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Ruthenium(II) Polypyridyl Complexes and Their Use as Probes and Photoreactive Agents for G-quadruplexes Labelling. Molecules 2022; 27:molecules27051541. [PMID: 35268640 PMCID: PMC8912042 DOI: 10.3390/molecules27051541] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 02/21/2022] [Accepted: 02/22/2022] [Indexed: 02/01/2023] Open
Abstract
Due to their optical and electrochemical properties, ruthenium(II) polypyridyl complexes have been used in a wide array of applications. Since the discovery of the light-switch ON effect of [Ru(bpy)2dppz]2+ when interacting with DNA, the design of new Ru(II) complexes as light-up probes for specific regions of DNA has been intensively explored. Amongst them, G-quadruplexes (G4s) are of particular interest. These structures formed by guanine-rich parts of DNA and RNA may be associated with a wide range of biological events. However, locating them and understanding their implications in biological pathways has proven challenging. Elegant approaches to tackle this challenge relies on the use of photoprobes capable of marking, reversibly or irreversibly, these G4s. Indeed, Ru(II) complexes containing ancillary π-deficient TAP ligands can create a covalently linked adduct with G4s after a photoinduced electron transfer from a guanine residue to the excited complex. Through careful design of the ligands, high selectivity of interaction with G4 structures can be achieved. This allows the creation of specific Ru(II) light-up probes and photoreactive agents for G4 labelling, which is at the core of this review composed of an introduction dedicated to a brief description of G-quadruplex structures and two main sections. The first one will provide a general picture of ligands and metal complexes interacting with G4s. The second one will focus on an exhaustive and comprehensive overview of the interactions and (photo)reactions of Ru(II) complexes with G4s.
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2
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Beseiso D, Chen EV, McCarthy SE, Martin KN, Gallagher EP, Miao J, Yatsunyk L. OUP accepted manuscript. Nucleic Acids Res 2022; 50:2959-2972. [PMID: 35212369 PMCID: PMC8934647 DOI: 10.1093/nar/gkac091] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 01/26/2022] [Accepted: 01/28/2022] [Indexed: 11/13/2022] Open
Abstract
G-quadruplexes (GQs) are non-canonical DNA structures composed of stacks of stabilized G-tetrads. GQs play an important role in a variety of biological processes and may form at telomeres and oncogene promoters among other genomic locations. Here, we investigate nine variants of telomeric DNA from Tetrahymena thermophila with the repeat (TTGGGG)n. Biophysical data indicate that the sequences fold into stable four-tetrad GQs which adopt multiple conformations according to native PAGE. Excitingly, we solved the crystal structure of two variants, TET25 and TET26. The two variants differ by the presence of a 3′-T yet adopt different GQ conformations. TET25 forms a hybrid [3 + 1] GQ and exhibits a rare 5′-top snapback feature. Consequently, TET25 contains four loops: three lateral (TT, TT, and GTT) and one propeller (TT). TET26 folds into a parallel GQ with three TT propeller loops. To the best of our knowledge, TET25 and TET26 are the first reported hybrid and parallel four-tetrad unimolecular GQ structures. The results presented here expand the repertoire of available GQ structures and provide insight into the intricacy and plasticity of the 3D architecture adopted by telomeric repeats from T. thermophila and GQs in general.
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Affiliation(s)
- Dana Beseiso
- Department of Chemistry and Biochemistry, Swarthmore College, 500 College Ave, Swarthmore, PA 19081, USA
| | - Erin V Chen
- Department of Chemistry and Biochemistry, Swarthmore College, 500 College Ave, Swarthmore, PA 19081, USA
| | - Sawyer E McCarthy
- Department of Chemistry and Biochemistry, Swarthmore College, 500 College Ave, Swarthmore, PA 19081, USA
| | - Kailey N Martin
- Department of Chemistry and Biochemistry, Swarthmore College, 500 College Ave, Swarthmore, PA 19081, USA
| | - Elizabeth P Gallagher
- Department of Chemistry and Biochemistry, Swarthmore College, 500 College Ave, Swarthmore, PA 19081, USA
| | - Joanne Miao
- Department of Chemistry and Biochemistry, Swarthmore College, 500 College Ave, Swarthmore, PA 19081, USA
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Saran R, Piccolo KA, He Y, Kang Y, Huang PJJ, Wei C, Chen D, Dieckmann T, Liu J. Thioflavin T fluorescence and NMR spectroscopy suggesting a non-G-quadruplex structure for a sodium binding aptamer embedded in DNAzymes. CAN J CHEM 2021. [DOI: 10.1139/cjc-2021-0024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Recently, a Na+-binding aptamer was reported to be embedded in a few RNA-cleaving DNAzymes, including NaA43, Ce13d, and NaH1. The Na+ aptamer consists of multiple GG stretches, which is a prerequisite for the formation of G-quadruplex (G4) structures. These DNAzymes require Na+ for activity but show no activity in the presence of K+ or other metal ions. Given that DNA can selectively bind K+ by forming a G4 structure, this work aims to answer whether this Na+ aptamer also uses a G4 to bind Na+. Through comparative ThT fluorescence spectrometry studies, while a control G4 DNA exhibited notable fluorescence enhancement up to 5 mM K+ with a Kd of 0.28 ± 0.06 mM, the Ce13d DNAzyme fluorescence was negligibly perturbed with similar concentrations of K+. Opposed to this, Ce13d displayed specific remarkable fluorescence decrease with low millimolar concentrations of Na+. NMR experiments at two different pH values suggest that Ce13d adopts a significantly different conformation or equilibrium of conformations in the presence of Na+ versus K+ and has a more stable structure in the presence of Na+. Additionally, absence of characteristic G4 peaks in one-dimensional 1H NMR suggest that G4 is not responsible for the Na+ binding. This hypothesis is confirmed by the absence of characteristic peaks in the CD spectra of this sequence. Therefore, we concluded that the aptamer must be selective for Na+ and that it binds Na+ using a structural element that does not contain G4.
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Affiliation(s)
- Runjhun Saran
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
- Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Kyle A. Piccolo
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Yanping He
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
- Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
- State Key Laboratory of Precision Measurement Technology and Instruments, Tianjin University, Tianjin 300072, P.R. China
| | - Yongqiang Kang
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Molecular Science, Shanxi University, Taiyuan 030006, P.R. China
| | - Po-Jung Jimmy Huang
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
- Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Chunying Wei
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Molecular Science, Shanxi University, Taiyuan 030006, P.R. China
| | - Da Chen
- State Key Laboratory of Precision Measurement Technology and Instruments, Tianjin University, Tianjin 300072, P.R. China
| | - Thorsten Dieckmann
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Juewen Liu
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
- Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
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Tateishi-Karimata H, Banerjee D, Ohyama T, Matsumoto S, Miyoshi D, Nakano SI, Sugimoto N. Hydroxyl groups in cosolutes regulate the G-quadruplex topology of telomeric DNA. Biochem Biophys Res Commun 2020; 525:S0006-291X(20)30313-2. [PMID: 32081425 DOI: 10.1016/j.bbrc.2020.02.045] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 02/08/2020] [Indexed: 01/12/2023]
Abstract
Telomeric G-quadruplex topology has the ability to regulate telomerase activity, which counteracts the shortening of telomere with successive cell divisions, thereby causing genomic longevity. However, the detailed mechanism of G-quadruplexes topologies formed by telomeric sequences requires further investigation. In this study, we quantitatively investigated the effect of cosolutes, particularly the varying number of hydroxyl groups, on the structural transition between hybrid type and parallel G-quadruplexes formed by telomeric DNA sequences. Cosolutes with one or no hydroxyl groups in the vicinal position more efficiently induced the transition to parallel G-quadruplex from hybrid G-quadruplex than those with more hydroxyl groups. We also examined the effect of cosolute structures on the hydration of G-quadruplex formation; the results indicated that cosolutes with fewer hydroxyl groups lead to the release of greater amount of water during G-quadruplex formation. Molecular dynamics results showed that the parallel G-quadruplex was more dehydrated than the hybrid type G-quadruplex. Generally, a dehydrated structure is favored under crowding condition. Thus, depending on the surrounding cosolutes, the G-quadruplex topology can be controlled by the G-quadruplex hydration state.
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Affiliation(s)
| | - Dipanwita Banerjee
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, Japan
| | - Tatsuya Ohyama
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, Japan
| | - Saki Matsumoto
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, Japan
| | - Daisuke Miyoshi
- Graduate School of Frontiers of Innovative Research in Science and Technology (FIRST), Konan University, Japan
| | - Shu-Ich Nakano
- Graduate School of Frontiers of Innovative Research in Science and Technology (FIRST), Konan University, Japan
| | - Naoki Sugimoto
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, Japan; Graduate School of Frontiers of Innovative Research in Science and Technology (FIRST), Konan University, Japan.
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Parasitic Protozoa: Unusual Roles for G-Quadruplexes in Early-Diverging Eukaryotes. Molecules 2019; 24:molecules24071339. [PMID: 30959737 PMCID: PMC6480360 DOI: 10.3390/molecules24071339] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 04/02/2019] [Accepted: 04/03/2019] [Indexed: 12/17/2022] Open
Abstract
Guanine-quadruplex (G4) motifs, at both the DNA and RNA levels, have assumed an important place in our understanding of the biology of eukaryotes, bacteria and viruses. However, it is generally little known that their very first description, as well as the foundational work on G4s, was performed on protozoans: unicellular life forms that are often parasitic. In this review, we provide a historical perspective on the discovery of G4s, intertwined with their biological significance across the protozoan kingdom. This is a history in three parts: first, a period of discovery including the first characterisation of a G4 motif at the DNA level in ciliates (environmental protozoa); second, a period less dense in publications concerning protozoa, during which DNA G4s were discovered in both humans and viruses; and third, a period of renewed interest in protozoa, including more mechanistic work in ciliates but also in pathogenic protozoa. This last period has opened an exciting prospect of finding new anti-parasitic drugs to interfere with parasite biology, thus adding new compounds to the therapeutic arsenal.
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Tariq Z, Barthwal R. Binding of anticancer drug daunomycin to parallel G-quadruplex DNA [d-(TTGGGGT)]4 leads to thermal stabilization: A multispectroscopic investigation. Int J Biol Macromol 2018; 120:1965-1974. [DOI: 10.1016/j.ijbiomac.2018.09.154] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Revised: 09/21/2018] [Accepted: 09/24/2018] [Indexed: 10/28/2022]
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Barthwal R, Tariq Z. Molecular Recognition of Parallel G-quadruplex [d-(TTGGGGT)]₄ Containing Tetrahymena Telomeric DNA Sequence by Anticancer Drug Daunomycin: NMR-Based Structure and Thermal Stability. Molecules 2018; 23:molecules23092266. [PMID: 30189644 PMCID: PMC6225185 DOI: 10.3390/molecules23092266] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 08/27/2018] [Accepted: 09/04/2018] [Indexed: 11/17/2022] Open
Abstract
The anticancer drug daunomycin exerts its influence by multiple strategies of action to interfere with gene functioning. Besides inhibiting DNA/RNA synthesis and topoisomerase-II, it affects the functional pathway of telomere maintenance by the telomerase enzyme. We present evidence of the binding of daunomycin to parallel-stranded tetramolecular [d-(TTGGGGT)]4 guanine (G)-quadruplex DNA comprising telomeric DNA from Tetrahymena thermophilia by surface plasmon resonance and Diffusion Ordered SpectroscopY (DOSY). Circular Dichroism (CD) spectra show the disruption of daunomycin dimers, suggesting the end-stacking and groove-binding of the daunomycin monomer. Proton and phosphorus-31 Nuclear Magnetic Resonance (NMR) spectroscopy show a sequence-specific interaction and a clear proof of absence of intercalation of the daunomycin chromophore between base quartets or stacking between G-quadruplexes. Restrained molecular dynamics simulations using observed short interproton distance contacts depict interaction at the molecular level. The interactions involving ring A and daunosamine protons, the stacking of an aromatic ring of daunomycin with a terminal G6 quartet by displacing the T7 base, and external groove-binding close to the T1–T2 bases lead to the thermal stabilization of 15 °C, which is likely to inhibit the association of telomerase with telomeres. The findings have implications in the structure-based designing of anthracycline drugs as potent telomerase inhibitors.
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Affiliation(s)
- Ritu Barthwal
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee 247667, India.
| | - Zia Tariq
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee 247667, India.
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Rackwitz J, Bald I. Low-Energy Electron-Induced Strand Breaks in Telomere-Derived DNA Sequences-Influence of DNA Sequence and Topology. Chemistry 2018; 24:4680-4688. [PMID: 29359819 DOI: 10.1002/chem.201705889] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Indexed: 12/19/2022]
Abstract
During cancer radiation therapy high-energy radiation is used to reduce tumour tissue. The irradiation produces a shower of secondary low-energy (<20 eV) electrons, which are able to damage DNA very efficiently by dissociative electron attachment. Recently, it was suggested that low-energy electron-induced DNA strand breaks strongly depend on the specific DNA sequence with a high sensitivity of G-rich sequences. Here, we use DNA origami platforms to expose G-rich telomere sequences to low-energy (8.8 eV) electrons to determine absolute cross sections for strand breakage and to study the influence of sequence modifications and topology of telomeric DNA on the strand breakage. We find that the telomeric DNA 5'-(TTA GGG)2 is more sensitive to low-energy electrons than an intermixed sequence 5'-(TGT GTG A)2 confirming the unique electronic properties resulting from G-stacking. With increasing length of the oligonucleotide (i.e., going from 5'-(GGG ATT)2 to 5'-(GGG ATT)4 ), both the variety of topology and the electron-induced strand break cross sections increase. Addition of K+ ions decreases the strand break cross section for all sequences that are able to fold G-quadruplexes or G-intermediates, whereas the strand break cross section for the intermixed sequence remains unchanged. These results indicate that telomeric DNA is rather sensitive towards low-energy electron-induced strand breakage suggesting significant telomere shortening that can also occur during cancer radiation therapy.
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Affiliation(s)
- Jenny Rackwitz
- Institute of Chemistry-Physical Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam, Germany
| | - Ilko Bald
- Institute of Chemistry-Physical Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam, Germany.,Department 1-Analytical Chemistry and Reference Materials, BAM Federal Institute for Materials Research and Testing, Richard-Willstätter Str. 11, 12489, Berlin, Germany
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Harkness RW, Mittermaier AK. G-quadruplex dynamics. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2017. [PMID: 28642152 DOI: 10.1016/j.bbapap.2017.06.012] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
G-quadruplexes (GQs) are four-stranded nucleic acid secondary structures formed by guanosine (G)-rich DNA and RNA sequences. It is becoming increasingly clear that cellular processes including gene expression and mRNA translation are regulated by GQs. GQ structures have been extensively characterized, however little attention to date has been paid to their conformational dynamics, despite the fact that many biological GQ sequences populate multiple structures of similar free energies, leading to an ensemble of exchanging conformations. The impact of these dynamics on biological function is currently not well understood. Recently, structural dynamics have been demonstrated to entropically stabilize GQ ensembles, potentially modulating gene expression. Transient, low-populated states in GQ ensembles may additionally regulate nucleic acid interactions and function. This review will underscore the interplay of GQ dynamics and biological function, focusing on several dynamic processes for biological GQs and the characterization of GQ dynamics by nuclear magnetic resonance (NMR) spectroscopy in conjunction with other biophysical techniques. This article is part of a Special Issue entitled: Biophysics in Canada, edited by Lewis Kay, John Baenziger, Albert Berghuis and Peter Tieleman.
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Affiliation(s)
- Robert W Harkness
- McGill University Department of Chemistry, 801 Sherbrooke St. W., Montreal, QC H3A 0B8, Canada
| | - Anthony K Mittermaier
- McGill University Department of Chemistry, 801 Sherbrooke St. W., Montreal, QC H3A 0B8, Canada.
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ALS and FTD linked GGGGCC-repeat containing DNA oligonucleotide folds into two distinct G-quadruplexes. Biochim Biophys Acta Gen Subj 2016; 1861:1237-1245. [PMID: 27856299 DOI: 10.1016/j.bbagen.2016.11.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 11/11/2016] [Accepted: 11/13/2016] [Indexed: 01/24/2023]
Abstract
BACKGROUND The most common genetic cause of neurological disorders ALS and FTD is a largely increased number of GGGGCC repeats in C9orf72 gene. Non-canonical structures including G-quadruplexes adopted by expanded repeats are hypothesized to be crucial in pathogenesis. Recently, we have shown that structural polymorphism of oligonucleotide d(G4C2)3G4 is reduced by dG to 8Br-dG substitution. High-resolution structure of one of the two major G-quadruplexes adopts antiparallel topology comprising of four G-quartets. Herein, we describe the topology of the second major G-quadruplex structure and influence of folding conditions on relative populations of the two folds. METHODS Influence of folding conditions was explored by 1H 1D NMR. Determination of topology was achieved by 2D NMR complemented with PAGE and CD. UV melting experiment was used to explore thermal stability of structures. RESULTS Two structures adopted by oligonucleotide d(G4C2)3GGBrGG denoted AQU and NAN coexist in solution and ratio of their populations is determined by pH and rate of cooling when folding from thermally denatured state in the presence of K+ ions. CONCLUSIONS AQU is kinetically favored and forms by folding at low pH, while NAN is favored thermodynamically and at neutral pH. AQU and NAN share similar antiparallel topology with four G-quartets and three edgewise loops, however they exhibit distinct structural and dynamic properties. GENERAL SIGNIFICANCE Novel G-quadruplex topology adds insight into diverse polymorphism of DNA sequences comprising potentially pathological GGGGCC repeat. Relative populations of the two structures and their dependence on folding conditions contribute to understanding of factors that govern G-quadruplex folding. This article is part of a Special Issue entitled "Gquadruplex" Guest Editor: Dr. Concetta Giancola and Dr. Daniela Montesarchio.
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Kumar V, kashav T, Islam A, Ahmad F, Hassan MI. Structural insight into C9orf72 hexanucleotide repeat expansions: Towards new therapeutic targets in FTD-ALS. Neurochem Int 2016; 100:11-20. [DOI: 10.1016/j.neuint.2016.08.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 08/12/2016] [Accepted: 08/12/2016] [Indexed: 12/12/2022]
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Nelissen FHT, Tessari M, Wijmenga SS, Heus HA. Stable isotope labeling methods for DNA. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2016; 96:89-108. [PMID: 27573183 DOI: 10.1016/j.pnmrs.2016.06.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 06/02/2016] [Accepted: 06/02/2016] [Indexed: 06/06/2023]
Abstract
NMR is a powerful method for studying proteins and nucleic acids in solution. The study of nucleic acids by NMR is far more challenging than for proteins, which is mainly due to the limited number of building blocks and unfavorable spectral properties. For NMR studies of DNA molecules, (site specific) isotope enrichment is required to facilitate specific NMR experiments and applications. Here, we provide a comprehensive review of isotope-labeling strategies for obtaining stable isotope labeled DNA as well as specifically stable isotope labeled building blocks required for enzymatic DNA synthesis.
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Affiliation(s)
- Frank H T Nelissen
- Institute for Molecules and Materials, Radboud University, 6525 AJ Nijmegen, The Netherlands.
| | - Marco Tessari
- Institute for Molecules and Materials, Radboud University, 6525 AJ Nijmegen, The Netherlands.
| | - Sybren S Wijmenga
- Institute for Molecules and Materials, Radboud University, 6525 AJ Nijmegen, The Netherlands.
| | - Hans A Heus
- Institute for Molecules and Materials, Radboud University, 6525 AJ Nijmegen, The Netherlands.
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Zheng C, Liu Y, Liu Y, Qin X, Zhou Y, Liu J. Dinuclear ruthenium complexes display loop isomer selectivity to c-MYC DNA G-quadriplex and exhibit anti-tumour activity. J Inorg Biochem 2016; 156:122-32. [DOI: 10.1016/j.jinorgbio.2016.01.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 12/30/2015] [Accepted: 01/07/2016] [Indexed: 12/18/2022]
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Largy E, Mergny JL, Gabelica V. Role of Alkali Metal Ions in G-Quadruplex Nucleic Acid Structure and Stability. Met Ions Life Sci 2016; 16:203-58. [PMID: 26860303 DOI: 10.1007/978-3-319-21756-7_7] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
G-quadruplexes are guanine-rich nucleic acids that fold by forming successive quartets of guanines (the G-tetrads), stabilized by intra-quartet hydrogen bonds, inter-quartet stacking, and cation coordination. This specific although highly polymorphic type of secondary structure deviates significantly from the classical B-DNA duplex. G-quadruplexes are detectable in human cells and are strongly suspected to be involved in a number of biological processes at the DNA and RNA levels. The vast structural polymorphism exhibited by G-quadruplexes, together with their putative biological relevance, makes them attractive therapeutic targets compared to canonical duplex DNA. This chapter focuses on the essential and specific coordination of alkali metal cations by G-quadruplex nucleic acids, and most notably on studies highlighting cation-dependent dissimilarities in their stability, structure, formation, and interconversion. Section 1 surveys G-quadruplex structures and their interactions with alkali metal ions while Section 2 presents analytical methods used to study G-quadruplexes. The influence of alkali cations on the stability, structure, and kinetics of formation of G-quadruplex structures of quadruplexes will be discussed in Sections 3 and 4. Section 5 focuses on the cation-induced interconversion of G-quadruplex structures. In Sections 3 to 5, we will particularly emphasize the comparisons between cations, most often K(+) and Na(+) because of their prevalence in the literature and in cells.
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Affiliation(s)
- Eric Largy
- ARNA Laboratory, Université Bordeaux, IECB, 2, rue Robert Escarpit, F-33600, Pessac, France.,ARNA Laboratory, INSERM, U869, F-33000, Bordeaux, France
| | - Jean-Louis Mergny
- ARNA Laboratory, Université Bordeaux, IECB, 2, rue Robert Escarpit, F-33600, Pessac, France. .,ARNA Laboratory, INSERM, U869, F-33000, Bordeaux, France.
| | - Valérie Gabelica
- ARNA Laboratory, Université Bordeaux, IECB, 2, rue Robert Escarpit, F-33600, Pessac, France. .,ARNA Laboratory, INSERM, U869, F-33000, Bordeaux, France.
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König SLB, Evans AC, Huppert JL. Seven essential questions on G-quadruplexes. Biomol Concepts 2015; 1:197-213. [PMID: 25961997 DOI: 10.1515/bmc.2010.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The helical duplex architecture of DNA was discovered by Francis Crick and James Watson in 1951 and is well known and understood. However, nucleic acids can also adopt alternative structural conformations that are less familiar, although no less biologically relevant, such as the G-quadruplex. G-quadruplexes continue to be the subject of a rapidly expanding area of research, owing to their significant potential as therapeutic targets and their unique biophysical properties. This review begins by focusing on G-quadruplex structure, elucidating the intermolecular and intramolecular interactions underlying its formation and highlighting several substructural variants. A variety of methods used to characterize these structures are also outlined. The current state of G-quadruplex research is then addressed by proffering seven pertinent questions for discussion. This review concludes with an overview of possible directions for future research trajectories in this exciting and relevant field.
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Müller S, Rodriguez R. G-quadruplex interacting small molecules and drugs: from bench toward bedside. Expert Rev Clin Pharmacol 2014; 7:663-79. [DOI: 10.1586/17512433.2014.945909] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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17
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Zhang S, Wu Y, Zhang W. G-Quadruplex Structures and Their Interaction Diversity with Ligands. ChemMedChem 2014; 9:899-911. [DOI: 10.1002/cmdc.201300566] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Indexed: 12/22/2022]
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Shalaby T, Fiaschetti G, Nagasawa K, Shin-ya K, Baumgartner M, Grotzer M. G-quadruplexes as potential therapeutic targets for embryonal tumors. Molecules 2013; 18:12500-37. [PMID: 24152672 PMCID: PMC6269990 DOI: 10.3390/molecules181012500] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 09/18/2013] [Accepted: 09/25/2013] [Indexed: 12/27/2022] Open
Abstract
Embryonal tumors include a heterogeneous group of highly malignant neoplasms that primarily affect infants and children and are characterized by a high rate of mortality and treatment-related morbidity, hence improved therapies are clearly needed. G-quadruplexes are special secondary structures adopted in guanine (G)-rich DNA sequences that are often present in biologically important regions, e.g. at the end of telomeres and in the regulatory regions of oncogenes such as MYC. Owing to the significant roles that both telomeres and MYC play in cancer cell biology, G-quadruplexes have been viewed as emerging therapeutic targets in oncology and as tools for novel anticancer drug design. Several compounds that target these structures have shown promising anticancer activity in tumor xenograft models and some of them have entered Phase II clinical trials. In this review we examine approaches to DNA targeted cancer therapy, summarize the recent developments of G-quadruplex ligands as anticancer drugs and speculate on the future direction of such structures as a potential novel therapeutic strategy for embryonal tumors of the nervous system.
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Affiliation(s)
- Tarek Shalaby
- Division of Oncology, University Children's Hospital of Zurich, Zurich 8032, Switzerland.
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19
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Abstract
The folding of various intra- and intermolecular i-motif DNAs is systematically studied to expand the toolbox for the control of mechanical operations in DNA nanoarchitectures. We analyzed i-motif DNAs with two C-tracts under acidic conditions by gel electrophoresis, circular dichroism, and thermal denaturation and show that their intra- versus intermolecular folding primarily depends on the length of the C-tracts. Two stretches of six or fewer C-residues favor the intermolecular folding of i-motifs, whereas longer C-tracts promote the formation of intramolecular i-motif structures with unusually high thermal stability. We then introduced intra- and intermolecular i-motifs formed by DNAs containing two C-tracts into single-stranded regions within otherwise double-stranded DNA nanocircles. By adjusting the length of C-tracts we can control the intra- and intermolecular folding of i-motif DNAs and achieve programmable functionalization of dsDNA nanocircles. Single-stranded gaps in the nanocircle that are functionalized with an intramolecular i-motif enable the reversible contraction and extension of the DNA circle, as monitored by fluorescence quenching. Thereby, the nanocircle behaves as a proton-fueled DNA prototype machine. In contrast, nanorings containing intermolecular i-motifs induce the assembly of defined multicomponent DNA architectures in response to proton-triggered predicted structural changes, such as dimerization, "kiss", and cyclization. The resulting DNA nanostructures are verified by gel electrophoresis and visualized by atomic force microscopy, including different folding topologies of an intermolecular i-motif. The i-motif-functionalized DNA nanocircles may serve as a versatile tool for the formation of larger interlocked dsDNA nanostructures, like rotaxanes and catenanes, to achieve diverse mechanical operations.
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Affiliation(s)
- Tao Li
- Life and Medical Science (LIMES) Institute, Program Unit Chemical Biology and Medicinal Chemistry, University of Bonn, 53121 Bonn, Germany
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20
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Structural probes in quadruplex nucleic acid structure determination by NMR. Molecules 2012; 17:13073-86. [PMID: 23128087 PMCID: PMC6268857 DOI: 10.3390/molecules171113073] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Revised: 11/01/2012] [Accepted: 11/01/2012] [Indexed: 12/31/2022] Open
Abstract
Traditionally, isotope-labelled DNA and RNA have been fundamental to nucleic acid structural studies by NMR. Four-stranded nucleic acid architectures studies increasingly benefit from a plethora of nucleotide conjugates for resonance assignments, the identification of hydrogen bond alignments, and improving the population of preferred species within equilibria. In this paper, we review their use for these purposes. Most importantly we identify reasons for the failure of some modifications to result in quadruplex formation.
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21
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Adrian M, Heddi B, Phan AT. NMR spectroscopy of G-quadruplexes. Methods 2012; 57:11-24. [DOI: 10.1016/j.ymeth.2012.05.003] [Citation(s) in RCA: 184] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Revised: 05/15/2012] [Accepted: 05/16/2012] [Indexed: 12/24/2022] Open
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22
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Virgilio A, Esposito V, Citarella G, Pepe A, Mayol L, Galeone A. The insertion of two 8-methyl-2'-deoxyguanosine residues in tetramolecular quadruplex structures: trying to orientate the strands. Nucleic Acids Res 2011; 40:461-75. [PMID: 21908403 PMCID: PMC3245916 DOI: 10.1093/nar/gkr670] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In this article, we report a structural study, based on NMR and CD spectroscopies, and molecular modelling of all possible d(TG3T) and d(TG4T) analogues containing two 8-methyl-2′-deoxyguanosine residues (M). Particularly, the potential ability of these modified residues to orientate the strands and then to affect the folding topology of tetramolecular quadruplex structures has been investigated. Oligodeoxynucleotides (ODNs) TMMGT (T12) and TMMGGT (F12) form parallel tetramolecular quadruplexes, characterized by an all-syn M-tetrad at the 5′-side stacked to all-anti M- and G-tetrads. ODNs TMGMT (T13) and TMGGMT (F14) form parallel tetramolecular quadruplexes, in which an all-anti G core is sandwiched between two all-syn M-tetrads at the 5′- and the 3′-side. Notably, the quadruplex formed by T13 corresponds to an unprecedented structure in which the syn residues exceed in number the anti ones. Conversely, ODN TGMGMT (F24) adopts a parallel arrangement in which all-anti G-tetrads alternate with all-syn M-tetrads. Most importantly, all data strongly suggest that ODN TMGMGT (F13) forms an unprecedented anti-parallel tetramolecular quadruplex in which G and M residues adopt anti and syn glycosidic conformations, respectively. This article opens up new understandings and perspectives about the intricate relationship between the quadruplex strands orientation and the glycosidic conformation of the residues.
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Affiliation(s)
- Antonella Virgilio
- Dipartimento di Chimica delle Sostanze Naturali, Università degli Studi di Napoli Federico II, Via D. Montesano 49, I-80131 Napoli, Italy
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23
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Cang X, Šponer J, Cheatham TE. Insight into G-DNA structural polymorphism and folding from sequence and loop connectivity through free energy analysis. J Am Chem Soc 2011; 133:14270-9. [PMID: 21761922 PMCID: PMC3168932 DOI: 10.1021/ja107805r] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
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The lengths of G-tracts and their connecting loop sequences determine G-quadruplex folding and stability. Complete understanding of the sequence–structure relationships remains elusive. Here, single-loop G-quadruplexes were investigated using explicit solvent molecular dynamics (MD) simulations to characterize the effect of loop length, loop sequence, and G-tract length on the folding topologies and stability of G-quadruplexes. Eight loop types, including different variants of lateral, diagonal, and propeller loops, and six different loop sequences [d0 (i.e., no intervening residues in the loop), dT, dT2, dT3, dTTA, and dT4] were considered through MD simulation and free energy analysis. In most cases the free energetic estimates agree well with the experimental observations. The work also provides new insight into G-quadruplex folding and stability. This includes reporting the observed instability of the left propeller loop, which extends the rules for G-quadruplex folding. We also suggest a plausible explanation why human telomere sequences predominantly form hybrid-I and hybrid-II type structures in K+ solution. Overall, our calculation results indicate that short loops generally are less stable than longer loops, and we hypothesize that the extreme stability of sequences with very short loops could possibly derive from the formation of parallel multimers. The results suggest that free energy differences, estimated from MD and free energy analysis with current force fields and simulation protocols, are able to complement experiment and to help dissect and explain loop sequence, loop length, and G-tract length and orientation influences on G-quadruplex structure.
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Affiliation(s)
- Xiaohui Cang
- Department of Medicinal Chemistry, College of Pharmacy, Skaggs Hall 201, University of Utah, Salt Lake City, Utah 84112, USA
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24
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Víglaský V, Bauer L, Tlucková K. Structural features of intra- and intermolecular G-quadruplexes derived from telomeric repeats. Biochemistry 2010; 49:2110-20. [PMID: 20143878 DOI: 10.1021/bi902099u] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The 3' strand of telomeres is composed of tandem repeats of short G-rich sequences which protrude as single-stranded DNA overhangs. These repeats are G(3)T(2)A in humans and G(4)T(2) and G(4)T(4) in the ciliates Tetrahymena and Oxytricha, respectively. We analyzed different quadruplex-forming sequences derived from telomeric sequences, G(3+k)(T(n+k)G(3+k))(3) and G(3+k)(T(2)AG(3+k))(3), in the presence of Li(+), Na(+), and K(+) through the use of circular dichroism, UV spectroscopy, and electrophoresis, where k = 0 or 1 and n = 1-3. Results obtained under the given conditions can provide more detailed information about the quadruplex structure. The major findings are as follows. (i) G-Repeats in solution form a mix of topologically different structures; only G(3)(T(2)G(3))(3) and G(3)(TG(3))(3) repeats preferentially form the parallel interstrand structure. (ii) The Tetrahymena repeat can form at least two intramolecular conformers with different strand orientations and levels of stability. (iii) G-Quadruplex conformation and molecularity strongly depend on the type and concentration of ions used in the solution. The formation of intramolecular quadruplexes is governed by the length of the loops connecting G-runs. Intermolecular G-quadruplex forms are more likely to form in a higher concentration of ions for sequences where G-runs are separated by only one or two nucleotides.
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Affiliation(s)
- Viktor Víglaský
- Department of Biochemistry, Institute of Chemistry, Faculty of Sciences, P. J. Safarik University, 04154 Kosice, Slovakia.
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25
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Hu L, Lim KW, Bouaziz S, Phan AT. Giardia telomeric sequence d(TAGGG)4 forms two intramolecular G-quadruplexes in K+ solution: effect of loop length and sequence on the folding topology. J Am Chem Soc 2010; 131:16824-31. [PMID: 19874015 DOI: 10.1021/ja905611c] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Recently, it has been shown that in K(+) solution the human telomeric sequence d[TAGGG(TTAGGG)(3)] forms a (3 + 1) intramolecular G-quadruplex, while the Bombyx mori telomeric sequence d[TAGG(TTAGG)(3)], which differs from the human counterpart only by one G deletion in each repeat, forms a chair-type intramolecular G-quadruplex, indicating an effect of G-tract length on the folding topology of G-quadruplexes. To explore the effect of loop length and sequence on the folding topology of G-quadruplexes, here we examine the structure of the four-repeat Giardia telomeric sequence d[TAGGG(TAGGG)(3)], which differs from the human counterpart only by one T deletion within the non-G linker in each repeat. We show by NMR that this sequence forms two different intramolecular G-quadruplexes in K(+) solution. The first one is a novel basket-type antiparallel-stranded G-quadruplex containing two G-tetrads, a G x (A-G) triad, and two A x T base pairs; the three loops are consecutively edgewise-diagonal-edgewise. The second one is a propeller-type parallel-stranded G-quadruplex involving three G-tetrads; the three loops are all double-chain-reversal. Recurrence of several structural elements in the observed structures suggests a "cut and paste" principle for the design and prediction of G-quadruplex topologies, for which different elements could be extracted from one G-quadruplex and inserted into another.
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Affiliation(s)
- Lanying Hu
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
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26
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Fadrná E, Špačková N, Sarzyñska J, Koča J, Orozco M, Cheatham TE, Kulinski T, Šponer J. Single Stranded Loops of Quadruplex DNA As Key Benchmark for Testing Nucleic Acids Force Fields. J Chem Theory Comput 2009; 5:2514-30. [DOI: 10.1021/ct900200k] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Eva Fadrná
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic, Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61 704 Poznań, Poland, Joint IRB-BSC program on Computational Biology, Institute for Research in Biomedicine, Baldiri Reixac 10-12, 08028 Barcelona, Spain, Barcelona Supercomputing
| | - Nad’a Špačková
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic, Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61 704 Poznań, Poland, Joint IRB-BSC program on Computational Biology, Institute for Research in Biomedicine, Baldiri Reixac 10-12, 08028 Barcelona, Spain, Barcelona Supercomputing
| | - Joanna Sarzyñska
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic, Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61 704 Poznań, Poland, Joint IRB-BSC program on Computational Biology, Institute for Research in Biomedicine, Baldiri Reixac 10-12, 08028 Barcelona, Spain, Barcelona Supercomputing
| | - Jaroslav Koča
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic, Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61 704 Poznań, Poland, Joint IRB-BSC program on Computational Biology, Institute for Research in Biomedicine, Baldiri Reixac 10-12, 08028 Barcelona, Spain, Barcelona Supercomputing
| | - Modesto Orozco
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic, Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61 704 Poznań, Poland, Joint IRB-BSC program on Computational Biology, Institute for Research in Biomedicine, Baldiri Reixac 10-12, 08028 Barcelona, Spain, Barcelona Supercomputing
| | - Thomas E. Cheatham
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic, Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61 704 Poznań, Poland, Joint IRB-BSC program on Computational Biology, Institute for Research in Biomedicine, Baldiri Reixac 10-12, 08028 Barcelona, Spain, Barcelona Supercomputing
| | - Tadeusz Kulinski
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic, Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61 704 Poznań, Poland, Joint IRB-BSC program on Computational Biology, Institute for Research in Biomedicine, Baldiri Reixac 10-12, 08028 Barcelona, Spain, Barcelona Supercomputing
| | - Jiří Šponer
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic, Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61 704 Poznań, Poland, Joint IRB-BSC program on Computational Biology, Institute for Research in Biomedicine, Baldiri Reixac 10-12, 08028 Barcelona, Spain, Barcelona Supercomputing
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27
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Lim KW, Amrane S, Bouaziz S, Xu W, Mu Y, Patel DJ, Luu KN, Phan AT. Structure of the human telomere in K+ solution: a stable basket-type G-quadruplex with only two G-tetrad layers. J Am Chem Soc 2009; 131:4301-9. [PMID: 19271707 PMCID: PMC2662591 DOI: 10.1021/ja807503g] [Citation(s) in RCA: 377] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Previously, it has been reported that human telomeric DNA sequences could adopt in different experimental conditions four different intramolecular G-quadruplexes each involving three G-tetrad layers, namely, Na(+) solution antiparallel-stranded basket form, K(+) crystal parallel-stranded propeller form, K(+) solution (3 + 1) Form 1, and K(+) solution (3 + 1) Form 2. Here we present a new intramolecular G-quadruplex adopted by a four-repeat human telomeric sequence in K(+) solution (Form 3). This structure is a basket-type G-quadruplex with only two G-tetrad layers: loops are successively edgewise, diagonal, and edgewise; glycosidic conformations of guanines are syn x syn x anti x anti around each tetrad. Each strand of the core has both a parallel and an antiparallel adjacent strands; there are one narrow, one wide, and two medium grooves. Despite the presence of only two G-tetrads in the core, this structure is more stable than the three-G-tetrad intramolecular G-quadruplexes previously observed for human telomeric sequences in K(+) solution. Detailed structural elucidation of Form 3 revealed extensive base pairing and stacking in the loops capping both ends of the G-tetrad core, which might explain the high stability of the structure. This novel structure highlights the conformational heterogeneity of human telomeric DNA. It establishes a new folding principle for G-quadruplexes and suggests new loop sequences and structures for targeting in human telomeric DNA.
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Affiliation(s)
- Kah Wai Lim
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore
| | - Samir Amrane
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore
| | - Serge Bouaziz
- Unité de Pharmacologie Chimique et Génétique, INSERM U640 — CNRS UMR 8151, Université Paris Descartes, France
| | - Weixin Xu
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Yuguang Mu
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Dinshaw J. Patel
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, USA
| | - Kim Ngoc Luu
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, USA
| | - Anh Tuân Phan
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore
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28
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Amrane S, Ang RWL, Tan ZM, Li C, Lim JKC, Lim JMW, Lim KW, Phan AT. A novel chair-type G-quadruplex formed by a Bombyx mori telomeric sequence. Nucleic Acids Res 2008; 37:931-8. [PMID: 19103662 PMCID: PMC2647293 DOI: 10.1093/nar/gkn990] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Recently, the human telomeric d[TAGGG(TTAGGG)3] sequence has been shown to form in K+ solution an intramolecular (3+1) G-quadruplex structure, whose G-tetrad core contains three strands oriented in one direction and the fourth in the opposite direction. Here we present a study on the structure of the Bombyx mori telomeric d[TAGG(TTAGG)3] sequence, which differs from the human counterpart only by one G deletion in each repeat. We found that this sequence adopted multiple G-quadruplex structures in K+ solution. We have favored a major G-quadruplex form by a judicious U-for-T substitution in the sequence and determined the folding topology of this form. We showed by NMR that this was a new chair-type intramolecular G-quadruplex which involved a two-layer antiparallel G-tetrad core and three edgewise loops. Our result highlights the effect of G-tract length on the folding topology of G-quadruplexes, but also poses the question of whether a similar chair-type G-quadruplex fold exists in the human telomeric sequences.
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Affiliation(s)
- Samir Amrane
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371
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29
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Arola-Arnal A, Benet-Buchholz J, Neidle S, Vilar R. Effects of Metal Coordination Geometry on Stabilization of Human Telomeric Quadruplex DNA by Square-Planar and Square-Pyramidal Metal Complexes. Inorg Chem 2008; 47:11910-9. [DOI: 10.1021/ic8016547] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Anna Arola-Arnal
- Department of Chemistry, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom, CRUK Biomolecular Structure Group, The School of Pharmacy University of London, London WC1N 1AX, United Kingdom, and Institute of Chemical Research of Catalonia (ICIQ), Avgda. Països Catalans 16, 43007 Tarragona, Spain
| | - Jordi Benet-Buchholz
- Department of Chemistry, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom, CRUK Biomolecular Structure Group, The School of Pharmacy University of London, London WC1N 1AX, United Kingdom, and Institute of Chemical Research of Catalonia (ICIQ), Avgda. Països Catalans 16, 43007 Tarragona, Spain
| | - Stephen Neidle
- Department of Chemistry, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom, CRUK Biomolecular Structure Group, The School of Pharmacy University of London, London WC1N 1AX, United Kingdom, and Institute of Chemical Research of Catalonia (ICIQ), Avgda. Països Catalans 16, 43007 Tarragona, Spain
| | - Ramón Vilar
- Department of Chemistry, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom, CRUK Biomolecular Structure Group, The School of Pharmacy University of London, London WC1N 1AX, United Kingdom, and Institute of Chemical Research of Catalonia (ICIQ), Avgda. Països Catalans 16, 43007 Tarragona, Spain
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30
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Chen B, Liang J, Tian X, Liu X. G-quadruplex structure: a target for anticancer therapy and a probe for detection of potassium. BIOCHEMISTRY (MOSCOW) 2008; 73:853-61. [PMID: 18774931 DOI: 10.1134/s0006297908080026] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
G-Quadruplexes are four-stranded DNA structures that play important regulatory roles in the maintenance of telomere length by inhibiting telomerase activity. Telomeres are specialized functional DNA-protein structures consisting of a variable number of tandem G-rich repeats together with a group of specific proteins. Telomere losses during cell replication are compensated by telomerase, which adds telomeric repeats onto the chromosome ends in the presence of its substrate--the 3'-overhang. Recently, quadruplexes have been considered as a potential therapeutic target for human cancer because they can inhibit telomerase activity, and some quadruplex-interacting drugs can induce senescence and apoptosis of cancer cells. In addition, due to the potassium preference to the other cations, especially sodium ions, quadruplexes have been suggested for developing potassium detection probes with higher sensitivity and selectivity. This review will illustrate these two aspects to provide further understanding of G-quadruplex structures.
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Affiliation(s)
- Bo Chen
- Bioengineering Institute of Life Science Department, Zhejiang Sci-Tech University, Hangzhou, China
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31
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Neidle S, Parkinson GN. Quadruplex DNA crystal structures and drug design. Biochimie 2008; 90:1184-96. [DOI: 10.1016/j.biochi.2008.03.003] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2008] [Accepted: 03/11/2008] [Indexed: 10/22/2022]
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32
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Xu Y, Kaminaga K, Komiyama M. G-quadruplex formation by human telomeric repeats-containing RNA in Na+ solution. J Am Chem Soc 2008; 130:11179-84. [PMID: 18642813 DOI: 10.1021/ja8031532] [Citation(s) in RCA: 148] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
For a long time, telomeres have been considered to be transcriptionally silent. Very recently, a breaking finding from two groups demonstrated that telomere DNA is transcribed into telomeric repeat-containing RNA in mammalian cells (Azzalin, C. M.; Reichenbach, P.; Khoriauli, L.; Giulotto, E.; Lingner, J. Science 2007, 318, 798-801. Schoefter, S.; Blasco, M. A. Nat. Cell Biol. 2008, 10, 228-236). The telomeric RNA, a newly appeared player in telomere biology, may be a key component of telomere machinery. In the current study, we used a combination of NMR, circular dichroism (CD), matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOFMS), and gel electrophoresis to investigate the structural features of a human telomere RNA sequence. We demonstrated that human telomere RNA can form a parallel G-quadruplex structure in the presence of Na(+). Importantly, we found for the first time that the G-quadruplex forming telomere RNA protects itself from enzymatic digestion. These results provide valuable information to allow understanding of the structure and function of human telomeric RNA.
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Affiliation(s)
- Yan Xu
- Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan.
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33
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Esposito V, Galeone A, Mayol L, Oliviero G, Virgilio A, Randazzo L. A topological classification of G-quadruplex structures. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2008; 26:1155-9. [PMID: 18058556 DOI: 10.1080/15257770701527059] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
A topological classification of most quadruplex structures is proposed, based on two main characteristics: 1) the relative orientation of the strands and 2) the nature of the loops connecting the strands.
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Affiliation(s)
- V Esposito
- Dipartimento di Chimica delle Sostanze Naturali, Università degli Studi di Napoli Federico II, Napoli, Italy
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34
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Webba da Silva M. NMR methods for studying quadruplex nucleic acids. Methods 2008; 43:264-77. [PMID: 17967697 DOI: 10.1016/j.ymeth.2007.05.007] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2007] [Accepted: 05/16/2007] [Indexed: 12/22/2022] Open
Abstract
Solution NMR spectroscopy has traditionally played a central role in examining quadruplex structure, dynamics, and interactions. Here, an overview is given of the methods currently applied to structural, dynamics, thermodynamics, and kinetics studies of nucleic acid quadruplexes and associated cations.
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Affiliation(s)
- Mateus Webba da Silva
- School of Biomedical Sciences, University of Ulster, Cromore Road, Coleraine BT52 1SA, UK.
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35
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Patel DJ, Phan AT, Kuryavyi V. Human telomere, oncogenic promoter and 5'-UTR G-quadruplexes: diverse higher order DNA and RNA targets for cancer therapeutics. Nucleic Acids Res 2007; 35:7429-55. [PMID: 17913750 PMCID: PMC2190718 DOI: 10.1093/nar/gkm711] [Citation(s) in RCA: 729] [Impact Index Per Article: 42.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Guanine-rich DNA sequences can form G-quadruplexes stabilized by stacked G–G–G–G tetrads in monovalent cation-containing solution. The length and number of individual G-tracts and the length and sequence context of linker residues define the diverse topologies adopted by G-quadruplexes. The review highlights recent solution NMR-based G-quadruplex structures formed by the four-repeat human telomere in K+ solution and the guanine-rich strands of c-myc, c-kit and variant bcl-2 oncogenic promoters, as well as a bimolecular G-quadruplex that targets HIV-1 integrase. Such structure determinations have helped to identify unanticipated scaffolds such as interlocked G-quadruplexes, as well as novel topologies represented by double-chain-reversal and V-shaped loops, triads, mixed tetrads, adenine-mediated pentads and hexads and snap-back G-tetrad alignments. The review also highlights the recent identification of guanine-rich sequences positioned adjacent to translation start sites in 5′-untranslated regions (5′-UTRs) of RNA oncogenic sequences. The activity of the enzyme telomerase, which maintains telomere length, can be negatively regulated through G-quadruplex formation at telomeric ends. The review evaluates progress related to ongoing efforts to identify small molecule drugs that bind and stabilize distinct G-quadruplex scaffolds associated with telomeric and oncogenic sequences, and outlines progress towards identifying recognition principles based on several X-ray-based structures of ligand–G-quadruplex complexes.
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Affiliation(s)
- Dinshaw J Patel
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.
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36
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Phan AT, Kuryavyi V, Luu KN, Patel DJ. Structure of two intramolecular G-quadruplexes formed by natural human telomere sequences in K+ solution. Nucleic Acids Res 2007; 35:6517-25. [PMID: 17895279 PMCID: PMC2095816 DOI: 10.1093/nar/gkm706] [Citation(s) in RCA: 416] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Intramolecular G-quadruplexes formed by human telomere sequences are attractive anticancer targets. Recently, four-repeat human telomere sequences have been shown to form two different intramolecular (3 + 1) G-quadruplexes in K(+) solution (Form 1 and Form 2). Here we report on the solution structures of both Form 1 and Form 2 adopted by natural human telomere sequences. Both structures contain the (3 + 1) G-tetrad core with one double-chain-reversal and two edgewise loops, but differ in the successive order of loop arrangements within the G-quadruplex scaffold. Our results provide the structural details at the two ends of the G-tetrad core in the context of natural sequences and information on different loop conformations. This structural information might be important for our understanding of telomere G-quadruplex structures and for anticancer drug design targeted to such scaffolds.
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Affiliation(s)
- Anh Tuân Phan
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA and Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637551, Singapore
- *To whom correspondence should be addressed. +65 6514 1915+65 6794 1325 Correspondence may also be addressed to Dinshaw J. Patel. Tel:+ 1 212 639 7207+ 1 212 717 3066
| | - Vitaly Kuryavyi
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA and Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Kim Ngoc Luu
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA and Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Dinshaw J. Patel
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA and Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637551, Singapore
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37
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Phan AT, Kuryavyi V, Burge S, Neidle S, Patel DJ. Structure of an unprecedented G-quadruplex scaffold in the human c-kit promoter. J Am Chem Soc 2007; 129:4386-92. [PMID: 17362008 PMCID: PMC4693632 DOI: 10.1021/ja068739h] [Citation(s) in RCA: 368] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The c-kit oncogene is an important target in the treatment of gastrointestinal tumors. A potential approach to inhibition of the expression of this gene involves selective stabilization of G-quadruplex structures that may be induced to form in the c-kit promoter region. Here we report on the structure of an unprecedented intramolecular G-quadruplex formed by a G-rich sequence in the c-kit promoter in K+ solution. The structure represents a new folding topology with several unique features. Most strikingly, an isolated guanine is involved in G-tetrad core formation, despite the presence of four three-guanine tracts. There are four loops: two single-residue double-chain-reversal loops, a two-residue loop, and a five-residue stem-loop, which contain base-pairing alignments. This unique structural scaffold provides a highly specific platform for the future design of ligands specifically targeted to the promoter DNA of c-kit.
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Affiliation(s)
- Anh Tuân Phan
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10021
| | - Vitaly Kuryavyi
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10021
| | - Sarah Burge
- Cancer Research UK Biomolecular Structure Group, School of Pharmacy, University of London, London WC1N 1AX, United Kingdom
| | - Stephen Neidle
- Cancer Research UK Biomolecular Structure Group, School of Pharmacy, University of London, London WC1N 1AX, United Kingdom
| | - Dinshaw J. Patel
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10021
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38
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Qi H, Lin CP, Fu X, Wood LM, Liu AA, Tsai YC, Chen Y, Barbieri CM, Pilch DS, Liu LF. G-quadruplexes induce apoptosis in tumor cells. Cancer Res 2007; 66:11808-16. [PMID: 17178877 DOI: 10.1158/0008-5472.can-06-1225] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Several G-rich oligodeoxynucleotides (ODNs), which are capable of forming G-quadruplexes, have been shown to exhibit antiproliferative activity against tumor cell lines and antitumor activity in nude mice carrying prostate and breast tumor xenografts. However, the molecular basis for their antitumor activity remains unclear. In the current study, we showed that a variety of telomeric G-tail oligodeoxynucleotides (TG-ODNs) exhibited antiproliferative activity against many tumor cells in culture. Systematic mutational analysis of the TG-ODNs suggests that the antiproliferative activity depends on the G-quadruplex conformation of these TG-ODNs. TG-ODNs were also shown to induce poly(ADP-ribose) polymerase-1 cleavage, phosphatidylserine flipping, and caspase activation, indicative of induction of apoptosis. TG-ODN-induced apoptosis was largely ataxia telangiectasia mutated (ATM) dependent. Furthermore, TG-ODN-induced apoptosis was inhibited by the c-Jun NH(2)-terminal kinase (JNK) inhibitor SP600125. Indeed, TG-ODNs were shown to activate the JNK pathway in an ATM-dependent manner as evidenced by elevated phosphorylation of JNK and c-Jun. Interestingly, a number of G-quadruplex ODNs (GQ-ODN) derived from nontelomeric sequences also induced ATM/JNK-dependent apoptosis, suggesting a possible common mechanism of tumor cell killing by GQ-ODNs.
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Affiliation(s)
- Haiyan Qi
- Department of Pharmacology, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, USA.
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39
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Burge S, Parkinson GN, Hazel P, Todd AK, Neidle S. Quadruplex DNA: sequence, topology and structure. Nucleic Acids Res 2006; 34:5402-15. [PMID: 17012276 PMCID: PMC1636468 DOI: 10.1093/nar/gkl655] [Citation(s) in RCA: 1795] [Impact Index Per Article: 99.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
G-quadruplexes are higher-order DNA and RNA structures formed from G-rich sequences that are built around tetrads of hydrogen-bonded guanine bases. Potential quadruplex sequences have been identified in G-rich eukaryotic telomeres, and more recently in non-telomeric genomic DNA, e.g. in nuclease-hypersensitive promoter regions. The natural role and biological validation of these structures is starting to be explored, and there is particular interest in them as targets for therapeutic intervention. This survey focuses on the folding and structural features on quadruplexes formed from telomeric and non-telomeric DNA sequences, and examines fundamental aspects of topology and the emerging relationships with sequence. Emphasis is placed on information from the high-resolution methods of X-ray crystallography and NMR, and their scope and current limitations are discussed. Such information, together with biological insights, will be important for the discovery of drugs targeting quadruplexes from particular genes.
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Affiliation(s)
| | | | | | | | - Stephen Neidle
- To whom correspondence should be addressed. Tel: +44 207 753 5969; Fax: +44 207 753 5970;
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40
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Phan AT, Kuryavyi V, Patel DJ. DNA architecture: from G to Z. Curr Opin Struct Biol 2006; 16:288-98. [PMID: 16714104 PMCID: PMC4689308 DOI: 10.1016/j.sbi.2006.05.011] [Citation(s) in RCA: 214] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2006] [Revised: 04/10/2006] [Accepted: 05/10/2006] [Indexed: 12/27/2022]
Abstract
G-quadruplexes and Z-DNA are two important non-B forms of DNA architecture. Results on novel structural elements, folding and unfolding kinetics, and interactions with small molecules and proteins have been reported recently for these forms. These results will enhance our understanding of the biology of these structures and provide a platform for drug design.
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Affiliation(s)
- Anh Tuân Phan
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.
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41
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Hazel P, Parkinson GN, Neidle S. Predictive modelling of topology and loop variations in dimeric DNA quadruplex structures. Nucleic Acids Res 2006; 34:2117-27. [PMID: 16641317 PMCID: PMC1449907 DOI: 10.1093/nar/gkl182] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have used a combination of simulated annealing (SA), molecular dynamics (MD) and locally enhanced sampling (LES) methods in order to predict the favourable topologies and loop conformations of dimeric DNA quadruplexes with T2 or T3 loops. This follows on from our previous MD simulation studies on the influence of loop lengths on the topology of intramolecular quadruplex structures [P. Hazel et al. (2004) J. Am. Chem. Soc., 126, 16 405–16 415], which provided results consistent with biophysical data. The recent crystal structures of d(G4T3G4)2 and d(G4BrUT2G4) (P. Hazel et al. (2006) J. Am. Chem. Soc., in press) and the NMR-determined topology of d(TG4T2G4T)2 [A.T. Phan et al. (2004) J. Mol. Biol., 338, 93–102] have been used in the present study for comparison with simulation results. These together with MM-PBSA free-energy calculations indicate that lateral T3 loops are favoured over diagonal loops, in accordance with the experimental structures; however, distinct loop conformations have been predicted to be favoured compared to those found experimentally. Several lateral and diagonal loop conformations have been found to be similar in energy. The simulations suggest an explanation for the distinct patterns of observed dimer topology for sequences with T3 and T2 loops, which depend on the loop lengths, rather than only on G-quartet stability.
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Affiliation(s)
| | | | - Stephen Neidle
- To whom correspondence should be addressed. Tel: 44 207 753 5969; Fax: 44 207 753 5970;
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42
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Zhang N, Phan AT, Patel DJ. (3 + 1) Assembly of three human telomeric repeats into an asymmetric dimeric G-quadruplex. J Am Chem Soc 2006; 127:17277-85. [PMID: 16332077 PMCID: PMC4693638 DOI: 10.1021/ja0543090] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We present an NMR study on the structure of a DNA fragment of the human telomere containing three guanine-tracts, d(GGGTTAGGGTTAGGGT). This sequence forms in Na(+) solution a unique asymmetric dimeric quadruplex, in which the G-tetrad core involves all three G-tracts of one strand and only the last 3'-end G-tract of the other strand. We show that a three-repeat human telomeric sequence can also associate with a single-repeat human telomeric sequence into a structure with the same topology that we name (3 + 1) quadruplex assembly. In this G-quadruplex assembly, there are one syn.syn.syn.anti and two anti.anti.anti.syn G-tetrads, two edgewise loops, three G-tracts oriented in one direction and the fourth oriented in the opposite direction. We discuss the possible implications of the new folding topology for understanding the structure of telomeric DNA, including t-loop formation, and for targeting G-quadruplexes in the telomeres.
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43
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Jaumot J, Eritja R, Tauler R, Gargallo R. Resolution of a structural competition involving dimeric G-quadruplex and its C-rich complementary strand. Nucleic Acids Res 2006; 34:206-16. [PMID: 16397299 PMCID: PMC1325204 DOI: 10.1093/nar/gkj421] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The resolution of the dimeric intermolecular G-quadruplex/duplex competition of the telomeric DNA sequence 5′-TAG GGT TAG GGT-3′ and of its complementary 5′ ACC CTA ACC CTA-3′ is reported. To achieve this goal, melting experiments of both sequences and of the mixtures of these sequences were monitored by molecular absorption, molecular fluorescence and circular dichroism spectroscopies. Molecular fluorescence measurements were carried out using molecular beacons technology, in which the 5′-TAG GGT TAG GGT-3′ sequence was labelled with a fluorophore and a quencher at the ends of the strand. Mathematical analysis of experimental spectroscopic data was performed by means of multivariate curve resolution, allowing the calculation of concentration profiles and pure spectra of all resolved structures (dimeric antiparallel and parallel G-quadruplexes, Watson–Crick duplex and single strands) present in solution. Our results show that parallel G-quadruplex is more stable than antiparallel G-quadruplex. When the complementary C-rich strand is present, a mixture of both G-quadruplex structures and Watson–Crick duplex is observed, the duplex being the major species. In addition to melting temperatures, equilibrium constants for the parallel/antiparallel G-quadruplex equilibrium and for the G-quadruplex/duplex equilibrium were determined from the concentration profiles.
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Affiliation(s)
| | - Ramon Eritja
- Department of Structural Biology, IBMB-CSICJordi Girona 18-26, Barcelona, E-08034 Spain
| | - Romà Tauler
- Department of Environmental Chemistry, IIQAB-CSICJordi Girona 18-26, Barcelona, E-08034 Spain
| | - Raimundo Gargallo
- To whom correspondence should be addressed. Tel: +34 934034445; Fax: +34 934021233;
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44
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Rankin S, Reszka AP, Huppert J, Zloh M, Parkinson GN, Todd AK, Ladame S, Balasubramanian S, Neidle S. Putative DNA quadruplex formation within the human c-kit oncogene. J Am Chem Soc 2005; 127:10584-9. [PMID: 16045346 PMCID: PMC2195896 DOI: 10.1021/ja050823u] [Citation(s) in RCA: 468] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The DNA sequence, d(AGGGAGGGCGCTGGGAGGAGGG), occurs within the promoter region of the c-kit oncogene. We show here, using a combination of NMR, circular dichroism, and melting temperature measurements, that this sequence forms a four-stranded quadruplex structure under physiological conditions. Variations in the sequences that intervene between the guanine tracts have been examined, and surprisingly, none of these modified sequences forms a quadruplex arrangement under these conditions. This suggests that the occurrence of quadruplex-forming sequences within the human and other genomes is less than was hitherto expected. The c-kit quadruplex may be a new target for therapeutic intervention in cancers where there is elevated expression of the c-kit gene.
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Affiliation(s)
- Sarah Rankin
- Cancer Research UK Biomolecular Structure Group, The School of Pharmacy, University of London, 29-39 Brunswick Square, London WC1N 1AX, UK
| | - Anthony P. Reszka
- Cancer Research UK Biomolecular Structure Group, The School of Pharmacy, University of London, 29-39 Brunswick Square, London WC1N 1AX, UK
| | - Julian Huppert
- Cancer Research UK Biomolecular Structure Group, The School of Pharmacy, University Chemical Laboratory, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Mire Zloh
- Cancer Research UK Biomolecular Structure Group, The School of Pharmacy, University of London, 29-39 Brunswick Square, London WC1N 1AX, UK
| | - Gary N. Parkinson
- Cancer Research UK Biomolecular Structure Group, The School of Pharmacy, University of London, 29-39 Brunswick Square, London WC1N 1AX, UK
| | - Alan K. Todd
- Cancer Research UK Biomolecular Structure Group, The School of Pharmacy, University of London, 29-39 Brunswick Square, London WC1N 1AX, UK
| | - Sylvain Ladame
- Cancer Research UK Biomolecular Structure Group, The School of Pharmacy, University Chemical Laboratory, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Shankar Balasubramanian
- Cancer Research UK Biomolecular Structure Group, The School of Pharmacy, University Chemical Laboratory, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Stephen Neidle
- Cancer Research UK Biomolecular Structure Group, The School of Pharmacy, University of London, 29-39 Brunswick Square, London WC1N 1AX, UK
- E-mail:
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45
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Miyoshi D, Karimata H, Sugimoto N. Drastic Effect of a Single Base Difference between Human andTetrahymena Telomere Sequences on Their Structures under Molecular Crowding Conditions. Angew Chem Int Ed Engl 2005. [DOI: 10.1002/ange.200462667] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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46
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Miyoshi D, Karimata H, Sugimoto N. Drastic Effect of a Single Base Difference between Human andTetrahymena Telomere Sequences on Their Structures under Molecular Crowding Conditions. Angew Chem Int Ed Engl 2005; 44:3740-4. [PMID: 15861380 DOI: 10.1002/anie.200462667] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Daisuke Miyoshi
- Frontier Institute for Biomolecular Engineering Research, Konan University, Kobe, Japan
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47
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Rujan IN, Meleney JC, Bolton PH. Vertebrate telomere repeat DNAs favor external loop propeller quadruplex structures in the presence of high concentrations of potassium. Nucleic Acids Res 2005; 33:2022-31. [PMID: 15817566 PMCID: PMC1074753 DOI: 10.1093/nar/gki345] [Citation(s) in RCA: 148] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The circular dichroism, CD, spectra of the telomere repeats of vertebrates, d(TTAGGG), indicate that parallel type quadruplex structures or disordered single-stranded structures are formed in low salt. Anti-parallel quadruplex structures are favored in the presence of high concentrations, 140 mM, of sodium. External loop, also known as propeller, parallel type structures are favored in the presence of high concentrations, 100 mM, of potassium in the presence of either 5 or 140 mM sodium. The cation dependence of the CD spectra of the vertebrate telomere repeat DNAs is distinctly different from that of the telomere repeats of Tetrahymena and Oxytricha as well as that of the thrombin binding aptamer. These results indicate that the external loop structures may be present in vertebrate telomeres under the conditions of high potassium and low sodium concentration found in nuclei.
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Affiliation(s)
| | | | - Philip H. Bolton
- To whom correspondence should be addressed. Tel: +1 860 685 2668; Fax: +1 860 685 2211;
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48
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Phan AT, Modi YS, Patel DJ. Propeller-type parallel-stranded G-quadruplexes in the human c-myc promoter. J Am Chem Soc 2004; 126:8710-6. [PMID: 15250723 PMCID: PMC4692381 DOI: 10.1021/ja048805k] [Citation(s) in RCA: 426] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The nuclease-hypersensitivity element III1 in the c-myc promoter is a good anticancer target since it largely controls transcriptional activation of the important c-myc oncogene. Recently, the guanine-rich strand of this element has been shown to form an equilibrium between G-quadruplex structures built from two different sets of G-stretches; two models of intramolecular fold-back antiparallel-stranded G-quadruplexes, called "basket" and "chair" forms, were proposed. Here, we show by NMR that two sequences containing these two sets of G-stretches form intramolecular propeller-type parallel-stranded G-quadruplexes in K(+)-containing solution. The two structures involve a core of three stacked G-tetrads formed by four parallel G-stretches with all anti guanines and three double-chain-reversal loops bridging three G-tetrad layers. The central loop contains two or six residues, while the two other loops contain only one residue.
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Affiliation(s)
- Anh Tuân Phan
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA.
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