4) structure, effective donor-acceptor charge transfer interactions between the DAN and NDI residues attached to the extremities of the sequence were induced, providing pseudo-cyclic structures. Alternatively, insertion of NDI groups at both extremities produced TBA analogues stabilized by π-π stacking interactions. All the doubly-modified TBAs were characterized by different biophysical techniques and compared with the analogues carrying only the DAN or NDI residue and unmodified TBA. These modified TBAs exhibited higher nuclease resistance, and their G4 structures were markedly stabilized, as evidenced by increased Tm values compared to TBA. These favorable properties were also associated with improved anticoagulant activity for one DAN/NDI-modified TBA, and for one NDI/NDI-modified TBA. Our results indicated that TBA pseudo-cyclic structuring by ad hoc designed end-functionalization represents an efficient approach to improve the aptamer features, while pre-organizing and stabilizing the G4 structure but allowing sufficient flexibility to the aptamer folding, which is necessary for optimal thrombin recognition.
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Affiliation(s)
- Kévan Pérez de Carvasal
- Institut des Biomolécules Max Mousseron, University Montpellier, CNRS, ENSCM, 34095 Montpellier, France; (K.P.d.C.); (J.-J.V.); (M.S.)
| | - Claudia Riccardi
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, I-80126 Naples, Italy; (C.R.); (I.R.K.); (D.C.)
| | - Irene Russo Krauss
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, I-80126 Naples, Italy; (C.R.); (I.R.K.); (D.C.)
- CSGI—Consorzio Interuniversitario per lo Sviluppo dei Sistemi a Grande Interfase, Via della Lastruccia 3, I-50019 Sesto Fiorentino, Italy
| | - Domenico Cavasso
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, I-80126 Naples, Italy; (C.R.); (I.R.K.); (D.C.)
- CSGI—Consorzio Interuniversitario per lo Sviluppo dei Sistemi a Grande Interfase, Via della Lastruccia 3, I-50019 Sesto Fiorentino, Italy
| | - Jean-Jacques Vasseur
- Institut des Biomolécules Max Mousseron, University Montpellier, CNRS, ENSCM, 34095 Montpellier, France; (K.P.d.C.); (J.-J.V.); (M.S.)
| | - Michael Smietana
- Institut des Biomolécules Max Mousseron, University Montpellier, CNRS, ENSCM, 34095 Montpellier, France; (K.P.d.C.); (J.-J.V.); (M.S.)
| | - François Morvan
- Institut des Biomolécules Max Mousseron, University Montpellier, CNRS, ENSCM, 34095 Montpellier, France; (K.P.d.C.); (J.-J.V.); (M.S.)
| | - Daniela Montesarchio
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, I-80126 Naples, Italy; (C.R.); (I.R.K.); (D.C.)
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21
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Pruška A, Marchand A, Zenobi R. Novel Insight into Proximal DNA Domain Interactions from Temperature-Controlled Electrospray Ionization Mass Spectrometry. Angew Chem Int Ed Engl 2021; 60:15390-15398. [PMID: 33822450 PMCID: PMC8251475 DOI: 10.1002/anie.202016757] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 03/07/2021] [Indexed: 01/05/2023]
Abstract
Quadruplexes are non-canonical nucleic acid structures essential for many cellular processes. Hybrid quadruplex-duplex oligonucleotide assemblies comprised of multiple domains are challenging to study with conventional biophysical methods due to their structural complexity. Here, we introduce a novel method based on native mass spectrometry (MS) coupled with a custom-built temperature-controlled nanoelectrospray ionization (TCnESI) source designed to investigate interactions between proximal DNA domains. Thermal denaturation experiments were aimed to study unfolding of multi-stranded oligonucleotide constructs derived from biologically relevant structures and to identify unfolding intermediates. Using the TCnESI MS, we observed changes in Tm and thermodynamic characteristics of proximal DNA domains depending on the number of domains, their position, and order in a single experiment.
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Affiliation(s)
- Adam Pruška
- Department of Chemistry and Applied BiosciencesETH ZurichVladimir-Prelog-Weg 38093ZurichSwitzerland
| | - Adrien Marchand
- Department of Chemistry and Applied BiosciencesETH ZurichVladimir-Prelog-Weg 38093ZurichSwitzerland
| | - Renato Zenobi
- Department of Chemistry and Applied BiosciencesETH ZurichVladimir-Prelog-Weg 38093ZurichSwitzerland
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22
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Pruška A, Marchand A, Zenobi R. Novel Insight into Proximal DNA Domain Interactions from Temperature‐Controlled Electrospray Ionization Mass Spectrometry. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202016757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Adam Pruška
- Department of Chemistry and Applied Biosciences ETH Zurich Vladimir-Prelog-Weg 3 8093 Zurich Switzerland
| | - Adrien Marchand
- Department of Chemistry and Applied Biosciences ETH Zurich Vladimir-Prelog-Weg 3 8093 Zurich Switzerland
| | - Renato Zenobi
- Department of Chemistry and Applied Biosciences ETH Zurich Vladimir-Prelog-Weg 3 8093 Zurich Switzerland
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23
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Lyu X, Sang PB, Chai W. CST in maintaining genome stability: Beyond telomeres. DNA Repair (Amst) 2021; 102:103104. [PMID: 33780718 PMCID: PMC8081025 DOI: 10.1016/j.dnarep.2021.103104] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 03/17/2021] [Accepted: 03/18/2021] [Indexed: 12/12/2022]
Abstract
The human CST (CTC1-STN1-TEN1) complex is an RPA-like single-stranded DNA binding protein complex. While its telomeric functions have been well investigated, numerous studies have revealed that hCST also plays important roles in maintaining genome stability beyond telomeres. Here, we review and discuss recent discoveries on CST in various global genome maintenance pathways, including findings on the CST supercomplex structure, its functions in unperturbed DNA replication, stalled replication, double-strand break repair, and the ATR-CHK1 activation pathway. By summarizing these recent discoveries, we hope to offer new insights into genome maintenance mechanisms and the pathogenesis of CST mutation-associated diseases.
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Affiliation(s)
- Xinxing Lyu
- Institute of Basic Medicine, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong, 250062, China; Department of Cancer Biology, Cardinal Bernardin Cancer Center, Loyola University Chicago Stritch School of Medicine, Maywood, IL, 60153, United States
| | - Pau Biak Sang
- Department of Cancer Biology, Cardinal Bernardin Cancer Center, Loyola University Chicago Stritch School of Medicine, Maywood, IL, 60153, United States
| | - Weihang Chai
- Department of Cancer Biology, Cardinal Bernardin Cancer Center, Loyola University Chicago Stritch School of Medicine, Maywood, IL, 60153, United States.
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24
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Carrino S, Hennecker CD, Murrieta AC, Mittermaier A. Frustrated folding of guanine quadruplexes in telomeric DNA. Nucleic Acids Res 2021; 49:3063-3076. [PMID: 33693924 PMCID: PMC8034632 DOI: 10.1093/nar/gkab140] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 01/22/2021] [Accepted: 02/19/2021] [Indexed: 11/23/2022] Open
Abstract
Human chromosomes terminate in long, single-stranded, DNA overhangs of the repetitive sequence (TTAGGG)n. Sets of four adjacent TTAGGG repeats can fold into guanine quadruplexes (GQ), four-stranded structures that are implicated in telomere maintenance and cell immortalization and are targets in cancer therapy. Isolated GQs have been studied in detail, however much less is known about folding in long repeat sequences. Such chains adopt an enormous number of configurations containing various arrangements of GQs and unfolded gaps, leading to a highly frustrated energy landscape. To better understand this phenomenon, we used mutagenesis, thermal melting, and global analysis to determine stability, kinetic, and cooperativity parameters for GQ folding within chains containing 8–12 TTAGGG repeats. We then used these parameters to simulate the folding of 32-repeat chains, more representative of intact telomeres. We found that a combination of folding frustration and negative cooperativity between adjacent GQs increases TTAGGG unfolding by up to 40-fold, providing an abundance of unfolded gaps that are potential binding sites for telomeric proteins. This effect was most pronounced at the chain termini, which could promote telomere extension by telomerase. We conclude that folding frustration is an important and largely overlooked factor controlling the structure of telomeric DNA.
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Affiliation(s)
- Simone Carrino
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec, H3A 0B8, Canada
| | - Christopher D Hennecker
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec, H3A 0B8, Canada
| | - Ana C Murrieta
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec, H3A 0B8, Canada.,School of Engineering and Sciences, Instituto Tecnológico y de Estudios Superiores De Monterrey, Av. Eugenio Garza Sada 2501 Sur Col. Tecnológico C.P. 64849, Monterrey, Nuevo León, México
| | - Anthony Mittermaier
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec, H3A 0B8, Canada
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25
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Mustafa G, Shiekh S, Gc K, Abeysirigunawardena S, Balci H. Interrogating accessibility of telomeric sequences with FRET-PAINT: evidence for length-dependent telomere compaction. Nucleic Acids Res 2021; 49:3371-3380. [PMID: 33693934 PMCID: PMC8034622 DOI: 10.1093/nar/gkab067] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 01/23/2021] [Accepted: 03/08/2021] [Indexed: 12/25/2022] Open
Abstract
Single-stranded telomeric overhangs are ∼200 nucleotides long and can form tandem G-quadruplex (GQ) structures, which reduce their accessibility to nucleases and proteins that activate DNA damage response. Whether these tandem GQs further stack to form compact superstructures, which may provide better protection for longer telomeres, is not known. We report single-molecule measurements where the accessibility of 24-144 nucleotide long human telomeric DNA molecules is interrogated by a short PNA molecule that is complementary to a single GGGTTA repeat, as implemented in the FRET-PAINT method. Binding of the PNA strand to available GGGTTA sequences results in discrete FRET bursts which were analyzed in terms of their dwell times, binding frequencies, and topographic distributions. The binding frequencies were greater for binding to intermediate regions of telomeric DNA compared to 3'- or 5'-ends, suggesting these regions are more accessible. Significantly, the binding frequency per telomeric repeat monotonically decreased with increasing telomere length. These results are consistent with telomeres forming more compact structures at longer lengths, reducing accessibility of these critical genomic sites.
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Affiliation(s)
- Golam Mustafa
- Department of Physics, Kent State University, Kent, OH 44242, USA
| | - Sajad Shiekh
- Department of Physics, Kent State University, Kent, OH 44242, USA
| | - Keshav Gc
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH 44242, USA
| | | | - Hamza Balci
- Department of Physics, Kent State University, Kent, OH 44242, USA
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26
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Supramolecular Polymorphism of (G 4C 2) n Repeats Associated with ALS and FTD. Int J Mol Sci 2021; 22:ijms22094532. [PMID: 33926081 PMCID: PMC8123662 DOI: 10.3390/ijms22094532] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 04/21/2021] [Accepted: 04/23/2021] [Indexed: 12/25/2022] Open
Abstract
Guanine-rich DNA sequences self-assemble into highly stable fourfold structures known as DNA-quadruplexes (or G-quadruplexes). G-quadruplexes have furthermore the tendency to associate into one-dimensional supramolecular aggregates termed G-wires. We studied the formation of G-wires in solutions of the sequences d(G4C2)n with n = 1, 2, and 4. The d(G4C2)n repeats, which are associated with some fatal neurological disorders, especially amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), represent a challenging research topic due to their extensive structural polymorphism. We used dynamic light scattering (DLS) to measure translational diffusion coefficients and consequently resolve the length of the larger aggregates formed in solution. We found that all three sequences assemble into longer structures than previously reported. The d(G4C2) formed extremely long G-wires with lengths beyond 80 nm. The d(G4C2)2 formed a relatively short stacked dimeric quadruplex, while d(G4C2)4 formed multimers corresponding to seven stacked intramolecular quadruplexes. Profound differences between the multimerization properties of the investigated sequences were also confirmed by the AFM imaging of surface films. We propose that π-π stacking of the basic G-quadruplex units plays a vital role in the multimerization mechanism, which might be relevant for transformation from the regular medium-length to disease-related long d(G4C2)n repeats.
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27
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Monsen RC, Chakravarthy S, Dean WL, Chaires JB, Trent JO. The solution structures of higher-order human telomere G-quadruplex multimers. Nucleic Acids Res 2021; 49:1749-1768. [PMID: 33469644 PMCID: PMC7897503 DOI: 10.1093/nar/gkaa1285] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 12/21/2020] [Accepted: 01/13/2021] [Indexed: 12/17/2022] Open
Abstract
Human telomeres contain the repeat DNA sequence 5′-d(TTAGGG), with duplex regions that are several kilobases long terminating in a 3′ single-stranded overhang. The structure of the single-stranded overhang is not known with certainty, with disparate models proposed in the literature. We report here the results of an integrated structural biology approach that combines small-angle X-ray scattering, circular dichroism (CD), analytical ultracentrifugation, size-exclusion column chromatography and molecular dynamics simulations that provide the most detailed characterization to date of the structure of the telomeric overhang. We find that the single-stranded sequences 5′-d(TTAGGG)n, with n = 8, 12 and 16, fold into multimeric structures containing the maximal number (2, 3 and 4, respectively) of contiguous G4 units with no long gaps between units. The G4 units are a mixture of hybrid-1 and hybrid-2 conformers. In the multimeric structures, G4 units interact, at least transiently, at the interfaces between units to produce distinctive CD signatures. Global fitting of our hydrodynamic and scattering data to a worm-like chain (WLC) model indicates that these multimeric G4 structures are semi-flexible, with a persistence length of ∼34 Å. Investigations of its flexibility using MD simulations reveal stacking, unstacking, and coiling movements, which yield unique sites for drug targeting.
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Affiliation(s)
- Robert C Monsen
- Department of Biochemistry & Molecular Genetics, University of Louisville Medical School, Louisville, KY 40202, USA
| | - Srinivas Chakravarthy
- The Biophysics Collaborative Access Team (BioCAT), Department of Biological Chemical and Physical Sciences, Illinois Institute of Technology, Chicago, IL 60616, USA
| | - William L Dean
- James Graham Brown Cancer Center, University of Louisville Medical School, Louisville, KY 40202, USA
| | - Jonathan B Chaires
- Department of Biochemistry & Molecular Genetics, University of Louisville Medical School, Louisville, KY 40202, USA.,James Graham Brown Cancer Center, University of Louisville Medical School, Louisville, KY 40202, USA.,Department of Medicine, University of Louisville Medical School, Louisville, KY 40202, USA
| | - John O Trent
- Department of Biochemistry & Molecular Genetics, University of Louisville Medical School, Louisville, KY 40202, USA.,James Graham Brown Cancer Center, University of Louisville Medical School, Louisville, KY 40202, USA.,Department of Medicine, University of Louisville Medical School, Louisville, KY 40202, USA
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28
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TERRA G-quadruplex RNA interaction with TRF2 GAR domain is required for telomere integrity. Sci Rep 2021; 11:3509. [PMID: 33568696 PMCID: PMC7876106 DOI: 10.1038/s41598-021-82406-x] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Accepted: 01/13/2021] [Indexed: 12/15/2022] Open
Abstract
Telomere dysfunction causes chromosomal instability which is associated with many cancers and age-related diseases. The non-coding telomeric repeat-containing RNA (TERRA) forms a structural and regulatory component of the telomere that is implicated in telomere maintenance and chromosomal end protection. The basic N-terminal Gly/Arg-rich (GAR) domain of telomeric repeat-binding factor 2 (TRF2) can bind TERRA but the structural basis and significance of this interaction remains poorly understood. Here, we show that TRF2 GAR recognizes G-quadruplex features of TERRA. We show that small molecules that disrupt the TERRA-TRF2 GAR complex, such as N-methyl mesoporphyrin IX (NMM) or genetic deletion of TRF2 GAR domain, result in the loss of TERRA, and the induction of γH2AX-associated telomeric DNA damage associated with decreased telomere length, and increased telomere aberrations, including telomere fragility. Taken together, our data indicates that the G-quadruplex structure of TERRA is an important recognition element for TRF2 GAR domain and this interaction between TRF2 GAR and TERRA is essential to maintain telomere stability.
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29
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Gao C, Liu Z, Hou H, Ding J, Chen X, Xie C, Song Z, Hu Z, Feng M, Mohamed HI, Xu S, Parkinson GN, Haider S, Wei D. BMPQ-1 binds selectively to (3+1) hybrid topologies in human telomeric G-quadruplex multimers. Nucleic Acids Res 2020; 48:11259-11269. [PMID: 33080032 PMCID: PMC7672424 DOI: 10.1093/nar/gkaa870] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 09/23/2020] [Accepted: 10/14/2020] [Indexed: 12/21/2022] Open
Abstract
A single G-quadruplex forming sequence from the human telomere can adopt six distinct topologies that are inter-convertible under physiological conditions. This presents challenges to design ligands that show selectivity and specificity towards a particular conformation. Additional complexity is introduced in differentiating multimeric G-quadruplexes over monomeric species, which would be able to form in the single-stranded 3′ ends of telomeres. A few ligands have been reported that bind to dimeric quadruplexes, but their preclinical pharmacological evaluation is limited. Using multidisciplinary approaches, we identified a novel quinoline core ligand, BMPQ-1, which bound to human telomeric G-quadruplex multimers over monomeric G-quadruplexes with high selectivity, and induced the formation of G-quadruplex DNA along with the related DNA damage response at the telomere. BMPQ-1 reduced tumor cell proliferation with an IC50 of ∼1.0 μM and decreased tumor growth rate in mouse by half. Biophysical analysis using smFRET identified a mixture of multiple conformations coexisting for dimeric G-quadruplexes in solution. Here, we showed that the titration of BMPQ-1 shifted the conformational ensemble of multimeric G-quadruplexes towards (3+1) hybrid-2 topology, which became more pronounced as further G-quadruplex units are added.
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Affiliation(s)
- Chao Gao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.,National Reference Laboratory of Veterinary Drug Residues (HZAU) and MAO Key Laboratory for Detection of Veterinary Drug Residues, Huazhong AgriculturalUniversity, Wuhan, 430070, China.,College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Zhu Liu
- National Key Laboratory of Crop Genetic Improvement, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Haitao Hou
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.,Department of Chemistry, College of Science, Huazhong Agricultural University, Wuhan 430070, China
| | - Jieqin Ding
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.,Department of Chemistry, College of Science, Huazhong Agricultural University, Wuhan 430070, China
| | - Xin Chen
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Congbao Xie
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.,Department of Chemistry, College of Science, Huazhong Agricultural University, Wuhan 430070, China
| | - Zibing Song
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.,Department of Chemistry, College of Science, Huazhong Agricultural University, Wuhan 430070, China
| | - Zhe Hu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Mingqian Feng
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Hany I Mohamed
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.,Chemistry Department, Faculty of Science, Benha University, Benha 13518, Egypt
| | - Shengzhen Xu
- Department of Chemistry, College of Science, Huazhong Agricultural University, Wuhan 430070, China
| | - Gary N Parkinson
- UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1N 1AX, UK
| | - Shozeb Haider
- UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1N 1AX, UK
| | - Dengguo Wei
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China.,National Reference Laboratory of Veterinary Drug Residues (HZAU) and MAO Key Laboratory for Detection of Veterinary Drug Residues, Huazhong AgriculturalUniversity, Wuhan, 430070, China
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30
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Pirota V, Platella C, Musumeci D, Benassi A, Amato J, Pagano B, Colombo G, Freccero M, Doria F, Montesarchio D. On the binding of naphthalene diimides to a human telomeric G-quadruplex multimer model. Int J Biol Macromol 2020; 166:1320-1334. [PMID: 33166559 DOI: 10.1016/j.ijbiomac.2020.11.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 11/02/2020] [Accepted: 11/03/2020] [Indexed: 02/07/2023]
Abstract
To selectively target telomeric G-quadruplex (G4) DNA, monomeric and dimeric naphthalene diimides (NDIs) were investigated as binders of multimeric G4 structures able to discriminate duplex DNA. These NDIs were analysed by the affinity chromatography-based screening G4-CPG (G-quadruplex on Controlled Pore Glass), using the sequence d[AGGG(TTAGGG)7] (tel46), folding into two consecutive G4s, as model of the human telomeric G4 multimer. In parallel, a telomeric G4 monomer (tel26) and a duplex structure (ds27) were used as controls. According to G4-CPG screening, NDI-5 proved to be the best ligand in terms of dimeric G4 vs. duplex DNA selectivity and was analysed by circular dichroism (CD), gel electrophoresis, isothermal titration calorimetry (ITC) and fluorescence spectroscopy in its interactions with tel46. NDI-5 strongly binds and stabilizes tel46 G4, favouring a hybrid folding in K+-containing buffer. Under these conditions, the binding process comprises a first event involving three molecules of NDI-5 and a second one in which other six molecules bind to the DNA. In a metal cation-free system, NDI-5 induces tel46 G4 folding, as indicated by CD and PAGE, favouring an antiparallel structuring. Docking simulations showed that NDI-5 can effectively bind to the pocket between two G4 units, representing a promising ligand for multimeric G4s.
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Affiliation(s)
- Valentina Pirota
- Department of Chemistry, University of Pavia, 27100 Pavia, Italy
| | - Chiara Platella
- Department of Chemical Sciences, University of Naples Federico II, 80126 Naples, Italy
| | - Domenica Musumeci
- Department of Chemical Sciences, University of Naples Federico II, 80126 Naples, Italy
| | | | - Jussara Amato
- Department of Pharmacy, University of Naples Federico II, 80131 Naples, Italy
| | - Bruno Pagano
- Department of Pharmacy, University of Naples Federico II, 80131 Naples, Italy
| | - Giorgio Colombo
- Department of Chemistry, University of Pavia, 27100 Pavia, Italy
| | - Mauro Freccero
- Department of Chemistry, University of Pavia, 27100 Pavia, Italy
| | - Filippo Doria
- Department of Chemistry, University of Pavia, 27100 Pavia, Italy.
| | - Daniela Montesarchio
- Department of Chemical Sciences, University of Naples Federico II, 80126 Naples, Italy.
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31
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Ogloblina AM, Iaccarino N, Capasso D, Di Gaetano S, Garzarella EU, Dolinnaya NG, Yakubovskaya MG, Pagano B, Amato J, Randazzo A. Toward G-Quadruplex-Based Anticancer Agents: Biophysical and Biological Studies of Novel AS1411 Derivatives. Int J Mol Sci 2020; 21:E7781. [PMID: 33096752 PMCID: PMC7590035 DOI: 10.3390/ijms21207781] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 10/17/2020] [Accepted: 10/19/2020] [Indexed: 12/16/2022] Open
Abstract
Certain G-quadruplex forming guanine-rich oligonucleotides (GROs), including AS1411, are endowed with cancer-selective antiproliferative activity. They are known to bind to nucleolin protein, resulting in the inhibition of nucleolin-mediated phenomena. However, multiple nucleolin-independent biological effects of GROs have also been reported, allowing them to be considered promising candidates for multi-targeted cancer therapy. Herein, with the aim of optimizing AS1411 structural features to find GROs with improved anticancer properties, we have studied a small library of AS1411 derivatives differing in the sequence length and base composition. The AS1411 derivatives were characterized by using circular dichroism and nuclear magnetic resonance spectroscopies and then investigated for their enzymatic resistance in serum and nuclear extract, as well as for their ability to bind nucleolin, inhibit topoisomerase I, and affect the viability of MCF-7 human breast adenocarcinoma cells. All derivatives showed higher thermal stability and inhibitory effect against topoisomerase I than AS1411. In addition, most of them showed an improved antiproliferative activity on MCF-7 cells compared to AS1411 despite a weaker binding to nucleolin. Our results support the hypothesis that the antiproliferative properties of GROs are due to multi-targeted effects.
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Affiliation(s)
- Anna M. Ogloblina
- N.N. Blokhin National Medical Research Center of Oncology, Ministry of Health, 115478 Moscow, Russia; (A.M.O.); (M.G.Y.)
- Department of Pharmacy, University of Naples Federico II, Via D. Montesano 49, 80131 Naples, Italy; (N.I.); (E.U.G.); (A.R.)
| | - Nunzia Iaccarino
- Department of Pharmacy, University of Naples Federico II, Via D. Montesano 49, 80131 Naples, Italy; (N.I.); (E.U.G.); (A.R.)
| | - Domenica Capasso
- Center for Life Sciences and Technologies (CESTEV), University of Naples Federico II, Via A. De Amicis 95, 80145 Naples, Italy;
| | - Sonia Di Gaetano
- Institute of Biostructures and Bioimaging, National Research Council, Via Mezzocannone 16, 80134 Naples, Italy;
| | - Emanuele U. Garzarella
- Department of Pharmacy, University of Naples Federico II, Via D. Montesano 49, 80131 Naples, Italy; (N.I.); (E.U.G.); (A.R.)
| | - Nina G. Dolinnaya
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia;
| | - Marianna G. Yakubovskaya
- N.N. Blokhin National Medical Research Center of Oncology, Ministry of Health, 115478 Moscow, Russia; (A.M.O.); (M.G.Y.)
| | - Bruno Pagano
- Department of Pharmacy, University of Naples Federico II, Via D. Montesano 49, 80131 Naples, Italy; (N.I.); (E.U.G.); (A.R.)
| | - Jussara Amato
- Department of Pharmacy, University of Naples Federico II, Via D. Montesano 49, 80131 Naples, Italy; (N.I.); (E.U.G.); (A.R.)
| | - Antonio Randazzo
- Department of Pharmacy, University of Naples Federico II, Via D. Montesano 49, 80131 Naples, Italy; (N.I.); (E.U.G.); (A.R.)
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32
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Synthesis, Antiproliferative Activity, and DNA Binding Studies of Nucleoamino Acid-Containing Pt(II) Complexes. Pharmaceuticals (Basel) 2020; 13:ph13100284. [PMID: 33007911 PMCID: PMC7600948 DOI: 10.3390/ph13100284] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 09/25/2020] [Accepted: 09/28/2020] [Indexed: 11/17/2022] Open
Abstract
We here report our studies on the reaction with the platinum(II) ion of a nucleoamino acid constituted by the l-2,3-diaminopropanoic acid linked to the thymine nucleobase through a methylenecarbonyl linker. The obtained new platinum complexes, characterized by spectroscopic and mass spectrometric techniques, were envisaged to exploit synergistic effects due to the presence of both the platinum center and the nucleoamino acid moiety. The latter can be potentially useful to protect the complexes from early deactivation, as well as to facilitate their cell internalization. The biological activity of the complexes in terms of antiproliferative effects was evaluated in vitro on different cancer cell lines and healthy cells, showing the best results on human cervical adenocarcinoma (HeLa) cells along with good selectivity for cancer over normal cells. In contrast, the metal-free nucleoamino acid did not show any cytotoxicity on both normal and cancer cell lines. Finally, the ability of the novel Pt(II) complexes to bind various DNA model systems was investigated by circular dichroism (CD) spectroscopy and polyacrylamide gel electrophoresis analyses proving that the newly obtained compounds can potentially target DNA, similarly to other well-known anticancer Pt complexes, with a peculiar G-quadruplex vs. duplex selectivity.
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33
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Chaires JB, Gray RD, Dean WL, Monsen R, DeLeeuw LW, Stribinskis V, Trent JO. Human POT1 unfolds G-quadruplexes by conformational selection. Nucleic Acids Res 2020; 48:4976-4991. [PMID: 32232414 PMCID: PMC7229828 DOI: 10.1093/nar/gkaa202] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 03/13/2020] [Accepted: 03/18/2020] [Indexed: 12/14/2022] Open
Abstract
The reaction mechanism by which the shelterin protein POT1 (Protection of Telomeres 1) unfolds human telomeric G-quadruplex structures is not fully understood. We report here kinetic, thermodynamic, hydrodynamic and computational studies that show that a conformational selection mechanism, in which POT1 binding is coupled to an obligatory unfolding reaction, is the most plausible mechanism. Stopped-flow kinetic and spectroscopic titration studies, along with isothermal calorimetry, were used to show that binding of the single-strand oligonucleotide d[TTAGGGTTAG] to POT1 is both fast (80 ms) and strong (-10.1 ± 0.3 kcal mol-1). In sharp contrast, kinetic studies showed the binding of POT1 to an initially folded 24 nt G-quadruplex structure is four orders of magnitude slower. Fluorescence, circular dichroism and analytical ultracentrifugation studies showed that POT1 binding is coupled to quadruplex unfolding, with a final complex with a stoichiometry of 2 POT1 per 24 nt DNA. The binding isotherm for the POT1-quadruplex interaction was sigmoidal, indicative of a complex reaction. A conformational selection model that includes equilibrium constants for both G-quadruplex unfolding and POT1 binding to the resultant single-strand provided an excellent quantitative fit to the experimental binding data. POT1 unfolded and bound to any conformational form of human telomeric G-quadruplex (antiparallel, hybrid, parallel monomers or a 48 nt sequence with two contiguous quadruplexes), but did not avidly interact with duplex DNA or with other G-quadruplex structures. Finally, molecular dynamics simulations provided a detailed structural model of a 2:1 POT1:DNA complex that is fully consistent with experimental biophysical results.
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Affiliation(s)
- Jonathan B Chaires
- James Graham Brown Cancer Center, University of Louisville, 505 S. Hancock St., Louisville, KY 40202, USA
| | - Robert D Gray
- James Graham Brown Cancer Center, University of Louisville, 505 S. Hancock St., Louisville, KY 40202, USA
| | - William L Dean
- James Graham Brown Cancer Center, University of Louisville, 505 S. Hancock St., Louisville, KY 40202, USA
| | - Robert Monsen
- James Graham Brown Cancer Center, University of Louisville, 505 S. Hancock St., Louisville, KY 40202, USA
| | - Lynn W DeLeeuw
- James Graham Brown Cancer Center, University of Louisville, 505 S. Hancock St., Louisville, KY 40202, USA
| | - Vilius Stribinskis
- James Graham Brown Cancer Center, University of Louisville, 505 S. Hancock St., Louisville, KY 40202, USA
| | - John O Trent
- James Graham Brown Cancer Center, University of Louisville, 505 S. Hancock St., Louisville, KY 40202, USA
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34
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Jalalvand AR. A study originated from combination of electrochemistry and chemometrics for investigation of the inhibitory effects of ciprofloxacin as a potent inhibitor on cytochrome P450. Microchem J 2020. [DOI: 10.1016/j.microc.2020.105104] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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35
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Bryan TM. G-Quadruplexes at Telomeres: Friend or Foe? Molecules 2020; 25:molecules25163686. [PMID: 32823549 PMCID: PMC7464828 DOI: 10.3390/molecules25163686] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 08/09/2020] [Accepted: 08/10/2020] [Indexed: 12/28/2022] Open
Abstract
Telomeres are DNA-protein complexes that cap and protect the ends of linear chromosomes. In almost all species, telomeric DNA has a G/C strand bias, and the short tandem repeats of the G-rich strand have the capacity to form into secondary structures in vitro, such as four-stranded G-quadruplexes. This has long prompted speculation that G-quadruplexes play a positive role in telomere biology, resulting in selection for G-rich tandem telomere repeats during evolution. There is some evidence that G-quadruplexes at telomeres may play a protective capping role, at least in yeast, and that they may positively affect telomere maintenance by either the enzyme telomerase or by recombination-based mechanisms. On the other hand, G-quadruplex formation in telomeric DNA, as elsewhere in the genome, can form an impediment to DNA replication and a source of genome instability. This review summarizes recent evidence for the in vivo existence of G-quadruplexes at telomeres, with a focus on human telomeres, and highlights some of the many unanswered questions regarding the location, form, and functions of these structures.
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Affiliation(s)
- Tracy M Bryan
- Children's Medical Research Institute, Faculty of Medicine and Health, University of Sydney, Westmead, NSW 2145, Australia
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Cheng Y, Cheng M, Hao J, Jia G, Monchaud D, Li C. The noncovalent dimerization of a G-quadruplex/hemin DNAzyme improves its biocatalytic properties. Chem Sci 2020; 11:8846-8853. [PMID: 34123138 PMCID: PMC8163442 DOI: 10.1039/d0sc02907f] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Accepted: 07/15/2020] [Indexed: 12/31/2022] Open
Abstract
While many protein enzymes exert their functions through multimerization, which improves both selectivity and activity, this has not yet been demonstrated for other naturally occurring catalysts. Here, we report a multimerization effect applied to catalytic DNAs (or DNAzymes) and demonstrate that the enzymatic efficiency of G-quadruplexes (GQs) in interaction with the hemin cofactor is remarkably enhanced by homodimerization. The resulting non-covalent dimeric GQ-DNAzyme system provides hemin with a structurally defined active site in which both the cofactor (hemin) and the oxidant (H2O2) are activated. This new biocatalytic system efficiently performs peroxidase- and peroxygenase-type biotransformations of a broad range of substrates, thus providing new perspectives for biotechnological application of GQs.
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Affiliation(s)
- Yu Cheng
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences Dalian 116023 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Mingpan Cheng
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences Dalian 116023 China
| | - Jingya Hao
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences Dalian 116023 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Guoqing Jia
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences Dalian 116023 China
| | - David Monchaud
- Institut de Chimie Moléculaire de l' Université de Bourgogne (ICMUB), CNRS UMR 6302, UBFC Dijon 21078 Dijon France
| | - Can Li
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences Dalian 116023 China
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37
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Zhao J, Yang Z, Zhai Q, Wei D. Specific recognition of telomeric multimeric G-quadruplexes by a simple-structure quinoline derivative. Anal Chim Acta 2020; 1132:93-100. [PMID: 32980115 DOI: 10.1016/j.aca.2020.07.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 07/02/2020] [Accepted: 07/07/2020] [Indexed: 11/17/2022]
Abstract
The development of highly sensitive fluorescence probes for telomeric multimeric G-quadruplexes has attracted extensive attention. However, few probes reported have exhibited selectivity for telomeric multimeric G-quadruplexes. Thus, it is challenging to design fluorescence probes with high specificity and selectivity for telomeric multimeric G-quadruplexes. This study employed a commercially available quinoline derivative BEPQ-1 as an effective switch-on sensor for telomeric multimeric G-quadruplexes. The fluorescence intensity enhanced more than 20 folds upon the addition of telomeric multimeric G-quadruplexes. This probe exhibited good selectivity and sensitivity for telomeric multimeric G-quadruplexes. And the detection limit of BEPQ-1 for the telomeric multimeric G-quadruplex TTA45 was calculated to be 0.11 μM. The distinctive feature of BEPQ-1 is the simple structure and small size. In the light of binding mode, BEPQ-1 could even simultaneously bind to the end two G-quartets of the two adjacent G-quadruplex units in telomeric multimeric G-quadruplex by π-π stacking. To our knowledge, this is the first simple-structure fluorescence probe for telomeric multimeric G-quadruplex. This finding might provide a strategy to design specific probes for telomeric multimeric G-quadruplexes and contribute to understand the structures and functions of G-quadruplexes in the telomere region.
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Affiliation(s)
- Jingfang Zhao
- Department of Chemistry, College of Science, Huazhong Agricultural University, Wuhan, 430070, PR China
| | - Ziyan Yang
- Department of Chemistry, College of Science, Huazhong Agricultural University, Wuhan, 430070, PR China
| | - Qianqian Zhai
- Department of Chemistry, College of Science, Huazhong Agricultural University, Wuhan, 430070, PR China.
| | - Dengguo Wei
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China; State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, PR China.
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38
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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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39
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Design, Synthesis and Characterization of Cyclic NU172 Analogues: A Biophysical and Biological Insight. Int J Mol Sci 2020; 21:ijms21113860. [PMID: 32485818 PMCID: PMC7312020 DOI: 10.3390/ijms21113860] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 05/20/2020] [Accepted: 05/28/2020] [Indexed: 11/16/2022] Open
Abstract
NU172—a 26-mer oligonucleotide able to bind exosite I of human thrombin and inhibit its activity—was the first aptamer to reach Phase II clinical studies as an anticoagulant in heart disease treatments. With the aim of favoring its functional duplex-quadruplex conformation and thus improving its enzymatic stability, as well as its thrombin inhibitory activity, herein a focused set of cyclic NU172 analogues—obtained by connecting its 5′- and 3′-extremities with flexible linkers—was synthesized. Two different chemical approaches were exploited in the cyclization procedure, one based on the oxime ligation method and the other on Cu(I)-assisted azide-alkyne cycloaddition (CuAAC), affording NU172 analogues including circularizing linkers with different length and chemical nature. The resulting cyclic NU172 derivatives were characterized using several biophysical techniques (ultraviolet (UV) and circular dichroism (CD) spectroscopies, gel electrophoresis) and then investigated for their serum resistance and anticoagulant activity in vitro. All the cyclic NU172 analogues showed higher thermal stability and nuclease resistance compared to unmodified NU172. These favorable properties were, however, associated with reduced—even though still significant—anticoagulant activity, suggesting that the conformational constraints introduced upon cyclization were somehow detrimental for protein recognition. These results provide useful information for the design of improved analogues of NU172 and related duplex-quadruplex structures.
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40
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Trifunctionalized Naphthalene Diimides and Dimeric Analogues as G-Quadruplex-Targeting Anticancer Agents Selected by Affinity Chromatography. Int J Mol Sci 2020; 21:ijms21061964. [PMID: 32183038 PMCID: PMC7139804 DOI: 10.3390/ijms21061964] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 03/02/2020] [Accepted: 03/10/2020] [Indexed: 12/14/2022] Open
Abstract
A focused library of newly designed monomeric and dimeric naphthalene diimides (NDIs) was analyzed in its ability to recognize specific G-quadruplex (G4) structures discriminating duplex DNA. The best G4 ligands—according to an affinity chromatography-based screening method named G4-CPG—were tested on human cancer and healthy cells, inducing DNA damage at telomeres, and in parallel, showing selective antiproliferative activity on HeLa cancer cells with IC50 values in the low nanomolar range. CD and fluorescence spectroscopy studies allowed detailed investigation of the interaction in solution with different G4 and duplex DNA models of the most promising NDI of the series, as determined by combining the biophysical and biological assays’ data.
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41
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Zhang M, Hao N, Gao Y, Li L, Ye X. Characterization of mixed solutions of hyperbranched and linear polystyrenes by a combination of size‐exclusion chromatography and analytical ultracentrifugation. JOURNAL OF POLYMER SCIENCE 2020. [DOI: 10.1002/pol.20190306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Miao Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical PhysicsUniversity of Science and Technology of China Hefei Anhui China
| | - Nairong Hao
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical PhysicsUniversity of Science and Technology of China Hefei Anhui China
| | - Yating Gao
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical PhysicsUniversity of Science and Technology of China Hefei Anhui China
| | - Lianwei Li
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical PhysicsUniversity of Science and Technology of China Hefei Anhui China
| | - Xiaodong Ye
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical PhysicsUniversity of Science and Technology of China Hefei Anhui China
- CAS Key Laboratory of Soft Matter ChemistryUniversity of Science and Technology of China Hefei Anhui China
- Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education InstitutesUniversity of Science and Technology of China Hefei Anhui China
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42
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Yu Y, Zhang Q, Fei Y, Yan C, Ye T, Gao L, Gao H, Zhou X, Shao Y. Multicolorfully probing intramolecular G-Quadruplex tandem interface. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2020; 227:117655. [PMID: 31670046 DOI: 10.1016/j.saa.2019.117655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 10/08/2019] [Accepted: 10/10/2019] [Indexed: 06/10/2023]
Abstract
A long guanine-rich oliogonucleotide sequence can form multiple G-quadruplex (G4) tandem individuals in a single molecule with internal G4-G4 (inG4-G4) interfaces. The interface can exist at the stacked (s-inG4-G4) or unstacked (us-inG4-G4) state, dependent of the G4 conformation and environment. Because of the vital bioactivity of the G4 interface state, there is a great demand for developing a reliable multicolor fluorescence method to identify the interface state using a fluorophore that can emit at the individual wavelength for a specific interface. Herein, we found that a porphyrin with four dihydroxyphenyl substituents (OH2PP) can multicolorfully recognize the s-inG4-G4 dimer interface against the us-inG4-G4 dimer one. The s-inG4-G4 dimer cause significant red shifts in the excitation and emission bands of OH2PP in contrast to the us-inG4-G4 dimer and G4 monomers. OH2PP adopts a 1:1 binding mode with the s-inG4-G4 dimer, whereas a 2:1 binding mode occurs to the us-inG4-G4 dimer. The limit of detection (LOD) for the s-inG4-G4 structure is about tens of nM level. The observed binding dependence of OH2PP on the linker length between the G4 individuals suggests the interface binding with the s-inG4-G4 dimer. Deformation of the porphyrin macrocycle within the s-inG4-G4 interface confinement most likely contributes to the multicolorful response with the hyperporphyrin effect. Our work demonstrates that OH2PP is a promising fluorophore to fluorescently recognize the G4 multimer with an ideal interface-sensitive multicolor response.
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Affiliation(s)
- Yali Yu
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, 321004, Zhejiang, China
| | - Qingqing Zhang
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, 321004, Zhejiang, China
| | - Yifan Fei
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, 321004, Zhejiang, China
| | - Chenxiao Yan
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, 321004, Zhejiang, China
| | - Ting Ye
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, 321004, Zhejiang, China
| | - Longlong Gao
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, 321004, Zhejiang, China
| | - Heng Gao
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, 321004, Zhejiang, China
| | - Xiaoshun Zhou
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, 321004, Zhejiang, China
| | - Yong Shao
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, 321004, Zhejiang, China.
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Liu J, Feng W, Zhang W. A single-molecule study reveals novel rod-like structures formed by a thrombin aptamer repeat sequence. NANOSCALE 2020; 12:4159-4166. [PMID: 32022812 DOI: 10.1039/c9nr09054a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Thrombin aptamers (TBAs) have attracted much attention due to their various applications. The structures and properties of long ssDNA chains with multiple TBA repeat sequences are interesting and distinct from those of their monomers. Due to the complexity of the sample system, it is quite difficult to reveal the structure of such a long-chain ssDNA using traditional methods. In this work, we investigated the repeated ssDNA by using single-molecule magnetic tweezers and AFM imaging. To do that we developed the polymerase change-rolling circle amplification (PC-RCA) synthetic method and prepared two-end modified repeated ssDNA. The rod-like G4 structures formed by intramolecular stacking of the repeat sequence were for the first time identified. This novel structure is different from those higher-order quadruplex structures formed by G-tetrads or loop-mediated interactions. It is also quite interesting to find that the increase of the TBA copy number can unitize the diversity of TBA conformation to the best-fit binding structure for thrombin. The methodology developed in this work can be used for studying other repeat sequences in the genome, such as telomeric DNA as well as interactions of ssDNA with the binding molecule.
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Affiliation(s)
- Jianyu Liu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, People's Republic of China.
| | - Wei Feng
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, People's Republic of China
| | - Wenke Zhang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, People's Republic of China.
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Puig Lombardi E, Londoño-Vallejo A. A guide to computational methods for G-quadruplex prediction. Nucleic Acids Res 2020; 48:1-15. [PMID: 31754698 PMCID: PMC6943126 DOI: 10.1093/nar/gkz1097] [Citation(s) in RCA: 93] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 10/31/2019] [Accepted: 11/04/2019] [Indexed: 12/31/2022] Open
Abstract
Guanine-rich nucleic acids can fold into the non-B DNA or RNA structures called G-quadruplexes (G4). Recent methodological developments have allowed the characterization of specific G-quadruplex structures in vitro as well as in vivo, and at a much higher throughput, in silico, which has greatly expanded our understanding of G4-associated functions. Typically, the consensus motif G3+N1-7G3+N1-7G3+N1-7G3+ has been used to identify potential G-quadruplexes from primary sequence. Since, various algorithms have been developed to predict the potential formation of quadruplexes directly from DNA or RNA sequences and the number of studies reporting genome-wide G4 exploration across species has rapidly increased. More recently, new methodologies have also appeared, proposing other estimates which consider non-canonical sequences and/or structure propensity and stability. The present review aims at providing an updated overview of the current open-source G-quadruplex prediction algorithms and straightforward examples of their implementation.
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Affiliation(s)
- Emilia Puig Lombardi
- Telomeres and Cancer Laboratory, Institut Curie, PSL Research University, Sorbonne Universités, CNRS UMR3244, 75005 Paris, France
| | - Arturo Londoño-Vallejo
- Telomeres and Cancer Laboratory, Institut Curie, PSL Research University, Sorbonne Universités, CNRS UMR3244, 75005 Paris, France
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45
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Lowran K, Campbell L, Popp P, Wu CG. Assembly of a G-Quadruplex Repair Complex by the FANCJ DNA Helicase and the REV1 Polymerase. Genes (Basel) 2019; 11:E5. [PMID: 31861576 PMCID: PMC7017153 DOI: 10.3390/genes11010005] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Accepted: 12/17/2019] [Indexed: 12/14/2022] Open
Abstract
The FANCJ helicase unfolds G-quadruplexes (G4s) in human cells to support DNA replication. This action is coupled to the recruitment of REV1 polymerase to synthesize DNA across from a guanine template. The precise mechanisms of these reactions remain unclear. While FANCJ binds to G4s with an AKKQ motif, it is not known whether this site recognizes damaged G4 structures. FANCJ also has a PIP-like (PCNA Interacting Protein) region that may recruit REV1 to G4s either directly or through interactions mediated by PCNA protein. In this work, we measured the affinities of a FANCJ AKKQ peptide for G4s formed by (TTAGGG)4 and (GGGT)4 using fluorescence spectroscopy and biolayer interferometry (BLI). The effects of 8-oxoguanine (8oxoG) on these interactions were tested at different positions. BLI assays were then performed with a FANCJ PIP to examine its recruitment of REV1 and PCNA. FANCJ AKKQ bound tightly to a TTA loop and was sequestered away from the 8oxoG. Reducing the loop length between guanine tetrads increased the affinity of the peptide for 8oxoG4s. FANCJ PIP targeted both REV1 and PCNA but favored interactions with the REV1 polymerase. The impact of these results on the remodeling of damaged G4 DNA is discussed herein.
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Affiliation(s)
- Kaitlin Lowran
- Department of Chemistry, Oakland University, Rochester, MI 48309, USA; (K.L.); (L.C.)
| | - Laura Campbell
- Department of Chemistry, Oakland University, Rochester, MI 48309, USA; (K.L.); (L.C.)
| | - Phillip Popp
- Case Western Reserve University, Cleveland, OH 44106, USA;
| | - Colin G. Wu
- Department of Chemistry, Oakland University, Rochester, MI 48309, USA; (K.L.); (L.C.)
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46
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Moccia F, Riccardi C, Musumeci D, Leone S, Oliva R, Petraccone L, Montesarchio D. Insights into the G-rich VEGF-binding aptamer V7t1: when two G-quadruplexes are better than one! Nucleic Acids Res 2019; 47:8318-8331. [PMID: 31276595 PMCID: PMC6735921 DOI: 10.1093/nar/gkz589] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 06/24/2019] [Accepted: 06/25/2019] [Indexed: 12/20/2022] Open
Abstract
The G-quadruplex-forming VEGF-binding aptamer V7t1 was previously found to be highly polymorphic in a K+-containing solution and, to restrict its conformational preferences to a unique, well-defined form, modified nucleotides (LNA and/or UNA) were inserted in its sequence. We here report an in-depth biophysical characterization of V7t1 in a Na+-rich medium, mimicking the extracellular environment in which VEGF targeting should occur, carried out combining several techniques to analyse the conformational behaviour of the aptamer and its binding to the protein. Our results demonstrate that, in the presence of high Na+ concentrations, V7t1 behaves in a very different way if subjected or not to annealing procedures, as evidenced by native gel electrophoresis, size exclusion chromatography and dynamic light scattering analysis. Indeed, not-annealed V7t1 forms both monomeric and dimeric G-quadruplexes, while the annealed oligonucleotide is a monomeric species. Remarkably, only the dimeric aptamer efficiently binds VEGF, showing higher affinity for the protein compared to the monomeric species. These findings provide new precious information for the development of improved V7t1 analogues, allowing more efficient binding to the cancer-related protein and the design of effective biosensors or theranostic devices based on VEGF targeting.
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Affiliation(s)
- Federica Moccia
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, I-80126 Napoli, Italy
| | - Claudia Riccardi
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, I-80126 Napoli, Italy
| | - Domenica Musumeci
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, I-80126 Napoli, Italy.,Institute of Biostructures and Bioimages, CNR, Via Mezzocannone 16, I-80134 Napoli, Italy
| | - Serena Leone
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, I-80126 Napoli, Italy
| | - Rosario Oliva
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, I-80126 Napoli, Italy
| | - Luigi Petraccone
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, I-80126 Napoli, Italy
| | - Daniela Montesarchio
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, I-80126 Napoli, Italy.,Institute for Endocrinology and Oncology 'Gaetano Salvatore', CNR, Via Pansini 5, 80131 Napoli, Italy
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47
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Geng Y, Liu C, Zhou B, Cai Q, Miao H, Shi X, Xu N, You Y, Fung CP, Din RU, Zhu G. The crystal structure of an antiparallel chair-type G-quadruplex formed by Bromo-substituted human telomeric DNA. Nucleic Acids Res 2019; 47:5395-5404. [PMID: 30957851 PMCID: PMC6547763 DOI: 10.1093/nar/gkz221] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 03/18/2019] [Accepted: 04/04/2019] [Indexed: 12/28/2022] Open
Abstract
Human telomeric guanine-rich DNA, which could adopt different G-quadruplex structures, plays important roles in protecting the cell from recombination and degradation. Although many of these structures were determined, the chair-type G-quadruplex structure remains elusive. Here, we present a crystal structure of the G-quadruplex composed of the human telomeric sequence d[GGGTTAGG8GTTAGGGTTAGG20G] with two dG to 8Br-dG substitutions at positions 8 and 20 with syn conformation in the K+ solution. It forms a novel three-layer chair-type G-quadruplex with two linking trinucleotide loops. Particularly, T5 and T17 are coplanar with two water molecules stacking on the G-tetrad layer in a sandwich-like mode through a coordinating K+ ion and an A6•A18 base pair. While a twisted Hoogsteen A12•T10 base pair caps on the top of G-tetrad core. The three linking TTA loops are edgewise and each DNA strand has two antiparallel adjacent strands. Our findings contribute to a deeper understanding and highlight the unique roles of loop and water molecule in the folding of the G-quadruplex.
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Affiliation(s)
- Yanyan Geng
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Changdong Liu
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Bo Zhou
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China.,Institute for Advanced Study, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Qixu Cai
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Haitao Miao
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Xiao Shi
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Naining Xu
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Yingying You
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Chun Po Fung
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Rahman Ud Din
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Guang Zhu
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China.,State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
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48
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Hu MH, Lin XT, Liu B, Tan JH. Dimeric aryl-substituted imidazoles may inhibit ALT cancer by targeting the multimeric G-quadruplex in telomere. Eur J Med Chem 2019; 186:111891. [PMID: 31759730 DOI: 10.1016/j.ejmech.2019.111891] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Revised: 11/10/2019] [Accepted: 11/14/2019] [Indexed: 11/17/2022]
Abstract
In 10-15% of cancers, telomere maintenance is provided by a telomerase-independent mechanism known as alternative lengthening of telomere (ALT), making telomerase inhibitors ineffective on these cancers. Ligands that stabilize telomeric G-quadruplex (G4) are considered to be able to inhibit either the ALT process or disrupt the T-loop structure, which would be promising therapeutic agents for ALT cancers. Notably, the 3'-terminal overhang of telomeric DNA might fold into multimeric G4 containing consecutive G4 subunits, which offers an attractive target for selective ligands considering large numbers of G4s widespread in the genome. In this study, a dimeric aryl-substituted imidazole (DIZ-3) was developed as a selective multimeric G4 ligand based on a G4-ligand-dimerizing strategy. Biophysical experiments revealed that DIZ-3 intercalated into the G4-G4 interface, stabilizing the higher-order structure. Furthermore, this ligand was demonstrated to induce cell cycle arrest and apoptosis, and thus inhibited cell proliferation in an ALT cancer cell line. Cancer cells were more sensitive to DIZ-3, relative to normal cells. Notably, DIZ-3 had little effect on the transcription of several G4-dependent oncogenes. This study provides a nice example for discovering dimeric agents to potentially treat ALT cancers via targeting telomeric multimeric G4.
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Affiliation(s)
- Ming-Hao Hu
- School of Pharmaceutical Sciences, Shenzhen University Health Science Center, Shenzhen, 518060, China.
| | - Xiao-Tong Lin
- School of Pharmaceutical Sciences, Shenzhen University Health Science Center, Shenzhen, 518060, China
| | - Bin Liu
- Shenzhen Key Laboratory of Polymer Science and Technology, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, China
| | - Jia-Heng Tan
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China
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49
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Riccardi C, Meyer A, Vasseur JJ, Russo Krauss I, Paduano L, Morvan F, Montesarchio D. Fine-tuning the properties of the thrombin binding aptamer through cyclization: Effect of the 5'-3' connecting linker on the aptamer stability and anticoagulant activity. Bioorg Chem 2019; 94:103379. [PMID: 31699393 DOI: 10.1016/j.bioorg.2019.103379] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 09/21/2019] [Accepted: 10/21/2019] [Indexed: 12/14/2022]
Abstract
A small library of cyclic TBA analogues (named cycTBA I-IV), obtained by covalently connecting its 5'- and 3'-ends with flexible linkers, has been synthesized with the aim of improving its chemical and enzymatic stability, as well as its anticoagulant properties. Two chemical procedures have been exploited to achieve the desired cyclization, based on the oxime ligation method (providing cycTBA I and II) or on Cu(I)-assisted azide-alkyne cycloaddition (CuAAC) protocols (for cycTBA III and IV), leading to analogues containing circularizing linkers with different chemical nature and length, overall spanning from 22 to 48 atoms. The resulting cyclic TBAs have been characterized using a variety of biophysical methods (UV, CD, gel electrophoresis, SE-HPLC analyses) and then tested for their serum resistance and anticoagulant activity under in vitro experiments. A fine-tuning of the length and flexibility of the linker allowed identifying a cyclic analogue, cycTBA II, with improved anticoagulant activity, associated with a dramatically stabilized G-quadruplex structure (ΔTm = +17 °C) and a 6.6-fold higher enzymatic resistance in serum compared to unmodified TBA.
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Affiliation(s)
- Claudia Riccardi
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, I-80126 Napoli, Italy
| | - Albert Meyer
- Institut des Biomolécules Max Mousseron, Université de Montpellier, CNRS, ENSCM, Montpellier, France
| | - Jean-Jacques Vasseur
- Institut des Biomolécules Max Mousseron, Université de Montpellier, CNRS, ENSCM, Montpellier, France
| | - Irene Russo Krauss
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, I-80126 Napoli, Italy; CSGI - Consorzio Interuniversitario per lo Sviluppo dei Sistemi a Grande Interfase, Via della Lastruccia 3, I-50019 Sesto Fiorentino (Fi), Italy
| | - Luigi Paduano
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, I-80126 Napoli, Italy; CSGI - Consorzio Interuniversitario per lo Sviluppo dei Sistemi a Grande Interfase, Via della Lastruccia 3, I-50019 Sesto Fiorentino (Fi), Italy
| | - François Morvan
- Institut des Biomolécules Max Mousseron, Université de Montpellier, CNRS, ENSCM, Montpellier, France.
| | - Daniela Montesarchio
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, I-80126 Napoli, Italy.
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50
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Synthesis, DNA binding studies, and antiproliferative activity of novel Pt(II)-complexes with an L-alanyl-based ligand. J Inorg Biochem 2019; 203:110868. [PMID: 31837618 DOI: 10.1016/j.jinorgbio.2019.110868] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 09/22/2019] [Accepted: 09/24/2019] [Indexed: 12/14/2022]
Abstract
An artificial alanine-based amino acid {(S)-2-amino-3-[4-propyl-3-(thiophen-2-yl)-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-1-yl]propanoic acid, here named TioxAla}, bearing a substituted triazolyl-thione group on the side chain and able to bind RNA biomedical targets, was here chosen as a valuable scaffold for the synthesis of new platinum complexes with potential dual action owing to the concomitant presence of the metal centre and the amino acid moiety. Three new platinum complexes, obtained from the reaction of TioxAla with K2PtCl4, were characterized by mass spectrometry, nuclear magnetic resonance and UV-vis spectroscopy: one compound (Pt1, bis-{(S)-2-amino-3-[4-propyl-3-(thiophen-2-yl)-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-1-yl]propanoate-O,S} platinum(II)) consisted of two amino acid units coordinating the Pt(II) ion; the other two, Pt2 [potassium dichloro-{(S)-2-amino-3-[4-propyl-3-(thiophen-2-yl)-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-1-yl]propanoate (O,S)} platinum(II)] and Pt3 [potassium dichloro-{(S)-2-amino-3-[4-propyl-3-(thiophen-2-yl)-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-1-yl]propanoate (O,N)} platinum(II)], were isomers bearing one TioxAla unit, and two chlorides as Pt-ligands. Pt coordination involved preferentially the amino, carboxylic and thione functions of TioxAla. By preliminary antiproliferative assays, a moderate cytotoxic activity on cancer cells was observed only for Pt2 and Pt3, while no anticancer activity was found for both the chloride-free complex (Pt1) and TioxAla. This cytotoxicity, however lower than that of cisplatin, well correlated with the marked ability, here found only for Pt2 and Pt3 complexes, to bind DNA sequences either in random coil or in structured forms (duplex and G-quadruplex), as verified by spectroscopic and spectrometric analysis.
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