1
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Katrivas L, Makarovsky A, Kempinski B, Randazzo A, Improta R, Rotem D, Porath D, Kotlyar AB. Ag +-Mediated Folding of Long Polyguanine Strands to Double and Quadruple Helixes. NANOMATERIALS (BASEL, SWITZERLAND) 2024; 14:663. [PMID: 38668157 PMCID: PMC11055002 DOI: 10.3390/nano14080663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2024] [Revised: 04/03/2024] [Accepted: 04/07/2024] [Indexed: 04/29/2024]
Abstract
Metal-mediated base pairing of DNA has been a topic of extensive research spanning over more than four decades. Precise positioning of a single metal ion by predetermining the DNA sequence, as well as improved conductivity offered by the ions, make these structures interesting candidates in the context of using DNA in nanotechnology. Here, we report the formation and characterization of conjugates of long (kilo bases) homoguanine DNA strands with silver ions. We demonstrate using atomic force microscopy (AFM) and scanning tunneling microscope (STM) that binding of silver ions leads to folding of homoguanine DNA strands in a "hairpin" fashion to yield double-helical, left-handed molecules composed of G-G base pairs each stabilized by a silver ion. Further folding of the DNA-silver conjugate yields linear molecules in which the two halves of the double helix are twisted one against the other in a right-handed fashion. Quantum mechanical calculations on smaller molecular models support the helical twist directions obtained by the high resolution STM analysis. These long guanine-based nanostructures bearing a chain of silver ions have not been synthesized and studied before and are likely to possess conductive properties that will make them attractive candidates for nanoelectronics.
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Affiliation(s)
- Liat Katrivas
- Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences and Nanotechnology Center, Tel Aviv University, Ramat Aviv, Tel-Aviv 6997801, Israel; (L.K.); (B.K.)
| | - Anna Makarovsky
- Institute of Chemistry and The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 7610001, Israel; (A.M.); (D.R.)
| | - Benjamin Kempinski
- Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences and Nanotechnology Center, Tel Aviv University, Ramat Aviv, Tel-Aviv 6997801, Israel; (L.K.); (B.K.)
| | - Antonio Randazzo
- Department of Pharmacy, University of Naples Federico II, Via D. Montesano 49, I-80131 Napoli, Italy;
| | - Roberto Improta
- Istituto di Biostrutture e Bioimmagini-CNR (IBB-CNR), Via De Amicis 95, I-80145 Napoli, Italy;
| | - Dvir Rotem
- Institute of Chemistry and The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 7610001, Israel; (A.M.); (D.R.)
| | - Danny Porath
- Institute of Chemistry and The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 7610001, Israel; (A.M.); (D.R.)
| | - Alexander B. Kotlyar
- Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences and Nanotechnology Center, Tel Aviv University, Ramat Aviv, Tel-Aviv 6997801, Israel; (L.K.); (B.K.)
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2
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Pokorná P, Mlýnský V, Bussi G, Šponer J, Stadlbauer P. Molecular dynamics simulations reveal the parallel stranded d(GGGA) 3GGG DNA quadruplex folds via multiple paths from a coil-like ensemble. Int J Biol Macromol 2024; 261:129712. [PMID: 38286387 DOI: 10.1016/j.ijbiomac.2024.129712] [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: 09/21/2023] [Revised: 01/10/2024] [Accepted: 01/16/2024] [Indexed: 01/31/2024]
Abstract
G-quadruplexes (G4s) are non-canonical nucleic acid structures that fold through complex processes. Characterization of the G4 folding landscape may help to elucidate biological roles of G4s but is challenging both experimentally and computationally. Here, we achieved complete folding of a three-quartet parallel DNA G4 with (GGGA)3GGG sequence using all-atom explicit-solvent enhanced-sampling molecular dynamics (MD) simulations. The simulations suggested early formation of guanine stacks in the G-tracts, which behave as semi-rigid blocks in the folding process. The folding continues via the formation of a collapsed compact coil-like ensemble. Structuring of the G4 from the coil then proceeds via various cross-like, hairpin, slip-stranded and two-quartet ensembles and can bypass the G-triplex structure. Folding of the parallel G4 does not appear to involve any salient intermediates and is a multi-pathway process. We also carried out an extended set of simulations of parallel G-hairpins. While parallel G-hairpins are extremely unstable when isolated, they are more stable inside the coil structure. On the methodology side, we show that the AMBER DNA force field predicts the folded G4 to be less stable than the unfolded ensemble, uncovering substantial force-field issues. Overall, we provide unique atomistic insights into the folding landscape of parallel-stranded G4 but also reveal limitations of current state-of-the-art MD techniques.
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Affiliation(s)
- Pavlína Pokorná
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 61200, Czech Republic
| | - Vojtěch Mlýnský
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 61200, Czech Republic
| | - Giovanni Bussi
- Scuola Internazionale Superiore di Studi Avanzati (SISSA), via Bonomea 265, Trieste 34136, Italy
| | - Jiří Šponer
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 61200, Czech Republic
| | - Petr Stadlbauer
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, Brno 61200, Czech Republic.
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3
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Khan S, Singh A, Nain N, Kukreti S. Alkali cation-mediated topology displayed by an exonic G-rich sequence of TRPA1 gene. J Biomol Struct Dyn 2023; 41:9997-10008. [PMID: 36458452 DOI: 10.1080/07391102.2022.2150686] [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: 09/14/2022] [Accepted: 11/17/2022] [Indexed: 12/04/2022]
Abstract
G-rich sequences are intrinsic parts of the genome, widespread in promoters, telomeres, or other regulatory regions. The in vivo existence and biological significance have established the functional aspect of G-quadruplex structures and thus have developed immense interest in exploring their therapeutic aspects. Herein, using biophysical methods, we examined the structural status and comprehensive cation-dependence of a 17-bp G-rich genomic sequence (SKGT17) located in the coding region of the human TRPA1 gene, known to be associated with various neurovascular, cardiovascular, and respiratory conditions. TRPA1 is primarily seen as a therapeutic target for the development of novel analgesics. Bioinformatics analysis has suggested that 17-bp quadruplex motif is a binding site for transcription factor 'Sp1'. The formation and recognition of SKGT17 G-quadruplex might impact its regulatory functioning. Biophysical studies confirmed that the presence of alkali metal ions facilitated the formation of G-quadruplex in parallel topology. Native gel further substantiated the formation of a biomolecular species. Circular dichroism (CD), UV-thermal melting (Tm), and CD melting confirmed the formation of parallel G-quadruplex with metal ion-dependent stability. The stability of the G-quadruplex formed is found to be significantly high in the presence of K+ ions than that of other ions. Intriguingly, we have also established that this segment of the TRAP1 gene favors G-quadruplex formation over its participation in the corresponding duplex formation under K+ ions conditions. This study attempts to explain the rationale for the stabilization of G-quadruplex in the presence of alkali metal ions and may add to a better understanding and insights into DNA-metal ions interactions.
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Affiliation(s)
- Shoaib Khan
- Nucleic Acid Research Laboratory, Department of Chemistry, University of Delhi, Delhi, India
| | - Anju Singh
- Department of Chemistry, Ramjas College, University of Delhi, Delhi, India
| | - Nishu Nain
- Nucleic Acid Research Laboratory, Department of Chemistry, University of Delhi, Delhi, India
| | - Shrikant Kukreti
- Nucleic Acid Research Laboratory, Department of Chemistry, University of Delhi, Delhi, India
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4
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Neupane A, Chariker JH, Rouchka EC. Structural and Functional Classification of G-Quadruplex Families within the Human Genome. Genes (Basel) 2023; 14:genes14030645. [PMID: 36980918 PMCID: PMC10048163 DOI: 10.3390/genes14030645] [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: 02/13/2023] [Revised: 02/22/2023] [Accepted: 03/02/2023] [Indexed: 03/08/2023] Open
Abstract
G-quadruplexes (G4s) are short secondary DNA structures located throughout genomic DNA and transcribed RNA. Although G4 structures have been shown to form in vivo, no current search tools that examine these structures based on previously identified G-quadruplexes and filter them based on similar sequence, structure, and thermodynamic properties are known to exist. We present a framework for clustering G-quadruplex sequences into families using the CD-HIT, MeShClust, and DNACLUST methods along with a combination of Starcode and BLAST. Utilizing this framework to filter and annotate clusters, 95 families of G-quadruplex sequences were identified within the human genome. Profiles for each family were created using hidden Markov models to allow for the identification of additional family members and generate homology probability scores. The thermodynamic folding energy properties, functional annotation of genes associated with the sequences, scores from different prediction algorithms, and transcription factor binding motifs within a family were used to annotate and compare the diversity within and across clusters. The resulting set of G-quadruplex families can be used to further understand how different regions of the genome are regulated by factors targeting specific structures common to members of a specific cluster.
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Affiliation(s)
- Aryan Neupane
- School of Graduate and Interdisciplinary Studies, University of Louisville, Louisville, KY 40292, USA
| | - Julia H. Chariker
- Department of Neuroscience Training, University of Louisville, Louisville, KY 40292, USA
- Kentucky IDeA Network of Biomedical Research Excellence (KY INBRE) Bioinformatics Core, University of Louisville, Louisville, KY 40292, USA
| | - Eric C. Rouchka
- Kentucky IDeA Network of Biomedical Research Excellence (KY INBRE) Bioinformatics Core, University of Louisville, Louisville, KY 40292, USA
- Department of Biochemistry and Molecular Genetics, University of Louisville, Louisville, KY 40292, USA
- Correspondence: ; Tel.: +1-(502)-852-3060
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Ye M, Chen EV, Pfeil SH, Martin KN, Atrafi T, Yun S, Martinez Z, Yatsunyk LA. Homopurine guanine-rich sequences in complex with N-methyl mesoporphyrin IX form parallel G-quadruplex dimers and display a unique symmetry tetrad. Bioorg Med Chem 2023; 77:117112. [PMID: 36508994 PMCID: PMC9812923 DOI: 10.1016/j.bmc.2022.117112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 11/24/2022] [Accepted: 11/28/2022] [Indexed: 12/03/2022]
Abstract
DNA can fold into G-quadruplexes (GQs), non-canonical secondary structures formed by π-π stacking of G-tetrads. GQs are important in many biological processes, which makes them promising therapeutic targets. We identified a 42-nucleotide long, purine-only G-rich sequence from human genome, which contains eight G-stretches connected by A and AAAA loops. We divided this sequence into five unique segments, four guanine stretches each, named GA1-5. In order to investigate the role of adenines in GQ structure formation, we performed biophysical and X-ray crystallographic studies of GA1-5 and their complexes with a highly selective GQ ligand, N-methyl mesoporphyrin IX (NMM). Our data indicate that all variants form parallel GQs whose stability depends on the number of flexible AAAA loops. GA1-3 bind NMM with 1:1 stoichiometry. The Ka for GA1 and GA3 is modest, ∼0.3 μM -1, and that for GA2 is significantly higher, ∼1.2 μM -1. NMM stabilizes GA1-3 by 14.6, 13.1, and 7.0 °C, respectively, at 2 equivalents. We determined X-ray crystal structures of GA1-NMM (1.98 Å resolution) and GA3-NMM (2.01 Å). The structures confirm the parallel topology of GQs with all adenines forming loops and display NMM binding at the 3' G-tetrad. Both complexes dimerize through the 5' interface. We observe two novel structural features: 1) a 'symmetry tetrad' at the dimer interface, which is formed by two guanines from each GQ monomer and 2) a NMM dimer in GA1-NMM. Our structural work confirms great flexibility of adenines as structural elements in GQ formation and contributes greatly to our understanding of the structural diversity of GQs and their modes of interaction with small molecule ligands.
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Affiliation(s)
- Ming Ye
- Department of Chemistry and Biochemistry, Swarthmore College, Swarthmore, PA 19081, United States
| | - Erin V Chen
- Department of Chemistry and Biochemistry, Swarthmore College, Swarthmore, PA 19081, United States
| | - Shawn H Pfeil
- Department of Physics, West Chester University, West Chester, PA 19383, United States
| | - Kailey N Martin
- Department of Chemistry and Biochemistry, Swarthmore College, Swarthmore, PA 19081, United States
| | - Tamanaa Atrafi
- Department of Chemistry and Biochemistry, Swarthmore College, Swarthmore, PA 19081, United States
| | - Sara Yun
- Department of Chemistry and Biochemistry, Swarthmore College, Swarthmore, PA 19081, United States
| | - Zahara Martinez
- Department of Chemistry and Biochemistry, Swarthmore College, Swarthmore, PA 19081, United States
| | - Liliya A Yatsunyk
- Department of Chemistry and Biochemistry, Swarthmore College, Swarthmore, PA 19081, United States.
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6
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Tsao L, Shepardson-Fungairiño S, Murayama H, Cecere A, Wren E, Núñez M. Assessing the Potential for DNA Quadruplex Formation in the Predatory Bacterium Bdellovibrio bacteriovorus. Biochemistry 2022; 61:2073-2087. [PMID: 36193632 PMCID: PMC9536305 DOI: 10.1021/acs.biochem.2c00443] [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: 07/29/2022] [Revised: 08/25/2022] [Indexed: 11/29/2022]
Abstract
During its life cycle, the predatory bacterium Bdellovibrio bacteriovorus switches between an attack and a growth phase, each of which is characterized by a distinct pattern of gene expression. Twenty-one potential G-quadruplex-forming sequences (PQFS) have been identified in the Bdellovibrio genome. These G-rich sequences are prevalent within open reading frames and nearly evenly distributed between the template and the coding strand, suggesting that they could play a role in gene expression and life cycle switching. Published transcriptomic data show that the genes nearest these sequences are not (de)activated together during the same phases of the life cycle. We explored the biophysical properties of three identified PQFS using circular dichroism (CD) spectroscopy and gel electrophoresis and demonstrated that all three sequences fold into stable unimolecular quadruplexes with distinct topologies. In the presence of their complementary strands, each forms an equilibrium mixture of duplex and quadruplex in which quadruplex formation is favored at higher temperatures. Once the quadruplexes are folded, they are slow to form a duplex when the complementary strand is added, with one sequence requiring the equivalent of many Bdellovibrio lifetimes to do so. Using a variety of cosolutes, we showed that molecular crowding mimicking cellular conditions stabilizes the quadruplex structures and induces structural transitions to the parallel topology regardless of the original topology. Taken together, these experiments suggest that Bdellovibrio PQFS are capable of forming quadruplexes in vivo and thereby playing a role in gene expression.
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Affiliation(s)
- Lucille
H. Tsao
- Department of Chemistry and
Program in Biochemistry, Wellesley College, Wellesley, Massachusetts 02481, United States
| | - Sally Shepardson-Fungairiño
- Department of Chemistry and
Program in Biochemistry, Wellesley College, Wellesley, Massachusetts 02481, United States
| | - Hikari Murayama
- Department of Chemistry and
Program in Biochemistry, Wellesley College, Wellesley, Massachusetts 02481, United States
| | - Amelia Cecere
- Department of Chemistry and
Program in Biochemistry, Wellesley College, Wellesley, Massachusetts 02481, United States
| | - Elizabeth Wren
- Department of Chemistry and
Program in Biochemistry, Wellesley College, Wellesley, Massachusetts 02481, United States
| | - Megan Núñez
- Department of Chemistry and
Program in Biochemistry, Wellesley College, Wellesley, Massachusetts 02481, United States
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7
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Jana J, Vianney YM, Schröder N, Weisz K. Guiding the folding of G-quadruplexes through loop residue interactions. Nucleic Acids Res 2022; 50:7161-7175. [PMID: 35758626 PMCID: PMC9262619 DOI: 10.1093/nar/gkac549] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/25/2022] [Accepted: 06/14/2022] [Indexed: 12/24/2022] Open
Abstract
A G-rich sequence was designed to allow folding into either a stable parallel or hybrid-type topology. With the parent sequence featuring coexisting species, various related sequences with single and double mutations and with a shortened central propeller loop affected the topological equilibrium. Two simple modifications, likewise introduced separately to all sequences, were employed to lock folds into one of the topologies without noticeable structural alterations. The unique combination of sequence mutations, high-resolution NMR structural information, and the thermodynamic stability for both topological competitors identified critical loop residue interactions. In contrast to first loop residues, which are mostly disordered and exposed to solvent in both propeller and lateral loops bridging a narrow groove, the last loop residue in a lateral three-nucleotide loop is engaged in stabilizing stacking interactions. The propensity of single-nucleotide loops to favor all-parallel topologies by enforcing a propeller-like conformation of an additional longer loop is shown to result from their preference in linking two outer tetrads of the same tetrad polarity. Taken together, the present studies contribute to a better structural and thermodynamic understanding of delicate loop interactions in genomic and artificially designed quadruplexes, e.g. when employed as therapeutics or in other biotechnological applications.
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Affiliation(s)
- Jagannath Jana
- Institute of Biochemistry, Universität Greifswald, D-17489 Greifswald, Germany
| | | | - Nina Schröder
- Institute of Biochemistry, Universität Greifswald, D-17489 Greifswald, Germany
| | - Klaus Weisz
- To whom correspondence should be addressed. Tel: +49 3834 420 4426; Fax: +49 3834 420 4427;
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8
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Kankia B. Trinity of G-tetrads and origin of translation. Biol Direct 2022; 17:12. [PMID: 35637509 PMCID: PMC9153121 DOI: 10.1186/s13062-022-00327-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 05/23/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The RNA world hypothesis cannot address most of the questions of the origin of life without violating the continuity principle (small Darwinian steps without foresight and miracles). Moreover, the RNA world is an isolated system incapable of accommodating the genetic code and evolving into extant biochemistry. All these problems are rooted in the central assumption of the hypothesis: de novo appearance of the ribozymes, production of which represents a multistep reaction requiring the complementarity principle. Thus, even the basis of the RNA world is at odds with the continuity principle-it uses foresight (multistep reaction) and a miracle (complementarity principle). Can a three-dimensional (3D) architecture, capable of molecular recognition and catalysis, be formed in a single-step reaction without the complementarity or any other preexisting rules? HYPOTHESIS At first glance, the above question sounds rhetoric since the complementarity principle is the essential feature of the RNA world; it turns an RNA polymer into a genetic material. Without it, the RNA world becomes as shapeless and unconvincing as other hypotheses based on the non-hereditary molecules (i.e., protein world). However, it was suggested recently that the quadruplexes could initiate life and take necessary evolutionary steps before the arrival of the complementarity rules. The hypothesis relies on the unique properties of guanines (Gs) to self-assemble into G-tetrads and efficiently polymerize without any external help or preexisting rules. Interestingly, polyG folds into an unusually stable and well-structured monomolecular architecture that uses the quadruplex domain (QD) assembly. The QD has a strictly defined zigzag-like building pattern to accommodate only three G-tetrads. Since both QD architecture and codon length are based on triplets, the inevitable question arises: are they related? Or could QD play the role of the early adapter and determine the codon length? The current paper is an attempt to answer this question. CONCLUSION While without translation apparatus most of the steps of the extant translation are physically impossible, the QD-mediated translation is sterically feasible and can be explained by physicochemical properties of the QD and the amino acids without violating the continuity principle. Astonishingly, the quadruplex world hypothesis can address all the shortcomings of the RNA world, including its most significant challenge-step-by-step evolution from the polymerization of the first polynucleotide to the extant biochemistry.
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Affiliation(s)
- Besik Kankia
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, 43210, USA. .,Institute of Biophysics, Ilia State University, 0162, Tbilisi, Republic of Georgia.
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9
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Devi G, Winnerdy FR, Ang JCY, Lim KW, Phan AT. Four-Layered Intramolecular Parallel G-Quadruplex with Non-Nucleotide Loops: An Ultra-Stable Self-Folded DNA Nano-Scaffold. ACS NANO 2022; 16:533-540. [PMID: 34927423 DOI: 10.1021/acsnano.1c07630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
A four-stranded scaffold of nucleic acids termed G-quadruplex (G4) has found growing applications in nano- and biotechnology. Propeller loops are a hallmark of the most stable intramolecular parallel-stranded G4s. To date, propeller loops have been observed to span only a maximum of three G-tetrad layers. Going beyond that would allow creation of more stable scaffolds useful for building robust nanodevices. Here we investigate the formation of propeller loops spanning more than three layers. We show that native nucleotide sequences are incompatible toward this goal, and we report on synthetic non-nucleotide linkers that form a propeller loop across four layers. With the established linkers, we constructed a four-layered intramolecular parallel-stranded G4, which exhibited ultrahigh thermal stability. Control on loop design would augment the toolbox toward engineering of G4-based nanoscaffolds for diverse applications.
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Affiliation(s)
- Gitali Devi
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Fernaldo Richtia Winnerdy
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Jason Cheng Yu Ang
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Kah Wai Lim
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Anh Tuân Phan
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
- NTU Institute of Structural Biology, Nanyang Technological University, Singapore 636921, Singapore
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10
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Green AT, Pickard AJ, Li R, MacKerell AD, Bierbach U, Cho SS. Computational and Experimental Characterization of rDNA and rRNA G-Quadruplexes. J Phys Chem B 2022; 126:609-619. [PMID: 35026949 DOI: 10.1021/acs.jpcb.1c08340] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
DNA G-quadruplexes in human telomeres and gene promoters are being extensively studied for their role in controlling the growth of cancer cells. G-quadruplexes have been unambiguously shown to exist both in vitro and in vivo, including in the guanine (G)-rich DNA genes encoding pre-ribosomal RNA (pre-rRNA), which is transcribed in the cell's nucleolus. Recent studies strongly suggest that these DNA sequences ("rDNA"), and the transcribed rRNA, are a potential anticancer target through the inhibition of RNA polymerase I (Pol I) in ribosome biogenesis, but the structures of ribosomal G-quadruplexes at atomic resolution are unknown and very little biophysical characterization has been performed on them to date. In the present study, circular dichroism (CD) spectroscopy is used to show that two putative rDNA G-quadruplex sequences, NUC 19P and NUC 23P and their counterpart rRNAs, predominantly adopt parallel topologies, reminiscent of the analogous telomeric quadruplex structures. Based on this information, we modeled parallel topology atomistic structures of the putative ribosomal G-quadruplexes. We then validated and refined the modeled ribosomal G-quadruplex structures using all-atom molecular dynamics (MD) simulations with the CHARMM36 force field in the presence and absence of stabilizing K+. Motivated by preliminary MD simulations of the telomeric parallel G-quadruplex (TEL 24P) in which the K+ ion is expelled, we used updated CHARMM36 force field K+ parameters that were optimized, targeting the data from quantum mechanical calculations and the polarizable Drude model force field. In subsequent MD simulations with optimized CHARMM36 parameters, the K+ ions are predominantly in the G-quadruplex channel and the rDNA G-quadruplexes have more well-defined, predominantly parallel-topology structures as compared to rRNA. In addition, NUC 19P is more structured than NUC 23P, which contains extended loops. Results from this study set the structural foundation for understanding G-quadruplex functions and the design of novel chemotherapeutics against these nucleolar targets and can be readily extended to other DNA and RNA G-quadruplexes.
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Affiliation(s)
- Adam T Green
- Department of Physics, Wake Forest University, Winston-Salem, North Carolina 27109, United States
| | - Amanda J Pickard
- Department of Chemistry, Wake Forest University, Wake Downtown Campus, Winston-Salem, North Carolina 27101, United States
| | - Rongzhong Li
- Department of Physics, Wake Forest University, Winston-Salem, North Carolina 27109, United States.,Department of Computer Science, Wake Forest University, Winston-Salem, North Carolina 27109, United States
| | - Alexander D MacKerell
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland 21201, United States
| | - Ulrich Bierbach
- Department of Chemistry, Wake Forest University, Wake Downtown Campus, Winston-Salem, North Carolina 27101, United States
| | - Samuel S Cho
- Department of Physics, Wake Forest University, Winston-Salem, North Carolina 27109, United States.,Department of Computer Science, Wake Forest University, Winston-Salem, North Carolina 27109, United States
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11
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Liu YC, Yang DY, Sheu SY. Insights into the free energy landscape and salt-controlled mechanism of the conformational conversions between human telomeric G-quadruplex structures. Int J Biol Macromol 2021; 191:230-242. [PMID: 34536474 DOI: 10.1016/j.ijbiomac.2021.09.057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/23/2021] [Accepted: 09/10/2021] [Indexed: 12/16/2022]
Abstract
G-quadruplexes have become attractive drug targets in cancer therapy. However, due to the polymorphism of G-quadruplex structures, it is difficult to experimentally verify the relevant structures of multiple intermediates and transition states in dynamic equilibrium. Hence, understanding the mechanism by which structural conversions of G-quadruplexes occur is still challenging. We conducted targeted molecular dynamics simulation with umbrella sampling to investigate how salt affects the conformational conversion of human telomeric G-quadruplex. Our results explore a unique view into the structures and energy barrier of the intermediates and transition states in the interconversion process. The pathway of G-quadruplex conformational interconversion was mapped out by a free energy landscape, consisting of branched parallel pathways with multiple energy basins. We propose a salt-controlled mechanism that as the salt concentration increases, the conformational conversion mechanism switches from multi-pathway folding to sequential folding pathways. The hybrid-I and hybrid-II structures are intermediates in the basket-propeller transformation. In high-salt solutions, the conformational conversion upon K+ binding is more feasible than upon Na+ binding. The free energy barrier for conformational conversions ranges from 1.6 to 4.6 kcal/mol. Our work will be beneficial in developing anticancer agents.
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Affiliation(s)
- Yu-Cheng Liu
- Institute of Biomedical Informatics, National Yang Ming Chiao Tung University, Taipei 112, Taiwan
| | - Dah-Yen Yang
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan.
| | - Sheh-Yi Sheu
- Institute of Biomedical Informatics, National Yang Ming Chiao Tung University, Taipei 112, Taiwan; Department of Life Sciences and Institute of Genome Sciences, National Yang Ming Chiao Tung University, Taipei 112, Taiwan.
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12
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Fardian-Melamed N, Katrivas L, Rotem D, Kotlyar A, Porath D. Electronic Level Structure of Novel Guanine Octuplex DNA Single Molecules. NANO LETTERS 2021; 21:8987-8992. [PMID: 34694812 DOI: 10.1021/acs.nanolett.1c02269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Throughout the past few decades, guanine quadruplex DNA structures have attracted much interest both from a fundamental material science perspective and from a technologically oriented perspective. Novel guanine octuplex DNA, formed from coiled quadruplex DNA, was recently discovered as a stable and rigid DNA-based nanostructure. A detailed electronic structure study of this new nanomaterial, performed by scanning tunneling spectroscopy on a subsingle-molecule level at cryogenic temperature, is presented herein. The electronic levels and lower energy gap of guanine octuplex DNA compared to quadruplex DNA dictate higher transverse conductivity through guanine octads than through guanine tetrads.
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Affiliation(s)
- Natalie Fardian-Melamed
- Institute of Chemistry and The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Liat Katrivas
- Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences, and The Center of Nanoscience and Nanotechnology, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Dvir Rotem
- Institute of Chemistry and The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Alexander Kotlyar
- Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences, and The Center of Nanoscience and Nanotechnology, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Danny Porath
- Institute of Chemistry and The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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13
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Grün JT, Schwalbe H. Folding dynamics of polymorphic G-quadruplex structures. Biopolymers 2021; 113:e23477. [PMID: 34664713 DOI: 10.1002/bip.23477] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 09/30/2021] [Accepted: 09/30/2021] [Indexed: 12/14/2022]
Abstract
G-quadruplexes (G4), found in numerous places within the human genome, are involved in essential processes of cell regulation. Chromosomal DNA G4s are involved for example, in replication and transcription as first steps of gene expression. Hence, they influence a plethora of downstream processes. G4s possess an intricate structure that differs from canonical B-form DNA. Identical DNA G4 sequences can adopt multiple long-lived conformations, a phenomenon known as G4 polymorphism. A detailed understanding of the molecular mechanisms that drive G4 folding is essential to understand their ambivalent regulatory roles. Disentangling the inherent dynamic and polymorphic nature of G4 structures thus is key to unravel their biological functions and make them amenable as molecular targets in novel therapeutic approaches. We here review recent experimental approaches to monitor G4 folding and discuss structural aspects for possible folding pathways. Substantial progress in the understanding of G4 folding within the recent years now allows drawing comprehensive models of the complex folding energy landscape of G4s that we herein evaluate based on computational and experimental evidence.
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Affiliation(s)
- J Tassilo Grün
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Harald Schwalbe
- Institute for Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe-University, Frankfurt/M, Germany.,Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Frankfurt/M, Germany
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14
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Ravichandran S, Razzaq M, Parveen N, Ghosh A, Kim KK. The effect of hairpin loop on the structure and gene expression activity of the long-loop G-quadruplex. Nucleic Acids Res 2021; 49:10689-10706. [PMID: 34450640 PMCID: PMC8501965 DOI: 10.1093/nar/gkab739] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 08/10/2021] [Accepted: 08/24/2021] [Indexed: 12/29/2022] Open
Abstract
G-quadruplex (G4), a four-stranded DNA or RNA structure containing stacks of guanine tetrads, plays regulatory roles in many cellular functions. So far, conventional G4s containing loops of 1–7 nucleotides have been widely studied. Increasing experimental evidence suggests that unconventional G4s, such as G4s containing long loops (long-loop G4s), play a regulatory role in the genome by forming a stable structure. Other secondary structures such as hairpins in the loop might thus contribute to the stability of long-loop G4s. Therefore, investigation of the effect of the hairpin-loops on the structure and function of G4s is required. In this study, we performed a systematic biochemical investigation of model G4s containing long loops with various sizes and structures. We found that the long-loop G4s are less stable than conventional G4s, but their stability increased when the loop forms a hairpin (hairpin-G4). We also verified the biological significance of hairpin-G4s by showing that hairpin-G4s present in the genome also form stable G4s and regulate gene expression as confirmed by in cellulo reporter assays. This study contributes to expanding the scope and diversity of G4s, thus facilitating future studies on the role of G4s in the human genome.
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Affiliation(s)
- Subramaniyam Ravichandran
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon 16419, Republic of Korea
| | - Maria Razzaq
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon 16419, Republic of Korea
| | - Nazia Parveen
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon 16419, Republic of Korea
| | - Ambarnil Ghosh
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon 16419, Republic of Korea
| | - Kyeong Kyu Kim
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon 16419, Republic of Korea
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15
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Jana J, Weisz K. Thermodynamic Stability of G-Quadruplexes: Impact of Sequence and Environment. Chembiochem 2021; 22:2848-2856. [PMID: 33844423 PMCID: PMC8518667 DOI: 10.1002/cbic.202100127] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 04/09/2021] [Indexed: 12/19/2022]
Abstract
G-quadruplexes have attracted growing interest in recent years due to their occurrence in vivo and their possible biological functions. In addition to being promising targets for drug design, these four-stranded nucleic acid structures have also been recognized as versatile tools for various technological applications. Whereas a large number of studies have yielded insight into their remarkable structural diversity, our current knowledge on G-quadruplex stabilities as a function of sequence and environmental factors only gradually emerges with an expanding collection of thermodynamic data. This minireview provides an overview of general rules that may be used to better evaluate quadruplex thermodynamic stabilities but also discusses present challenges in predicting most stable folds for a given sequence and environment.
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Affiliation(s)
- Jagannath Jana
- Institute of BiochemistryUniversität GreifswaldFelix-Hausdorff Str. 417489GreifswaldGermany
| | - Klaus Weisz
- Institute of BiochemistryUniversität GreifswaldFelix-Hausdorff Str. 417489GreifswaldGermany
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16
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Gudanis D, Zielińska K, Baranowski D, Kierzek R, Kozłowski P, Gdaniec Z. Impact of a Single Nucleotide Change or Non-Nucleoside Modifications in G-Rich Region on the Quadruplex-Duplex Hybrid Formation. Biomolecules 2021; 11:biom11081236. [PMID: 34439902 PMCID: PMC8392043 DOI: 10.3390/biom11081236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 08/13/2021] [Accepted: 08/15/2021] [Indexed: 12/02/2022] Open
Abstract
In this paper, a method to discriminate between two target RNA sequences that differ by one nucleotide only is presented. The method relies on the formation of alternative structures, i.e., quadruplex–duplex hybrid (QDH) and duplex with dangling ends (Dss), after hybridization of DNA or RNA G-rich oligonucleotides with target sequences containing 5′–GGGCUGG–3′ or 5′–GGGCGGG–3′ fragments. Using biophysical methods, we studied the effect of oligonucleotide types (DNA, RNA), non-nucleotide modifications (aliphatic linkers or abasic), and covalently attached G4 ligand on the ability of G-rich oligonucleotides to assemble a G-quadruplex motif. We demonstrated that all examined non-nucleotide modifications could mimic the external loops in the G-quadruplex domain of QDH structures without affecting their stability. Additionally, some modifications, in particular the presence of two abasic residues in the G-rich oligonucleotide, can induce the formation of non-canonical QDH instead of the Dss structure upon hybridization to a target sequence containing the GGGCUGG motif. Our results offer new insight into the sequential requirements for the formation of G-quadruplexes and provide important data on the effects of non-nucleotide modifications on G-quadruplex formation.
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Affiliation(s)
- Dorota Gudanis
- Correspondence: (D.G.); (Z.G.); Tel.: +48-61-852-85-03 (ext. 1286) (D.G.)
| | | | | | | | | | - Zofia Gdaniec
- Correspondence: (D.G.); (Z.G.); Tel.: +48-61-852-85-03 (ext. 1286) (D.G.)
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17
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Jin M, Li J, Chen Y, Zhao J, Zhang J, Zhang Z, Du P, Zhang L, Lu X. Near-Infrared Small Molecule as a Specific Fluorescent Probe for Ultrasensitive Recognition of Antiparallel Human Telomere G-Quadruplexes. ACS APPLIED MATERIALS & INTERFACES 2021; 13:32743-32752. [PMID: 34228441 DOI: 10.1021/acsami.1c07101] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In the past 10 years, many fluorescent probes have been developed to recognize G-quadruplexes (G4s) since G4s play an important role in biological systems. However, the selectivity and sensitivity of existing probes for G4s limit their further applications. Herein, we design and synthesize a new probe (TOVJ) by introducing 9-vinyljulolidine into TO. The new probe exhibits almost no fluorescence in an aqueous solution. Upon interacting with G4s, especially the antiparallel G4s, the fluorescence intensity was greatly enhanced (maximum 2742-fold) with a large Stokes shift of 198 nm and the maximum emission peak at 694 nm (near-infrared region). TOVJ showed high sensitivity and selectivity to G4s over other DNA topologies (ssDNA/dsDNA), especially to antiparallel G4s. For antiparallel human telomere G4 detection, the limits of detection of Hum24 and 22AG Na+ were as low as 164 and 231 pM, respectively. This indicates that TOVJ is a highly sensitive fluorescence sensor that can be effectively used for antiparallel human telomere G4 detection. The result of live-cell imaging showed that TOVJ could enter live cells and locate in the mitochondria.
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Affiliation(s)
- Ming Jin
- Tianjin Key Laboratory of Molecular Optoelectronic, Department of Chemistry, Tianjin University, Tianjin 300072, People's Republic of China
| | - Jing Li
- Tianjin Key Laboratory of Molecular Optoelectronic, Department of Chemistry, Tianjin University, Tianjin 300072, People's Republic of China
| | - Yang Chen
- Tianjin Key Laboratory of Molecular Optoelectronic, Department of Chemistry, Tianjin University, Tianjin 300072, People's Republic of China
| | - Jie Zhao
- Tianjin Key Laboratory of Molecular Optoelectronic, Department of Chemistry, Tianjin University, Tianjin 300072, People's Republic of China
| | - Jiahui Zhang
- Tianjin Key Laboratory of Molecular Optoelectronic, Department of Chemistry, Tianjin University, Tianjin 300072, People's Republic of China
| | - Zhen Zhang
- Tianjin Key Laboratory of Molecular Optoelectronic, Department of Chemistry, Tianjin University, Tianjin 300072, People's Republic of China
| | - Peiyao Du
- Tianjin Key Laboratory of Molecular Optoelectronic, Department of Chemistry, Tianjin University, Tianjin 300072, People's Republic of China
| | - Libing Zhang
- Tianjin Key Laboratory of Molecular Optoelectronic, Department of Chemistry, Tianjin University, Tianjin 300072, People's Republic of China
| | - Xiaoquan Lu
- Key Laboratory of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, People's Republic of China
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18
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Abstract
The RNA world hypothesis relies on the double-helix complementarity principle for both replication and catalytic activity of RNA. However, the de novo appearance of the complementarity rules, without previous evolution steps, is doubtful. Another major problem of the RNA world is its isolated nature, making it almost impossible to accommodate the genetic code and transform it into modern biochemistry. These and many other unanswered questions of the RNA world led to suggestions that some simpler molecules must have preceded RNA. Most of these alternative hypotheses proposed the double-helical polymers with different backbones but used the same complementarity principle. The current paper describes a fundamentally different idea: the de novo appearance of a nucleic acid polymer without any preexisting rules or requirements. This approach, coined as the quadruplex world hypothesis, is based on (i) the ability of guanines to form stable G-tetrads that facilitate polymerization; and (ii) the unique property of polyguanines to fold into a monomolecular tetrahelix with a strictly defined building pattern and tertiary structure. The tetrahelix is capable of high-affinity intermolecular interactions and catalytic activities. The quadruplex world hypothesis has the potential to address almost all the shortcomings of the RNA world.
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Affiliation(s)
- Besik Kankia
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, 43210, USA. .,Institute of Biophysics, Ilia State University, Tbilisi, 0162, Republic of Georgia.
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19
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Harpster C, Boyle E, Musier-Forsyth K, Kankia B. HIV-1 genomic RNA U3 region forms a stable quadruplex-hairpin structure. Biophys Chem 2021; 272:106567. [PMID: 33713997 PMCID: PMC8051326 DOI: 10.1016/j.bpc.2021.106567] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/22/2021] [Accepted: 02/28/2021] [Indexed: 01/14/2023]
Abstract
The U3 promoter region of the HIV-1 long terminal repeat (LTR) has previously been shown to fold into a series of dynamic G-quadruplex structures. Among the G-quadruplexes identified in the LTR sequence, LTR-III was shown to be the most stable in vitro. NMR studies of this 28-nucleotide (nt) DNA revealed a unique quadruplex-hairpin structure. Whether the hairpin forms in RNA element is unknown and the role of the hairpin in the structure and stability of quadruplexes has not been characterized. Here, we used optical and thermodynamic studies to address these questions. The wild-type LTR-III RNA formed a monomolecular quadruplex with a parallel topology using only propeller loops, including the hairpin loop element. By comparison to the WT and variant RNAs, LTR-III DNA structures were more heterogeneous and less stable. Increased stability of the RNA suggests that the RNA quadruplex-hairpin structure may be a more attractive therapeutic target than the analogous DNA element.
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Affiliation(s)
- Chelsea Harpster
- Department of Chemistry and Biochemistry, Center for Retroviral Research and Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Elaina Boyle
- Department of Chemistry and Biochemistry, Center for Retroviral Research and Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Karin Musier-Forsyth
- Department of Chemistry and Biochemistry, Center for Retroviral Research and Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Besik Kankia
- Department of Chemistry and Biochemistry, Center for Retroviral Research and Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA.
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20
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Lejault P, Mitteaux J, Sperti FR, Monchaud D. How to untie G-quadruplex knots and why? Cell Chem Biol 2021; 28:436-455. [PMID: 33596431 DOI: 10.1016/j.chembiol.2021.01.015] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 12/08/2020] [Accepted: 01/20/2021] [Indexed: 12/12/2022]
Abstract
For over two decades, the prime objective of the chemical biology community studying G-quadruplexes (G4s) has been to use chemicals to interact with and stabilize G4s in cells to obtain mechanistic interpretations. This strategy has been undoubtedly successful, as demonstrated by recent advances. However, these insights have also led to a fundamental rethinking of G4-targeting strategies: due to the prevalence of G4s in the human genome, transcriptome, and ncRNAome (collectively referred to as the G4ome), and their involvement in human diseases, should we continue developing G4-stabilizing ligands or should we invest in designing molecular tools to unfold G4s? Here, we first focus on how, when, and where G4s fold in cells; then, we describe the enzymatic systems that have evolved to counteract G4 folding and how they have been used as tools to manipulate G4s in cells; finally, we present strategies currently being implemented to devise new molecular G4 unwinding agents.
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Affiliation(s)
- Pauline Lejault
- Institut de Chimie Moléculaire de l'Université de Bourgogne, ICMUB CNRS UMR 6302, UBFC Dijon, France
| | - Jérémie Mitteaux
- Institut de Chimie Moléculaire de l'Université de Bourgogne, ICMUB CNRS UMR 6302, UBFC Dijon, France
| | - Francesco Rota Sperti
- Institut de Chimie Moléculaire de l'Université de Bourgogne, ICMUB CNRS UMR 6302, UBFC Dijon, France
| | - David Monchaud
- Institut de Chimie Moléculaire de l'Université de Bourgogne, ICMUB CNRS UMR 6302, UBFC Dijon, France.
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21
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Katrivas L, Fardian-Melamed N, Rotem D, Porath D, Kotlyar A. Formation of Novel Octuplex DNA Molecules from Guanine Quadruplexes. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2006932. [PMID: 33475220 DOI: 10.1002/adma.202006932] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 12/14/2020] [Indexed: 06/12/2023]
Abstract
Guanine quadruplex (G4)-DNA structures have sparked the interest of many scientists due to their important biological roles and their potential use in molecular nanoelectronics and nanotechnology. The high guanine content in G4-DNA endows it with mechanical stability, robustness, and improved charge transport properties-attractive attributes for a molecular nanowire. The self-driven formation of a novel G4-DNA-based nanostructure, coined guanine octuplex (G8)-DNA, is reported herein. Atomic force microscopy and scanning tunneling microscopy characterization of this molecule reveal its organized coiled-coil structure, which is found to be stable under different temperatures and surrounding conditions. G8-DNA exhibits enhanced stiffness, mechanical and thermodynamic stability when compared to its parent G4-DNA. These, along with its high guanine content, make G8-DNA a compelling new molecule, and a highly prospective candidate for molecular nanoelectronics.
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Affiliation(s)
- Liat Katrivas
- Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences, and, The Center of Nanoscience and Nanotechnology, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978, Israel
| | - Natalie Fardian-Melamed
- Institute of Chemistry and The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel
| | - Dvir Rotem
- Institute of Chemistry and The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel
| | - Danny Porath
- Institute of Chemistry and The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel
| | - Alexander Kotlyar
- Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences, and, The Center of Nanoscience and Nanotechnology, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978, Israel
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22
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Kankia B. Quadruplex-Templated and Catalyzed Ligation of Nucleic Acids. Chembiochem 2020; 22:1261-1267. [PMID: 33217115 DOI: 10.1002/cbic.202000754] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 11/19/2020] [Indexed: 11/05/2022]
Abstract
Template-guided chemical reactions between nucleic acid strands are an important process in biomedical research. However, almost all of these reactions employ an oligonucleotide-templated approach that is based on the double-helix alignment. The moderate stability of the double helix makes this approach unsuitable for many chemical reactions, so alternative nucleic acid alignment mechanisms, demonstrating higher thermal and chemical stability, are desirable. Earlier, we described a noncovalent coupling mechanism between DNA strands through a quadruplex-and-Mg2+ connection (QMC). QMC is based on G-quadruplexes and allows unusually stable and specific interactions. Herein, a novel catalytic nucleic acid reaction, based on QMC, is described. This approach uses G-tetrads as a structural and recognition element without employing Watson-Crick complementarity rules at any stage of substrate/catalyst formation or interaction between them. Quadruplex-templated ligation can be achieved through the self-ligation of two nucleic acid strands, or through a quadruplex catalyst, which forms a G-triplex and specifically connects the strands. The process is extraordinarily robust and efficient. For instance, the ligation of carbodiimide-activated substrates can proceed in boiling solutions, and complete ligation is demonstrated within a minute. The quadruplex-templated and catalyzed reactions will create new opportunities for chemical reactions requiring harsh experimental conditions.
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Affiliation(s)
- Besik Kankia
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
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23
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Gudanis D, Kaniowski D, Kulik K, Baranowski D, Gdaniec Z, Nawrot B. Formation of an RNA Quadruplex-Duplex Hybrid in Living Cells between mRNA of the Epidermal Growth Factor Receptor (EGFR) and a G-Rich Antisense Oligoribonucleotide. Cells 2020; 9:cells9112375. [PMID: 33138194 PMCID: PMC7692301 DOI: 10.3390/cells9112375] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/23/2020] [Accepted: 10/26/2020] [Indexed: 02/07/2023] Open
Abstract
Antisense DNA oligonucleotides, short interfering RNAs (siRNAs), and CRISPR/Cas9 genetic tools are the most useful therapeutic nucleic acids regulating gene expression based on the antisense specificity towards messenger RNA. Here, we present an effective novel strategy for inhibiting translation based on the antisense-controlled formation of an RNA quadruplex-duplex hybrid (QDH) between a G-rich RNA antisense oligoribonucleotide (Q-ASO) and specific mRNA, comprising two distant G-tracts. We selected epidermal growth factor receptor (EGFR) as a well-established target protein in anticancer therapy. The chemically modified, bi-functional anti-EGFR Q-ASO and a 56-nt long EGFR mRNA fragment, in the presence of potassium ions, were shown to form in vitro very stable parallel G-quadruplex containing a 28-nt long external loop folding to two duplex-stem structure. Besides, the Q-ASOs effectively reduced EGFR mRNA levels compared to the non-modified RNA and DNA antisense oligonucleotides (rASO, dASO). In addition, the hybridization specificity of Q-ASO comprising a covalently attached fluorescent tag was confirmed in living cells by visualization of the G4 green fluorescent species in the presence of other antisense inhibitors under competitive conditions. The results presented here offer novel insights into the potential application of Q-ASOs for the detection and/or alteration of (patho)biological processes through RNA:RNA quadruplex-duplex formation in cellular systems.
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Affiliation(s)
- Dorota Gudanis
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Poland; (D.B.); (Z.G.)
- Correspondence: ; Tel.: +48-61-852-85-03 (ext. 1286)
| | - Damian Kaniowski
- Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, 90-363 Lodz, Poland; (D.K.); (K.K.); (B.N.)
| | - Katarzyna Kulik
- Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, 90-363 Lodz, Poland; (D.K.); (K.K.); (B.N.)
| | - Daniel Baranowski
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Poland; (D.B.); (Z.G.)
| | - Zofia Gdaniec
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Poland; (D.B.); (Z.G.)
| | - Barbara Nawrot
- Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, 90-363 Lodz, Poland; (D.K.); (K.K.); (B.N.)
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24
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Chalikian TV, Liu L, Macgregor RB. Duplex-tetraplex equilibria in guanine- and cytosine-rich DNA. Biophys Chem 2020; 267:106473. [PMID: 33031980 DOI: 10.1016/j.bpc.2020.106473] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 09/03/2020] [Indexed: 02/07/2023]
Abstract
Noncanonical four-stranded DNA structures, including G-quadruplexes and i-motifs, have been discovered in the cell and are implicated in a variety of genomic regulatory functions. The tendency of a specific guanine- and cytosine-rich region of genomic DNA to adopt a four-stranded conformation depends on its ability to overcome the constraints of duplex base-pairing by undergoing consecutive duplex-to-coil and coil-to-tetraplex transitions. The latter ability is determined by the balance between the free energies of participating ordered and disordered structures. In this review, we present an overview of the literature on the stability of G-quadruplex and i-motif structures and discuss the extent of duplex-tetraplex competition as a function of the sequence context of the DNA and environmental conditions including temperature, pH, salt, molecular crowding, and the presence of G-quadruplex-binding ligands. We outline how the results of in vitro studies can be expanded to understanding duplex-tetraplex equilibria in vivo.
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Affiliation(s)
- Tigran V Chalikian
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Toronto, Ontario M5S 3M2, Canada.
| | - Lutan Liu
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Toronto, Ontario M5S 3M2, Canada
| | - Robert B Macgregor
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Toronto, Ontario M5S 3M2, Canada
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25
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Prasad B, Das RN, Jamroskovic J, Kumar R, Hedenström M, Sabouri N, Chorell E. The Relation Between Position and Chemical Composition of Bis-Indole Substituents Determines Their Interactions with G-Quadruplex DNA. Chemistry 2020; 26:9561-9572. [PMID: 32187406 PMCID: PMC7497243 DOI: 10.1002/chem.202000579] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 03/16/2020] [Indexed: 01/20/2023]
Abstract
G-quadruplex (G4) DNA structures are linked to fundamental biological processes and human diseases, which has triggered the development of compounds that affect these DNA structures. However, more knowledge is needed about how small molecules interact with G4 DNA structures. This study describes the development of a new class of bis-indoles (3,3-diindolyl-methyl derivatives) and detailed studies of how they interact with G4 DNA using orthogonal assays, biophysical techniques, and computational studies. This revealed compounds that strongly bind and stabilize G4 DNA structures, and detailed binding interactions which for example, show that charge variance can play a key role in G4 DNA binding. Furthermore, the structure-activity relationships generated opened the possibilities to replace or introduce new substituents on the core structure, which is of key importance to optimize compound properties or introduce probes to further expand the possibilities of these compounds as tailored research tools to study G4 biology.
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Affiliation(s)
| | | | - Jan Jamroskovic
- Department of Medical Biochemistry and BiophysicsUmeå University90187UmeåSweden
| | | | | | - Nasim Sabouri
- Department of Medical Biochemistry and BiophysicsUmeå University90187UmeåSweden
| | - Erik Chorell
- Department of ChemistryUmeå University90187UmeåSweden
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26
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Odermatt DC, Lee WTC, Wild S, Jozwiakowski SK, Rothenberg E, Gari K. Cancer-associated mutations in the iron-sulfur domain of FANCJ affect G-quadruplex metabolism. PLoS Genet 2020; 16:e1008740. [PMID: 32542039 PMCID: PMC7316351 DOI: 10.1371/journal.pgen.1008740] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 06/25/2020] [Accepted: 03/25/2020] [Indexed: 11/19/2022] Open
Abstract
FANCJ/BRIP1 is an iron-sulfur (FeS) cluster-binding DNA helicase involved in DNA inter-strand cross-link (ICL) repair and G-quadruplex (G4) metabolism. Mutations in FANCJ are associated with Fanconi anemia and an increased risk for developing breast and ovarian cancer. Several cancer-associated mutations are located in the FeS domain of FANCJ, but how they affect FeS cluster binding and/or FANCJ activity has remained mostly unclear. Here we show that the FeS cluster is indispensable for FANCJ's ability to unwind DNA substrates in vitro and to provide cellular resistance to agents that induce ICLs. Moreover, we find that FANCJ requires an intact FeS cluster for its ability to unfold G4 structures on the DNA template in a primer extension assay with the lagging-strand DNA polymerase delta. Surprisingly, however, FANCJ variants that are unable to bind an FeS cluster and to unwind DNA in vitro can partially suppress the formation of replisome-associated G4 structures that we observe in a FANCJ knock-out cell line. This may suggest a partially retained cellular activity of FANCJ variants with alterations in the FeS domain. On the other hand, FANCJ knock-out cells expressing FeS cluster-deficient variants display a similar-enhanced-sensitivity towards pyridostatin (PDS) and CX-5461, two agents that stabilise G4 structures, as FANCJ knock-out cells. Mutations in FANCJ that abolish FeS cluster binding may hence be predictive of an increased cellular sensitivity towards G4-stabilising agents.
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Affiliation(s)
- Diana C. Odermatt
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Wei Ting C. Lee
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York, United States of America
| | - Sebastian Wild
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | | | - Eli Rothenberg
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York, United States of America
| | - Kerstin Gari
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
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27
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Effects of Length and Loop Composition on Structural Diversity and Similarity of (G 3TG 3N mG 3TG 3) G-Quadruplexes. Molecules 2020; 25:molecules25081779. [PMID: 32294984 PMCID: PMC7221631 DOI: 10.3390/molecules25081779] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 04/09/2020] [Accepted: 04/09/2020] [Indexed: 11/17/2022] Open
Abstract
A G-rich sequence containing three loops to connect four G-tracts with each ≥2 guanines can possibly form G-quadruplex structures. Given that all G-quadruplex structures comprise the stacking of G-quartets, the loop sequence plays a major role on their folding topology and thermal stability. Here circular dichroism, NMR, and PAGE are used to study the effect of loop length and base composition in the middle loop, and a single base difference in loop 1 and 3 on G-quadruplex formation of (G3HG3NmG3HG3) sequences with and without flanking nucleotides, where H is T, A, or C and N is T, A, C, or G. In addition, melting curve for G-quadruplex unfolding was used to provide relatively thermal stability of G-quadruplex structure after the addition of K+ overnight. We further studied the effects of K+ concentration on their stability and found structural changes in several sequences. Such (G3HG3NmG3HG3) configuration can be found in a number of native DNA sequences. The study of structural diversity and similarity from these sequences may allow us to establish the correlation between model sequences and native sequences. Moreover, several sequences upon interaction with a G-quadruplex ligand, BMVC, show similar spectral change, implying that structural similarity is crucial for drug development.
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28
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Puig Lombardi E, Holmes A, Verga D, Teulade-Fichou MP, Nicolas A, Londoño-Vallejo A. Thermodynamically stable and genetically unstable G-quadruplexes are depleted in genomes across species. Nucleic Acids Res 2020; 47:6098-6113. [PMID: 31114920 PMCID: PMC6614823 DOI: 10.1093/nar/gkz463] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 05/10/2019] [Accepted: 05/14/2019] [Indexed: 12/29/2022] Open
Abstract
G-quadruplexes play various roles in multiple biological processes, which can be positive when a G4 is involved in the regulation of gene expression or detrimental when the folding of a stable G4 impairs DNA replication promoting genome instability. This duality interrogates the significance of their presence within genomes. To address the potential biased evolution of G4 motifs, we analyzed their occurrence, features and polymorphisms in a large spectrum of species. We found extreme bias of the short-looped G4 motifs, which are the most thermodynamically stable in vitro and thus carry the highest folding potential in vivo. In the human genome, there is an over-representation of single-nucleotide-loop G4 motifs (G4-L1), which are highly conserved among humans and show a striking excess of the thermodynamically least stable G4-L1A (G3AG3AG3AG3) sequences. Functional assays in yeast showed that G4-L1A caused the lowest levels of both spontaneous and G4-ligand-induced instability. Analyses across 600 species revealed the depletion of the most stable G4-L1C/T quadruplexes in most genomes in favor of G4-L1A in vertebrates or G4-L1G in other eukaryotes. We discuss how these trends might be the result of species-specific mutagenic processes associated to a negative selection against the most stable motifs, thus neutralizing their detrimental effects on genome stability while preserving positive G4-associated biological roles.
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Affiliation(s)
| | - Allyson Holmes
- Institut Curie, PSL Research University, UMR3244 CNRS, 75005 Paris, France
| | - Daniela Verga
- Institut Curie, PSL Research University, Sorbonne Universités, UPMC, CNRS, Inserm, UMR9187/U1196, 91495 Orsay, France
| | - Marie-Paule Teulade-Fichou
- Institut Curie, PSL Research University, Sorbonne Universités, UPMC, CNRS, Inserm, UMR9187/U1196, 91495 Orsay, France
| | - Alain Nicolas
- Institut Curie, PSL Research University, UMR3244 CNRS, 75005 Paris, France
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29
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Takahashi S, Sugimoto N. Stability prediction of canonical and non-canonical structures of nucleic acids in various molecular environments and cells. Chem Soc Rev 2020; 49:8439-8468. [DOI: 10.1039/d0cs00594k] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This review provides the biophysicochemical background and recent advances in stability prediction of canonical and non-canonical structures of nucleic acids in various molecular environments and cells.
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Affiliation(s)
- Shuntaro Takahashi
- Frontier Institute for Biomolecular Engineering Research (FIBER)
- Konan University
- Kobe
- Japan
| | - Naoki Sugimoto
- Frontier Institute for Biomolecular Engineering Research (FIBER)
- Konan University
- Kobe
- Japan
- Graduate School of Frontiers of Innovative Research in Science and Technology (FIRST)
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30
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Lightfoot HL, Hagen T, Tatum NJ, Hall J. The diverse structural landscape of quadruplexes. FEBS Lett 2019; 593:2083-2102. [PMID: 31325371 DOI: 10.1002/1873-3468.13547] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Revised: 07/09/2019] [Accepted: 07/15/2019] [Indexed: 12/15/2022]
Abstract
G-quadruplexes are secondary structures formed in G-rich sequences in DNA and RNA. Considerable research over the past three decades has led to in-depth insight into these unusual structures in DNA. Since the more recent exploration into RNA G-quadruplexes, such structures have demonstrated their in cellulo existence, function and roles in pathology. In comparison to Watson-Crick-based secondary structures, most G-quadruplexes display highly redundant structural characteristics. However, numerous reports of G-quadruplex motifs/structures with unique features (e.g. bulges, long loops, vacancy) have recently surfaced, expanding the repertoire of G-quadruplex scaffolds. This review addresses G-quadruplex formation and structure, including recent reports of non-canonical G-quadruplex structures. Improved methods of detection will likely further expand this collection of novel structures and ultimately change the face of quadruplex-RNA targeting as a therapeutic strategy.
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Affiliation(s)
- Helen L Lightfoot
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, ETH Zurich, Switzerland
| | - Timo Hagen
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, ETH Zurich, Switzerland
| | - Natalie J Tatum
- Newcastle Cancer Centre, Northern Institute for Cancer Research, Medical School, Newcastle University, Newcastle upon Tyne, UK
| | - Jonathan Hall
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, ETH Zurich, Switzerland
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31
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Cheng M, Cheng Y, Hao J, Jia G, Zhou J, Mergny JL, Li C. Loop permutation affects the topology and stability of G-quadruplexes. Nucleic Acids Res 2019; 46:9264-9275. [PMID: 30184167 PMCID: PMC6182180 DOI: 10.1093/nar/gky757] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 08/21/2018] [Indexed: 12/14/2022] Open
Abstract
G-quadruplexes are unusual DNA and RNA secondary structures ubiquitous in a variety of organisms including vertebrates, plants, viruses and bacteria. The folding topology and stability of intramolecular G-quadruplexes are determined to a large extent by their loops. Loop permutation is defined as swapping two or three of these regions so that intramolecular G-quadruplexes only differ in the sequential order of their loops. Over the past two decades, both length and base composition of loops have been studied extensively, but a systematic study on the effect of loop permutation has been missing. In the present work, 99 sequences from 21 groups with different loop permutations were tested. To our surprise, both conformation and thermal stability are greatly dependent on loop permutation. Loop permutation actually matters as much as loop length and base composition on G-quadruplex folding, with effects on Tm as high as 17°C. Sequences containing a longer central loop have a high propensity to adopt a stable non-parallel topology. Conversely, sequences containing a short central loop tend to form a parallel topology of lower stability. In addition, over half of interrogated sequences were found in the genomes of diverse organisms, implicating their potential regulatory roles in the genome or as therapeutic targets. This study illustrates the structural roles of loops in G-quadruplex folding and should help to establish rules to predict the folding pattern and stability of G-quadruplexes.
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Affiliation(s)
- Mingpan Cheng
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.,University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China
| | - 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, No. 19A Yuquan Road, Beijing 100049, 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, No. 19A Yuquan Road, Beijing 100049, China
| | - Guoqing Jia
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Jun Zhou
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Jean-Louis Mergny
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.,ARNA Laboratory, Inserm U1212, CNRS UMR5320, IECB, Université de Bordeaux, Pessac 33607, France.,Institute of Biophysics of the CAS, v.v.i., Královopolská 135, 612 65 Brno, Czech Republic
| | - Can Li
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
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32
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Lages A, Proud CG, Holloway JW, Vorechovsky I. Thioflavin T Monitoring of Guanine Quadruplex Formation in the rs689-Dependent INS Intron 1. MOLECULAR THERAPY-NUCLEIC ACIDS 2019; 16:770-777. [PMID: 31150930 PMCID: PMC6539410 DOI: 10.1016/j.omtn.2019.04.026] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 04/27/2019] [Accepted: 04/27/2019] [Indexed: 12/21/2022]
Abstract
The human proinsulin gene (INS) contains a thymine-to-adenine variant (rs689) located in the 3′ splice site (3′ ss) recognition motif of the first intron. The adenine at rs689 is strongly associated with type 1 diabetes. By weakening the polypyrimidine tract, the adenine allele reduces the efficiency of intron 1 splicing, which can be ameliorated by antisense oligonucleotides blocking a splicing silencer located upstream of the 3′ ss. The silencer is surrounded by guanine-rich tracts that may form guanine quadruplexes (G4s) and modulate the accessibility of the silencer. Here, we employed thioflavin T (ThT) to monitor G4 formation in synthetic DNAs and RNAs derived from INS intron 1. We show that the antisense target is surrounded by ThT-positive segments in each direction, with oligoribonucleotides exhibiting consistently higher fluorescence than their DNA counterparts. The signal was reduced for ThT-positive oligonucleotides that were extended into the silencer, indicating that flanking G4s have a potential to mask target accessibility. Real-time monitoring of ThT fluorescence during INS transcription in vitro revealed a negative correlation with ex vivo splicing activities of corresponding INS constructs. Together, these results provide a better characterization of antisense targets in INS primary transcripts for restorative strategies designed to improve the INS splicing defect associated with type 1 diabetes.
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Affiliation(s)
- Ana Lages
- University of Southampton, Faculty of Medicine, Southampton SO16 6YD, UK
| | - Christopher G Proud
- University of Southampton, Faculty of Medicine, Southampton SO16 6YD, UK; Lifelong Health and Hopwood Centre for Neurobiology, South Australian Health and Medical Research Institute, Adelaide, SA 5000, Australia; School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - John W Holloway
- University of Southampton, Faculty of Medicine, Southampton SO16 6YD, UK
| | - Igor Vorechovsky
- University of Southampton, Faculty of Medicine, Southampton SO16 6YD, UK.
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33
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Beniaminov A, Shchyolkina A, Kaluzhny D. Conformational features of intramolecular G4-DNA constrained by single-nucleotide loops. Biochimie 2019; 160:122-128. [PMID: 30840852 DOI: 10.1016/j.biochi.2019.02.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 02/22/2019] [Indexed: 11/28/2022]
Abstract
Conformation of the telomeric DNA fragment dG3(TTAG3)3 depends on multiple factors including solution conditions, length, and the nucleotide sequence of the flanking regions. In potassium solution, this sequence tends to adopt hybrid (3 + 1) G-quadruplex (G4) Form 1 or Form 2 conformation contingent on the flanking nucleotides. Theoretically, other (3 + 1) G4 folds (beyond Forms 1 and 2) are not sterically forbidden, but are presumably energetically disfavored. We report here on the effect of substituting the TTA loop with a single T nucleotide for one, two, or three loops of telomeric DNA that allowed us to expand the conformational diversity of the G4 DNA. Circular dichroism, gel migration, and chemical probing with DMS and ZnP1 (a porphyrin derivative sensitive to G4 conformation) were applied to monitor conformations that occurred upon shortening each loop to a single nucleotide. We found that all oligonucleotide models formed an intramolecular quadruplex structure and that shortening the loops led to the prevalence of G4 with quartets of the same polarity. Despite similar CD signatures, each modified sequence had one of three specific patterns of light-induced oxidation with ZnP1. According to the predominant modification pattern, folding of each sequence could be assigned to one of three major G4 conformations: parallel and two different (3 + 1) G4 folds. We here provide novel experimental evidence of the propensity for modified telomeric sequences to form a (3 + 1) G4 conformer containing one lateral and two propeller loops.
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Affiliation(s)
- Artemy Beniaminov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991, Moscow, Russia
| | - Anna Shchyolkina
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991, Moscow, Russia
| | - Dmitry Kaluzhny
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991, Moscow, Russia.
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34
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Fleming AM, Nguyen NLB, Burrows CJ. Colocalization of m 6A and G-Quadruplex-Forming Sequences in Viral RNA (HIV, Zika, Hepatitis B, and SV40) Suggests Topological Control of Adenosine N 6-Methylation. ACS CENTRAL SCIENCE 2019; 5:218-228. [PMID: 30834310 PMCID: PMC6396389 DOI: 10.1021/acscentsci.8b00963] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Indexed: 05/09/2023]
Abstract
This Outlook calls attention to two seemingly disparate and emerging fields regarding viral genomics that may be correlated in a way previously overlooked. First, we describe identification of conserved potential G-quadruplex-forming sequences (PQSs) in viral genomes relevant to human health. Studies have demonstrated that PQSs are highly conserved and can fold to G-quadruplexes (G4s) to regulate viral processes. Key examples include G4s as a countermeasure to the host's immune system or G4-guided regulation of replication or transcription. Second, emerging data are discussed concerning the epitranscriptomic modification N 6-methyladenosine (m6A) in viral RNA installed by host proteins in a consensus sequence favoring 5'-GG(m6A)C-3'. The proposed pathways by which m6A is written, read, and erased in viral RNA genomes and the impact this has on viral replication are described. The structural reason why certain sites are selected for modification while others are not is still mysterious. Finally, we discuss our new observations regarding these previous sequencing data that identify m6A installation within the loops of two-tetrad PQSs in the RNA genomes of the Zika, HIV, hepatitis B, and SV40 viruses. We hypothesize that conserved viral PQSs can provide a framework (sequence and/or structural) for m6A installation. We also discuss literature sources suggesting that PQSs as sites of RNA modification could be a general phenomenon. We anticipate our observations will provide ample opportunities for exciting discoveries regarding the interplay between G4 structures and epitranscriptomic modifications of RNA.
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Affiliation(s)
- Aaron M. Fleming
- Department of Chemistry, University
of Utah, Salt Lake
City, Utah 84112-0850, United States
| | - Ngoc L. B. Nguyen
- Department of Chemistry, University
of Utah, Salt Lake
City, Utah 84112-0850, United States
| | - Cynthia J. Burrows
- Department of Chemistry, University
of Utah, Salt Lake
City, Utah 84112-0850, United States
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35
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Hadži S, Kocman V, Oblak D, Plavec J, Lah J. Energetic Basis of AGCGA-Rich DNA Folding into a Tetrahelical Structure. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201813502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- San Hadži
- Faculty of Chemistry and Chemical Technology; University of Ljubljana; Večna pot 113 Ljubljana Slovenia
| | - Vojč Kocman
- National Institute of Chemistry; Hajdrihova 19 Slovenia
| | - Domen Oblak
- Faculty of Chemistry and Chemical Technology; University of Ljubljana; Večna pot 113 Ljubljana Slovenia
| | - Janez Plavec
- Faculty of Chemistry and Chemical Technology; University of Ljubljana; Večna pot 113 Ljubljana Slovenia
- National Institute of Chemistry; Hajdrihova 19 Slovenia
| | - Jurij Lah
- Faculty of Chemistry and Chemical Technology; University of Ljubljana; Večna pot 113 Ljubljana Slovenia
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36
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Hadži S, Kocman V, Oblak D, Plavec J, Lah J. Energetic Basis of AGCGA‐Rich DNA Folding into a Tetrahelical Structure. Angew Chem Int Ed Engl 2019; 58:2387-2391. [DOI: 10.1002/anie.201813502] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Indexed: 11/09/2022]
Affiliation(s)
- San Hadži
- Faculty of Chemistry and Chemical TechnologyUniversity of Ljubljana Večna pot 113 Ljubljana Slovenia
| | - Vojč Kocman
- National Institute of Chemistry Hajdrihova 19 Slovenia
| | - Domen Oblak
- Faculty of Chemistry and Chemical TechnologyUniversity of Ljubljana Večna pot 113 Ljubljana Slovenia
| | - Janez Plavec
- Faculty of Chemistry and Chemical TechnologyUniversity of Ljubljana Večna pot 113 Ljubljana Slovenia
- National Institute of Chemistry Hajdrihova 19 Slovenia
| | - Jurij Lah
- Faculty of Chemistry and Chemical TechnologyUniversity of Ljubljana Večna pot 113 Ljubljana Slovenia
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37
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Kankia B. Stability Factors of the Parallel Quadruplexes: DNA Versus RNA. J Phys Chem B 2019; 123:1060-1067. [PMID: 30648871 DOI: 10.1021/acs.jpcb.8b11559] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
One of the most stable quadruplexes is formed by the G3T sequence (GGGTGGGTGGGTGGG) that folds into a parallel quadruplex with three G-tetrads and chain-reversal T-loops. For example, in 1 mM K+, it unfolds at 75 °C and at physiological conditions, it unfolds above 100 °C. The RNA analogue, ggguggguggguggg (g3u), which employs exactly same folding topology, demonstrates even higher thermal stability. Here, we performed melting experiments of G3T, g3u, and more than 30 chimeric constructs (G3T with RNA nucleotides at certain positions). Although the g3u quadruplex is 13 °C more stable than G3T, majority of G → g (DNA-for-RNA) substitutions destabilize G3T. Only three G → g and loop T → u substitutions stabilize the structure. However, stabilization effects of these six substitutions overcome destabilization of other nine G → g, resulting in higher stability of all-RNA g3u. The present work clearly indicates that the stacking interactions are more favorable in parallel DNA quadruplexes, whereas the chain-reversal loops play an important role in higher stability of RNA quadruplexes. In addition, we have shown that the 5'-end of RNA quadruplexes represents a more favorable target for stacking interactions than the 3'-end. Based on the current study, rational design of the quadruplexes for particular biotechnological applications and drugs, targeting the quadruplexes, may be envisaged.
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Affiliation(s)
- Besik Kankia
- Department of Chemistry and Biochemistry , The Ohio State University , Columbus , Ohio 43210 , United States.,Institute of Biophysics , Ilia State University , Tbilisi 0162 , Republic of Georgia
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38
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Varizhuk AM, Protopopova AD, Tsvetkov VB, Barinov NA, Podgorsky VV, Tankevich MV, Vlasenok MA, Severov VV, Smirnov IP, Dubrovin EV, Klinov DV, Pozmogova GE. Polymorphism of G4 associates: from stacks to wires via interlocks. Nucleic Acids Res 2018; 46:8978-8992. [PMID: 30107602 PMCID: PMC6158749 DOI: 10.1093/nar/gky729] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Revised: 07/30/2018] [Accepted: 07/31/2018] [Indexed: 01/16/2023] Open
Abstract
We examined the assembly of DNA G-quadruplexes (G4s) into higher-order structures using atomic force microscopy, optical and electrophoretic methods, NMR spectroscopy and molecular modeling. Our results suggest that parallel blunt-ended G4s with single-nucleotide or modified loops may form different types of multimers, ranging from stacks of intramolecular structures and/or interlocked dimers and trimers to wires. Decreasing the annealing rate and increasing salt or oligonucleotide concentrations shifted the equilibrium from intramolecular G4s to higher-order structures. Control antiparallel and hybrid G4s demonstrated no polymorphism or aggregation in our experiments. The modification that mimics abasic sites (1',2'-dideoxyribose residues) in loops enhanced the oligomerization/multimerization of both the 2-tetrad and 3-tetrad G4 motifs. Our results shed light on the rules that govern G4 rearrangements. Gaining control over G4 folding enables the harnessing of the full potential of such structures for guided assembly of supramolecular DNA structures for nanotechnology.
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Affiliation(s)
- Anna M Varizhuk
- Biophysics Department, Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow 119435, Russia
| | - Anna D Protopopova
- Biophysics Department, Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow 119435, Russia
| | - Vladimir B Tsvetkov
- Biophysics Department, Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow 119435, Russia
| | - Nikolay A Barinov
- Biophysics Department, Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow 119435, Russia
| | - Victor V Podgorsky
- Biophysics Department, Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow 119435, Russia
| | - Maria V Tankevich
- Biophysics Department, Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow 119435, Russia
| | - Maria A Vlasenok
- Biophysics Department, Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow 119435, Russia
| | - Vyacheslav V Severov
- Biophysics Department, Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow 119435, Russia
| | - Igor P Smirnov
- Biophysics Department, Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow 119435, Russia
| | - Evgeniy V Dubrovin
- Biophysics Department, Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow 119435, Russia
| | - Dmitry V Klinov
- Biophysics Department, Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow 119435, Russia
| | - Galina E Pozmogova
- Biophysics Department, Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow 119435, Russia
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39
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Jin M, Liu X, Zhang X, Wang L, Bing T, Zhang N, Zhang Y, Shangguan D. Thiazole Orange-Modified Carbon Dots for Ratiometric Fluorescence Detection of G-Quadruplex and Double-Stranded DNA. ACS APPLIED MATERIALS & INTERFACES 2018; 10:25166-25173. [PMID: 29979027 DOI: 10.1021/acsami.8b07869] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
A new carbon dot (CD)-based nanoprobe for the ratiometric fluorescence detection of DNA was constructed in this work. Thiazole orange (TO), a specific organic small molecular probe toward DNA, is covalently linked to the surface of CDs, acting as the recognition element and the fluorescence response unit. In the absence of DNA, the nanoprobe only emitted the blue fluorescence of CDs, whereas TO was almost nonfluorescent. Upon addition of DNA, a turn-on emission at 530 nm appeared and gradually enhanced along with the increasing of the target DNA, whereas the fluorescence of CDs was unchanged, which realized the ratiometric detection of the target DNA. The CD-TO nanoprobe showed good selectivity to parallel G-quadruplex (G4) and double-stranded (ds) DNA over antiparallel G4 and single-stranded DNA. Moreover, the ratiometric fluorescence nanoprobe exhibited high sensitivity for ssab (a dsDNA) and c-myc (a parallel G4) with a low detection limit of 0.90 and 3.31 nM, respectively. Additionally, the G4/hemin peroxidase activity inhibition experiment demonstrated that CD-TO bound to the G4s through the end-stacking mode.
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Affiliation(s)
- Ming Jin
- College of Chemistry and Chemical Engineering , Lanzhou University , Lanzhou 730000 , China
| | - Xiangjun Liu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry , Chinese Academy of Sciences , Beijing 100190 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Xin Zhang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry , Chinese Academy of Sciences , Beijing 100190 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Linlin Wang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry , Chinese Academy of Sciences , Beijing 100190 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Tao Bing
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry , Chinese Academy of Sciences , Beijing 100190 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Nan Zhang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry , Chinese Academy of Sciences , Beijing 100190 , China
| | - Yun Zhang
- College of Chemistry and Chemical Engineering , Lanzhou University , Lanzhou 730000 , China
| | - Dihua Shangguan
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry , Chinese Academy of Sciences , Beijing 100190 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
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40
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Kankia B. Monomolecular tetrahelix of polyguanine with a strictly defined folding pattern. Sci Rep 2018; 8:10115. [PMID: 29973629 PMCID: PMC6031693 DOI: 10.1038/s41598-018-28572-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 06/25/2018] [Indexed: 11/10/2022] Open
Abstract
The G3TG3TG3TG3 (G3T) sequence folds into a monomolecular quadruplex with all-parallel G3 segments connected to each other by chain-reversal loops. The homopolymer consisting of n number of G3T domains directly conjugated to each other folds into an uninterrupted and unusually stable polymer, tetrahelical monomolecular DNA (tmDNA). It was demonstrated that the tmDNA architecture has strong potential in nanotechnologies as highly programmable building material, high affinity coupler and the driving force for endergonic reactions. Here, we explore capability of analogous DNA sequences (i.e., monomolecular quadruplexes with G2 or G4 segments) to construct tmDNA architecture. The study demonstrates that tmDNA can have only one building pattern based on a quadruplex domain with three G-tetrads and single-nucleotide loops, G3N (N = G, A, C and T); all other domains demonstrate antiparallel topologies unsuitable for tmDNA. The present study also suggests that polyguanine is capable of tmDNA formation with strictly defined building pattern; G3 segments connected to each other by chain-reversal G-loops. These findings can have significant impact on (i) DNA nanotechnologies; (ii) structure prediction of G-rich sequences of genome; and (iii) modeling of abiogenesis.
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Affiliation(s)
- Besik Kankia
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, 43210, USA.
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41
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Tucker BA, Hudson JS, Ding L, Lewis E, Sheardy RD, Kharlampieva E, Graves D. Stability of the Na + Form of the Human Telomeric G-Quadruplex: Role of Adenines in Stabilizing G-Quadruplex Structure. ACS OMEGA 2018; 3:844-855. [PMID: 30023791 PMCID: PMC6045420 DOI: 10.1021/acsomega.7b01649] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 01/09/2018] [Indexed: 06/08/2023]
Abstract
G-quadruplexes are higher order DNA structures that play significant roles in gene transcription and telomeric maintenance. The formation and stability of the G-quadruplex structures are under thermodynamic control and may be of biological significance for regulatory function of cellular processes. Here, we report the structural influence and energetic contributions of the adenine bases in the loop sequences that flank G-repeats in human telomeric DNA sequence. Spectroscopic and calorimetric techniques are used to measure the thermal stability and thermodynamic contributions to the stability of human telomeric G-quadruplexes that have been designed with systematic changes of A to T throughout the telomeric sequence. These studies demonstrate that the thermal stability of the G-quadruplex structure is directly related to the number and position of the adenines that are present in the telomeric sequence. The melting temperature (Tm) was reduced from 59 °C for the wild-type sequence to 47 °C for the sequence where all four adenines were replaced with thymines (0123TTT). Furthermore, the enthalpy required for transitioning from the folded to unfolded G-quadruplex structure was reduced by 15 kcal/mol when the adenines were replaced with thymines (37 kcal/mol for the wild-type telomeric sequence reduced to 22 kcal/mol for the sequence where all four adenines were replaced with thymines (0123TTT)). The circular dichroism melting studies for G-quadruplex sequences having a single A to T change showed significantly sloping pretransition baselines and their differential scanning calorimetry (DSC) thermograms revealed biphasic melting profiles. In contrast, the deoxyoligonucleotides having sequences with two or more A to T changes did not exhibit sloping baselines or biphasic DSC thermograms. We attribute the biphasic unfolding profile and reduction in the enthalpy of unfolding to the energetic contributions of adenine hydrogen bonding within the loops as well as the adenine stacking to the G-tetrads of the G-quadruplex structure.
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Affiliation(s)
- Brenna A. Tucker
- Department
of Chemistry, Department of Biochemistry and Molecular Genetics, and Comprehensive
Cancer Center, University of Alabama at
Birmingham, Birmingham, Alabama 35294, United States
| | - Jason S. Hudson
- Department
of Chemistry, Department of Biochemistry and Molecular Genetics, and Comprehensive
Cancer Center, University of Alabama at
Birmingham, Birmingham, Alabama 35294, United States
| | - Lei Ding
- Department
of Chemistry, Department of Biochemistry and Molecular Genetics, and Comprehensive
Cancer Center, University of Alabama at
Birmingham, Birmingham, Alabama 35294, United States
| | - Edwin Lewis
- Department
of Chemistry, Mississippi State University, Mississippi, Mississippi
State 39762, United
States
| | - Richard D. Sheardy
- Department
of Chemistry & Biochemistry, Texas Women’s
University, Denton, Texas 782042, United States
| | - Eugenia Kharlampieva
- Department
of Chemistry, Department of Biochemistry and Molecular Genetics, and Comprehensive
Cancer Center, University of Alabama at
Birmingham, Birmingham, Alabama 35294, United States
| | - David Graves
- Department
of Chemistry, Department of Biochemistry and Molecular Genetics, and Comprehensive
Cancer Center, University of Alabama at
Birmingham, Birmingham, Alabama 35294, United States
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Lech CJ, Phan AT. Ball with hair: modular functionalization of highly stable G-quadruplex DNA nano-scaffolds through N2-guanine modification. Nucleic Acids Res 2017; 45:6265-6274. [PMID: 28499037 PMCID: PMC5499775 DOI: 10.1093/nar/gkx243] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 05/10/2017] [Indexed: 12/13/2022] Open
Abstract
Functionalized nanoparticles have seen valuable applications, particularly in the delivery of therapeutic and diagnostic agents in biological systems. However, the manufacturing of such nano-scale systems with the consistency required for biological application can be challenging, as variation in size and shape have large influences in nanoparticle behavior in vivo. We report on the development of a versatile nano-scaffold based on the modular functionalization of a DNA G-quadruplex. DNA sequences are functionalized in a modular fashion using well-established phosphoramidite chemical synthesis with nucleotides containing modification of the amino (N2) position of the guanine base. In physiological conditions, these sequences fold into well-defined G-quadruplex structures. The resulting DNA nano-scaffolds are thermally stable, consistent in size, and functionalized in a manner that allows for control over the density and relative orientation of functional chemistries on the nano-scaffold surface. Various chemistries including small modifications (N2-methyl-guanine), bulky aromatic modifications (N2-benzyl-guanine), and long chain-like modifications (N2-6-amino-hexyl-guanine) are tested and are found to be generally compatible with G-quadruplex formation. Furthermore, these modifications stabilize the G-quadruplex scaffold by 2.0–13.3 °C per modification in the melting temperature, with concurrent modifications producing extremely stable nano-scaffolds. We demonstrate the potential of this approach by functionalizing nano-scaffolds for use within the biotin–avidin conjugation approach.
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Affiliation(s)
- Christopher Jacques Lech
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371
| | - Anh Tuân Phan
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371
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43
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Sagi J. In What Ways Do Synthetic Nucleotides and Natural Base Lesions Alter the Structural Stability of G-Quadruplex Nucleic Acids? J Nucleic Acids 2017; 2017:1641845. [PMID: 29181193 PMCID: PMC5664352 DOI: 10.1155/2017/1641845] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 08/15/2017] [Indexed: 01/03/2023] Open
Abstract
Synthetic analogs of natural nucleotides have long been utilized for structural studies of canonical and noncanonical nucleic acids, including the extensively investigated polymorphic G-quadruplexes (GQs). Dependence on the sequence and nucleotide modifications of the folding landscape of GQs has been reviewed by several recent studies. Here, an overview is compiled on the thermodynamic stability of the modified GQ folds and on how the stereochemical preferences of more than 70 synthetic and natural derivatives of nucleotides substituting for natural ones determine the stability as well as the conformation. Groups of nucleotide analogs only stabilize or only destabilize the GQ, while the majority of analogs alter the GQ stability in both ways. This depends on the preferred syn or anti N-glycosidic linkage of the modified building blocks, the position of substitution, and the folding architecture of the native GQ. Natural base lesions and epigenetic modifications of GQs explored so far also stabilize or destabilize the GQ assemblies. Learning the effect of synthetic nucleotide analogs on the stability of GQs can assist in engineering a required stable GQ topology, and exploring the in vitro action of the single and clustered natural base damage on GQ architectures may provide indications for the cellular events.
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Affiliation(s)
- Janos Sagi
- Rimstone Laboratory, RLI, Carlsbad, CA 92010, USA
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44
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Relations between the loop transposition of DNA G-quadruplex and the catalytic function of DNAzyme. Biochim Biophys Acta Gen Subj 2017; 1861:1913-1920. [PMID: 28533132 DOI: 10.1016/j.bbagen.2017.05.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 04/26/2017] [Accepted: 05/18/2017] [Indexed: 01/11/2023]
Abstract
The structures of DNA G-quadruplexes are essential for their functions in vivo and in vitro. Our present study revealed that sequential order of the three G-quadruplex loops, that is, loop transposition, could be a critical factor to determinate the G-quadruplex conformation and consequently improved the catalytic function of G-quadruplex based DNAzyme. In the presence of 100mM K+, loop transposition induced one of the G-quadruplex isomers which shared identical loops but differed in the sequential order of loops into a hybrid topology while the others into predominately parallel topologies. 1D NMR spectroscopy and mutation analysis suggested that the hydrogen bonding from loops residues with nucleotides in flanking sequences may be responsible for the stabilization of the different conformations. A well-known DNAzyme consisting of G-quadruplex and hemin (Ferriprotoporphyrin IX chloride) was chosen to test the catalytic function. We found that the loop transposition could enhance the reaction rate obviously by increasing the hemin binding affinity to G-quadruplex. These findings disclose the relations between the loop transposition, G-quadruplex conformation and catalytic function of DNAzyme.
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45
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Šponer J, Bussi G, Stadlbauer P, Kührová P, Banáš P, Islam B, Haider S, Neidle S, Otyepka M. Folding of guanine quadruplex molecules-funnel-like mechanism or kinetic partitioning? An overview from MD simulation studies. Biochim Biophys Acta Gen Subj 2016; 1861:1246-1263. [PMID: 27979677 DOI: 10.1016/j.bbagen.2016.12.008] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 12/04/2016] [Accepted: 12/11/2016] [Indexed: 01/18/2023]
Abstract
BACKGROUND Guanine quadruplexes (GQs) play vital roles in many cellular processes and are of much interest as drug targets. In contrast to the availability of many structural studies, there is still limited knowledge on GQ folding. SCOPE OF REVIEW We review recent molecular dynamics (MD) simulation studies of the folding of GQs, with an emphasis paid to the human telomeric DNA GQ. We explain the basic principles and limitations of all types of MD methods used to study unfolding and folding in a way accessible to non-specialists. We discuss the potential role of G-hairpin, G-triplex and alternative GQ intermediates in the folding process. We argue that, in general, folding of GQs is fundamentally different from funneled folding of small fast-folding proteins, and can be best described by a kinetic partitioning (KP) mechanism. KP is a competition between at least two (but often many) well-separated and structurally different conformational ensembles. MAJOR CONCLUSIONS The KP mechanism is the only plausible way to explain experiments reporting long time-scales of GQ folding and the existence of long-lived sub-states. A significant part of the natural partitioning of the free energy landscape of GQs comes from the ability of the GQ-forming sequences to populate a large number of syn-anti patterns in their G-tracts. The extreme complexity of the KP of GQs typically prevents an appropriate description of the folding landscape using just a few order parameters or collective variables. GENERAL SIGNIFICANCE We reconcile available computational and experimental studies of GQ folding and formulate basic principles characterizing GQ folding landscapes. This article is part of a Special Issue entitled "G-quadruplex" Guest Editor: Dr. Concetta Giancola and Dr. Daniela Montesarchio.
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Affiliation(s)
- Jiří Šponer
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno, Czech Republic; Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, 17. listopadu 12, 771 46 Olomouc, Czech Republic.
| | - Giovanni Bussi
- Scuola Internazionale Superiore di Studi Avanzati, Via Bonomea 265, 34136 Trieste, Italy
| | - Petr Stadlbauer
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno, Czech Republic; Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, 17. listopadu 12, 771 46 Olomouc, Czech Republic
| | - Petra Kührová
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, 17. listopadu 12, 771 46 Olomouc, Czech Republic
| | - Pavel Banáš
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, 17. listopadu 12, 771 46 Olomouc, Czech Republic
| | - Barira Islam
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, 612 65 Brno, Czech Republic
| | - Shozeb Haider
- UCL School of Pharmacy, 29-39 Brunswick Square, London WC1N 1AX, UK
| | - Stephen Neidle
- UCL School of Pharmacy, 29-39 Brunswick Square, London WC1N 1AX, UK
| | - Michal Otyepka
- Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, 17. listopadu 12, 771 46 Olomouc, Czech Republic
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Bhattacharyya D, Mirihana Arachchilage G, Basu S. Metal Cations in G-Quadruplex Folding and Stability. Front Chem 2016; 4:38. [PMID: 27668212 PMCID: PMC5016522 DOI: 10.3389/fchem.2016.00038] [Citation(s) in RCA: 364] [Impact Index Per Article: 45.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 08/25/2016] [Indexed: 12/23/2022] Open
Abstract
This review is focused on the structural and physicochemical aspects of metal cation coordination to G-Quadruplexes (GQ) and their effects on GQ stability and conformation. G-quadruplex structures are non-canonical secondary structures formed by both DNA and RNA. G-quadruplexes regulate a wide range of important biochemical processes. Besides the sequence requirements, the coordination of monovalent cations in the GQ is essential for its formation and determines the stability and polymorphism of GQ structures. The nature, location, and dynamics of the cation coordination and their impact on the overall GQ stability are dependent on several factors such as the ionic radii, hydration energy, and the bonding strength to the O6 of guanines. The intracellular monovalent cation concentration and the localized ion concentrations determine the formation of GQs and can potentially dictate their regulatory roles. A wide range of biochemical and biophysical studies on an array of GQ enabling sequences have generated at a minimum the knowledge base that allows us to often predict the stability of GQs in the presence of the physiologically relevant metal ions, however, prediction of conformation of such GQs is still out of the realm.
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Affiliation(s)
| | | | - Soumitra Basu
- Department of Chemistry and Biochemistry, Kent State UniversityKent, OH, USA
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47
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Sheu SY, Huang CH, Zhou JK, Yang DY. Relative stability of G-quadruplex structures: Interactions between the human Bcl2 promoter region and derivatives of carbazole and diphenylamine. Biopolymers 2016; 101:1038-50. [PMID: 24723333 DOI: 10.1002/bip.22497] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 04/07/2014] [Accepted: 04/07/2014] [Indexed: 01/24/2023]
Abstract
The bcl2 promoter region forms a G-quadruplex structure, which is a crucial target for anticancer drug development. In this study, we provide theoretical predictions of the stability of different G-quadruplex folds of the 23-mer bcl2 promoter region and G-quadruplex ligand. We take into account the whole G-quadruplex structure, including bound-cations and solvent effects, in order to compute the ligand binding free energy using molecular dynamics simulation. Two series of the carbazole and diphenylamine derivatives are used to screen for the most potent drug in terms of stabilization. The energy analysis identifies the predominant energy components affecting the stability of the various different G-quadruplex folds. The energy associated with the stability of the G-quadruplex-K(+) structures obtained displays good correlation with experimental Tm measurements. We found that loop orientation has an intrinsic influence on G-quadruplex stability and that the basket structure is the most stable. Furthermore, parallel loops are the most effective drug binding site. Our studies also demonstrate that rigidity and planarity are the key structural elements of a drug that stabilizes the G-quadruplex structure. BMVC-4 is the most potential G-quadruplex ligand. This approach demonstrates significant promise and should benefit drug design.
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Affiliation(s)
- Sheh-Yi Sheu
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, 112, Taiwan; Institute of Biomedical informatics, National Yang-Ming University, Taipei, 112, Taiwan
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48
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Gogichaishvili S, Johnson J, Gvarjaladze D, Lomidze L, Kankia B. Isothermal amplification of DNA using quadruplex primers with fluorescent pteridine base analogue 3-methyl isoxanthopterin. Biopolymers 2016; 101:583-90. [PMID: 24122726 DOI: 10.1002/bip.22421] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 09/24/2013] [Indexed: 11/08/2022]
Abstract
We previously developed a method, known as quadruplex priming amplification (QPA), which greatly simplifies DNA amplification and quantification assays. QPA employs specific primers based on GGGTGGGTGGGTGGG (G3T) sequence, which upon polymerase elongation spontaneously dissociates from the target and folds into a stable quadruplex. Fluorescent nucleotide analogs, when incorporated into these primers, emit light upon quadruplex formation and permit simple, specific, and sensitive quantification without the attachment of probe molecules. Here, we studied optical [fluorescence and circular dichroism (CD)] and thermodynamic properties of the G3T sequence and variants incorporating 3-methylisoxanthopterin (3MI), a highly fluorescent nucleotide analog suitable for QPA. CD studies demonstrate that the incorporation of 3MI does not change the overall tertiary structure of G3T; however, thermal unfolding experiments revealed that it significantly destabilizes the quadruplex. Enzymatic studies revealed that Taq and Bst are practically unable to incorporate any nucleotides opposite to template 3MI. Based on this knowledge, we designed QPA assays with truncated targets that demonstrate efficient amplification around 55°C. Overall, these studies suggest that 3MI-based QPA is a useful assay for DNA amplification and detection.
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Affiliation(s)
- Shota Gogichaishvili
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, 43210; Andronikashvili Institute of Physics, Tbilisi, 0177, Republic of Georgia
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Fujii T, Sugimoto N. Loop nucleotides impact the stability of intrastrand i-motif structures at neutral pH. Phys Chem Chem Phys 2016; 17:16719-22. [PMID: 26058487 DOI: 10.1039/c5cp02794b] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The stability of i-motif structures at neutral pH is of interest due to the potential of these structures to impact gene expression. A systematic investigation of loop sequence and length revealed that certain loop nucleobases stabilize i-motif quadruplexes.
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Affiliation(s)
- Taiga Fujii
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 8-9-1 Minatojima-minamimachi, Chuo-ku, Kobe 650-0047, Japan.
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50
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Russo Krauss I, Ramaswamy S, Neidle S, Haider S, Parkinson GN. Structural Insights into the Quadruplex-Duplex 3' Interface Formed from a Telomeric Repeat: A Potential Molecular Target. J Am Chem Soc 2016; 138:1226-33. [PMID: 26730610 DOI: 10.1021/jacs.5b10492] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
We report here on an X-ray crystallographic and molecular modeling investigation into the complex 3' interface formed between putative parallel stranded G-quadruplexes and a duplex DNA sequence constructed from the human telomeric repeat sequence TTAGGG. Our crystallographic approach provides a detailed snapshot of a telomeric 3' quadruplex-duplex junction: a junction that appears to have the potential to form a unique molecular target for small molecule binding and interference with telomere-related functions. This unique target is particularly relevant as current high-affinity compounds that bind putative G-quadruplex forming sequences only rarely have a high degree of selectivity for a particular quadruplex. Here DNA junctions were assembled using different putative quadruplex-forming scaffolds linked at the 3' end to a telomeric duplex sequence and annealed to a complementary strand. We successfully generated a series of G-quadruplex-duplex containing crystals, both alone and in the presence of ligands. The structures demonstrate the formation of a parallel folded G-quadruplex and a B-form duplex DNA stacked coaxially. Most strikingly, structural data reveals the consistent formation of a TAT triad platform between the two motifs. This triad allows for a continuous stack of bases to link the quadruplex motif with the duplex region. For these crystal structures formed in the absence of ligands, the TAT triad interface occludes ligand binding at the 3' quadruplex-duplex interface, in agreement with in silico docking predictions. However, with the rearrangement of a single nucleotide, a stable pocket can be produced, thus providing an opportunity for the binding of selective molecules at the interface.
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Affiliation(s)
- Irene Russo Krauss
- Department of Chemical Sciences, University of Naples Federico II , I-80126 Napoli, Italy
| | - Sneha Ramaswamy
- UCL School of Pharmacy, University College London , London WC1N 1AX, United Kingdom
| | - Stephen Neidle
- UCL School of Pharmacy, University College London , London WC1N 1AX, United Kingdom
| | - Shozeb Haider
- UCL School of Pharmacy, University College London , London WC1N 1AX, United Kingdom
| | - Gary N Parkinson
- UCL School of Pharmacy, University College London , London WC1N 1AX, United Kingdom
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