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Bednarz A, Rosendal RT, Lund LM, Birkedal V. Probing G-quadruplex-ligand binding using DNA intrinsic fluorescence. Biochimie 2024:S0300-9084(24)00145-7. [PMID: 38936685 DOI: 10.1016/j.biochi.2024.06.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 06/24/2024] [Accepted: 06/24/2024] [Indexed: 06/29/2024]
Abstract
G-quadruplexes (G4s) are helical four-stranded nucleic acid structures that can form in guanine-rich sequences, which are mostly found in functional cellular regions, such as telomeres, promoters, and DNA replication origins. Great efforts are being made to target these structures towards the development of specific small molecule G4 binders for novel anti-cancer, neurological, and viral therapies. Here, we introduce an optical assay based on quenching of the intrinsic fluorescence of DNA G-quadruplexes for assessing and comparing the G4 binding affinity of various small molecule ligands in solutions. We show that the approach allows direct quantification of ligand binding to distinctive G4 topologies. We believe that this method will facilitate quick and reliable evaluation of small molecule G4 ligands and support their development.
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Affiliation(s)
- Aleksandra Bednarz
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Denmark; Department of Chemistry, Aarhus University, Denmark
| | - Rebecca Torp Rosendal
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Denmark; Department of Chemistry, Aarhus University, Denmark
| | - Line Mørkholt Lund
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Denmark; Department of Chemistry, Aarhus University, Denmark
| | - Victoria Birkedal
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Denmark; Department of Chemistry, Aarhus University, Denmark.
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2
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Ciaco S, Aronne R, Fiabane M, Mori M. The Rise of Bacterial G-Quadruplexes in Current Antimicrobial Discovery. ACS OMEGA 2024; 9:24163-24180. [PMID: 38882119 PMCID: PMC11170735 DOI: 10.1021/acsomega.4c01731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 05/10/2024] [Accepted: 05/17/2024] [Indexed: 06/18/2024]
Abstract
Antimicrobial resistance (AMR) is a silent critical issue that poses several challenges to health systems. While the discovery of novel antibiotics is currently stalled and prevalently focused on chemical variations of the scaffolds of available drugs, novel targets and innovative strategies are urgently needed to face this global threat. In this context, bacterial G-quadruplexes (G4s) are emerging as timely and profitable targets for the design and development of antimicrobial agents. Indeed, they are expressed in regulatory regions of bacterial genomes, and their modulation has been observed to provide antimicrobial effects with translational perspectives in the context of AMR. In this work, we review the current knowledge of bacterial G4s as well as their modulation by small molecules, including tools and techniques suitable for these investigations. Finally, we critically analyze the needs and future directions in the field, with a focus on the development of small molecules as bacterial G4s modulators endowed with remarkable drug-likeness.
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Affiliation(s)
- Stefano Ciaco
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - Rossella Aronne
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - Martina Fiabane
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
| | - Mattia Mori
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
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3
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Zhang Q, Liu A, Song X, Xu S, Da L, Lin D, Jiang C. Ultrasensitive Fluorescent Microsensors Based on Aptamers Modified with SYBR Green I for Visual Quantitative Detection of Organophosphate Pesticides. Anal Chem 2024; 96:9636-9642. [PMID: 38808501 DOI: 10.1021/acs.analchem.4c01307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2024]
Abstract
Organophosphate pesticides (OPs) are widely utilized in agricultural production, and the residues threaten public health and environmental safety due to their toxicity. Herein, a novel and simple DNA aptamer-based sensor has been fabricated for the rapid, visual, and quantitative detection of profenofos and isocarbophos. The proposed DNA aptamers with a G-quadruplex spatial structure could be recognized by SYBR Green I (SG-I), resulting in strong green fluorescence emitted by SG-I. The DNA aptamers exhibit a higher specific binding ability to target OP molecules through aromatic ring stacking, disrupting the interaction between SG-I and DNA aptamers to induce green fluorescence quenching. Meanwhile, the fluorescence wavelength of G-quadruplex fluorescence emission peaks changes, accompanied by an obvious fluorescence variation from green to blue. SG-I-modified aptasensor without any additive reference fluorescence units for use in multicolor fluorescence assay for selective monitoring of OPs was first developed. The developed aptasensor provides a favorable linear range from 0 to 200 nM, with a low detection limit of 2.48 and 3.01 nM for profenofos and isocarbophos, respectively. Moreover, it offers high selectivity and stability in real sample detection with high recoveries. Then, a self-designed portable smartphone sensing platform was successfully used for quantitative result outputs, demonstrating experience in designing a neotype sensing strategy for point-of-care pesticide monitoring.
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Affiliation(s)
- Qianru Zhang
- Institute of Solid State Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, China
- Department of Chemistry, University of Science and Technology of China, Hefei 230026, China
- School of Chemistry and Materials Engineering, Huainan Normal University, Huainan, Anhui 232038, China
| | - Anqi Liu
- Institute of Solid State Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - Xin Song
- Hefei Public Security Bureau, Hefei, Anhui 230001, China
| | - Shihao Xu
- Institute of Solid State Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - Liangguo Da
- School of Chemistry and Materials Engineering, Huainan Normal University, Huainan, Anhui 232038, China
| | - Dan Lin
- Institute of Solid State Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, China
- State Key Laboratory of Transducer Technology, Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - Changlong Jiang
- Institute of Solid State Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, China
- State Key Laboratory of Transducer Technology, Chinese Academy of Sciences, Hefei, Anhui 230031, China
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4
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Boyer JA, Sharma M, Dorso MA, Mai N, Amor C, Reiter JM, Kannan R, Gadal S, Xu J, Miele M, Li Z, Chen X, Chang Q, Pareja F, Worland S, Warner D, Sperry S, Chiang GG, Thompson PA, Yang G, Ouerfelli O, de Stanchina E, Wendel HG, Rosen EY, Chandarlapaty S, Rosen N. eIF4A controls translation of estrogen receptor alpha and is a therapeutic target in advanced breast cancer. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.08.593195. [PMID: 38766126 PMCID: PMC11100762 DOI: 10.1101/2024.05.08.593195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
The majority of human breast cancers are dependent on hormone-stimulated estrogen receptor alpha (ER) and are sensitive to its inhibition. Treatment resistance arises in most advanced cancers due to genetic alterations that promote ligand independent activation of ER itself or ER target genes. Whereas re-targeting of the ER ligand binding domain (LBD) with newer ER antagonists can work in some cases, these drugs are largely ineffective in many genetic backgrounds including ER fusions that lose the LBD or in cancers that hyperactivate ER targets. By identifying the mechanism of ER translation, we herein present an alternative strategy to target ER and difficult to treat ER variants. We find that ER translation is cap-independent and mTOR inhibitor insensitive, but dependent on 5' UTR elements and sensitive to pharmacologic inhibition of the translation initiation factor eIF4A, an mRNA helicase. EIF4A inhibition rapidly reduces expression of ER and short-lived targets of ER such as cyclin D1 and other components of the cyclin D-CDK complex in breast cancer cells. These effects translate into suppression of growth of a variety of ligand-independent breast cancer models including those driven by ER fusion proteins that lack the ligand binding site. The efficacy of eIF4A inhibition is enhanced when it is combined with fulvestrant-an ER degrader. Concomitant inhibition of ER synthesis and induction of its degradation causes synergistic and durable inhibition of ER expression and tumor growth. The clinical importance of these findings is confirmed by results of an early clinical trial (NCT04092673) of the selective eIF4A inhibitor zotatifin in patients with estrogen receptor positive metastatic breast cancer. Multiple clinical responses have been observed on combination therapy including durable regressions. These data suggest that eIF4A inhibition could be a useful new strategy for treating advanced ER+ breast cancer.
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Affiliation(s)
- Jacob A. Boyer
- Louis V. Gerstner Jr. Graduate School of Biomedical Sciences, Memorial Sloan-Kettering Cancer Center, New York, NY, USA
- Program in Molecular Pharmacology, Department of Medicine, Memorial Sloan-Kettering Cancer Center (MSKCC), New York, NY, USA
- Ludwig Institute for Cancer Research, Princeton University, Princeton, NJ, USA
| | - Malvika Sharma
- Program in Molecular Pharmacology, Department of Medicine, Memorial Sloan-Kettering Cancer Center (MSKCC), New York, NY, USA
| | - Madeline A. Dorso
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Nicholas Mai
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Corina Amor
- Louis V. Gerstner Jr. Graduate School of Biomedical Sciences, Memorial Sloan-Kettering Cancer Center, New York, NY, USA
- Department of Cancer Biology and Genetics, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Jason M. Reiter
- Program in Molecular Pharmacology, Department of Medicine, Memorial Sloan-Kettering Cancer Center (MSKCC), New York, NY, USA
| | - Ram Kannan
- Department of Cancer Biology and Genetics, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Sunyana Gadal
- Program in Molecular Pharmacology, Department of Medicine, Memorial Sloan-Kettering Cancer Center (MSKCC), New York, NY, USA
| | - Jianing Xu
- Program in Molecular Pharmacology, Department of Medicine, Memorial Sloan-Kettering Cancer Center (MSKCC), New York, NY, USA
| | - Matthew Miele
- Microchemistry and Proteomics Core Facility, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Zhuoning Li
- Microchemistry and Proteomics Core Facility, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Xiaoping Chen
- Antitumor Assessment Core Facility, Memorial Sloan Kettering Cancer Center, New York, NY 11065, USA
| | - Qing Chang
- Antitumor Assessment Core Facility, Memorial Sloan Kettering Cancer Center, New York, NY 11065, USA
| | - Fresia Pareja
- Department of Pathology and Laboratory Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Stephan Worland
- Department of Cancer Biology, eFFECTOR Therapeutics, Inc., San Diego, CA, United States
| | - Douglas Warner
- Department of Cancer Biology, eFFECTOR Therapeutics, Inc., San Diego, CA, United States
| | - Sam Sperry
- Department of Cancer Biology, eFFECTOR Therapeutics, Inc., San Diego, CA, United States
| | - Gary G. Chiang
- Department of Cancer Biology, eFFECTOR Therapeutics, Inc., San Diego, CA, United States
| | - Peggy A. Thompson
- Department of Cancer Biology, eFFECTOR Therapeutics, Inc., San Diego, CA, United States
| | - Guangli Yang
- The Organic Synthesis Core Facility, MSK, New York, NY, USA
| | | | - Elisa de Stanchina
- Antitumor Assessment Core Facility, Memorial Sloan Kettering Cancer Center, New York, NY 11065, USA
| | - Hans-Guido Wendel
- Department of Cancer Biology and Genetics, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Ezra Y. Rosen
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Sarat Chandarlapaty
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, New York
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Department of Medicine, Weill Cornell Medicine, New York, NY, USA
| | - Neal Rosen
- Program in Molecular Pharmacology, Department of Medicine, Memorial Sloan-Kettering Cancer Center (MSKCC), New York, NY, USA
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5
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Markovitsi D. Processes triggered in guanine quadruplexes by direct absorption of UV radiation: From fundamental studies toward optoelectronic biosensors. Photochem Photobiol 2024; 100:262-274. [PMID: 37365765 DOI: 10.1111/php.13826] [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: 05/03/2023] [Revised: 05/29/2023] [Accepted: 05/30/2023] [Indexed: 06/28/2023]
Abstract
Guanine quadruplexes (GQs) are four-stranded DNA/RNA structures exhibiting an important polymorphism. During the past two decades, their study by time-resolved spectroscopy, from femtoseconds to milliseconds, associated to computational methods, shed light on the primary processes occurring when they absorb UV radiation. Quite recently, their utilization in label-free and dye-free biosensors was explored by a few groups. In view of such developments, this review discusses the outcomes of the fundamental studies that could contribute to the design of future optoelectronic biosensors using fluorescence or charge carriers stemming directly from GQs, without mediation of other molecules, as it is the currently the case. It explains how the excited state relaxation influences both the fluorescence intensity and the efficiency of low-energy photoionization, occurring via a complex mechanism. The corresponding quantum yields, determined with excitation at 266/267 nm, fall in the range of (3.0-9.5) × 10-4 and (3.2-9.2) × 10-3 , respectively. These values, significantly higher than the corresponding values found for duplexes, depend strongly on certain structural factors (molecularity, metal cations, peripheral bases, number of tetrads …) which intervene in the relaxation process. Accordingly, these features can be tuned to optimize the desired signal.
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Affiliation(s)
- Dimitra Markovitsi
- CNRS, Institut de Chimie Physique, UMR8000, Université Paris-Saclay, Orsay, France
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6
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Tevonyan LL, Beniaminov AD, Kaluzhny DN. Quenching of G4-DNA intrinsic fluorescence by ligands. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2024; 53:47-56. [PMID: 38217705 DOI: 10.1007/s00249-023-01696-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 11/10/2023] [Accepted: 12/11/2023] [Indexed: 01/15/2024]
Abstract
G-quadruplex (G4) structures formed by the guanine-rich DNA regions exhibit several distinctive optical properties, including UV absorption and circular dichroism spectra. Some G4 DNA possess intrinsic UV fluorescence whose origin is not completely clear to date. In this work, we study the effect of TMPyP4 and Methylene Blue on the intrinsic fluorescence of the dimeric G4 DNA structure formed by two d(G3T)4 sequences. We demonstrate that binding of the ligands results in quenching of the intrinsic fluorescence, although the conformation of the G4 DNA and its dimeric structure remain preserved. The binding sites of the ligands were suggested by the photoinduced oxidation of guanines and analysis of binding isoterms. We discuss how DNA-ligand complexes can affect the intrinsic fluorescence of G4 DNA.
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Affiliation(s)
- Liana L Tevonyan
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991, Moscow, Russia
| | - Artemy D Beniaminov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991, Moscow, Russia
| | - Dmitry N Kaluzhny
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991, Moscow, Russia.
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7
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Lyu K, Kwok CK. RNA G-quadruplex (rG4) structure detection using RTS and SHALiPE assays. Methods Enzymol 2023; 691:63-80. [PMID: 37914452 DOI: 10.1016/bs.mie.2023.06.003] [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] [Indexed: 11/03/2023]
Abstract
RNA G-quadruplexes (rG4s) are non-canonical RNA secondary structures that were first reported several decades ago. Latest studies have suggested that they are widespread in the transcriptomes of diverse species, and they have been demonstrated to have key roles in various fundamental cellular processes. Among the RNA secondary structure probing assays developed recently, Reverse transcriptase stalling (RTS) and selective 2'-hydroxyl acylation analyzed by lithium ion-based primer extension (SHALiPE) enabled the identification and characterization of distinct structural features of an rG4 structure of interest. Herein, we present an experimental protocol describing in detail the procedures involved in the preparation of in vitro transcribed RNAs, buffers, and reagents for RTS and SHALiPE assays, as well as performing RTS and SHALiPE assays, to examine the formation of rG4 and reveal the rG4 structural conformation at nucleotide resolution in vitro. RTS and SHALiPE assays can be performed by an experienced molecular biologist or chemical biologist with a basic understanding of nucleic acids. The duration for the preparation of in vitro transcription and RNA preparation is around 2 days, and the duration for RTS and SHALiPE assays is approximately 5 h.
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Affiliation(s)
- Kaixin Lyu
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong SAR, P.R. China
| | - Chun Kit Kwok
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong SAR, P.R. China; Shenzhen Research Institute of City University of Hong Kong, Shenzhen, China.
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8
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Balanikas E, Gustavsson T, Markovitsi D. Fluorescence of Bimolecular Guanine Quadruplexes: From Femtoseconds to Nanoseconds. J Phys Chem B 2023; 127:172-179. [PMID: 36577031 DOI: 10.1021/acs.jpcb.2c07647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The paper deals with the fluorescence of guanine quadruplexes (G4) formed by association of two DNA strands d(GGGGTTTTGGGG) in the presence of K+ cations, noted as OXY/K+ in reference to the protozoon Oxytricha nova, whose telomere contains TTTTGGGG repeats. They were studied by steady-state and time-resolved techniques, time-correlated single photon counting, and fluorescence upconversion. The maximum of the OXY/K+ fluorescence spectrum is located at 334 nm, and the quantum yield is 5.8 × 10-4. About 75% of the photons are emitted before 100 ps and stem from ππ* states, possibly with a small contribution of charge transfer. Time-resolved fluorescence anisotropy measurements indicate that ultrafast (<330 fs) excitation transfer, due to internal conversion among exciton states, is more efficient in OXY/K+ compared to previously studied G4 structures. This is attributed to the arrangement of the peripheral thymines in two diagonal loops with restricted mobility, facilitating the interaction among them and with guanines. Thymines should also be responsible for a weak intensity excimer/exciplex emission band, peaking at 445 nm. Finally, the longest living fluorescence component (∼2.1 ns) is observed at the blue side of the spectrum. So far, high-energy long-lived emitting states had been reported only for double-stranded structures but not for G4.
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Affiliation(s)
| | - Thomas Gustavsson
- CEA, CNRS, LIDYL, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
| | - Dimitra Markovitsi
- CEA, CNRS, LIDYL, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France.,CNRS, Institut de Chimie Physique, UMR8000, Université Paris-Saclay, 91405 Orsay, France
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9
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Spiridonova VA, Naumova YO, Nikolaeva PA, Novikova TM, Kolomijtseva GY. Thermodynamics and Kinetics of Unfolding of Antiparallel G-Quadruplexes in Anti-Thrombin Aptamers. BIOCHEMISTRY. BIOKHIMIIA 2022; 87:1292-1300. [PMID: 36509716 DOI: 10.1134/s0006297922110086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The process of unfolding of G-quadruplex structure in the RE31 DNA-aptamer and in its complex with thrombin under the action of the fluorescently labeled complementary oligonucleotides of varying length with formation of double-helix structures has been studied. It has been suggested that G-quadruplex unfolding involves formation of an intermediate complex with an oligonucleotide. Thermodynamic parameters and kinetics of unfolding of the free aptamer and its complex with thrombin differ. Extension of the oligonucleotide sequence complementary to G-quadruplex by two nucleotides to cover the so-called "hinge region" had little impact on the conformational transition of G-quadruplex of the free aptamer. However, a pronounced effect has been observed for the aptamer-protein complex. Most likely these differences could be explained by the thrombin-induced conformational transition of the aptamer involving the hinge region.
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Affiliation(s)
- Vera A Spiridonova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Yulia O Naumova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Polina A Nikolaeva
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Tatiana M Novikova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Galina Ya Kolomijtseva
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.
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10
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Lopez A, Liu J. Probing metal-dependent G-quadruplexes using the intrinsic fluorescence of DNA. Chem Commun (Camb) 2022; 58:10225-10228. [PMID: 36001027 DOI: 10.1039/d2cc03967b] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
K+ enhanced the intrinsic fluorescence of a series of G-quadruplex DNAs, while Pb2+ quenched the fluorescence. The metals showed interesting quadruplex binding kinetics with various DNA sequences.
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Affiliation(s)
- Anand Lopez
- Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada.
| | - Juewen Liu
- Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada.
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11
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Liu H, Chu Z, Yang X. A Key Molecular Regulator, RNA G-Quadruplex and Its Function in Plants. FRONTIERS IN PLANT SCIENCE 2022; 13:926953. [PMID: 35783953 PMCID: PMC9242502 DOI: 10.3389/fpls.2022.926953] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Accepted: 05/24/2022] [Indexed: 06/15/2023]
Abstract
RNA structure plays key roles in plant growth, development, and adaptation. One of the complex RNA structures is the RNA G-quadruplex (RG4) where guanine-rich sequences are folded into two or more layers of G-quartets. Previous computational predictions of RG4 revealed that it is widespread across the whole transcriptomes in many plant species, raising the hypothesis that RG4 is likely to be an important regulatory motif in plants. Recently, with the advances in both high-throughput sequencing and cell imaging technologies, RG4 can be detected in living cells as well as at the genome-wide scale. Here, we provide a comprehensive review of recent developments in new methods for detecting RG4 in plants. We also summarize the new functions of RG4 in regulating plant growth and development. We then discuss the possible role of RG4 in adapting to environmental conditions along with evolutionary perspectives.
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Affiliation(s)
- Haifeng Liu
- State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Taian, China
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
| | - Zhaohui Chu
- State Key Laboratory of Hybrid Rice, Hubei Hongshan Laboratory, College of Life Sciences, Wuhan University, Wuhan, China
| | - Xiaofei Yang
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai, China
- CAS-JIC Centre of Excellence for Plant and Microbial Science, Shanghai, China
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12
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Lockd promotes myoblast proliferation and muscle regeneration via binding with DHX36 to facilitate 5' UTR rG4 unwinding and Anp32e translation. Cell Rep 2022; 39:110927. [PMID: 35675771 DOI: 10.1016/j.celrep.2022.110927] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 02/10/2022] [Accepted: 05/18/2022] [Indexed: 11/20/2022] Open
Abstract
Adult muscle stem cells, also known as satellite cells (SCs), play pivotal roles in muscle regeneration, and long non-coding RNA (lncRNA) functions in SCs remain largely unknown. Here, we identify a lncRNA, Lockd, which is induced in activated SCs upon acute muscle injury. We demonstrate that Lockd promotes SC proliferation; deletion of Lockd leads to cell-cycle arrest, and in vivo repression of Lockd in mouse muscles hinders regeneration process. Mechanistically, we show that Lockd directly interacts with RNA helicase DHX36 and the 5'end of Lockd possesses the strongest binding with DHX36. Furthermore, we demonstrate that Lockd stabilizes the interaction between DHX36 and EIF3B proteins; synergistically, this complex unwinds the RNA G-quadruplex (rG4) structure formed at Anp32e mRNA 5' UTR and promotes the translation of ANP32E protein, which is required for myoblast proliferation. Altogether, our findings identify a regulatory Lockd/DHX36/Anp32e axis that promotes myoblast proliferation and acute-injury-induced muscle regeneration.
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13
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Mou X, Liew SW, Kwok CK. Identification and targeting of G-quadruplex structures in MALAT1 long non-coding RNA. Nucleic Acids Res 2022; 50:397-410. [PMID: 34904666 PMCID: PMC8754639 DOI: 10.1093/nar/gkab1208] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 10/07/2021] [Accepted: 11/24/2021] [Indexed: 12/11/2022] Open
Abstract
RNA G-quadruplexes (rG4s) have functional roles in many cellular processes in diverse organisms. While a number of rG4 examples have been reported in coding messenger RNAs (mRNA), so far only limited works have studied rG4s in non-coding RNAs (ncRNAs), especially in long non-coding RNAs (lncRNAs) that are of emerging interest and significance in biology. Herein, we report that MALAT1 lncRNA contains conserved rG4 motifs, forming thermostable rG4 structures with parallel topology. We also show that rG4s in MALAT1 lncRNA can interact with NONO protein with high specificity and affinity in vitro and in nuclear cell lysate, and we provide cellular data to support that NONO protein recognizes MALAT1 lncRNA via rG4 motifs. Notably, we demonstrate that rG4s in MALAT1 lncRNA can be targeted by the rG4-specific small molecule, peptide, and L-aptamer, leading to the dissociation of MALAT1 rG4-NONO protein interaction. Altogether, this study uncovers new and important rG4s in MALAT1 lncRNAs, reveals their specific interactions with NONO protein, offers multiple strategies for targeting MALAT1 and its RNA-protein complex via its rG4 structure and illustrates the prevalence and significance of rG4s in ncRNAs.
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Affiliation(s)
- Xi Mou
- Department of Chemistry and State Key Laboratory of Marine Pollution, City
University of Hong Kong, Kowloon Tong, Hong Kong
SAR, China
| | - Shiau Wei Liew
- Department of Chemistry and State Key Laboratory of Marine Pollution, City
University of Hong Kong, Kowloon Tong, Hong Kong
SAR, China
| | - Chun Kit Kwok
- Department of Chemistry and State Key Laboratory of Marine Pollution, City
University of Hong Kong, Kowloon Tong, Hong Kong
SAR, China
- Shenzhen Research Institute of City University of Hong Kong,
Shenzhen, China
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14
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Feng H, Kwok CK. Spectroscopic analysis reveals the effect of hairpin loop formation on G-quadruplex structures. RSC Chem Biol 2022; 3:431-435. [PMID: 35441140 PMCID: PMC8984947 DOI: 10.1039/d2cb00045h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 02/28/2022] [Indexed: 12/02/2022] Open
Abstract
We study and uncover the effect of hairpin structures in loops of G-quadruplexes using spectroscopic methods. Notably, we show that the sequence, structure, and position of the hairpin loop control the spectroscopic properties of long loop G-quadruplexes, and highlight that intrinsic fluorescence can be used to monitor the formation of non-canonical G-quadruplexes. This work studies the intrinsic fluorescence properties of long-loop G-quadruplexes (G4) with hairpin loop structures, revealing the unique information of G4 provided by intrinsic fluorescence compared to other spectroscopic assays.![]()
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Affiliation(s)
- Hengxin Feng
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
| | - Chun Kit Kwok
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
- Shenzhen Research Institute of City University of Hong Kong, Shenzhen, China
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15
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Balanikas E, Martinez-Fernandez L, Improta R, Podbevšek P, Baldacchino G, Markovitsi D. The Structural Duality of Nucleobases in Guanine Quadruplexes Controls Their Low-Energy Photoionization. J Phys Chem Lett 2021; 12:8309-8313. [PMID: 34428044 DOI: 10.1021/acs.jpclett.1c01846] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Guanine quadruplexes are four-stranded DNA/RNA structures composed of a guanine core (vertically stacked guanine tetrads) and peripheral groups (dangling ends and/or loops). Such a dual structural arrangement of the nucleobases favors their photoionization at energies significantly lower than the guanine ionization potential. This effect is important with respect to the oxidative DNA damage and for applications in the field of optoelectronics. Photoionization quantum yields, determined at 266 nm by nanosecond transient absorption spectroscopy, strongly depend on both the type and position of the peripheral nucleobases. The highest value (1.5 × 10-2) is found for the tetramolecular structure (AG4A)4 in which adenines are intermittently stacked on the adjacent guanine tetrads, as determined by nuclear magnetic resonance spectroscopy. Quantum chemistry calculations show that peripheral nucleobases interfere in a key step preceding electron ejection: charge separation, initiated by the population of charge transfer states during the relaxation of electronic excited states.
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Affiliation(s)
| | - Lara Martinez-Fernandez
- Departamento de Química, Facultad de Ciencias and Institute for Advanced Research in Chemistry (IADCHEM), Universidad Autónoma de Madrid, Campus de Excelencia UAM-CSIC, Cantoblanco, 28049 Madrid, Spain
| | - Roberto Improta
- Istituto Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche, Via Mezzocannone 16, I-80134 Napoli, Italy
| | - Peter Podbevšek
- Slovenian NMR Center, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia
| | - Gérard Baldacchino
- Université Paris-Saclay, CEA, CNRS, LIDYL, F-91191 Gif-sur-Yvette, France
| | - Dimitra Markovitsi
- Université Paris-Saclay, CEA, CNRS, LIDYL, F-91191 Gif-sur-Yvette, France
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16
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Lyu K, Chow EYC, Mou X, Chan TF, Kwok CK. RNA G-quadruplexes (rG4s): genomics and biological functions. Nucleic Acids Res 2021; 49:5426-5450. [PMID: 33772593 PMCID: PMC8191793 DOI: 10.1093/nar/gkab187] [Citation(s) in RCA: 79] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 03/02/2021] [Accepted: 03/24/2021] [Indexed: 02/07/2023] Open
Abstract
G-quadruplexes (G4s) are non-classical DNA or RNA secondary structures that have been first observed decades ago. Over the years, these four-stranded structural motifs have been demonstrated to have significant regulatory roles in diverse biological processes, but challenges remain in detecting them globally and reliably. Compared to DNA G4s (dG4s), the study of RNA G4s (rG4s) has received less attention until recently. In this review, we will summarize the innovative high-throughput methods recently developed to detect rG4s on a transcriptome-wide scale, highlight the many novel and important functions of rG4 being discovered in vivo across the tree of life, and discuss the key biological questions to be addressed in the near future.
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Affiliation(s)
- Kaixin Lyu
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
| | - Eugene Yui-Ching Chow
- School of Life Sciences, and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
| | - Xi Mou
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
| | - Ting-Fung Chan
- School of Life Sciences, and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
| | - Chun Kit Kwok
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China.,Shenzhen Research Institute of City University of Hong Kong, Shenzhen, China
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17
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Volek M, Kolesnikova S, Svehlova K, Srb P, Sgallová R, Streckerová T, Redondo JA, Veverka V, Curtis EA. Overlapping but distinct: a new model for G-quadruplex biochemical specificity. Nucleic Acids Res 2021; 49:1816-1827. [PMID: 33544841 PMCID: PMC7913677 DOI: 10.1093/nar/gkab037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 01/09/2021] [Accepted: 01/18/2021] [Indexed: 11/29/2022] Open
Abstract
G-quadruplexes are noncanonical nucleic acid structures formed by stacked guanine tetrads. They are capable of a range of functions and thought to play widespread biological roles. This diversity raises an important question: what determines the biochemical specificity of G-quadruplex structures? The answer is particularly important from the perspective of biological regulation because genomes can contain hundreds of thousands of G-quadruplexes with a range of functions. Here we analyze the specificity of each sequence in a 496-member library of variants of a reference G-quadruplex with respect to five functions. Our analysis shows that the sequence requirements of G-quadruplexes with these functions are different from one another, with some mutations altering biochemical specificity by orders of magnitude. Mutations in tetrads have larger effects than mutations in loops, and changes in specificity are correlated with changes in multimeric state. To complement our biochemical data we determined the solution structure of a monomeric G-quadruplex from the library. The stacked and accessible tetrads rationalize why monomers tend to promote a model peroxidase reaction and generate fluorescence. Our experiments support a model in which the sequence requirements of G-quadruplexes with different functions are overlapping but distinct. This has implications for biological regulation, bioinformatics, and drug design.
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Affiliation(s)
- Martin Volek
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 166 10, Czech Republic.,Department of Genetics and Microbiology, Faculty of Science, Charles University in Prague, Prague 128 44, Czech Republic
| | - Sofia Kolesnikova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 166 10, Czech Republic.,Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague 166 28, Czech Republic
| | - Katerina Svehlova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 166 10, Czech Republic.,Department of Genetics and Microbiology, Faculty of Science, Charles University in Prague, Prague 128 44, Czech Republic
| | - Pavel Srb
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 166 10, Czech Republic
| | - Ráchel Sgallová
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 166 10, Czech Republic.,Department of Low-Temperature Physics, Faculty of Mathematics and Physics, Charles University in Prague, Prague 180 00, Czech Republic
| | - Tereza Streckerová
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 166 10, Czech Republic.,Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague 166 28, Czech Republic
| | - Juan A Redondo
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 166 10, Czech Republic
| | - Václav Veverka
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 166 10, Czech Republic.,Department of Cell Biology, Faculty of Science, Charles University in Prague, Prague 128 44, Czech Republic
| | - Edward A Curtis
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 166 10, Czech Republic
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18
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Abstract
The intrinsic fluorescence of nucleic acids is extremely weak compared to that of the fluorescent labels used to probe their structural and functional behavior. Thus, for technical reasons, the investigation of the intrinsic DNA fluorescence was limited for a long time. But with the improvement in spectroscopic techniques, the situation started to change around the turn of the century. During the past two decades, various factors modulating the static and dynamic properties of the DNA fluorescence have been determined; it was shown that, under certain conditions, quantum yields may be up 100 times higher than what was known so far. The ensemble of these studies opened up new paths for the development of label-free DNA fluorescence for biochemical applications. In parallel, these studies have shed new light on the primary processes leading to photoreactions that damage DNA when it absorbs UV radiation.We have been studying a variety of DNA systems, ranging from the monomeric nucleobases to double-stranded and four-stranded structures using fluorescence spectroscopy. The specificity of our work resides in the quantitative association of the steady-state fluorescence spectra with time-resolved data recorded from the femtosecond to the nanosecond timescales, made possible by the development of specific methodologies.Among others, our fluorescence studies provide information on the energy and the polarization of electronic transitions. These are valuable indicators for the evolution of electronic excitations in complex systems, where the electronic coupling between chromophores plays a key role. Highlighting collective effects that originate from electronic interactions in DNA multimers is the objective of the present Account.In contrast to the monomeric chromophores, whose fluorescence decays within a few picoseconds, that of DNA multimers persists on the nanosecond timescale. Even if long-lived states represent only a small fraction of electronic excitations, they may be crucial to the DNA photoreactivity because the probability to reach reactive conformations increases over time, owing to the incessant structural dynamics of nucleic acids.Our femtosecond studies have revealed that an ultrafast excitation energy transfer takes place among the nucleobases within duplexes and G-quadruplexes. Such an ultrafast process is possible when collective states are populated directly upon photon absorption. At much longer times, we discovered an unexpected long-lived high-energy emission stemming from what was coined "HELM excitons". These collective states, whose emission increases with the duplex size, could be responsible for the delayed fluorescence of ππ* states observed for genomic DNA.Most studies dealing with excited-state relaxation in DNA were carried out with excitation in the absorption band peaking at around 260 nm. We went beyond this and also performed the first time-resolved study with excitation in the UVA spectral range, where a very weak absorption tail is present. The resulting fluorescence decays are much slower and the fluorescence quantum yields are much higher than for UVC excitation. We showed that the base pairing of DNA strands enhances the UVA fluorescence and, in parallel, increases the photoreactivity because it modifies the nature of the involved collective excited states.
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Affiliation(s)
- Thomas Gustavsson
- Université Paris-Saclay, CEA, CNRS, LIDYL, F-91191 Gif-sur-Yvette, France
| | - Dimitra Markovitsi
- Université Paris-Saclay, CEA, CNRS, LIDYL, F-91191 Gif-sur-Yvette, France
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19
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Ogloblina AM, Iaccarino N, Capasso D, Di Gaetano S, Garzarella EU, Dolinnaya NG, Yakubovskaya MG, Pagano B, Amato J, Randazzo A. Toward G-Quadruplex-Based Anticancer Agents: Biophysical and Biological Studies of Novel AS1411 Derivatives. Int J Mol Sci 2020; 21:E7781. [PMID: 33096752 PMCID: PMC7590035 DOI: 10.3390/ijms21207781] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 10/17/2020] [Accepted: 10/19/2020] [Indexed: 12/16/2022] Open
Abstract
Certain G-quadruplex forming guanine-rich oligonucleotides (GROs), including AS1411, are endowed with cancer-selective antiproliferative activity. They are known to bind to nucleolin protein, resulting in the inhibition of nucleolin-mediated phenomena. However, multiple nucleolin-independent biological effects of GROs have also been reported, allowing them to be considered promising candidates for multi-targeted cancer therapy. Herein, with the aim of optimizing AS1411 structural features to find GROs with improved anticancer properties, we have studied a small library of AS1411 derivatives differing in the sequence length and base composition. The AS1411 derivatives were characterized by using circular dichroism and nuclear magnetic resonance spectroscopies and then investigated for their enzymatic resistance in serum and nuclear extract, as well as for their ability to bind nucleolin, inhibit topoisomerase I, and affect the viability of MCF-7 human breast adenocarcinoma cells. All derivatives showed higher thermal stability and inhibitory effect against topoisomerase I than AS1411. In addition, most of them showed an improved antiproliferative activity on MCF-7 cells compared to AS1411 despite a weaker binding to nucleolin. Our results support the hypothesis that the antiproliferative properties of GROs are due to multi-targeted effects.
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Affiliation(s)
- Anna M. Ogloblina
- N.N. Blokhin National Medical Research Center of Oncology, Ministry of Health, 115478 Moscow, Russia; (A.M.O.); (M.G.Y.)
- Department of Pharmacy, University of Naples Federico II, Via D. Montesano 49, 80131 Naples, Italy; (N.I.); (E.U.G.); (A.R.)
| | - Nunzia Iaccarino
- Department of Pharmacy, University of Naples Federico II, Via D. Montesano 49, 80131 Naples, Italy; (N.I.); (E.U.G.); (A.R.)
| | - Domenica Capasso
- Center for Life Sciences and Technologies (CESTEV), University of Naples Federico II, Via A. De Amicis 95, 80145 Naples, Italy;
| | - Sonia Di Gaetano
- Institute of Biostructures and Bioimaging, National Research Council, Via Mezzocannone 16, 80134 Naples, Italy;
| | - Emanuele U. Garzarella
- Department of Pharmacy, University of Naples Federico II, Via D. Montesano 49, 80131 Naples, Italy; (N.I.); (E.U.G.); (A.R.)
| | - Nina G. Dolinnaya
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia;
| | - Marianna G. Yakubovskaya
- N.N. Blokhin National Medical Research Center of Oncology, Ministry of Health, 115478 Moscow, Russia; (A.M.O.); (M.G.Y.)
| | - Bruno Pagano
- Department of Pharmacy, University of Naples Federico II, Via D. Montesano 49, 80131 Naples, Italy; (N.I.); (E.U.G.); (A.R.)
| | - Jussara Amato
- Department of Pharmacy, University of Naples Federico II, Via D. Montesano 49, 80131 Naples, Italy; (N.I.); (E.U.G.); (A.R.)
| | - Antonio Randazzo
- Department of Pharmacy, University of Naples Federico II, Via D. Montesano 49, 80131 Naples, Italy; (N.I.); (E.U.G.); (A.R.)
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20
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Umar MI, Kwok CK. Specific suppression of D-RNA G-quadruplex-protein interaction with an L-RNA aptamer. Nucleic Acids Res 2020; 48:10125-10141. [PMID: 32976590 PMCID: PMC7544233 DOI: 10.1093/nar/gkaa759] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 08/28/2020] [Accepted: 09/04/2020] [Indexed: 02/06/2023] Open
Abstract
G-quadruplexes (G4s) are nucleic acid structure motifs that are of significance in chemistry and biology. The function of G4s is often governed by their interaction with G4-binding proteins. Few categories of G4-specific tools have been developed to inhibit G4-protein interactions; however, until now there is no aptamer tool being developed to do so. Herein, we present a novel L-RNA aptamer that can generally bind to D-RNA G-quadruplex (rG4) structure, and interfere with rG4-protein interaction. Using hTERC rG4 as the target for in vitro selection, we report the shortest L-aptamer being developed so far, with only 25 nucleotides. Notably, this new aptamer, L-Apt.4-1c, adopts a stem-loop structure with the loop folding into an rG4 motif with two G-quartet, demonstrates preferential binding toward rG4s over non-G4s and DNA G-quadruplexes (dG4s), and suppresses hTERC rG4-nucleolin interactions. We also show that inhibition of rG4-protein interaction using L-RNA aptamer L-Apt.4-1c is comparable to or better than G4-specific ligands such as carboxypyridostatin and QUMA-1 respectively, highlighting that our approach and findings expand the current G4 toolbox, and open a new avenue for diverse applications.
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Affiliation(s)
- Mubarak I Umar
- Department of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong SAR, China
| | - Chun Kit Kwok
- Department of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong SAR, China
- Shenzhen Research Institute of City University of Hong Kong, Shenzhen, China
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21
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Imperatore C, Varriale A, Rivieccio E, Pennacchio A, Staiano M, D’Auria S, Casertano M, Altucci C, Valadan M, Singh M, Menna M, Varra M. Spectroscopic Properties of Two 5'-(4-Dimethylamino)Azobenzene Conjugated G-Quadruplex Forming Oligonucleotides. Int J Mol Sci 2020; 21:E7103. [PMID: 32993097 PMCID: PMC7582650 DOI: 10.3390/ijms21197103] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/10/2020] [Accepted: 09/24/2020] [Indexed: 12/12/2022] Open
Abstract
The synthesis of two 5'-end (4-dimethylamino)azobenzene conjugated G-quadruplex forming aptamers, the thrombin binding aptamer (TBA) and the HIV-1 integrase aptamer (T30695), was performed. Their structural behavior was investigated by means of UV, CD, fluorescence spectroscopy, and gel electrophoresis techniques in K+-containing buffers and water-ethanol blends. Particularly, we observed that the presence of the 5'-(4-dimethylamino)azobenzene moiety leads TBA to form multimers instead of the typical monomolecular chair-like G-quadruplex and almost hampers T30695 G-quadruplex monomers to dimerize. Fluorescence studies evidenced that both the conjugated G-quadruplexes possess unique fluorescence features when excited at wavelengths corresponding to the UV absorption of the conjugated moiety. Furthermore, a preliminary investigation of the trans-cis conversion of the dye incorporated at the 5'-end of TBA and T30695 showed that, unlike the free dye, in K+-containing water-ethanol-triethylamine blend the trans-to-cis conversion was almost undetectable by means of a standard UV spectrophotometer.
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Affiliation(s)
- Concetta Imperatore
- Department of Pharmacy, School of Medicine, University of Naples “Federico II”, Via D. Montesano 49, 80131 Naples, Italy; (C.I.); (E.R.); (M.C.); (M.M.)
| | - Antonio Varriale
- Institute of Food Sciences, National Research Council of Italy, via Roma 64, 83100 Avellino, Italy; (A.V.); (A.P.); (M.S.); (S.D.)
| | - Elisa Rivieccio
- Department of Pharmacy, School of Medicine, University of Naples “Federico II”, Via D. Montesano 49, 80131 Naples, Italy; (C.I.); (E.R.); (M.C.); (M.M.)
| | - Angela Pennacchio
- Institute of Food Sciences, National Research Council of Italy, via Roma 64, 83100 Avellino, Italy; (A.V.); (A.P.); (M.S.); (S.D.)
| | - Maria Staiano
- Institute of Food Sciences, National Research Council of Italy, via Roma 64, 83100 Avellino, Italy; (A.V.); (A.P.); (M.S.); (S.D.)
| | - Sabato D’Auria
- Institute of Food Sciences, National Research Council of Italy, via Roma 64, 83100 Avellino, Italy; (A.V.); (A.P.); (M.S.); (S.D.)
| | - Marcello Casertano
- Department of Pharmacy, School of Medicine, University of Naples “Federico II”, Via D. Montesano 49, 80131 Naples, Italy; (C.I.); (E.R.); (M.C.); (M.M.)
| | - Carlo Altucci
- Department of Physics “Ettore Pancini”, University of Naples Federico II, Via Cinthia, 21—Building 6, 80126 Naples, Italy; (C.A.); (M.V.); (M.S.)
| | - Mohammadhassan Valadan
- Department of Physics “Ettore Pancini”, University of Naples Federico II, Via Cinthia, 21—Building 6, 80126 Naples, Italy; (C.A.); (M.V.); (M.S.)
| | - Manjot Singh
- Department of Physics “Ettore Pancini”, University of Naples Federico II, Via Cinthia, 21—Building 6, 80126 Naples, Italy; (C.A.); (M.V.); (M.S.)
| | - Marialuisa Menna
- Department of Pharmacy, School of Medicine, University of Naples “Federico II”, Via D. Montesano 49, 80131 Naples, Italy; (C.I.); (E.R.); (M.C.); (M.M.)
| | - Michela Varra
- Department of Pharmacy, School of Medicine, University of Naples “Federico II”, Via D. Montesano 49, 80131 Naples, Italy; (C.I.); (E.R.); (M.C.); (M.M.)
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22
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Zuffo M, Gandolfini A, Heddi B, Granzhan A. Harnessing intrinsic fluorescence for typing of secondary structures of DNA. Nucleic Acids Res 2020; 48:e61. [PMID: 32313962 PMCID: PMC7293009 DOI: 10.1093/nar/gkaa257] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 03/28/2020] [Accepted: 04/03/2020] [Indexed: 12/15/2022] Open
Abstract
High-throughput investigation of structural diversity of nucleic acids is hampered by the lack of suitable label-free methods, combining fast and cheap experimental workflow with high information content. Here, we explore the use of intrinsic fluorescence emitted by nucleic acids for this scope. After a preliminary assessment of suitability of this phenomenon for tracking conformational changes of DNA, we examined steady-state emission spectra of an 89-membered set of oligonucleotides with reported conformation (G-quadruplexes (G4s), i-motifs, single- and double-strands) by means of multivariate analysis. Principal component analysis of emission spectra resulted in successful clustering of oligonucleotides into three corresponding conformational groups, without discrimination between single- and double-stranded structures. Linear discriminant analysis was exploited for the assessment of novel sequences, allowing the evaluation of their G4-forming propensity. Our method does not require any labeling agent or dye, avoiding the related bias, and can be utilized to screen novel sequences of interest in a high-throughput and cost-effective manner. In addition, we observed that left-handed (Z-) G4 structures were systematically more fluorescent than most other G4 structures, almost reaching the quantum yield of 5'-d[(G3T)3G3]-3' (G3T, the most fluorescent G4 structure reported to date).
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Affiliation(s)
- Michela Zuffo
- CNRS UMR9187, INSERM U1196, Institut Curie, PSL Research University, F-91405 Orsay, France.,CNRS UMR9187, INSERM U1196, Université Paris-Saclay, F-91405 Orsay, France
| | - Aurélie Gandolfini
- CNRS UMR9187, INSERM U1196, Institut Curie, PSL Research University, F-91405 Orsay, France.,CNRS UMR9187, INSERM U1196, Université Paris-Saclay, F-91405 Orsay, France
| | - Brahim Heddi
- Laboratoire de Biologie et de Pharmacologie Appliquée, CNRS UMR8113, École Normale Supérieure Paris-Saclay, F-94235 Cachan, France
| | - Anton Granzhan
- CNRS UMR9187, INSERM U1196, Institut Curie, PSL Research University, F-91405 Orsay, France.,CNRS UMR9187, INSERM U1196, Université Paris-Saclay, F-91405 Orsay, France
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23
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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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24
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Abstract
Guanine (G)-rich sequences in RNA can fold into diverse RNA G-quadruplex (rG4) structures to mediate various biological functions and cellular processes in eukaryotic organisms. However, the presence, locations, and functions of rG4s in prokaryotes are still elusive. We used QUMA-1, an rG4-specific fluorescent probe, to detect rG4 structures in a wide range of bacterial species both in vitro and in live cells and found rG4 to be an abundant RNA secondary structure across those species. Subsequently, to identify bacterial rG4 sites in the transcriptome, the model Escherichia coli strain and a major human pathogen, Pseudomonas aeruginosa, were subjected to recently developed high-throughput rG4 structure sequencing (rG4-seq). In total, 168 and 161 in vitro rG4 sites were found in E. coli and P. aeruginosa, respectively. Genes carrying these rG4 sites were found to be involved in virulence, gene regulation, cell envelope synthesis, and metabolism. More importantly, biophysical assays revealed the formation of a group of rG4 sites in mRNAs (such as hemL and bswR), and they were functionally validated in cells by genetic (point mutation and lux reporter assays) and phenotypic experiments, providing substantial evidence for the formation and function of rG4s in bacteria. Overall, our study uncovers important regulatory functions of rG4s in bacterial pathogenicity and metabolic pathways and strongly suggests that rG4s exist and can be detected in a wide range of bacterial species.IMPORTANCE G-quadruplex in RNA (rG4) mediates various biological functions and cellular processes in eukaryotic organisms. However, the presence, locations, and functions of rG4 are still elusive in prokaryotes. Here, we found that rG4 is an abundant RNA secondary structure across a wide range of bacterial species. Subsequently, the transcriptome-wide rG4 structure sequencing (rG4-seq) revealed that the model E. coli strain and a major human pathogen, P. aeruginosa, have 168 and 161 in vitro rG4 sites, respectively, involved in virulence, gene regulation, cell envelope, and metabolism. We further verified the regulatory functions of two rG4 sites in bacteria (hemL and bswR). Overall, this finding strongly suggests that rG4s play key regulatory roles in a wide range of bacterial species.
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25
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Ma C, Chan RCT, Chan CTL, Wong AKW, Kwok WM. Real-time Monitoring Excitation Dynamics of Human Telomeric Guanine Quadruplexes: Effect of Folding Topology, Metal Cation, and Confinement by Nanocavity Water Pool. J Phys Chem Lett 2019; 10:7577-7585. [PMID: 31769690 DOI: 10.1021/acs.jpclett.9b02932] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Guanine(G)-rich human telomeric (HT) DNA repeats, crucial to maintenance of genome stability, readily form G-quadruplexes (GQs) with various folding topologies. Research on excitation dynamics of HT-GQs is, however, scarce. Herein, we report a femtosecond time-resolved fluorescence coupled with transient absorption investigation on HT-GQ with the basket-type structure in Na+ solution. The result unveils an unusual multichannel nonradiative mechanism dominated by states with varying character of charge transfer lasting ten and hundreds of picoseconds, accounting altogether for an overwhelming ∼85% of the overall deactivation involving proton transfer. Our comparative study shows that encapsulating the GQ in nanocavity water pool or changing it into hydrid-type topologies with the presence of K+ ions alter differently energies and lifetimes of these states, yet without affecting the nature of the electronic excitation involved. The finding of this work underscores a leading role of structural rigidity in regulating the interplay with the microenvironment of photoexcited monomolecularly folded HT-GQs.
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Affiliation(s)
- Chensheng Ma
- College of Chemistry and Environmental Engineering , Shenzhen University , Shenzhen , Guangdong P. R. China
| | - Ruth C-T Chan
- College of Chemistry and Environmental Engineering , Shenzhen University , Shenzhen , Guangdong P. R. China
| | - Chris T-L Chan
- College of Chemistry and Environmental Engineering , Shenzhen University , Shenzhen , Guangdong P. R. China
| | - Allen K-W Wong
- Department of Applied Biology and Chemical Technology , The Hong Kong Polytechnic University , Hung Hom, Kowloon , Hong Kong , P. R. China
| | - Wai-Ming Kwok
- Department of Applied Biology and Chemical Technology , The Hong Kong Polytechnic University , Hung Hom, Kowloon , Hong Kong , P. R. China
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Kolesnikova S, Srb P, Vrzal L, Lawrence MS, Veverka V, Curtis EA. GTP-Dependent Formation of Multimeric G-Quadruplexes. ACS Chem Biol 2019; 14:1951-1963. [PMID: 31433157 DOI: 10.1021/acschembio.9b00428] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
G-Quadruplexes are noncanonical nucleic acid structures made up of stacked guanosine tetrads connected by short loops. They are frequently used building blocks in synthetic biology and thought to play widespread biological roles. Multimerization can change the functional properties of G-quadruplexes, and understanding the factors that modulate this process remains an important goal. Here, we report the discovery of a novel mechanism by which the formation of multimeric G-quadruplexes can be controlled using GTP. We show that GTP likely inhibits multimer formation by becoming incorporated into a tetrad in the monomeric form of the structure and define the sequence requirements of G-quadruplexes that form GTP-dependent structures. These experiments provide new insights into the small molecule control of G-quadruplex multimerization. They also suggest possible roles for GTP-dependent multimeric G-quadruplexes in both synthetic and natural biological systems.
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Affiliation(s)
- Sofia Kolesnikova
- Institute of Organic Chemistry and Biochemistry ASCR, Prague 166 10, Czech Republic
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague 166 28, Czech Republic
| | - Pavel Srb
- Institute of Organic Chemistry and Biochemistry ASCR, Prague 166 10, Czech Republic
| | - Lukáš Vrzal
- Institute of Organic Chemistry and Biochemistry ASCR, Prague 166 10, Czech Republic
| | - Michael S. Lawrence
- Cancer Center and Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, United States
| | - Václav Veverka
- Institute of Organic Chemistry and Biochemistry ASCR, Prague 166 10, Czech Republic
- Department of Cell Biology, Charles University in Prague, Faculty of Science, Prague 128 44, Czech Republic
| | - Edward A. Curtis
- Institute of Organic Chemistry and Biochemistry ASCR, Prague 166 10, Czech Republic
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Bansal A, Kukreti S. The four repeat Giardia lamblia telomere forms tetramolecular G-quadruplex with antiparallel topology. J Biomol Struct Dyn 2019; 38:1975-1983. [DOI: 10.1080/07391102.2019.1623074] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Aparna Bansal
- Nucleic Acids Research Lab, Department of Chemistry, University of Delhi (North Campus), Delhi, India
- Department of Chemistry, Hansraj College, University of Delhi (North Campus), Delhi, India
| | - Shrikant Kukreti
- Nucleic Acids Research Lab, Department of Chemistry, University of Delhi (North Campus), Delhi, India
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Chan CY, Umar MI, Kwok CK. Spectroscopic analysis reveals the effect of a single nucleotide bulge on G-quadruplex structures. Chem Commun (Camb) 2019; 55:2616-2619. [PMID: 30724299 DOI: 10.1039/c8cc09929d] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Here we investigate and reveal the effect of bulge position and bulge identity on G-quadruplexes using label-free spectroscopic techniques. Notably, we report significant differences in the spectroscopic features of bulged DNA and RNA G-quadruplexes, and demonstrate that intrinsic fluorescence can be generally used to detect the formation of canonical and non-canonical G-quadruplexes.
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Affiliation(s)
- Chun-Yin Chan
- Department of Chemistry, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China.
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Kwok CK, Marsico G, Balasubramanian S. Detecting RNA G-Quadruplexes (rG4s) in the Transcriptome. Cold Spring Harb Perspect Biol 2018; 10:10/7/a032284. [PMID: 29967010 DOI: 10.1101/cshperspect.a032284] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
RNA G-quadruplex (rG4) secondary structures are proposed to play key roles in fundamental biological processes that include the modulation of transcriptional, co-transcriptional, and posttranscriptional events. Recent methodological developments that include predictive algorithms and structure-based sequencing have enabled the detection and mapping of rG4 structures on a transcriptome-wide scale at high sensitivity and resolution. The data generated by these studies provide valuable insights into the potentially diverse roles of rG4s in biology and open up a number of mechanistic hypotheses. Herein we highlight these methodologies and discuss the associated findings in relation to rG4-related biological mechanisms.
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Affiliation(s)
- Chun Kit Kwok
- Department of Chemistry, City University of Hong Kong, Hong Kong SAR, China
| | - Giovanni Marsico
- Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom.,Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge CB2 0RE, United Kingdom
| | - Shankar Balasubramanian
- Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom.,Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge CB2 0RE, United Kingdom
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Majerová T, Streckerová T, Bednárová L, Curtis EA. Sequence Requirements of Intrinsically Fluorescent G-Quadruplexes. Biochemistry 2018; 57:4052-4062. [PMID: 29898365 DOI: 10.1021/acs.biochem.8b00252] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
G-Quadruplexes are four-stranded nucleic acid structures typically stabilized by GGGG tetrads. These structures are intrinsically fluorescent, which expands the known scope of nucleic acid function and raises the possibility that they could eventually be used as signaling components in label-free sensors constructed from DNA or RNA. In this study, we systematically investigated the effects of mutations in tetrads, loops, and overhanging nucleotides on the fluorescence intensity and maximum emission wavelength of >500 sequence variants of a reference DNA G-quadruplex. Some of these mutations modestly increased the fluorescence intensity of this G-quadruplex, while others shifted its maximum emission wavelength. Mutations that increased the fluorescence intensity were distinct from those that increased the maximum emission wavelength, suggesting a trade-off between these two biochemical properties. The fluorescence intensity and maximum emission wavelength were also correlated with multimeric state: the most fluorescent G-quadruplexes were monomers, while those with the highest maximum emission wavelengths typically formed dimeric structures. Oligonucleotides containing multiple G-quadruplexes were in some cases more fluorescent than those containing a single G-quadruplex, although this depended on the length and sequence of the spacer linking the G-quadruplexes. These experiments provide new insights into the properties of fluorescent G-quadruplexes and should aid in the development of improved label-free nucleic acid sensors.
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Affiliation(s)
- Tat'ána Majerová
- The Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences , Prague 166 10 , Czech Republic
| | - Tereza Streckerová
- The Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences , Prague 166 10 , Czech Republic.,Department of Biochemistry and Microbiology , University of Chemistry and Technology , Prague 166 10 , Czech Republic
| | - Lucie Bednárová
- The Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences , Prague 166 10 , Czech Republic
| | - Edward A Curtis
- The Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences , Prague 166 10 , Czech Republic
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31
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Qiao JQ, Cao ZM, Liang C, Chen HJ, Zheng WJ, Lian HZ. Study on the polymorphism of G-quadruplexes by reversed-phase HPLC and LC–MS. J Chromatogr A 2018; 1542:61-71. [DOI: 10.1016/j.chroma.2018.02.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 02/03/2018] [Accepted: 02/11/2018] [Indexed: 12/16/2022]
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Kwok CK, Merrick CJ. G-Quadruplexes: Prediction, Characterization, and Biological Application. Trends Biotechnol 2017; 35:997-1013. [PMID: 28755976 DOI: 10.1016/j.tibtech.2017.06.012] [Citation(s) in RCA: 240] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 06/14/2017] [Accepted: 06/15/2017] [Indexed: 02/08/2023]
Abstract
Guanine (G)-rich sequences in nucleic acids can assemble into G-quadruplex structures that involve G-quartets linked by loop nucleotides. The structural and topological diversity of G-quadruplexes have attracted great attention for decades. Recent methodological advances have advanced the identification and characterization of G-quadruplexes in vivo as well as in vitro, and at a much higher resolution and throughput, which has greatly expanded our current understanding of G-quadruplex structure and function. Accumulating knowledge about the structural properties of G-quadruplexes has helped to design and develop a repertoire of molecular and chemical tools for biological applications. This review highlights how these exciting methods and findings have opened new doors to investigate the potential functions and applications of G-quadruplexes in basic and applied biosciences.
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Affiliation(s)
- Chun Kit Kwok
- Department of Chemistry, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China.
| | - Catherine J Merrick
- Centre for Applied Entomology and Parasitology, Faculty of Natural Sciences, Keele University, Keele, Staffordshire, UK.
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Trachman RJ, Truong L, Ferré-D'Amaré AR. Structural Principles of Fluorescent RNA Aptamers. Trends Pharmacol Sci 2017; 38:928-939. [PMID: 28728963 DOI: 10.1016/j.tips.2017.06.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 06/21/2017] [Accepted: 06/21/2017] [Indexed: 11/26/2022]
Abstract
Several aptamer RNAs have been selected in vitro that bind to otherwise weakly fluorescent small molecules and enhance their fluorescence several thousand-fold. By genetically tagging cellular RNAs of interest with these aptamers and soaking cells in their cell-permeable cognate small-molecule fluorophores, it is possible to use them to study RNA localization and trafficking. These aptamers have also been fused to metabolite-binding RNAs to generate fluorescent biosensors. The 3D structures of three unrelated fluorogenic RNAs have been determined, and reveal a shared reliance on base quadruples (tetrads) to constrain the photo-excited chromophore. The structural diversity of fluorogenic RNAs and the chemical diversity of potential fluorophores to be activated are likely to yield a variety of future fluorogenic RNA tags that are optimized for different applications in RNA imaging and in the design of fluorescent RNA biosensors.
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Affiliation(s)
- Robert J Trachman
- Biochemistry and Biophysics Center, National Heart, Lung and Blood Institute, 50 South Drive MSC 8012, Bethesda, MD 20892-8012, USA
| | - Lynda Truong
- Biochemistry and Biophysics Center, National Heart, Lung and Blood Institute, 50 South Drive MSC 8012, Bethesda, MD 20892-8012, USA
| | - Adrian R Ferré-D'Amaré
- Biochemistry and Biophysics Center, National Heart, Lung and Blood Institute, 50 South Drive MSC 8012, Bethesda, MD 20892-8012, USA.
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Trachman RJ, Demeshkina NA, Lau MWL, Panchapakesan SSS, Jeng SCY, Unrau PJ, Ferré-D'Amaré AR. Structural basis for high-affinity fluorophore binding and activation by RNA Mango. Nat Chem Biol 2017; 13:807-813. [PMID: 28553947 PMCID: PMC5550021 DOI: 10.1038/nchembio.2392] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 03/22/2017] [Indexed: 02/08/2023]
Abstract
Genetically encoded fluorescent protein tags revolutionized proteome studies, while the lack of intrinsically fluorescent RNAs has hindered transcriptome exploration. Among several RNA-fluorophore complexes that potentially address this problem, RNA Mango has an exceptionally high affinity for its thiazole orange (TO)-derived fluorophore, TO1-Biotin (Kd ~3 nM), and in complex with related ligands, is one of the most red-shifted fluorescent macromolecular tags known. To elucidate how this small aptamer exhibits such properties, which make it well suited for studying low-copy cellular RNAs, we determined its 1.7 Å resolution co-crystal structure. Unexpectedly, the entire ligand, including TO, biotin, and the linker connecting them, abuts one of the near-planar faces of the three-tiered G-quadruplex. The two heterocycles of TO are held in place by two loop adenines and make a 45° angle with respect to each other. Minimizing this angle would increase quantum yield and further improve this tool for in vivo RNA visualization.
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Affiliation(s)
- Robert J Trachman
- Biochemistry and Biophysics Center, National Heart, Lung and Blood Institute, Bethesda, Maryland, USA
| | - Natalia A Demeshkina
- Biochemistry and Biophysics Center, National Heart, Lung and Blood Institute, Bethesda, Maryland, USA
| | - Matthew W L Lau
- Biochemistry and Biophysics Center, National Heart, Lung and Blood Institute, Bethesda, Maryland, USA
| | | | - Sunny C Y Jeng
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Peter J Unrau
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Adrian R Ferré-D'Amaré
- Biochemistry and Biophysics Center, National Heart, Lung and Blood Institute, Bethesda, Maryland, USA
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35
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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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36
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Bose S, Chakrabarty S, Ghosh D. Electrostatic Origin of the Red Solvatochromic Shift of DFHBDI in RNA Spinach. J Phys Chem B 2017; 121:4790-4798. [DOI: 10.1021/acs.jpcb.7b02445] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Samik Bose
- Physical and Materials
Chemistry
Division, CSIR-National Chemical Laboratory, Pune 411008, India
| | - Suman Chakrabarty
- Physical and Materials
Chemistry
Division, CSIR-National Chemical Laboratory, Pune 411008, India
| | - Debashree Ghosh
- Physical and Materials
Chemistry
Division, CSIR-National Chemical Laboratory, Pune 411008, India
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37
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Dolinnaya NG, Ogloblina AM, Yakubovskaya MG. Structure, Properties, and Biological Relevance of the DNA and RNA G-Quadruplexes: Overview 50 Years after Their Discovery. BIOCHEMISTRY (MOSCOW) 2017; 81:1602-1649. [PMID: 28260487 PMCID: PMC7087716 DOI: 10.1134/s0006297916130034] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
G-quadruplexes (G4s), which are known to have important roles in regulation of key biological processes in both normal and pathological cells, are the most actively studied non-canonical structures of nucleic acids. In this review, we summarize the results of studies published in recent years that change significantly scientific views on various aspects of our understanding of quadruplexes. Modern notions on the polymorphism of DNA quadruplexes, on factors affecting thermodynamics and kinetics of G4 folding–unfolding, on structural organization of multiquadruplex systems, and on conformational features of RNA G4s and hybrid DNA–RNA G4s are discussed. Here we report the data on location of G4 sequence motifs in the genomes of eukaryotes, bacteria, and viruses, characterize G4-specific small-molecule ligands and proteins, as well as the mechanisms of their interactions with quadruplexes. New information on the structure and stability of G4s in telomeric DNA and oncogene promoters is discussed as well as proof being provided on the occurrence of G-quadruplexes in cells. Prominence is given to novel experimental techniques (single molecule manipulations, optical and magnetic tweezers, original chemical approaches, G4 detection in situ, in-cell NMR spectroscopy) that facilitate breakthroughs in the investigation of the structure and functions of G-quadruplexes.
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Affiliation(s)
- N G Dolinnaya
- Lomonosov Moscow State University, Department of Chemistry, Moscow, 119991, Russia.
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Sherlock ME, Rumble CA, Kwok CK, Breffke J, Maroncelli M, Bevilacqua PC. Steady-State and Time-Resolved Studies into the Origin of the Intrinsic Fluorescence of G-Quadruplexes. J Phys Chem B 2016; 120:5146-58. [PMID: 27267433 DOI: 10.1021/acs.jpcb.6b03790] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Stretches of guanines in DNA and RNA can fold into guanine quadruplex structures (GQSs). These structures protect telomeres in DNA and regulate gene expression in RNA. GQSs have an intrinsic fluorescence that is sensitive to different parameters, including loop sequence and length. However, the dependence of GQS fluorescence on solution and sequence parameters and the origin of this fluorescence are poorly understood. Herein we examine effects of dangling nucleotides and cosolute conditions on GQS fluorescence using both steady-state and time-resolved fluorescence spectroscopy. The quantum yield of dGGGTGGGTGGGTGGG, termed "dG3T", is found to be modest at ∼2 × 10(-3). Nevertheless, dG3T and its variants are significantly brighter than the common nucleic acid fluorophore 2-aminopurine (2AP) largely due to their sizable extinction coefficients. Dangling 5'-end nucleotides generally reduce emission and blue-shift the resultant spectrum, whereas dangling 3'-end nucleotides slightly enhance fluorescence, particularly on the red side of the emission band. Time-resolved fluorescence decays are broadly distributed in time and require three exponential components for accurate fits. Time-resolved emission spectra suggest the presence of two emitting populations centered at ∼330 and ∼390 nm, with the redder component being a well-defined long-lived (∼1 ns) entity. Insights into GQS fluorescence obtained here should be useful in designing brighter intrinsic RNA and DNA quadruplexes for use in label-free biotechnological applications.
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Affiliation(s)
- Madeline E Sherlock
- Department of Chemistry, ‡Center for RNA Molecular Biology, and §Department of Biochemistry and Molecular Biology, Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Christopher A Rumble
- Department of Chemistry, ‡Center for RNA Molecular Biology, and §Department of Biochemistry and Molecular Biology, Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Chun Kit Kwok
- Department of Chemistry, ‡Center for RNA Molecular Biology, and §Department of Biochemistry and Molecular Biology, Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Jens Breffke
- Department of Chemistry, ‡Center for RNA Molecular Biology, and §Department of Biochemistry and Molecular Biology, Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Mark Maroncelli
- Department of Chemistry, ‡Center for RNA Molecular Biology, and §Department of Biochemistry and Molecular Biology, Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Philip C Bevilacqua
- Department of Chemistry, ‡Center for RNA Molecular Biology, and §Department of Biochemistry and Molecular Biology, Pennsylvania State University , University Park, Pennsylvania 16802, United States
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Kormuth KA, Woolford JL, Armitage BA. Homologous PNA Hybridization to Noncanonical DNA G-Quadruplexes. Biochemistry 2016; 55:1749-57. [PMID: 26950608 DOI: 10.1021/acs.biochem.6b00026] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Potential guanine (G) quadruplex-forming sequences (QFSs) found throughout the genomes and transcriptomes of organisms have emerged as biologically relevant structures. These G-quadruplexes represent novel opportunities for gene regulation at the DNA and RNA levels. Recently, the definition of functional QFSs has been expanding to include a variety of unconventional motifs, including relatively long loop sequences (i.e., >7 nucleotides) separating adjacent G-tracts. We have identified a QFS within the 25S rDNA gene from Saccharomyces cerevisae that features a long loop separating the two 3'-most G-tracts. An oligonucleotide based on this sequence, QFS3, folds into a stable G-quadruplex in vitro. We have studied the interaction between QFS3 and several loop mutants with a small, homologous (G-rich) peptide nucleic acid (PNA) oligomer that is designed to form a DNA/PNA heteroquadruplex. The PNA successfully invades the DNA quadruplex target to form a stable heteroquadruplex, but with surprisingly high PNA:DNA ratios based on surface plasmon resonance and mass spectrometric results. A model for high stoichiometry PNA-DNA heteroquadruplexes is proposed, and the implications for quadruplex targeting by G-rich PNA are discussed.
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Affiliation(s)
- Karen A Kormuth
- Department of Chemistry, ‡Department of Biological Sciences, and §Center for Nucleic Acids Science and Technology, Carnegie Mellon University , 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213-3890, United States
| | - John L Woolford
- Department of Chemistry, ‡Department of Biological Sciences, and §Center for Nucleic Acids Science and Technology, Carnegie Mellon University , 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213-3890, United States
| | - Bruce A Armitage
- Department of Chemistry, ‡Department of Biological Sciences, and §Center for Nucleic Acids Science and Technology, Carnegie Mellon University , 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213-3890, United States
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Crenshaw E, Leung BP, Kwok CK, Sharoni M, Olson K, Sebastian NP, Ansaloni S, Schweitzer-Stenner R, Akins MR, Bevilacqua PC, Saunders AJ. Amyloid Precursor Protein Translation Is Regulated by a 3'UTR Guanine Quadruplex. PLoS One 2015; 10:e0143160. [PMID: 26618502 PMCID: PMC4664259 DOI: 10.1371/journal.pone.0143160] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 11/02/2015] [Indexed: 12/13/2022] Open
Abstract
A central event in Alzheimer’s disease is the accumulation of amyloid β (Aβ) peptides generated by the proteolytic cleavage of the amyloid precursor protein (APP). APP overexpression leads to increased Aβ generation and Alzheimer’s disease in humans and altered neuronal migration and increased long term depression in mice. Conversely, reduction of APP expression results in decreased Aβ levels in mice as well as impaired learning and memory and decreased numbers of dendritic spines. Together these findings indicate that therapeutic interventions that aim to restore APP and Aβ levels must do so within an ideal range. To better understand the effects of modulating APP levels, we explored the mechanisms regulating APP expression focusing on post-transcriptional regulation. Such regulation can be mediated by RNA regulatory elements such as guanine quadruplexes (G-quadruplexes), non-canonical structured RNA motifs that affect RNA stability and translation. Via a bioinformatics approach, we identified a candidate G-quadruplex within the APP mRNA in its 3’UTR (untranslated region) at residues 3008–3027 (NM_201414.2). This sequence exhibited characteristics of a parallel G-quadruplex structure as revealed by circular dichroism spectrophotometry. Further, as with other G-quadruplexes, the formation of this structure was dependent on the presence of potassium ions. This G-quadruplex has no apparent role in regulating transcription or mRNA stability as wild type and mutant constructs exhibited equivalent mRNA levels as determined by real time PCR. Instead, we demonstrate that this G-quadruplex negatively regulates APP protein expression using dual luciferase reporter and Western blot analysis. Taken together, our studies reveal post-transcriptional regulation by a 3’UTR G-quadruplex as a novel mechanism regulating APP expression.
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Affiliation(s)
- Ezekiel Crenshaw
- Department of Biology, Drexel University, Philadelphia, PA, United States of America
| | - Brian P. Leung
- Department of Biology, Drexel University, Philadelphia, PA, United States of America
- Department of Chemistry, Drexel University, Philadelphia, PA, United States of America
| | - Chun Kit Kwok
- Department of Chemistry, Pennsylvania State University, University Park, PA, United States of America
- Department of Biochemistry & Molecular Biology, Center for RNA Molecular Biology, Pennsylvania State University, University Park, PA, United States of America
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - Michal Sharoni
- Department of Biology, Drexel University, Philadelphia, PA, United States of America
| | - Kalee Olson
- Department of Chemistry, Pennsylvania State University, University Park, PA, United States of America
| | - Neeraj P. Sebastian
- Department of Biology, Drexel University, Philadelphia, PA, United States of America
| | - Sara Ansaloni
- Department of Biology, Drexel University, Philadelphia, PA, United States of America
| | | | - Michael R. Akins
- Department of Biology, Drexel University, Philadelphia, PA, United States of America
- Department of Neurobiology & Anatomy, Drexel University College of Medicine, Philadelphia, PA, United States of America
| | - Philip C. Bevilacqua
- Department of Chemistry, Pennsylvania State University, University Park, PA, United States of America
- Department of Biochemistry & Molecular Biology, Center for RNA Molecular Biology, Pennsylvania State University, University Park, PA, United States of America
| | - Aleister J. Saunders
- Department of Biology, Drexel University, Philadelphia, PA, United States of America
- Department of Biochemistry & Molecular Biology, Drexel University College of Medicine, Philadelphia, PA, United States of America
- Department of Neurobiology & Anatomy, Drexel University College of Medicine, Philadelphia, PA, United States of America
- * E-mail:
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Kwok CK, Balasubramanian S. Targeted Detection of G-Quadruplexes in Cellular RNAs. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201500891] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Kwok CK, Balasubramanian S. Targeted Detection of G-Quadruplexes in Cellular RNAs. Angew Chem Int Ed Engl 2015; 54:6751-4. [PMID: 25907625 PMCID: PMC4510783 DOI: 10.1002/anie.201500891] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 03/25/2015] [Indexed: 02/03/2023]
Abstract
The G-quadruplex (G4) is a non-canonical nucleic acid structure which regulates important cellular processes. RNA G4s have recently been shown to exist in human cells and be biologically significant. Described herein is a new approach to detect and map RNA G4s in cellular transcripts. This method exploits the specific control of RNA G4-cation and RNA G4-ligand interactions during reverse transcription, by using a selective reverse transcriptase to monitor RNA G4-mediated reverse transcriptase stalling (RTS) events. Importantly, a ligation-amplification strategy is coupled with RTS, and enables detection and mapping of G4s in important, low-abundance cellular RNAs. Strong evidence is provided for G4 formation in full-length cellular human telomerase RNA, offering important insights into its cellular function.
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Affiliation(s)
- Chun Kit Kwok
- The University of Cambridge, Department of Chemistry, Lensfield Road, Cambridge, CB2 1EW (UK)
| | - Shankar Balasubramanian
- The University of Cambridge, Department of Chemistry, Lensfield Road, Cambridge, CB2 1EW (UK).
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Changenet-Barret P, Hua Y, Markovitsi D. Electronic excitations in Guanine quadruplexes. Top Curr Chem (Cham) 2015; 356:183-201. [PMID: 24563011 DOI: 10.1007/128_2013_511] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Guanine rich DNA strands, such as those encountered at the extremities of human chromosomes, have the ability to form four-stranded structures (G-quadruplexes) whose building blocks are guanine tetrads. G-quadruplex structures are intensively studied in respect of their biological role, as targets for anticancer therapy and, more recently, of their potential applications in the field of molecular electronics. Here we focus on their electronic excited states which are compared to those of non-interacting mono-nucleotides and those of single and double stranded structures. Particular emphasis is given to excited state relaxation processes studied by time-resolved fluorescence spectroscopy from femtosecond to nanosecond time scales. They include ultrafast energy transfer and trapping of ππ* excitations by charge transfer states. The effect of various structural parameters, such as the nature of the metal cations located in the central cavity of G-quadruplexes, the number of tetrads or the conformation of the constitutive single strands, are examined.
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Kwok CK, Ding Y, Shahid S, Assmann SM, Bevilacqua PC. A stable RNA G-quadruplex within the 5'-UTR of Arabidopsis thaliana ATR mRNA inhibits translation. Biochem J 2015; 467:91-102. [PMID: 25793418 DOI: 10.1042/bj20141063] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Guanine quadruplex structures (GQSs) play important roles in the regulation of gene expression and cellular processes. Recent studies provide strong evidence for the formation and function of DNA and RNA GQSs in human cells. However, whether GQSs form and are functional in plants remains essentially unexplored. On the basis of circular dichroism (CD)-detected titration, UV-detected melting, in-line probing (ILP) and reporter gene assay studies, we report the first example of a plant RNA GQS that inhibits translation. This GQS is located within the 5'-UTR of the ATAXIA TELANGIECTASIA-MUTATED AND RAD3-RELATED (ATR) mRNA of Arabidopsis thaliana (mouse-ear cress). We show that this GQS is highly stable and is thermodynamically favoured over a competing hairpin structure in the 5'-UTR at physiological K⁺ and Mg²⁺ concentrations. Results from ILP reveal the secondary structure of the RNA and support formation of the GQS in vitro in the context of the complete 5'-UTR. Transient reporter gene assays performed in living plants reveal that the GQS inhibits translation but not transcription, implicating this GQS as a translational repressor in vivo. Our results provide the first complete demonstration of the formation and function of a regulatory RNA GQS in plants and open new avenues to explore potential functional roles of GQS in the plant kingdom.
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Affiliation(s)
- Chun Kit Kwok
- *Department of Chemistry, Pennsylvania State University, University Park, PA 16802, U.S.A
| | - Yiliang Ding
- *Department of Chemistry, Pennsylvania State University, University Park, PA 16802, U.S.A
| | - Saima Shahid
- †Center for RNA Molecular Biology, Pennsylvania State University, University Park, PA 16802, U.S.A
| | - Sarah M Assmann
- †Center for RNA Molecular Biology, Pennsylvania State University, University Park, PA 16802, U.S.A
| | - Philip C Bevilacqua
- *Department of Chemistry, Pennsylvania State University, University Park, PA 16802, U.S.A
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Agarwala P, Kumar S, Pandey S, Maiti S. Human telomeric RNA G-quadruplex response to point mutation in the G-quartets. J Phys Chem B 2015; 119:4617-27. [PMID: 25763809 DOI: 10.1021/acs.jpcb.5b00619] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Many putative G-quadruplex forming sequences have been predicted to exist in the human genome and transcriptome. As these sequences are subject to point mutations or SNPs (single nucleotide polymorphisms) during the course of evolution, we attempt to understand impact of these mutations in context of RNA G-quadruplex formation using human telomeric RNA (TERRA) as a model sequence. Our studies suggest that G-quadruplex stability is sensitive to substitution of the guanines comprising G-quartets. While central G-quartet plays a crucial role in maintaining the DNA G-quadruplex stability as evident in literature, there is equal importance of three G-quartets in the stability of RNA quadruplex structure. The work here highlights the alterations in the G-quartet are detrimental to the integrity of overall RNA G-quadruplex structure. Furthermore, TmPyP4 molecules are shown to exhibit similar binding behavior toward telomeric RNA G-quadruplex harboring base substitutions employing CD titrations and isothermal titration calorimetry; well indicating that mutation does not influence TmPyP4 recognition ability as it affects the stability of RNA G-quadruplex. Thus, our study implicates that mutation in G-quartets causes destabilization of RNA G-quadruplex without affecting its trans factor binding ability.
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Affiliation(s)
- Prachi Agarwala
- †Academy of Scientific and Innovative Research (AcSIR), Anusandhan Bhawan, 2 Rafi Marg, New Delhi 110001, India.,‡Proteomics and Structural Biology Unit, CSIR-Institute of Genomics and Integrative Biology, Mall Road, New Delhi 110 007, India
| | - Santosh Kumar
- ‡Proteomics and Structural Biology Unit, CSIR-Institute of Genomics and Integrative Biology, Mall Road, New Delhi 110 007, India
| | - Satyaprakash Pandey
- †Academy of Scientific and Innovative Research (AcSIR), Anusandhan Bhawan, 2 Rafi Marg, New Delhi 110001, India.,‡Proteomics and Structural Biology Unit, CSIR-Institute of Genomics and Integrative Biology, Mall Road, New Delhi 110 007, India
| | - Souvik Maiti
- †Academy of Scientific and Innovative Research (AcSIR), Anusandhan Bhawan, 2 Rafi Marg, New Delhi 110001, India.,‡Proteomics and Structural Biology Unit, CSIR-Institute of Genomics and Integrative Biology, Mall Road, New Delhi 110 007, India.,§CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India
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Dolgosheina EV, Jeng SCY, Panchapakesan SSS, Cojocaru R, Chen PSK, Wilson PD, Hawkins N, Wiggins PA, Unrau PJ. RNA mango aptamer-fluorophore: a bright, high-affinity complex for RNA labeling and tracking. ACS Chem Biol 2014; 9:2412-20. [PMID: 25101481 DOI: 10.1021/cb500499x] [Citation(s) in RCA: 296] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Because RNA lacks strong intrinsic fluorescence, it has proven challenging to track RNA molecules in real time. To address this problem and to allow the purification of fluorescently tagged RNA complexes, we have selected a high affinity RNA aptamer called RNA Mango. This aptamer binds a series of thiazole orange (fluorophore) derivatives with nanomolar affinity, while increasing fluorophore fluorescence by up to 1,100-fold. Visualization of RNA Mango by single-molecule fluorescence microscopy, together with injection and imaging of RNA Mango/fluorophore complex in C. elegans gonads demonstrates the potential for live-cell RNA imaging with this system. By inserting RNA Mango into a stem loop of the bacterial 6S RNA and biotinylating the fluorophore, we demonstrate that the aptamer can be used to simultaneously fluorescently label and purify biologically important RNAs. The high affinity and fluorescent properties of RNA Mango are therefore expected to simplify the study of RNA complexes.
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Affiliation(s)
- Elena V Dolgosheina
- Department of Molecular Biology and Biochemistry and ‡Department of Chemistry, Simon Fraser University , 8888 University Road, Burnaby, British Columbia V5A 1S6, Canada
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Dhayan H, Baydoun AR, Kukol A. G-quadruplex formation of FXYD1 pre-mRNA indicates the possibility of regulating expression of its protein product. Arch Biochem Biophys 2014; 560:52-8. [DOI: 10.1016/j.abb.2014.07.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 06/25/2014] [Accepted: 07/10/2014] [Indexed: 11/25/2022]
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Jodoin R, Bauer L, Garant JM, Mahdi Laaref A, Phaneuf F, Perreault JP. The folding of 5'-UTR human G-quadruplexes possessing a long central loop. RNA (NEW YORK, N.Y.) 2014; 20:1129-1141. [PMID: 24865610 PMCID: PMC4114690 DOI: 10.1261/rna.044578.114] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 04/21/2014] [Indexed: 05/31/2023]
Abstract
G-quadruplexes are widespread four-stranded structures that are adopted by G-rich regions of both DNA and RNA and are involved in essential biological processes such as mRNA translation. They are formed by the stacking of two or more G-quartets that are linked together by three loops. Although the maximal loop length is usually fixed to 7 nt in most G-quadruplex-predicting software, it has already been demonstrated that artificial DNA G-quadruplexes containing two distal loops that are limited to 1 nt each and a central loop up to 30 nt long are likely to form in vitro. This report demonstrates that such structures possessing a long central loop are actually found in the 5'-UTRs of human mRNAs. Firstly, 1453 potential G-quadruplex-forming sequences (PG4s) were identified through a bioinformatic survey that searched for sequences respecting the requirement for two 1-nt long distal loops and a long central loop of 2-90 nt in length. Secondly, in vitro in-line probing experiments confirmed and characterized the folding of eight candidates possessing central loops of 10-70 nt long. Finally, the biological effect of several G-quadruplexes with a long central loop on mRNA expression was studied in cellulo using a luciferase gene reporter assay. Clearly, the actual definition of G-quadruplex-forming sequences is too conservative and must be expanded to include the long central loop. This greatly expands the number of expected PG4s in the transcriptome. Consideration of these new candidates might aid in elucidating the potentially important biological implications of the G-quadruplex structure.
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Affiliation(s)
- Rachel Jodoin
- Département de Biochimie, Faculté de Médecine et des Sciences de la Santé, Pavillon de Recherche Appliquée au Cancer, Université de Sherbrooke, Québec, Canada J1E 4K8
| | - Lubos Bauer
- Département de Biochimie, Faculté de Médecine et des Sciences de la Santé, Pavillon de Recherche Appliquée au Cancer, Université de Sherbrooke, Québec, Canada J1E 4K8
| | - Jean-Michel Garant
- Département de Biochimie, Faculté de Médecine et des Sciences de la Santé, Pavillon de Recherche Appliquée au Cancer, Université de Sherbrooke, Québec, Canada J1E 4K8
| | - Abdelhamid Mahdi Laaref
- Département de Biochimie, Faculté de Médecine et des Sciences de la Santé, Pavillon de Recherche Appliquée au Cancer, Université de Sherbrooke, Québec, Canada J1E 4K8
| | - Francis Phaneuf
- Département de Biochimie, Faculté de Médecine et des Sciences de la Santé, Pavillon de Recherche Appliquée au Cancer, Université de Sherbrooke, Québec, Canada J1E 4K8
| | - Jean-Pierre Perreault
- Département de Biochimie, Faculté de Médecine et des Sciences de la Santé, Pavillon de Recherche Appliquée au Cancer, Université de Sherbrooke, Québec, Canada J1E 4K8
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Tippana R, Xiao W, Myong S. G-quadruplex conformation and dynamics are determined by loop length and sequence. Nucleic Acids Res 2014; 42:8106-14. [PMID: 24920827 PMCID: PMC4081081 DOI: 10.1093/nar/gku464] [Citation(s) in RCA: 128] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The quadruplex forming G-rich sequences are unevenly distributed throughout the human genome. Their enrichment in oncogenic promoters and telomeres has generated interest in targeting G-quadruplex (GQ) for an anticancer therapy. Here, we present a quantitative analysis on the conformations and dynamics of GQ forming sequences measured by single molecule fluorescence. Additionally, we relate these properties to GQ targeting ligands and G4 resolvase 1 (G4R1) protein binding. Our result shows that both the loop (non-G components) length and sequence contribute to the conformation of the GQ. Real time single molecule traces reveal that the folding dynamics also depend on the loop composition. We demonstrate that GQ-stabilizing small molecules, N-methyl mesoporphyrin IX (NMM), its analog, NMP and the G4R1 protein bind selectively to the parallel GQ conformation. Our findings point to the complexity of GQ folding governed by the loop length and sequence and how the GQ conformation determines the small molecule and protein binding propensity.
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Affiliation(s)
- Ramreddy Tippana
- Bioengineering Department, University of Illinois, 1304 W. Springfield Ave., Urbana, IL 61801, USA
| | - Weikun Xiao
- Bioengineering Department, University of Illinois, 1304 W. Springfield Ave., Urbana, IL 61801, USA
| | - Sua Myong
- Bioengineering Department, University of Illinois, 1304 W. Springfield Ave., Urbana, IL 61801, USA Biophysics and Computational Biology, 1110 W. Green St., Urbana, IL 61801, USA Institute for Genomic Biology, 1206 Gregory Drive, Urbana, IL 61801, USA Physics Frontier Center (Center of Physics for Living Cells), University of Illinois, 1110 W. Green St., Urbana, IL 61801, USA
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50
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Tanaka A, Choi J, Majima T. Folding and structural polymorphism of G-quadruplex formed from a long telomeric sequence containing six GGG tracts. RSC Adv 2014. [DOI: 10.1039/c4ra08053j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
A long telomeric sequence preferentially forms a thermodynamically stable G-quadruplex at the 3′ end rather than at the 5′ end or at internal positions.
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Affiliation(s)
- Atsushi Tanaka
- The Institute of Scientific and Industrial Research (SANKEN)
- Osaka University
- Osaka 567-0047, Japan
| | - Jungkweon Choi
- The Institute of Scientific and Industrial Research (SANKEN)
- Osaka University
- Osaka 567-0047, Japan
| | - Tetsuro Majima
- The Institute of Scientific and Industrial Research (SANKEN)
- Osaka University
- Osaka 567-0047, Japan
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