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Guzmán-Lorite M, Rosu F, Marina ML, García MC, Gabelica V. miRNA and DNA analysis by negative ion electron transfer dissociation and infrared multiple-photon dissociation mass spectrometry. Anal Chim Acta 2024; 1299:342431. [PMID: 38499418 DOI: 10.1016/j.aca.2024.342431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 02/15/2024] [Accepted: 02/26/2024] [Indexed: 03/20/2024]
Abstract
BACKGROUND The use of simple and hybrid fragmentation techniques for the identification of molecules in tandem mass spectrometry provides different and complementary information on the structure of molecules. Nevertheless, these techniques have not been as widely explored for oligonucleotides as for peptides or proteins. The analysis of microRNAs (miRNAs) warrants special attention, given their regulatory role and their relationship with several diseases. The application of different fragmentation techniques will be very interesting for their identification. RESULTS Four synthetic miRNAs and a DNA sequence were fragmented in an ESI-FT-ICR mass spectrometer using both simple and hybrid fragmentation techniques: CID, nETD followed by CID, IRMPD, and, for the first time, nETD in combination with IRMPD. The main fragmentation channel was base loss. The use of nETD-IRMPD resulted in d/z, a/w, and c/y ions at higher intensities. Moreover, nETD-IRMPD provided high sequence coverage and low internal fragmentation. Native MS analysis revealed that only miR159 and the DNA sequence formed stable dimers under physiological ionic strength. The use of organic co-solvents or additives resulted in a lower sequence coverage due to lesser overall ionization efficiency. NOVELTY This work demonstrates that the combination of nETD and IRMPD for miRNA fragmentation constitutes a suitable alternative to common fragmentation methods. This strategy resulted in efficient fragmentation of [miRNA]5- using low irradiation times and fewer internal fragments while ensuring a high sequence coverage. Moreover, given that such low charge states predominate upon spraying in physiological-like conditions, native MS can be applied for obtaining structural information at the same time.
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Affiliation(s)
- Miriam Guzmán-Lorite
- Universidad de Alcalá, Departamento de Química Analítica, Química Física e Ingeniería Química, Ctra. Madrid-Barcelona Km. 33.600, 28871, Alcalá de Henares (Madrid), Spain
| | - Frédéric Rosu
- Université de Bordeaux, CNRS, INSERM, IECB, UAR3033, US01, F-33600, Pessac, France
| | - María Luisa Marina
- Universidad de Alcalá, Departamento de Química Analítica, Química Física e Ingeniería Química, Ctra. Madrid-Barcelona Km. 33.600, 28871, Alcalá de Henares (Madrid), Spain; Universidad de Alcalá, Instituto de Investigación Química "Andrés M. Del Río", Ctra. Madrid-Barcelona Km. 33.600, 28871, Alcalá de Henares (Madrid), Spain
| | - María Concepción García
- Universidad de Alcalá, Departamento de Química Analítica, Química Física e Ingeniería Química, Ctra. Madrid-Barcelona Km. 33.600, 28871, Alcalá de Henares (Madrid), Spain; Universidad de Alcalá, Instituto de Investigación Química "Andrés M. Del Río", Ctra. Madrid-Barcelona Km. 33.600, 28871, Alcalá de Henares (Madrid), Spain.
| | - Valérie Gabelica
- Université de Bordeaux, CNRS, INSERM, IECB, UAR3033, US01, F-33600, Pessac, France; Université de Bordeaux, CNRS, INSERM, ARNA, UMR 5320, U1212, IECB, F-33600, Pessac, France
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2
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Huang R, Feng Y, Gao Z, Ahmed A, Zhang W. The Epigenomic Features and Potential Functions of PEG- and PDS-Favorable DNA G-Quadruplexes in Rice. Int J Mol Sci 2024; 25:634. [PMID: 38203805 PMCID: PMC10779103 DOI: 10.3390/ijms25010634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 12/26/2023] [Accepted: 12/29/2023] [Indexed: 01/12/2024] Open
Abstract
A G-quadruplex (G4) is a typical non-B DNA structure and involved in various DNA-templated events in eukaryotic genomes. PEG and PDS chemicals have been widely applied for promoting the folding of in vivo or in vitro G4s. However, how PEG and PDS preferentially affect a subset of G4 formation genome-wide is still largely unknown. We here conducted a BG4-based IP-seq in vitro under K++PEG or K++PDS conditions in the rice genome. We found that PEG-favored IP-G4s+ have distinct sequence features, distinct genomic distributions and distinct associations with TEGs, non-TEGs and subtypes of TEs compared to PDS-favored ones. Strikingly, PEG-specific IP-G4s+ are associated with euchromatin with less enrichment levels of DNA methylation but with more enriched active histone marks, while PDS-specific IP-G4s+ are associated with heterochromatin with higher enrichment levels of DNA methylation and repressive marks. Moreover, we found that genes with PEG-specific IP-G4s+ are more expressed than those with PDS-specific IP-G4s+, suggesting that PEG/PDS-specific IP-G4s+ alone or coordinating with epigenetic marks are involved in the regulation of the differential expression of related genes, therefore functioning in distinct biological processes. Thus, our study provides new insights into differential impacts of PEG and PDS on G4 formation, thereby advancing our understanding of G4 biology.
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Affiliation(s)
| | | | | | | | - Wenli Zhang
- State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, CIC-MCP, Nanjing Agricultural University, No.1 Weigang, Nanjing 210095, China; (R.H.); (Y.F.); (Z.G.); (A.A.)
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3
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Neupane A, Chariker JH, Rouchka EC. Analysis of Nucleotide Variations in Human G-Quadruplex Forming Regions Associated with Disease States. Genes (Basel) 2023; 14:2125. [PMID: 38136947 PMCID: PMC10742762 DOI: 10.3390/genes14122125] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 11/20/2023] [Accepted: 11/23/2023] [Indexed: 12/24/2023] Open
Abstract
While the role of G quadruplex (G4) structures has been identified in cancers and metabolic disorders, single nucleotide variations (SNVs) and their effect on G4s in disease contexts have not been extensively studied. The COSMIC and CLINVAR databases were used to detect SNVs present in G4s to identify sequence level changes and their effect on the alteration of the G4 secondary structure. A total of 37,515 G4 SNVs in the COSMIC database and 2378 in CLINVAR were identified. Of those, 7236 COSMIC (19.3%) and 457 (19%) of the CLINVAR variants result in G4 loss, while 2728 (COSMIC) and 129 (CLINVAR) SNVs gain a G4 structure. The remaining variants potentially affect the folding energy without affecting the presence of a G4. Analysis of mutational patterns in the G4 structure shows a higher selective pressure (3-fold) in the coding region on the template strand compared to the reverse strand. At the same time, an equal proportion of SNVs were observed among intronic, promoter, and enhancer regions across strands.
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Affiliation(s)
- Aryan Neupane
- School of Graduate and Interdisciplinary Studies, University of Louisville, Louisville, KY 40292, USA;
| | - Julia H. Chariker
- Department of Neuroscience Training, University of Louisville, Louisville, KY 40292, USA;
- Kentucky IDeA Network of Biomedical Research Excellence (KY INBRE) Bioinformatics Core, University of Louisville, Louisville, KY 40292, USA
| | - Eric C. Rouchka
- Kentucky IDeA Network of Biomedical Research Excellence (KY INBRE) Bioinformatics Core, University of Louisville, Louisville, KY 40292, USA
- Department of Biochemistry and Molecular Genetics, University of Louisville, Louisville, KY 40292, USA
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4
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Pandey A, Roy S, Srivatsan SG. Probing the Competition between Duplex, G-Quadruplex and i-Motif Structures of the Oncogenic c-Myc DNA Promoter Region. Chem Asian J 2023; 18:e202300510. [PMID: 37541298 DOI: 10.1002/asia.202300510] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/09/2023] [Indexed: 08/06/2023]
Abstract
Development of probe systems that provide unique spectral signatures for duplex, G-quadruplex (GQ) and i-motif (iM) structures is very important to understand the relative propensity of a G-rich-C-rich promoter region to form these structures. Here, we devise a platform using a combination of two environment-sensitive nucleoside analogs namely, 5-fluorobenzofuran-modified 2'-deoxyuridine (FBF-dU) and 5-fluoro-2'-deoxyuridine (F-dU) to study the structures adopted by a promoter region of the c-Myc oncogene. FBF-dU serves as a dual-purpose probe containing a fluorescent and 19 F NMR label. When incorporated into the C-rich sequence, it reports the formation of different iMs via changes in its fluorescence properties and 19 F signal. F-dU incorporated into the G-rich ON reports the formation of a GQ structure whose 19 F signal is clearly different from the signals obtained for iMs. Rewardingly, the labeled ONs when mixed with respective complementary strands allows us to determine the relative population of different structures formed by the c-Myc promoter by the virtue of the probe's ability to produce distinct and resolved 19 F signatures for different structures. Our results indicate that at physiological pH and temperature the c-Myc promoter forms duplex, random coil and GQ structures, and does not form an iM. Whereas at acidic pH, the mixture largely forms iM and GQ structures. Taken together, our system will complement existing tools and provide unprecedented insights on the population equilibrium and dynamics of nucleic acid structures under different conditions.
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Affiliation(s)
- Akanksha Pandey
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune, Dr. Homi Bhabha Road, Pune, 411008, India
| | - Sarupa Roy
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune, Dr. Homi Bhabha Road, Pune, 411008, India
| | - Seergazhi G Srivatsan
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune, Dr. Homi Bhabha Road, Pune, 411008, India
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5
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Neupane A, Chariker JH, Rouchka EC. Analysis of nucleotide variations in human g-quadruplex forming regions associated with disease states. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.30.526341. [PMID: 36778288 PMCID: PMC9915501 DOI: 10.1101/2023.01.30.526341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
While the role of G4 G quadruplex structures has been identified in cancers and metabolic disorders, single nucleotide variations (SNVs) and their effect on G4s in disease contexts have not been extensively studied. The COSMIC and CLINVAR databases were used to detect SNVs present in G4s to identify sequence level changes and their effect on alteration of G4 secondary structure. 37,515 G4 SNVs in the COSMIC database and 2,115 in CLINVAR were identified. Of those, 7,236 COSMIC (19.3%) and 416 (18%) of the CLINVAR variants result in G4 loss, while 2,728 (COSMIC) and 112 (CLINVAR) SNVs gain a G4 structure. The gene ontology term "GnRH (Gonadotropin-releasing hormone) secretion" is enriched in 21 genes in this pathway that have a G4 destabilizing SNV. Analysis of mutational patterns in the G4 structure show a higher selective pressure (3-fold) in the coding region on the template strand compared to the non-template strand. At the same time, an equal proportion of SNVs were observed among intronic, promoter and enhancer regions across strands. Using GO and pathway enrichment, genes with SNVs for G4 forming propensity in the coding region are enriched for Regulation of Ras protein signal transduction and Src homology 3 (SH3) domain binding.
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Affiliation(s)
- Aryan Neupane
- School of Graduate and Interdisciplinary Studies, University of Louisville, Louisville, Kentucky, 40202, United States of America
| | - Julia H. Chariker
- Department of Neuroscience Training, University of Louisville, Louisville, Kentucky, 40292, United States of America
- KY INBRE Bioinformatics Core, University of Louisville, Louisville, Kentucky, 40292, United States of America
| | - Eric C. Rouchka
- KY INBRE Bioinformatics Core, University of Louisville, Louisville, Kentucky, 40292, United States of America
- Department of Biochemistry and Molecular Genetics, University of Louisville, Louisville, Kentucky 40292, United States of America
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Wu S, Jiang L, Lei L, Fu C, Huang J, Hu Y, Dong Y, Chen J, Zeng Q. Crosstalk between G-quadruplex and ROS. Cell Death Dis 2023; 14:37. [PMID: 36653351 PMCID: PMC9849334 DOI: 10.1038/s41419-023-05562-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 12/25/2022] [Accepted: 01/05/2023] [Indexed: 01/19/2023]
Abstract
The excessive production of reactive oxygen species (ROS) can lead to single nucleic acid base damage, DNA strand breakage, inter- and intra-strand cross-linking of nucleic acids, and protein-DNA cross-linking involved in the pathogenesis of cancer, neurodegenerative diseases, and aging. G-quadruplex (G4) is a stacked nucleic acid structure that is ubiquitous across regulatory regions of multiple genes. Abnormal formation and destruction of G4s due to multiple factors, including cations, helicases, transcription factors (TFs), G4-binding proteins, and epigenetic modifications, affect gene replication, transcription, translation, and epigenetic regulation. Due to the lower redox potential of G-rich sequences and unique structural characteristics, G4s are highly susceptible to oxidative damage. Additionally, the formation, stability, and biological regulatory role of G4s are affected by ROS. G4s are involved in regulating gene transcription, translation, and telomere length maintenance, and are therefore key players in age-related degeneration. Furthermore, G4s also mediate the antioxidant process by forming stress granules and activating Nrf2, which is suggestive of their involvement in developing ROS-related diseases. In this review, we have summarized the crosstalk between ROS and G4s, and the possible regulatory mechanisms through which G4s play roles in aging and age-related diseases.
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Affiliation(s)
- Songjiang Wu
- Department of Dermatology, Third Xiangya Hospital, Central South University, 138 Tongzipo Road, 410013, Changsha, Hunan, PR China
| | - Ling Jiang
- Department of Dermatology, Third Xiangya Hospital, Central South University, 138 Tongzipo Road, 410013, Changsha, Hunan, PR China
| | - Li Lei
- Department of Dermatology, Third Xiangya Hospital, Central South University, 138 Tongzipo Road, 410013, Changsha, Hunan, PR China
| | - Chuhan Fu
- Department of Dermatology, Third Xiangya Hospital, Central South University, 138 Tongzipo Road, 410013, Changsha, Hunan, PR China
| | - Jinhua Huang
- Department of Dermatology, Third Xiangya Hospital, Central South University, 138 Tongzipo Road, 410013, Changsha, Hunan, PR China
| | - Yibo Hu
- Department of Dermatology, Third Xiangya Hospital, Central South University, 138 Tongzipo Road, 410013, Changsha, Hunan, PR China
| | - Yumeng Dong
- Department of Dermatology, Third Xiangya Hospital, Central South University, 138 Tongzipo Road, 410013, Changsha, Hunan, PR China
| | - Jing Chen
- Department of Dermatology, Third Xiangya Hospital, Central South University, 138 Tongzipo Road, 410013, Changsha, Hunan, PR China.
| | - Qinghai Zeng
- Department of Dermatology, Third Xiangya Hospital, Central South University, 138 Tongzipo Road, 410013, Changsha, Hunan, PR China.
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7
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Ye M, Chen EV, Pfeil SH, Martin KN, Atrafi T, Yun S, Martinez Z, Yatsunyk LA. Homopurine guanine-rich sequences in complex with N-methyl mesoporphyrin IX form parallel G-quadruplex dimers and display a unique symmetry tetrad. Bioorg Med Chem 2023; 77:117112. [PMID: 36508994 PMCID: PMC9812923 DOI: 10.1016/j.bmc.2022.117112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 11/24/2022] [Accepted: 11/28/2022] [Indexed: 12/03/2022]
Abstract
DNA can fold into G-quadruplexes (GQs), non-canonical secondary structures formed by π-π stacking of G-tetrads. GQs are important in many biological processes, which makes them promising therapeutic targets. We identified a 42-nucleotide long, purine-only G-rich sequence from human genome, which contains eight G-stretches connected by A and AAAA loops. We divided this sequence into five unique segments, four guanine stretches each, named GA1-5. In order to investigate the role of adenines in GQ structure formation, we performed biophysical and X-ray crystallographic studies of GA1-5 and their complexes with a highly selective GQ ligand, N-methyl mesoporphyrin IX (NMM). Our data indicate that all variants form parallel GQs whose stability depends on the number of flexible AAAA loops. GA1-3 bind NMM with 1:1 stoichiometry. The Ka for GA1 and GA3 is modest, ∼0.3 μM -1, and that for GA2 is significantly higher, ∼1.2 μM -1. NMM stabilizes GA1-3 by 14.6, 13.1, and 7.0 °C, respectively, at 2 equivalents. We determined X-ray crystal structures of GA1-NMM (1.98 Å resolution) and GA3-NMM (2.01 Å). The structures confirm the parallel topology of GQs with all adenines forming loops and display NMM binding at the 3' G-tetrad. Both complexes dimerize through the 5' interface. We observe two novel structural features: 1) a 'symmetry tetrad' at the dimer interface, which is formed by two guanines from each GQ monomer and 2) a NMM dimer in GA1-NMM. Our structural work confirms great flexibility of adenines as structural elements in GQ formation and contributes greatly to our understanding of the structural diversity of GQs and their modes of interaction with small molecule ligands.
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Affiliation(s)
- Ming Ye
- Department of Chemistry and Biochemistry, Swarthmore College, Swarthmore, PA 19081, United States
| | - Erin V Chen
- Department of Chemistry and Biochemistry, Swarthmore College, Swarthmore, PA 19081, United States
| | - Shawn H Pfeil
- Department of Physics, West Chester University, West Chester, PA 19383, United States
| | - Kailey N Martin
- Department of Chemistry and Biochemistry, Swarthmore College, Swarthmore, PA 19081, United States
| | - Tamanaa Atrafi
- Department of Chemistry and Biochemistry, Swarthmore College, Swarthmore, PA 19081, United States
| | - Sara Yun
- Department of Chemistry and Biochemistry, Swarthmore College, Swarthmore, PA 19081, United States
| | - Zahara Martinez
- Department of Chemistry and Biochemistry, Swarthmore College, Swarthmore, PA 19081, United States
| | - Liliya A Yatsunyk
- Department of Chemistry and Biochemistry, Swarthmore College, Swarthmore, PA 19081, United States.
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8
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Jose D, Michael MM, Bentsen C, Rosenblum B, Zelaya A. A Spectroscopic Approach to Unravel the Local Conformations of a G-Quadruplex Using CD-Active Fluorescent Base Analogues. Biochemistry 2022; 61:2720-2732. [DOI: 10.1021/acs.biochem.2c00461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Davis Jose
- Department of Chemistry and Physics, Monmouth University, West Long Branch, New Jersey07764, United States
| | - Miya Mary Michael
- Department of Chemistry and Physics, Monmouth University, West Long Branch, New Jersey07764, United States
| | - Christopher Bentsen
- Department of Chemistry and Physics, Monmouth University, West Long Branch, New Jersey07764, United States
| | - Brandon Rosenblum
- Department of Chemistry and Physics, Monmouth University, West Long Branch, New Jersey07764, United States
| | - Adriana Zelaya
- Department of Chemistry and Physics, Monmouth University, West Long Branch, New Jersey07764, United States
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9
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Abstract
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Oxidation of a guanine nucleotide in DNA yields an 8-oxoguanine
nucleotide (oxoG) and is a mutagenic event in the genome.
Due to different arrangements of hydrogen-bond donors and acceptors, oxoG can affect the secondary structure of nucleic acids. We
have investigated base pairing preferences of oxoG in the
core of a tetrahelical G-quadruplex structure, adopted by analogues
of d(TG4T). Using spectroscopic methods, we have shown
that G-quartets can be fully substituted with oxoG nucleobases
to form an oxoG-quartet with a revamped hydrogen-bonding
scheme. While an oxoG-quartet can be incorporated into
the G-quadruplex core without distorting the phosphodiester backbone,
larger dimensions of the central cavity change the cation localization
and exchange properties.
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Affiliation(s)
- Simon Aleksič
- Slovenian NMR Centre, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia.,Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, 1000 Ljubljana, Slovenia
| | - Peter Podbevšek
- Slovenian NMR Centre, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
| | - Janez Plavec
- Slovenian NMR Centre, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia.,Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, 1000 Ljubljana, Slovenia.,EN-FIST Centre of Excellence, Trg OF 13, 1000 Ljubljana, Slovenia
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10
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Vo T, Brownmiller T, Hall K, Jones TL, Choudhari S, Grammatikakis I, Ludwig K, Caplen N. HNRNPH1 destabilizes the G-quadruplex structures formed by G-rich RNA sequences that regulate the alternative splicing of an oncogenic fusion transcript. Nucleic Acids Res 2022; 50:6474-6496. [PMID: 35639772 PMCID: PMC9226515 DOI: 10.1093/nar/gkac409] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 04/07/2022] [Accepted: 05/06/2022] [Indexed: 11/13/2022] Open
Abstract
In the presence of physiological monovalent cations, thousands of RNA G-rich sequences can form parallel G-quadruplexes (G4s) unless RNA-binding proteins inhibit, destabilize, or resolve the formation of such secondary RNA structures. Here, we have used a disease-relevant model system to investigate the biophysical properties of the RNA-binding protein HNRNPH1's interaction with G-rich sequences. We demonstrate the importance of two EWSR1-exon 8 G-rich regions in mediating the exclusion of this exon from the oncogenic EWS-FLI1 transcripts expressed in a subset of Ewing sarcomas, using complementary analysis of tumor data, long-read sequencing, and minigene studies. We determined that HNRNPH1 binds the EWSR1-exon 8 G-rich sequences with low nM affinities irrespective of whether in a non-G4 or G4 state but exhibits different kinetics depending on RNA structure. Specifically, HNRNPH1 associates and dissociates from G4-folded RNA faster than the identical sequences in a non-G4 state. Importantly, we demonstrate using gel shift and spectroscopic assays that HNRNPH1, particularly the qRRM1-qRRM2 domains, destabilizes the G4s formed by the EWSR1-exon 8 G-rich sequences in a non-catalytic fashion. Our results indicate that HNRNPH1's binding of G-rich sequences favors the accumulation of RNA in a non-G4 state and that this contributes to its regulation of RNA processing.
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Affiliation(s)
- Tam Vo
- Functional Genetics Section, Genetics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Tayvia Brownmiller
- Functional Genetics Section, Genetics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Katherine Hall
- Functional Genetics Section, Genetics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Tamara L Jones
- Functional Genetics Section, Genetics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sulbha Choudhari
- CCR-SF Bioinformatics Group, Biomedical Informatics and Data Science Directorate, Frederick National Laboratory for Cancer Research, Frederick, MD, 21702, USA
| | - Ioannis Grammatikakis
- Regulatory RNAs and Cancer Section, Genetics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Katelyn R Ludwig
- Functional Genetics Section, Genetics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Natasha J Caplen
- Functional Genetics Section, Genetics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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11
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Properties of Parallel Tetramolecular G-Quadruplex Carrying N-Acetylgalactosamine as Potential Enhancer for Oligonucleotide Delivery to Hepatocytes. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27123944. [PMID: 35745067 PMCID: PMC9228010 DOI: 10.3390/molecules27123944] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 06/08/2022] [Accepted: 06/17/2022] [Indexed: 01/09/2023]
Abstract
The development of oligonucleotide conjugates for in vivo targeting is one of the most exciting areas for oligonucleotide therapeutics. A major breakthrough in this field was the development of multifunctional GalNAc-oligonucleotides with high affinity to asialoglycoprotein receptors (ASGPR) that directed therapeutic oligonucleotides to hepatocytes. In the present study, we explore the use of G-rich sequences functionalized with one unit of GalNAc at the 3'-end for the formation of tetrameric GalNAc nanostructures upon formation of a parallel G-quadruplex. These compounds are expected to facilitate the synthetic protocols by providing the multifunctionality needed for the binding to ASGPR. To this end, several G-rich oligonucleotides carrying a TGGGGGGT sequence at the 3'-end functionalized with one molecule of N-acetylgalactosamine (GalNAc) were synthesized together with appropriate control sequences. The formation of a self-assembled parallel G-quadruplex was confirmed through various biophysical techniques such as circular dichroism, nuclear magnetic resonance, polyacrylamide electrophoresis and denaturation curves. Binding experiments to ASGPR show that the size and the relative position of the therapeutic cargo are critical for the binding of these nanostructures. The biological properties of the resulting parallel G-quadruplex were evaluated demonstrating the absence of the toxicity in cell lines. The internalization preferences of GalNAc-quadruplexes to hepatic cells were also demonstrated as well as the enhancement of the luciferase inhibition using the luciferase assay in HepG2 cell lines versus HeLa cells. All together, we demonstrate that tetramerization of G-rich oligonucleotide is a novel and simple route to obtain the beneficial effects of multivalent N-acetylgalactosamine functionalization.
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12
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Ghafouri-Fard S, Abak A, Baniahmad A, Hussen BM, Taheri M, Jamali E, Dinger ME. Interaction between non-coding RNAs, mRNAs and G-quadruplexes. Cancer Cell Int 2022; 22:171. [PMID: 35488342 PMCID: PMC9052686 DOI: 10.1186/s12935-022-02601-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 04/19/2022] [Indexed: 12/01/2022] Open
Abstract
G-quadruplexes are secondary helical configurations established between guanine-rich nucleic acids. The structure is seen in the promoter regions of numerous genes under certain situations. Predicted G-quadruplex-forming sequences are distributed across the genome in a non-random way. These structures are formed in telomeric regions of the human genome and oncogenic promoter G-rich regions. Identification of mechanisms of regulation of stability of G-quadruplexes has practical significance for understanding the molecular basis of genetic diseases such as cancer. A number of non-coding RNAs such as H19, XIST, FLJ39051 (GSEC), BC200 (BCYRN1), TERRA, pre-miRNA-1229, pre-miRNA-149 and miR-1587 have been found to contain G-quadraplex-forming regions or affect configuration of these structures in target genes. In the current review, we outline the recent research on the interaction between G-quadruplexes and non-coding RNAs, other RNA transcripts and DNA molecules.
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Affiliation(s)
- Soudeh Ghafouri-Fard
- Department of Medical Genetics, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Atefe Abak
- Phytochemistry Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Aria Baniahmad
- Institute of Human Genetics, Jena University Hospital, 07740, Jena, Germany
| | - Bashdar Mahmud Hussen
- Department of Pharmacognosy, College of Pharmacy, Hawler Medical University, Erbil, Kurdistan Region, Iraq.,Center of Research and Strategic Studies, Lebanese French University, Erbil, Kurdistan Region, Iraq
| | - Mohammad Taheri
- Institute of Human Genetics, Jena University Hospital, 07740, Jena, Germany.
| | - Elena Jamali
- Skull Base Research Center, Loghman Hakin Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Marcel E Dinger
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia.
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13
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Gabelica V. Native Mass Spectrometry and Nucleic Acid G-Quadruplex Biophysics: Advancing Hand in Hand. Acc Chem Res 2021; 54:3691-3699. [PMID: 34546031 DOI: 10.1021/acs.accounts.1c00396] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
While studying nucleic acids to reveal the weak interactions responsible for their three-dimensional structure and for their interactions with drugs, we also contributed to the field of biomolecular mass spectrometry, both in terms of fundamental understanding and with new methodological developments. A first goal was to develop mass spectrometry approaches to detect noncovalent interactions between antitumor drugs and their DNA target. Twenty years ago, our attention turned toward specific DNA structures such as the G-quadruplex (a structure formed by guanine-rich strands). Mass spectrometry allows one to discern which molecules interact with one another by measuring the masses of the complexes, and quantify the affinities by measuring their abundance. The most important findings came from unexpected masses. For example, we showed the formation of higher- or lower-order structures by G-quadruplexes used in traditional biophysical assays. We also derived complete thermodynamic and kinetic description of G-quadruplex folding pathways by measuring cation binding, one at a time. Getting quantitative information requires accounting for nonspecific adduct formation and for the response factors of the different molecular forms. With these caveats in mind, the approach is now mature enough for routine biophysical characterization of nucleic acids. A second goal is to obtain more detailed structural information on each of the complexes separated by the mass spectrometer. One such approach is ion mobility spectrometry, and even today the challenge lies in the structural interpretation of the measurements. We showed that, although structures such as G-quadruplexes are well-preserved in the MS conditions, double helices actually get more compact in the gas phase. These major rearrangements forced us to challenge comfortable assumptions. Further work is still needed to generalize how to deduce structures in solution from ion mobility spectrometry data and, in particular, how to account for the electrospray charging mechanisms and for ion internal energy effects. These studies also called for complementary approaches to ion mobility spectrometry. Recently, we applied isotope exchange labeling mass spectrometry to characterize nucleic acid structures for the first time, and we reported the first ever circular dichroism ion spectroscopy measurement on mass-selected trapped ions. Circular dichroism plays a key role in assigning the stacking topology, and our new method now opens the door to characterizing a wide variety of chiral molecules by mass spectrometry. In summary, advanced mass spectrometry approaches to characterize gas-phase structures work well for G-quadruplexes because they are stiffened by inner cations. The next objective will be to generalize these methodologies to a wider range of nucleic acid structures.
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Affiliation(s)
- Valérie Gabelica
- Université de Bordeaux, CNRS, INSERM,
ARNA, UMR 5320, U1212, IECB, F-33600 Pessac, France
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14
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Largy E, König A, Ghosh A, Ghosh D, Benabou S, Rosu F, Gabelica V. Mass Spectrometry of Nucleic Acid Noncovalent Complexes. Chem Rev 2021; 122:7720-7839. [PMID: 34587741 DOI: 10.1021/acs.chemrev.1c00386] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Nucleic acids have been among the first targets for antitumor drugs and antibiotics. With the unveiling of new biological roles in regulation of gene expression, specific DNA and RNA structures have become very attractive targets, especially when the corresponding proteins are undruggable. Biophysical assays to assess target structure as well as ligand binding stoichiometry, affinity, specificity, and binding modes are part of the drug development process. Mass spectrometry offers unique advantages as a biophysical method owing to its ability to distinguish each stoichiometry present in a mixture. In addition, advanced mass spectrometry approaches (reactive probing, fragmentation techniques, ion mobility spectrometry, ion spectroscopy) provide more detailed information on the complexes. Here, we review the fundamentals of mass spectrometry and all its particularities when studying noncovalent nucleic acid structures, and then review what has been learned thanks to mass spectrometry on nucleic acid structures, self-assemblies (e.g., duplexes or G-quadruplexes), and their complexes with ligands.
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Affiliation(s)
- Eric Largy
- Univ. Bordeaux, CNRS, INSERM, ARNA, UMR 5320, U1212, IECB, F-33600 Pessac, France
| | - Alexander König
- Univ. Bordeaux, CNRS, INSERM, ARNA, UMR 5320, U1212, IECB, F-33600 Pessac, France
| | - Anirban Ghosh
- Univ. Bordeaux, CNRS, INSERM, ARNA, UMR 5320, U1212, IECB, F-33600 Pessac, France
| | - Debasmita Ghosh
- Univ. Bordeaux, CNRS, INSERM, ARNA, UMR 5320, U1212, IECB, F-33600 Pessac, France
| | - Sanae Benabou
- Univ. Bordeaux, CNRS, INSERM, ARNA, UMR 5320, U1212, IECB, F-33600 Pessac, France
| | - Frédéric Rosu
- Univ. Bordeaux, CNRS, INSERM, IECB, UMS 3033, F-33600 Pessac, France
| | - Valérie Gabelica
- Univ. Bordeaux, CNRS, INSERM, ARNA, UMR 5320, U1212, IECB, F-33600 Pessac, France
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15
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Ribaudo G, Ongaro A, Oselladore E, Memo M, Gianoncelli A. Combining Electrospray Mass Spectrometry (ESI-MS) and Computational Techniques in the Assessment of G-Quadruplex Ligands: A Hybrid Approach to Optimize Hit Discovery. J Med Chem 2021; 64:13174-13190. [PMID: 34510895 PMCID: PMC8474113 DOI: 10.1021/acs.jmedchem.1c00962] [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] [Indexed: 12/05/2022]
Abstract
![]()
Guanine-rich sequences
forming G-quadruplexes (GQs) are present
in several genomes, ranging from viral to human. Given their peculiar
localization, the induction of GQ formation or GQ stabilization with
small molecules represents a strategy for interfering with crucial
biological functions. Investigating the recognition event at the molecular
level, with the aim of fully understanding the triggered pharmacological
effects, is challenging. Native electrospray ionization mass spectrometry
(ESI-MS) is being optimized to study these noncovalent assemblies.
Quantitative parameters retrieved from ESI-MS studies, such as binding
affinity, the equilibrium binding constant, and sequence selectivity,
will be overviewed. Computational experiments supporting the ESI-MS
investigation and boosting its efficiency in the search for GQ ligands
will also be discussed with practical examples. The combination of
ESI-MS and in silico techniques in a hybrid high-throughput-screening
workflow represents a valuable tool for the medicinal chemist, providing
data on the quantitative and structural aspects of ligand–GQ
interactions.
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Affiliation(s)
- Giovanni Ribaudo
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123 Brescia, Italy
| | - Alberto Ongaro
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123 Brescia, Italy
| | - Erika Oselladore
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123 Brescia, Italy
| | - Maurizio Memo
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123 Brescia, Italy
| | - Alessandra Gianoncelli
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123 Brescia, Italy
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16
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Balasubramaniyam T, Oh KI, Jin HS, Ahn HB, Kim BS, Lee JH. Non-Canonical Helical Structure of Nucleic Acids Containing Base-Modified Nucleotides. Int J Mol Sci 2021; 22:9552. [PMID: 34502459 PMCID: PMC8430589 DOI: 10.3390/ijms22179552] [Citation(s) in RCA: 3] [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: 08/02/2021] [Revised: 08/27/2021] [Accepted: 08/29/2021] [Indexed: 12/12/2022] Open
Abstract
Chemically modified nucleobases are thought to be important for therapeutic purposes as well as diagnosing genetic diseases and have been widely involved in research fields such as molecular biology and biochemical studies. Many artificially modified nucleobases, such as methyl, halogen, and aryl modifications of purines at the C8 position and pyrimidines at the C5 position, are widely studied for their biological functions. DNA containing these modified nucleobases can form non-canonical helical structures such as Z-DNA, G-quadruplex, i-motif, and triplex. This review summarizes the synthesis of chemically modified nucleotides: (i) methylation, bromination, and arylation of purine at the C8 position and (ii) methylation, bromination, and arylation of pyrimidine at the C5 position. Additionally, we introduce the non-canonical structures of nucleic acids containing these modifications.
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Affiliation(s)
- Thananjeyan Balasubramaniyam
- Department of Chemistry, Gyeongsang National University, Jinju 52828, Gyeongnam, Korea; (T.B.); (K.-I.O.); (H.-S.J.); (H.-B.A.)
- The Research Institute of Natural Science, Gyeongsang National University, Jinju 52828, Gyeongnam, Korea
| | - Kwnag-Im Oh
- Department of Chemistry, Gyeongsang National University, Jinju 52828, Gyeongnam, Korea; (T.B.); (K.-I.O.); (H.-S.J.); (H.-B.A.)
- The Research Institute of Natural Science, Gyeongsang National University, Jinju 52828, Gyeongnam, Korea
| | - Ho-Seong Jin
- Department of Chemistry, Gyeongsang National University, Jinju 52828, Gyeongnam, Korea; (T.B.); (K.-I.O.); (H.-S.J.); (H.-B.A.)
| | - Hye-Bin Ahn
- Department of Chemistry, Gyeongsang National University, Jinju 52828, Gyeongnam, Korea; (T.B.); (K.-I.O.); (H.-S.J.); (H.-B.A.)
| | - Byeong-Seon Kim
- The Research Institute of Natural Science, Gyeongsang National University, Jinju 52828, Gyeongnam, Korea
- Department of Chemistry Education, Gyeongsang National University, Jinju 52828, Gyeongnam, Korea
| | - Joon-Hwa Lee
- Department of Chemistry, Gyeongsang National University, Jinju 52828, Gyeongnam, Korea; (T.B.); (K.-I.O.); (H.-S.J.); (H.-B.A.)
- The Research Institute of Natural Science, Gyeongsang National University, Jinju 52828, Gyeongnam, Korea
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17
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Gudanis D, Zielińska K, Baranowski D, Kierzek R, Kozłowski P, Gdaniec Z. Impact of a Single Nucleotide Change or Non-Nucleoside Modifications in G-Rich Region on the Quadruplex-Duplex Hybrid Formation. Biomolecules 2021; 11:biom11081236. [PMID: 34439902 PMCID: PMC8392043 DOI: 10.3390/biom11081236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 08/13/2021] [Accepted: 08/15/2021] [Indexed: 12/02/2022] Open
Abstract
In this paper, a method to discriminate between two target RNA sequences that differ by one nucleotide only is presented. The method relies on the formation of alternative structures, i.e., quadruplex–duplex hybrid (QDH) and duplex with dangling ends (Dss), after hybridization of DNA or RNA G-rich oligonucleotides with target sequences containing 5′–GGGCUGG–3′ or 5′–GGGCGGG–3′ fragments. Using biophysical methods, we studied the effect of oligonucleotide types (DNA, RNA), non-nucleotide modifications (aliphatic linkers or abasic), and covalently attached G4 ligand on the ability of G-rich oligonucleotides to assemble a G-quadruplex motif. We demonstrated that all examined non-nucleotide modifications could mimic the external loops in the G-quadruplex domain of QDH structures without affecting their stability. Additionally, some modifications, in particular the presence of two abasic residues in the G-rich oligonucleotide, can induce the formation of non-canonical QDH instead of the Dss structure upon hybridization to a target sequence containing the GGGCUGG motif. Our results offer new insight into the sequential requirements for the formation of G-quadruplexes and provide important data on the effects of non-nucleotide modifications on G-quadruplex formation.
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Affiliation(s)
- Dorota Gudanis
- Correspondence: (D.G.); (Z.G.); Tel.: +48-61-852-85-03 (ext. 1286) (D.G.)
| | | | | | | | | | - Zofia Gdaniec
- Correspondence: (D.G.); (Z.G.); Tel.: +48-61-852-85-03 (ext. 1286) (D.G.)
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18
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Tabor N, Ngwa C, Mitteaux J, Meyer MD, Moruno-Manchon JF, Zhu L, Liu F, Monchaud D, McCullough LD, Tsvetkov AS. Differential responses of neurons, astrocytes, and microglia to G-quadruplex stabilization. Aging (Albany NY) 2021; 13:15917-15941. [PMID: 34139671 PMCID: PMC8266374 DOI: 10.18632/aging.203222] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 06/12/2021] [Indexed: 12/29/2022]
Abstract
The G-quadruplex (G4-DNA or G4) is a secondary DNA structure formed by DNA sequences containing multiple runs of guanines. While it is now firmly established that stabilized G4s lead to enhanced genomic instability in cancer cells, whether and how G4s contribute to genomic instability in brain cells is still not clear. We previously showed that, in cultured primary neurons, small-molecule G4 stabilizers promote formation of DNA double-strand breaks (DSBs) and downregulate the Brca1 gene. Here, we determined if G4-dependent Brca1 downregulation is unique to neurons or if the effects in neurons also occur in astrocytes and microglia. We show that primary neurons, astrocytes and microglia basally exhibit different G4 landscapes. Stabilizing G4-DNA with the G4 ligand pyridostatin (PDS) differentially modifies chromatin structure in these cell types. Intriguingly, PDS promotes DNA DSBs in neurons, astrocytes and microglial cells, but fails to downregulate Brca1 in astrocytes and microglia, indicating differences in DNA damage and repair pathways between brain cell types. Taken together, our findings suggest that stabilized G4-DNA contribute to genomic instability in the brain and may represent a novel senescence pathway in brain aging.
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Affiliation(s)
- Natalie Tabor
- Department of Neurology, The University of Texas McGovern Medical School at Houston, Houston, TX 77030, USA
| | - Conelius Ngwa
- Department of Neurology, The University of Texas McGovern Medical School at Houston, Houston, TX 77030, USA
| | - Jeremie Mitteaux
- Institut de Chimie Moléculaire (ICMUB), UBFC Dijon, CNRS UMR6302, Dijon, France
| | - Matthew D. Meyer
- Shared Equipment Authority, Rice University, Houston, TX 77005, USA
| | - Jose F. Moruno-Manchon
- Department of Neurology, The University of Texas McGovern Medical School at Houston, Houston, TX 77030, USA
| | - Liang Zhu
- Biostatistics and Epidemiology Research Design Core Center for Clinical and Translational Sciences, The University of Texas McGovern Medical School at Houston, Houston, TX 77030, USA
- Department of Internal Medicine, The University of Texas McGovern Medical School at Houston, Houston, TX 77030, USA
| | - Fudong Liu
- Department of Neurology, The University of Texas McGovern Medical School at Houston, Houston, TX 77030, USA
| | - David Monchaud
- Institut de Chimie Moléculaire (ICMUB), UBFC Dijon, CNRS UMR6302, Dijon, France
| | - Louise D. McCullough
- Department of Neurology, The University of Texas McGovern Medical School at Houston, Houston, TX 77030, USA
- The University of Texas Graduate School of Biomedical Sciences, Houston, TX 77030, USA
| | - Andrey S. Tsvetkov
- Department of Neurology, The University of Texas McGovern Medical School at Houston, Houston, TX 77030, USA
- The University of Texas Graduate School of Biomedical Sciences, Houston, TX 77030, USA
- UTHealth Consortium on Aging, The University of Texas McGovern Medical School, Houston, TX 77030, USA
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19
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Bielskutė S, Plavec J, Podbevšek P. Oxidative lesions modulate G-quadruplex stability and structure in the human BCL2 promoter. Nucleic Acids Res 2021; 49:2346-2356. [PMID: 33638996 PMCID: PMC7913773 DOI: 10.1093/nar/gkab057] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/08/2021] [Accepted: 01/22/2021] [Indexed: 01/08/2023] Open
Abstract
Misregulation of BCL2 expression has been observed with many diseases and is associated with cellular exposure to reactive oxygen species. A region upstream of the P1 promoter in the human BCL2 gene plays a major role in regulating transcription. This G/C-rich region is highly polymorphic and capable of forming G-quadruplex structures. Herein we report that an oxidative event simulated with an 8-oxo-7,8-dihydroguanine (oxoG) substitution within a long G-tract results in a reduction of structural polymorphism. Surprisingly, oxoG within a 25-nt construct boosts thermal stability of the resulting G-quadruplex. This is achieved by distinct hydrogen bonding properties of oxoG, which facilitate formation of an antiparallel basket-type G-quadruplex with a three G-quartet core and a G·oxoG·C base triad. While oxoG has previously been considered detrimental for G-quadruplex formation, its stabilizing effect within a promoter described in this study suggests a potential novel regulatory role of oxidative stress in general and specifically in BCL2 gene transcription.
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Affiliation(s)
- Stasė Bielskutė
- Slovenian NMR Center, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia
| | - Janez Plavec
- Slovenian NMR Center, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia.,EN-FIST Center of Excellence, Trg OF 13, SI-1000 Ljubljana, Slovenia.,Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia
| | - Peter Podbevšek
- Slovenian NMR Center, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia
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20
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Ghosh A, Largy E, Gabelica V. DNA G-quadruplexes for native mass spectrometry in potassium: a database of validated structures in electrospray-compatible conditions. Nucleic Acids Res 2021; 49:2333-2345. [PMID: 33555347 PMCID: PMC7913678 DOI: 10.1093/nar/gkab039] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 12/22/2020] [Accepted: 01/19/2021] [Indexed: 02/07/2023] Open
Abstract
G-quadruplex DNA structures have become attractive drug targets, and native mass spectrometry can provide detailed characterization of drug binding stoichiometry and affinity, potentially at high throughput. However, the G-quadruplex DNA polymorphism poses problems for interpreting ligand screening assays. In order to establish standardized MS-based screening assays, we studied 28 sequences with documented NMR structures in (usually ∼100 mM) potassium, and report here their circular dichroism (CD), melting temperature (Tm), NMR spectra and electrospray mass spectra in 1 mM KCl/100 mM trimethylammonium acetate. Based on these results, we make a short-list of sequences that adopt the same structure in the MS assay as reported by NMR, and provide recommendations on using them for MS-based assays. We also built an R-based open-source application to build and consult a database, wherein further sequences can be incorporated in the future. The application handles automatically most of the data processing, and allows generating custom figures and reports. The database is included in the g4dbr package (https://github.com/EricLarG4/g4dbr) and can be explored online (https://ericlarg4.github.io/G4_database.html).
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Affiliation(s)
- Anirban Ghosh
- Univ. Bordeaux, CNRS, INSERM, ARNA, UMR 5320, U1212, IECB, F-33000 Bordeaux, France
| | - Eric Largy
- Univ. Bordeaux, CNRS, INSERM, ARNA, UMR 5320, U1212, IECB, F-33000 Bordeaux, France
| | - Valérie Gabelica
- Univ. Bordeaux, CNRS, INSERM, ARNA, UMR 5320, U1212, IECB, F-33000 Bordeaux, France
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21
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Stratmann LM, Kutin Y, Kasanmascheff M, Clever GH. Precise Distance Measurements in DNA G-Quadruplex Dimers and Sandwich Complexes by Pulsed Dipolar EPR Spectroscopy. Angew Chem Int Ed Engl 2021; 60:4939-4947. [PMID: 33063395 PMCID: PMC7984025 DOI: 10.1002/anie.202008618] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 09/12/2020] [Indexed: 12/20/2022]
Abstract
DNA G-quadruplexes show a pronounced tendency to form higher-order structures, such as π-stacked dimers and aggregates with aromatic binding partners. Reliable methods for determining the structure of these non-covalent adducts are scarce. Here, we use artificial square-planar Cu(pyridine)4 complexes, covalently incorporated into tetramolecular G-quadruplexes, as rigid spin labels for detecting dimeric structures and measuring intermolecular Cu2+ -Cu2+ distances via pulsed dipolar EPR spectroscopy. A series of G-quadruplex dimers of different spatial dimensions, formed in tail-to-tail or head-to-head stacking mode, were unambiguously distinguished. Measured distances are in full agreement with results of molecular dynamics simulations. Furthermore, intercalation of two well-known G-quadruplex binders, PIPER and telomestatin, into G-quadruplex dimers resulting in sandwich complexes was investigated, and previously unknown binding modes were discovered. Additionally, we present evidence that free G-tetrads also intercalate into dimers. Our transition metal labeling approach, combined with pulsed EPR spectroscopy, opens new possibilities for examining structures of non-covalent DNA aggregates.
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Affiliation(s)
- Lukas M. Stratmann
- Faculty of Chemistry and Chemical BiologyTU Dortmund UniversityOtto-Hahn-Strasse 644227DortmundGermany
| | - Yury Kutin
- Faculty of Chemistry and Chemical BiologyTU Dortmund UniversityOtto-Hahn-Strasse 644227DortmundGermany
| | - Müge Kasanmascheff
- Faculty of Chemistry and Chemical BiologyTU Dortmund UniversityOtto-Hahn-Strasse 644227DortmundGermany
| | - Guido H. Clever
- Faculty of Chemistry and Chemical BiologyTU Dortmund UniversityOtto-Hahn-Strasse 644227DortmundGermany
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22
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Guiblet WM, Cremona MA, Harris RS, Chen D, Eckert KA, Chiaromonte F, Huang YF, Makova KD. Non-B DNA: a major contributor to small- and large-scale variation in nucleotide substitution frequencies across the genome. Nucleic Acids Res 2021; 49:1497-1516. [PMID: 33450015 PMCID: PMC7897504 DOI: 10.1093/nar/gkaa1269] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 12/14/2020] [Accepted: 01/11/2021] [Indexed: 12/12/2022] Open
Abstract
Approximately 13% of the human genome can fold into non-canonical (non-B) DNA structures (e.g. G-quadruplexes, Z-DNA, etc.), which have been implicated in vital cellular processes. Non-B DNA also hinders replication, increasing errors and facilitating mutagenesis, yet its contribution to genome-wide variation in mutation rates remains unexplored. Here, we conducted a comprehensive analysis of nucleotide substitution frequencies at non-B DNA loci within noncoding, non-repetitive genome regions, their ±2 kb flanking regions, and 1-Megabase windows, using human-orangutan divergence and human single-nucleotide polymorphisms. Functional data analysis at single-base resolution demonstrated that substitution frequencies are usually elevated at non-B DNA, with patterns specific to each non-B DNA type. Mirror, direct and inverted repeats have higher substitution frequencies in spacers than in repeat arms, whereas G-quadruplexes, particularly stable ones, have higher substitution frequencies in loops than in stems. Several non-B DNA types also affect substitution frequencies in their flanking regions. Finally, non-B DNA explains more variation than any other predictor in multiple regression models for diversity or divergence at 1-Megabase scale. Thus, non-B DNA substantially contributes to variation in substitution frequencies at small and large scales. Our results highlight the role of non-B DNA in germline mutagenesis with implications to evolution and genetic diseases.
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Affiliation(s)
- Wilfried M Guiblet
- Bioinformatics and Genomics Graduate Program, Penn State University, UniversityPark, PA 16802, USA
| | - Marzia A Cremona
- Department of Statistics, The Pennsylvania State University, University Park, PA 16802, USA
- Department of Operations and Decision Systems, Université Laval, Canada
- CHU de Québec – Université Laval Research Center, Canada
| | - Robert S Harris
- Department of Biology, Penn State University, University Park, PA 16802, USA
| | - Di Chen
- Intercollege Graduate Degree Program in Genetics, Huck Institutes of the Life Sciences, Penn State University, UniversityPark, PA 16802, USA
| | - Kristin A Eckert
- Department of Pathology, Penn State University, College of Medicine, Hershey, PA 17033, USA
- Center for Medical Genomics, Penn State University, University Park and Hershey, PA, USA
| | - Francesca Chiaromonte
- Department of Statistics, The Pennsylvania State University, University Park, PA 16802, USA
- Center for Medical Genomics, Penn State University, University Park and Hershey, PA, USA
- EMbeDS, Sant’Anna School of Advanced Studies, 56127 Pisa, Italy
| | - Yi-Fei Huang
- Department of Biology, Penn State University, University Park, PA 16802, USA
- Center for Medical Genomics, Penn State University, University Park and Hershey, PA, USA
| | - Kateryna D Makova
- Department of Biology, Penn State University, University Park, PA 16802, USA
- Center for Medical Genomics, Penn State University, University Park and Hershey, PA, USA
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23
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Xiang X, Bao Y, Sun L, Zhang Y, Guo X. A stable uncompleted tetramolecular G-quadruplex formed by d(AG nA) under acidic condition. Int J Biol Macromol 2021; 176:66-71. [PMID: 33577823 DOI: 10.1016/j.ijbiomac.2021.02.059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 02/06/2021] [Accepted: 02/07/2021] [Indexed: 01/12/2023]
Abstract
In this work, the effects of terminal adenines on the formation and stability of tetramolecular G-quadruplexes (G4s) have been studied by electrospray ionization mass spectrometry (ESI-MS), UV, CD and NMR spectroscopy. Several evidences suggested that the sequences d(AGnA) (n = 4 or 5) form stable uncompleted tetramolecular G4 at acidic condition which is different from the canonical one in the neutral condition. In addition, hydrolysis of guanine has also been observed in acidic condition that may occur for unpaired strands rather than in complete G4. Thus, a new G4 topology containing incomplete G-quartet is proposed that is very stable and particularly presents in acidic ammonium ions solution. The information presented in this study provides the new insight on the polymorphism of G4s in acidic environment, which may help understand of the special role of adenines on the formation of G4s.
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Affiliation(s)
- Xiaoxuan Xiang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, China
| | - Ying Bao
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, China
| | - Likang Sun
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, China
| | - Yujing Zhang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, China
| | - Xinhua Guo
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, China; Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, College of Life Science, Jilin University, Changchun 130012, China.
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A two-quartet G-quadruplex topology of human KIT2 is conformationally selected by a perylene derivative. Biochimie 2020; 179:77-84. [DOI: 10.1016/j.biochi.2020.09.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/11/2020] [Accepted: 09/14/2020] [Indexed: 12/19/2022]
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25
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Stratmann LM, Kutin Y, Kasanmascheff M, Clever GH. Präzise Abstandsmessungen in DNA‐G‐Quadruplex‐Dimeren und Sandwichkomplexen über gepulste dipolare EPR‐Spektroskopie. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202008618] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Lukas M. Stratmann
- Fakultät für Chemie und Chemische Biologie TU Dortmund Otto-Hahn-Straße 6 44227 Dortmund Deutschland
| | - Yury Kutin
- Fakultät für Chemie und Chemische Biologie TU Dortmund Otto-Hahn-Straße 6 44227 Dortmund Deutschland
| | - Müge Kasanmascheff
- Fakultät für Chemie und Chemische Biologie TU Dortmund Otto-Hahn-Straße 6 44227 Dortmund Deutschland
| | - Guido H. Clever
- Fakultät für Chemie und Chemische Biologie TU Dortmund Otto-Hahn-Straße 6 44227 Dortmund Deutschland
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Romanucci V, Oliva R, Petraccone L, Claes S, Schols D, Zarrelli A, Di Fabio G. Synthesis of new riboflavin modified ODNs: Effect of riboflavin moiety on the G-quadruplex arrangement and stability. Bioorg Chem 2020; 104:104213. [PMID: 32919132 DOI: 10.1016/j.bioorg.2020.104213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 07/31/2020] [Accepted: 08/24/2020] [Indexed: 10/23/2022]
Abstract
In the panorama of modified G-quadruplexes (G4s) with interesting proprieties, here, it has been reported the synthesis of new modified d(TGGGAG) sequences forming G-quadruplexes, with the insertion of a riboflavin unit (Rf, vitamin B2). Exploiting the flavin similarity with the hydrogen bond pattern of guanine and aiming at mimic a typical nucleoside scaffold, the synthesis of the riboflavin building block 3 it has been efficiently carried out. The effect of insertion of riboflavin mimic nucleoside on the G-quadruplex properties has been here, for the first time investigated. A biophysical characterization of Rf-modified sequences (A-D) has been carried out by circular dichroism (CD), fluorescence spectroscopy, differential scanning calorimetry (DSC) and native gel electrophoresis. CD and electrophoresis data have suggested that Rf-modified sequences are able to form parallel tetramolecular G4 structures similar to that of the unmodified sequence. Analysis of the DSC thermograms has revealed that all modified G-quadruplexes have a higher thermal stability compared with the natural sequence, particularly the stabilisation is higher when the Rf residue is introduced at the 3'-end. Further, DSC analysis has revealed that the Rf residues introduced at the 3'-end are able to form additional stabilising interactions, energetically almost comparable to the enthalpic contribution of a G-tetrad. Fluorescence measurement are consistent with this result showing that the Rf residues introduced at 3'-end are able to form stacking interactions with the adjacent bases within the G-quadruplex structure. The whole of data suggested that the introduction of Rf unit can stabilize G-quadruplex structures and can be a promising candidate for future theranostic applications.
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Affiliation(s)
- Valeria Romanucci
- Department of Chemical Sciences, University of Napoli Federico II, Complesso di Monte Sant'Angelo, Via Cintia 4, I-80126 Napoli, Italy.
| | - Rosario Oliva
- Department of Chemical Sciences, University of Napoli Federico II, Complesso di Monte Sant'Angelo, Via Cintia 4, I-80126 Napoli, Italy; Physical Chemistry I - Biophysical Chemistry, TU Dortmund University, Otto-Hahn Strasse 4a, D-44227 Dortmund, Germany
| | - Luigi Petraccone
- Department of Chemical Sciences, University of Napoli Federico II, Complesso di Monte Sant'Angelo, Via Cintia 4, I-80126 Napoli, Italy
| | - Sandra Claes
- Department of Microbiology, Immunology and Transplantation, Rega Institute, KU Leuven, Herestraat 49, 3000 Leuven, Belgium
| | - Dominique Schols
- Department of Microbiology, Immunology and Transplantation, Rega Institute, KU Leuven, Herestraat 49, 3000 Leuven, Belgium
| | - Armando Zarrelli
- Department of Chemical Sciences, University of Napoli Federico II, Complesso di Monte Sant'Angelo, Via Cintia 4, I-80126 Napoli, Italy
| | - Giovanni Di Fabio
- Department of Chemical Sciences, University of Napoli Federico II, Complesso di Monte Sant'Angelo, Via Cintia 4, I-80126 Napoli, Italy.
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27
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Islam B, Stadlbauer P, Vorlíčková M, Mergny JL, Otyepka M, Šponer J. Stability of Two-Quartet G-Quadruplexes and Their Dimers in Atomistic Simulations. J Chem Theory Comput 2020; 16:3447-3463. [PMID: 32163706 DOI: 10.1021/acs.jctc.9b01068] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
G-quadruplexes (GQs) are four-stranded noncanonical DNA and RNA architectures that can be formed by guanine-rich sequences. The stability of GQs increases with the number of G-quartets, and three G-quartets generally form stable GQs. However, the stability of two-quartet GQs is an open issue. To understand the intrinsic stability of two-quartet GQ stems, we have carried out a series of unbiased molecular dynamics (MD) simulations (505 μs in total) of two- and four-quartet DNA and RNA GQs, with attention paid mainly to parallel-stranded arrangements. We used AMBER DNA parmOL15 and RNA parmOL3 force fields and tested different ion and water models. Two-quartet parallel-stranded DNA GQs unfolded in all the simulations, while the equivalent RNA GQ was stable in most of the simulations. GQs composed of two stacked units of two-quartet GQs were stable for both DNA and RNA. The simulations suggest that a minimum of three quartets are needed to form an intrinsically stable all-anti parallel-stranded DNA GQ. Parallel two-quartet DNA GQ may exist if substantially stabilized by another molecule or structural element, including multimerization. On the other hand, we predict that isolated RNA two-quartet parallel GQs may form, albeit being weakly stable. We also show that ionic parameters and water models should be chosen with caution because some parameter combinations can cause spurious instability of GQ stems. Some in-so-far unnoticed limitations of force-field description of multiple ions inside the GQs are discussed, which compromise the capability of simulations to fully capture the effect of increase in the number of quartets on the GQ stability.
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Affiliation(s)
- Barira Islam
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
| | - Petr Stadlbauer
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic.,Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacký University, tř. 17 listopadu 12, 771 46 Olomouc, Czech Republic
| | - Michaela Vorlíčková
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
| | - Jean-Louis Mergny
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
| | - Michal Otyepka
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic.,Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacký University, tř. 17 listopadu 12, 771 46 Olomouc, Czech Republic.,Department of Physical Chemistry, Faculty of Science, Palacký University, tř. 17 listopadu 12, 771 46 Olomouc, Czech Republic
| | - Jiří Šponer
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
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28
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Nuthanakanti A, Ahmed I, Khatik SY, Saikrishnan K, Srivatsan SG. Probing G-quadruplex topologies and recognition concurrently in real time and 3D using a dual-app nucleoside probe. Nucleic Acids Res 2020; 47:6059-6072. [PMID: 31106340 PMCID: PMC6614846 DOI: 10.1093/nar/gkz419] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 04/30/2019] [Accepted: 05/06/2019] [Indexed: 12/30/2022] Open
Abstract
Comprehensive understanding of structure and recognition properties of regulatory nucleic acid elements in real time and atomic level is highly important to devise efficient therapeutic strategies. Here, we report the establishment of an innovative biophysical platform using a dual-app nucleoside analog, which serves as a common probe to detect and correlate different GQ structures and ligand binding under equilibrium conditions and in 3D by fluorescence and X-ray crystallography techniques. The probe (SedU) is composed of a microenvironment-sensitive fluorophore and an excellent anomalous X-ray scatterer (Se), which is assembled by attaching a selenophene ring at 5-position of 2'-deoxyuridine. SedU incorporated into the loop region of human telomeric DNA repeat fluorescently distinguished subtle differences in GQ topologies and enabled quantify ligand binding to different topologies. Importantly, anomalous X-ray dispersion signal from Se could be used to determine the structure of GQs. As the probe is minimally perturbing, a direct comparison of fluorescence data and crystal structures provided structural insights on how the probe senses different GQ conformations without affecting the native fold. Taken together, our dual-app probe represents a new class of tool that opens up new experimental strategies to concurrently investigate nucleic acid structure and recognition in real time and 3D.
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Affiliation(s)
- Ashok Nuthanakanti
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune, Dr. Homi Bhabha Road, Pune 411008, India
| | - Ishtiyaq Ahmed
- Department of Biology, Indian Institute of Science Education and Research (IISER), Pune, Dr. Homi Bhabha Road, Pune 411008, India
| | - Saddam Y Khatik
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune, Dr. Homi Bhabha Road, Pune 411008, India
| | - Kayarat Saikrishnan
- Department of Biology, Indian Institute of Science Education and Research (IISER), Pune, Dr. Homi Bhabha Road, Pune 411008, India
- Correspondence may also be addressed to Kayarat Saikrishnan.
| | - Seergazhi G Srivatsan
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune, Dr. Homi Bhabha Road, Pune 411008, India
- To whom correspondence should be addressed. Tel: +91 2025908086;
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29
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Paudel HR, Das R, Wu CH, Wu JI. Self-assembling purine and pteridine quartets: how do π-conjugation patterns affect resonance-assisted hydrogen bonding? Org Biomol Chem 2020; 18:1078-1081. [PMID: 31967161 PMCID: PMC7053557 DOI: 10.1039/c9ob02412c] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Computed association strengths for 43 purine and pteridine quartets (38 to 100 kcal mol-1) show excellent linear correlation with π-conjugation gain in the assembled monomers (r2 = 0.965). Even quartets having the same secondary electrostatic interactions can display very different association strengths depending on the π-conjugation patterns of the monomeric units.
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Affiliation(s)
| | - Ranjita Das
- University of Houston, Department of Chemistry, USA.
| | - Chia-Hua Wu
- University of Houston, Department of Chemistry, USA.
| | - Judy I Wu
- University of Houston, Department of Chemistry, USA.
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30
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Moruno-Manchon JF, Lejault P, Wang Y, McCauley B, Honarpisheh P, Morales Scheihing DA, Singh S, Dang W, Kim N, Urayama A, Zhu L, Monchaud D, McCullough LD, Tsvetkov AS. Small-molecule G-quadruplex stabilizers reveal a novel pathway of autophagy regulation in neurons. eLife 2020; 9:e52283. [PMID: 32043463 PMCID: PMC7012600 DOI: 10.7554/elife.52283] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Accepted: 01/07/2020] [Indexed: 12/22/2022] Open
Abstract
Guanine-rich DNA sequences can fold into four-stranded G-quadruplex (G4-DNA) structures. G4-DNA regulates replication and transcription, at least in cancer cells. Here, we demonstrate that, in neurons, pharmacologically stabilizing G4-DNA with G4 ligands strongly downregulates the Atg7 gene. Atg7 is a critical gene for the initiation of autophagy that exhibits decreased transcription with aging. Using an in vitro assay, we show that a putative G-quadruplex-forming sequence (PQFS) in the first intron of the Atg7 gene folds into a G4. An antibody specific to G4-DNA and the G4-DNA-binding protein PC4 bind to the Atg7 PQFS. Mice treated with a G4 stabilizer develop memory deficits. Brain samples from aged mice contain G4-DNA structures that are absent in brain samples from young mice. Overexpressing the G4-DNA helicase Pif1 in neurons exposed to the G4 stabilizer improves phenotypes associated with G4-DNA stabilization. Our findings indicate that G4-DNA is a novel pathway for regulating autophagy in neurons.
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Affiliation(s)
- Jose F Moruno-Manchon
- Department of Neurobiology and AnatomyThe University of Texas McGovern Medical School at HoustonHoustonUnited States
| | - Pauline Lejault
- Institut de Chimie Moléculaire (ICMUB), UBFC Dijon, CNRS UMR6302DijonFrance
| | - Yaoxuan Wang
- Department of Neurobiology and AnatomyThe University of Texas McGovern Medical School at HoustonHoustonUnited States
| | - Brenna McCauley
- Huffington Center on AgingBaylor College of MedicineHoustonUnited States
| | - Pedram Honarpisheh
- Department of NeurologyThe University of Texas McGovern Medical School at HoustonHoustonUnited States
- The University of Texas Graduate School of Biomedical SciencesHoustonUnited States
| | - Diego A Morales Scheihing
- Department of NeurologyThe University of Texas McGovern Medical School at HoustonHoustonUnited States
| | - Shivani Singh
- Department of Microbiology and Molecular GeneticsThe University of Texas McGovern Medical School at HoustonHoustonUnited States
| | - Weiwei Dang
- Huffington Center on AgingBaylor College of MedicineHoustonUnited States
| | - Nayun Kim
- Department of Microbiology and Molecular GeneticsThe University of Texas McGovern Medical School at HoustonHoustonUnited States
| | - Akihiko Urayama
- Department of NeurologyThe University of Texas McGovern Medical School at HoustonHoustonUnited States
- The University of Texas Graduate School of Biomedical SciencesHoustonUnited States
| | - Liang Zhu
- Biostatistics and Epidemiology Research Design Core Center for Clinical and Translational SciencesThe University of Texas McGovern Medical School at HoustonHoustonUnited States
- Department of Internal MedicineThe University of Texas McGovern Medical School at HoustonHoustonUnited States
| | - David Monchaud
- Institut de Chimie Moléculaire (ICMUB), UBFC Dijon, CNRS UMR6302DijonFrance
| | - Louise D McCullough
- Department of NeurologyThe University of Texas McGovern Medical School at HoustonHoustonUnited States
- The University of Texas Graduate School of Biomedical SciencesHoustonUnited States
| | - Andrey S Tsvetkov
- Department of Neurobiology and AnatomyThe University of Texas McGovern Medical School at HoustonHoustonUnited States
- The University of Texas Graduate School of Biomedical SciencesHoustonUnited States
- UTHealth Consortium on AgingThe University of Texas McGovern Medical School at HoustonHoustonUnited States
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31
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Lee DSM, Ghanem LR, Barash Y. Integrative analysis reveals RNA G-quadruplexes in UTRs are selectively constrained and enriched for functional associations. Nat Commun 2020; 11:527. [PMID: 31988292 PMCID: PMC6985247 DOI: 10.1038/s41467-020-14404-y] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 01/03/2020] [Indexed: 11/17/2022] Open
Abstract
G-quadruplex (G4) sequences are abundant in untranslated regions (UTRs) of human messenger RNAs, but their functional importance remains unclear. By integrating multiple sources of genetic and genomic data, we show that putative G-quadruplex forming sequences (pG4) in 5' and 3' UTRs are selectively constrained, and enriched for cis-eQTLs and RNA-binding protein (RBP) interactions. Using over 15,000 whole-genome sequences, we find that negative selection acting on central guanines of UTR pG4s is comparable to that of missense variation in protein-coding sequences. At multiple GWAS-implicated SNPs within pG4 UTR sequences, we find robust allelic imbalance in gene expression across diverse tissue contexts in GTEx, suggesting that variants affecting G-quadruplex formation within UTRs may also contribute to phenotypic variation. Our results establish UTR G4s as important cis-regulatory elements and point to a link between disruption of UTR pG4 and disease.
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Affiliation(s)
- David S M Lee
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Louis R Ghanem
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, The Children's Hospital of Philadelphia and The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA.
| | - Yoseph Barash
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
- Department of Computer and Information Science, School of Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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32
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Ma Y, Iida K, Nagasawa K. Topologies of G-quadruplex: Biological functions and regulation by ligands. Biochem Biophys Res Commun 2020; 531:3-17. [PMID: 31948752 DOI: 10.1016/j.bbrc.2019.12.103] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Revised: 12/20/2019] [Accepted: 12/28/2019] [Indexed: 01/06/2023]
Abstract
G-Quadruplex (G4) is one of the higher-order structures occurring in guanine-rich sequences of nucleic acids, and plays critical roles in biological processes. The G4-forming sequences can generate three kinds of topologies, i.e., parallel, anti-parallel, and hybrid, and these polymorphic structures have an important influence on G4-related biological functions. In this review, we highlight variety of structures generated by G4s containing various sequences and under diverse conditions. We also discuss the G4 ligands which induce specific topologies and/or conversion between different topologies.
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Affiliation(s)
- Yue Ma
- Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Japan.
| | - Keisuke Iida
- Department of Chemistry, Chiba University, Japan
| | - Kazuo Nagasawa
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Japan.
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D'Atri V, Gabelica V. DNA and RNA telomeric G-quadruplexes: what topology features can be inferred from ion mobility mass spectrometry? Analyst 2019; 144:6074-6088. [PMID: 31528871 DOI: 10.1039/c9an01216h] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Maintenance of the telomeres is key to chromosome integrity and cell proliferation. The G-quadruplex structures formed by telomeric DNA and RNA (TTAGGG and UUAGGG repeats, respectively) are key to this process. However, because these sequences are particularly polymorphic, solving high-resolution structures is not always possible, and there is a need for new methodologies to characterize the multiple structures coexisting in solution. In this context, we evaluated whether ion mobility spectrometry coupled to native mass spectrometry could help separate and assign the G-quadruplex topologies. We explored the circular dichroism spectra, multimer formation, cation binding, and ion mobility spectra of several 4-repeat and 8-repeat telomeric DNA and RNA sequences, both in NH4+ and in K+. In 1 mM K+ and 100 mM trimethylammonium acetate, all RNAs fold intramolecularly (no multimer). In 8-repeat sequences, the subunits are not independent: in DNA the first subunit disfavors the folding of the second one, whereas in RNA the two subunits fold cooperatively via cation-mediated stacking. Ion mobility spectrometry shows that gas-phase structures keep a memory of - but are not identical to - the solution ones. At the native charge states, the loops can rearrange in a variety of ways (unless they are constrained by pre-formed hydrogen bonds), thereby wrapping the core and masking the strand arrangements. Our study highlights that, to progress towards structural assignment from IM-MS experiments, deeper understanding of the solution-to-gas-phase rearrangement mechanisms is warranted.
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Affiliation(s)
- Valentina D'Atri
- University of Bordeaux, INSERM and CNRS, ARNA Laboratory, IECB site, 2 rue Robert Escarpit, 33600 Pessac, France.
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34
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Lightfoot HL, Hagen T, Tatum NJ, Hall J. The diverse structural landscape of quadruplexes. FEBS Lett 2019; 593:2083-2102. [PMID: 31325371 DOI: 10.1002/1873-3468.13547] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Revised: 07/09/2019] [Accepted: 07/15/2019] [Indexed: 12/15/2022]
Abstract
G-quadruplexes are secondary structures formed in G-rich sequences in DNA and RNA. Considerable research over the past three decades has led to in-depth insight into these unusual structures in DNA. Since the more recent exploration into RNA G-quadruplexes, such structures have demonstrated their in cellulo existence, function and roles in pathology. In comparison to Watson-Crick-based secondary structures, most G-quadruplexes display highly redundant structural characteristics. However, numerous reports of G-quadruplex motifs/structures with unique features (e.g. bulges, long loops, vacancy) have recently surfaced, expanding the repertoire of G-quadruplex scaffolds. This review addresses G-quadruplex formation and structure, including recent reports of non-canonical G-quadruplex structures. Improved methods of detection will likely further expand this collection of novel structures and ultimately change the face of quadruplex-RNA targeting as a therapeutic strategy.
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Affiliation(s)
- Helen L Lightfoot
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, ETH Zurich, Switzerland
| | - Timo Hagen
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, ETH Zurich, Switzerland
| | - Natalie J Tatum
- Newcastle Cancer Centre, Northern Institute for Cancer Research, Medical School, Newcastle University, Newcastle upon Tyne, UK
| | - Jonathan Hall
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, ETH Zurich, Switzerland
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35
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Chawla M, Minenkov Y, Vu KB, Oliva R, Cavallo L. Structural and Energetic Impact of Non-natural 7-Deaza-8-azaguanine, 7-Deaza-8-azaisoguanine, and Their 7-Substituted Derivatives on Hydrogen-Bond Pairing with Cytosine and Isocytosine. Chembiochem 2019; 20:2262-2270. [PMID: 30983115 DOI: 10.1002/cbic.201900245] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Indexed: 12/12/2022]
Abstract
The impact of 7-deaza-8-azaguanine (DAG) and 7-deaza-8-azaisoguanine (DAiG) modifications on the geometry and stability of the G:C Watson-Crick (cWW) base pair and the G:iC and iG:C reverse Watson-Crick (tWW) base pairs has been characterized theoretically. In addition, the effect on the same base pairs of seven C7-substituted DAG and DAiG derivatives, some of which have been previously experimentally characterized, has been investigated. Calculations indicate that all of these modifications have a negligible impact on the geometry of the above base pairs, and that modification of the heterocycle skeleton has a small impact on the base-pair interaction energies. Instead, base-pair interaction energies are dependent on the nature of the C7 substituent. For the 7-substituted DAG-C cWW systems, a linear correlation between the base-pair interaction energy and the Hammett constant of the 7-substituent is found, with higher interaction energies corresponding to more electron-withdrawing substituents. Therefore, the explored modifications are expected to be accommodated in both parallel and antiparallel nucleic acid duplexes without perturbing their geometry, while the strength of a base pair (and duplex) featuring a DAG modification can, in principle, be tuned by incorporating different substituents at the C7 position.
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Affiliation(s)
- Mohit Chawla
- King Abdullah University of Science and Technology (KAUST), Physical Sciences and Engineering Division, Kaust Catalysis Center, Thuwal, 23955-6900, Saudi Arabia
| | - Yury Minenkov
- Moscow Institute of Physics and Technology, Institutskiy Pereulok 9, Dolgoprudny, Moscow Region, 141700, Russia
| | - Khanh B Vu
- NTT Hi-Tech Institute, Nguyen Tat Thanh University, 298-300A Nguyen Tat Thanh Street, Ho Chi Minh City, Vietnam
| | - Romina Oliva
- Department of Sciences and Technologies, University Parthenope of Naples, Centro Direzionale Isola C4, 80143, Naples, Italy
| | - Luigi Cavallo
- King Abdullah University of Science and Technology (KAUST), Physical Sciences and Engineering Division, Kaust Catalysis Center, Thuwal, 23955-6900, Saudi Arabia
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36
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Lin CYG, Chao JL, Tsai HK, Chalker D, Yao MC. Setting boundaries for genome-wide heterochromatic DNA deletions through flanking inverted repeats in Tetrahymena thermophila. Nucleic Acids Res 2019; 47:5181-5192. [PMID: 30918956 PMCID: PMC6547420 DOI: 10.1093/nar/gkz209] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Revised: 03/03/2019] [Accepted: 03/26/2019] [Indexed: 12/13/2022] Open
Abstract
Eukaryotic cells pack their genomic DNA into euchromatin and heterochromatin. Boundaries between these domains have been shown to be set by boundary elements. In Tetrahymena, heterochromatin domains are targeted for deletion from the somatic nuclei through a sophisticated programmed DNA rearrangement mechanism, resulting in the elimination of 34% of the germline genome in ∼10,000 dispersed segments. Here we showed that most of these deletions occur consistently with very limited variations in their boundaries among inbred lines. We identified several potential flanking regulatory sequences, each associated with a subset of deletions, using a genome-wide motif finding approach. These flanking sequences are inverted repeats with the copies located at nearly identical distances from the opposite ends of the deleted regions, suggesting potential roles in boundary determination. By removing and testing two such inverted repeats in vivo, we found that the ability for boundary maintenance of the associated deletion were lost. Furthermore, we analyzed the deletion boundaries in mutants of a known boundary-determining protein, Lia3p and found that the subset of deletions that are affected by LIA3 knockout contained common features of flanking regulatory sequences. This study suggests a common mechanism for setting deletion boundaries by flanking inverted repeats in Tetrahymena thermophila.
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Affiliation(s)
- Chih-Yi Gabriela Lin
- Institute of Molecular Biology, Academia Sinica, 11529 Taipei, Taiwan
- Genome and Systems Biology Degree Program, National Taiwan University, 10617 Taipei, Taiwan
| | - Ju-Lan Chao
- Institute of Molecular Biology, Academia Sinica, 11529 Taipei, Taiwan
| | - Huai-Kuang Tsai
- Genome and Systems Biology Degree Program, National Taiwan University, 10617 Taipei, Taiwan
- Institute of Information Science, Academia Sinica, 11529 Taipei, Taiwan
| | - Douglas Chalker
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Meng-Chao Yao
- Institute of Molecular Biology, Academia Sinica, 11529 Taipei, Taiwan
- Genome and Systems Biology Degree Program, National Taiwan University, 10617 Taipei, Taiwan
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37
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Abstract
DNA has played an early and powerful role in the development of bottom-up nanotechnologies, not least because of DNA's precise, predictable, and controllable properties of assembly on the nanometer scale. Watson-Crick complementarity has been used to build complex 2D and 3D architectures and design a number of nanometer-scale systems for molecular computing, transport, motors, and biosensing applications. Most of such devices are built with classical B-DNA helices and involve classical A-T/U and G-C base pairs. However, in addition to the above components underlying the iconic double helix, a number of alternative pairing schemes of nucleobases are known. This review focuses on two of these noncanonical classes of DNA helices: G-quadruplexes and the i-motif. The unique properties of these two classes of DNA helix have been utilized toward some remarkable constructions and applications: G-wires; nanostructures such as DNA origami; reconfigurable structures and nanodevices; the formation and utilization of hemin-utilizing DNAzymes, capable of generating varied outputs from biosensing nanostructures; composite nanostructures made up of DNA as well as inorganic materials; and the construction of nanocarriers that show promise for the therapeutics of diseases.
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Affiliation(s)
- Jean-Louis Mergny
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry & Chemical Engineering , Nanjing University , Nanjing 210023 , China.,ARNA Laboratory , Université de Bordeaux, Inserm U 1212, CNRS UMR5320, IECB , Pessac 33600 , France.,Institute of Biophysics of the CAS , v.v.i., Královopolská 135 , 612 65 Brno , Czech Republic
| | - Dipankar Sen
- Department of Molecular Biology & Biochemistry , Simon Fraser University , Burnaby , British Columbia V5A 1S6 , Canada.,Department of Chemistry , Simon Fraser University , Burnaby , British Columbia V5A 1S6 , Canada
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38
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Manna S, Sarkar D, Srivatsan SG. A Dual-App Nucleoside Probe Provides Structural Insights into the Human Telomeric Overhang in Live Cells. J Am Chem Soc 2018; 140:12622-12633. [PMID: 30192541 PMCID: PMC6348103 DOI: 10.1021/jacs.8b08436] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Understanding the topology adopted by individual G-quadruplex (GQ)-forming sequences in vivo and targeting a specific GQ motif among others in the genome will have a profound impact on GQ-directed therapeutic strategies. However, this remains a major challenge as most of the tools poorly distinguish different GQ conformations and are not suitable for both cell-free and in-cell analysis. Here, we describe an innovative probe design to investigate GQ conformations and recognition in both cell-free and native cellular environments by using a conformation-sensitive dual-app nucleoside analogue probe. The nucleoside probe, derived by conjugating fluorobenzofuran at the 5-position of 2'-deoxyuridine, is composed of a microenvironment-sensitive fluorophore and an in-cell NMR compatible 19F label. This noninvasive nucleoside, incorporated into the human telomeric DNA oligonucleotide repeat, serves as a common probe to distinguish different GQ topologies and quantify topology-specific binding of ligands by fluorescence and NMR techniques. Importantly, unique signatures displayed by the 19F-labeled nucleoside for different GQs enabled a systematic study in Xenopus laevis oocytes to provide new structural insights into the GQ topologies adopted by human telomeric overhang in cells, which so far has remained unclear. Studies using synthetic cell models, immunostaining on fixed cells, and crystallization conditions suggest that parallel GQ is the preferred conformation of telomeric DNA repeat. However, our findings using the dual-app probe clearly indicate that multiple structures including hybrid-type parallel-antiparallel and parallel GQs are formed in the cellular environment. Taken together, our findings open new experimental strategies to investigate topology, recognition, and therapeutic potential of individual GQ-forming motifs in a biologically relevant context.
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Affiliation(s)
- Sudeshna Manna
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune, Dr. Homi Bhabha Road, Pune 411008, India
| | - Debayan Sarkar
- Department of Biology, Indian Institute of Science Education and Research (IISER), Pune, Dr. Homi Bhabha Road, Pune 411008, India
| | - Seergazhi G. Srivatsan
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune, Dr. Homi Bhabha Road, Pune 411008, India
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39
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Saito Y, Hudson RH. Base-modified fluorescent purine nucleosides and nucleotides for use in oligonucleotide probes. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C-PHOTOCHEMISTRY REVIEWS 2018. [DOI: 10.1016/j.jphotochemrev.2018.07.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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40
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Manna S, Srivatsan SG. Fluorescence-based tools to probe G-quadruplexes in cell-free and cellular environments. RSC Adv 2018; 8:25673-25694. [PMID: 30210793 PMCID: PMC6130854 DOI: 10.1039/c8ra03708f] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 07/08/2018] [Indexed: 12/26/2022] Open
Abstract
Biophysical and biochemical investigations provide compelling evidence connecting the four-stranded G-quadruplex (GQ) structure with its role in regulating multiple cellular processes. Hence, modulating the function of GQs by using small molecule binders is being actively pursued as a strategy to develop new chemotherapeutic agents. However, sequence diversity and structural polymorphism of GQs have posed immense challenges in terms of understanding what conformation a G-rich sequence adopts inside the cell and how to specifically target a GQ motif amidst several other GQ-forming sequences. In this context, here we review recent developments in the applications of biophysical tools that use fluorescence readout to probe the GQ structure and recognition in cell-free and cellular environments. First, we provide a detailed discussion on the utility of covalently labeled environment-sensitive fluorescent nucleoside analogs in assessing the subtle difference in GQ structures and their ligand binding abilities. Furthermore, a detailed discussion on structure-specific antibodies and small molecule probes used to visualize and confirm the existence of DNA and RNA GQs in cells is provided. We also highlight the open challenges in the study of tetraplexes (GQ and i-motif structures) and how addressing these challenges by developing new tools and techniques will have a profound impact on tetraplex-directed therapeutic strategies.
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Affiliation(s)
- Sudeshna Manna
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), PuneDr. Homi Bhabha RoadPune 411008India
| | - Seergazhi G. Srivatsan
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), PuneDr. Homi Bhabha RoadPune 411008India
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41
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Karg B, Weisz K. Loop Length Affects Syn-Anti Conformational Rearrangements in Parallel G-Quadruplexes. Chemistry 2018; 24:10246-10252. [PMID: 29756658 DOI: 10.1002/chem.201801851] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Revised: 05/12/2018] [Indexed: 01/24/2023]
Abstract
A G-quadruplex forming sequence from the MYC promoter region was modified with syn-favoring 8-bromo-2'-deoxyguanosine residues. Depending on the number and position of modifications in the intramolecular parallel G-quadruplex, substitutions with the bromoguanosine analogue at the 5'-tetrad induce conformational rearrangements with concerted all-anti to all-syn transitions for all residues of the modified G-quartet. No unfavorable steric interactions of the C8-substituents in the medium grooves are apparent in the high-resolution structure as determined for a tetrasubstituted MYC quadruplex that exclusively forms the all-syn isomer. In contrast, considerable steric clashes with 5'-phosphate oxygen atoms for those analogues that follow a less flexible 1-nucleotide loop in the native all-anti conformation seem to constitute the major driving force for the tetrad inversion and allow for the rational design of appropriately substituted sequences. Correlations found between the population of species subjected to a tetrad flip and melting temperatures indicate that more effective conformational transitions are compromised by lower thermal stabilities of the modified parallel quadruplexes.
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Affiliation(s)
- Beatrice Karg
- Institute of Biochemistry, Ernst-Moritz-Arndt University Greifswald, Felix-Hausdorff-Str. 4, 17487, Greifswald, Germany
| | - Klaus Weisz
- Institute of Biochemistry, Ernst-Moritz-Arndt University Greifswald, Felix-Hausdorff-Str. 4, 17487, Greifswald, Germany
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42
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Moruno-Manchon JF, Koellhoffer EC, Gopakumar J, Hambarde S, Kim N, McCullough LD, Tsvetkov AS. The G-quadruplex DNA stabilizing drug pyridostatin promotes DNA damage and downregulates transcription of Brca1 in neurons. Aging (Albany NY) 2018; 9:1957-1970. [PMID: 28904242 PMCID: PMC5636668 DOI: 10.18632/aging.101282] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 08/25/2017] [Indexed: 01/01/2023]
Abstract
The G-quadruplex is a non-canonical DNA secondary structure formed by four DNA strands containing multiple runs of guanines. G-quadruplexes play important roles in DNA recombination, replication, telomere maintenance, and regulation of transcription. Small molecules that stabilize the G-quadruplexes alter gene expression in cancer cells. Here, we hypothesized that the G-quadruplexes regulate transcription in neurons. We discovered that pyridostatin, a small molecule that specifically stabilizes G-quadruplex DNA complexes, induced neurotoxicity and promoted the formation of DNA double–strand breaks (DSBs) in cultured neurons. We also found that pyridostatin downregulated transcription of the Brca1 gene, a gene that is critical for DSB repair. Importantly, in an in vitro gel shift assay, we discovered that an antibody specific to the G-quadruplex structure binds to a synthetic oligonucleotide, which corresponds to the first putative G-quadruplex in the Brca1 gene promoter. Our results suggest that the G-quadruplex complexes regulate transcription in neurons. Studying the G-quadruplexes could represent a new avenue for neurodegeneration and brain aging research.
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Affiliation(s)
- Jose F Moruno-Manchon
- Department of Neurobiology and Anatomy, the University of Texas McGovern Medical School at Houston, TX 77030, USA
| | - Edward C Koellhoffer
- Department of Neurology, the University of Texas McGovern Medical School at Houston, TX 77030, USA
| | - Jayakrishnan Gopakumar
- Summer Research Program at the University of Texas McGovern Medical School at Houston, TX 77030, USA
| | - Shashank Hambarde
- Department of Microbiology and Molecular Genetics, the University of Texas McGovern Medical School at Houston, TX 77030, USA
| | - Nayun Kim
- Department of Microbiology and Molecular Genetics, the University of Texas McGovern Medical School at Houston, TX 77030, USA.,The University of Texas Graduate School of Biomedical Sciences, Houston, TX 77030, USA
| | - Louise D McCullough
- Department of Neurology, the University of Texas McGovern Medical School at Houston, TX 77030, USA.,The University of Texas Graduate School of Biomedical Sciences, Houston, TX 77030, USA
| | - Andrey S Tsvetkov
- Department of Neurobiology and Anatomy, the University of Texas McGovern Medical School at Houston, TX 77030, USA.,The University of Texas Graduate School of Biomedical Sciences, Houston, TX 77030, USA.,UTHealth Consortium on Aging, the University of Texas McGovern Medical School, Houston, TX 77030, USA
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43
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Saikia N, Karna SP, Pandey R. Theoretical study of gas and solvent phase stability and molecular adsorption of noncanonical guanine bases on graphene. Phys Chem Chem Phys 2018. [PMID: 28627546 DOI: 10.1039/c7cp02944f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The gas and solvent phase stability of noncanonical (Gua)n nucleobases is investigated in the framework of dispersion-corrected density functional theory (DFT). The calculated results strongly support the high tendency for the dimerization of (Gua)n bases in both gas and solvent phases. An interplay between intermolecular and bifurcated H-bonds is suggested to govern the stability of (Gua)n bases which bears a correlation with the description of dispersion correction terms employed in the DFT calculations. For example, a higher polarity is predicted for (Gua)n bases by the dispersion-corrected DFT in contrast to the non-polar nature of (Gua)3 and (Gua)4 predicted by the hybrid meta-GGA calculations. This distinct variation becomes significant under physiological conditions as polar (Gua)n is likely to exhibit greater stabilization in the gas phase compared to solvated (Gua)n. Graphene acting as a substrate induces modification in base configurations via maximization of π-orbital overlap between the base and substrate. In solvent, the substrate-induced effects are further heightened with lowering of the dipole moments of (Gua)n as also displayed by the corresponding isosurface of the electrostatic potential. The graphene-induced stability in both gas and solvent phases appears to fulfill one of the prerequisite criteria for molecular self-assembly. The DFT results therefore provide atomistic insights into the stability and molecular assembly of free-standing noncanonical (Gua)n nucleobases which can be extended to understanding the self-assembly process of functional biomolecules on 2D materials for potential biosensing applications.
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Affiliation(s)
- Nabanita Saikia
- Department of Physics, Michigan Technological University, Houghton, Michigan, USA.
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44
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Barlev A, Sen D. DNA's Encounter with Ultraviolet Light: An Instinct for Self-Preservation? Acc Chem Res 2018; 51:526-533. [PMID: 29419284 DOI: 10.1021/acs.accounts.7b00582] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Photochemical modification is the major class of environmental damage suffered by DNA, the genetic material of all free-living organisms. Photolyases are enzymes that carry out direct photochemical repair (photoreactivation) of covalent pyrimidine dimers formed in DNA from exposure to ultraviolet light. The discovery of catalytic RNAs in the 1980s led to the "RNA world hypothesis", which posits that early in evolution RNA or a similar polymer served both genetic and catalytic functions. Intrigued by the RNA world hypothesis, we set out to test whether a catalytic RNA (or a surrogate, a catalytic DNA) with photolyase activity could be contemplated. In vitro selection from a random-sequence DNA pool yielded two DNA enzymes (DNAzymes): Sero1C, which requires serotonin as an obligate cofactor, and UV1C, which is cofactor-independent and optimally uses light of 300-310 nm wavelength to repair cyclobutane thymine dimers within a gapped DNA substrate. Both Sero1C and UV1C show multiple turnover kinetics, and UV1C repairs its substrate with a quantum yield of ∼0.05, on the same order as the quantum yields of certain classes of photolyase enzymes. Intensive study of UV1C has revealed that its catalytic core consists of a guanine quadruplex (G-quadruplex) positioned proximally to the bound substrate's thymine dimer. We hypothesize that electron transfer from photoexcited guanines within UV1C's G-quadruplex is responsible for substrate photoreactivation, analogous to electron transfer to pyrimidine dimers within a DNA substrate from photoexcited flavin cofactors located within natural photolyase enzymes. Though the analogy to evolution is necessarily limited, a comparison of the properties of UV1C and Sero1C, which arose out of the same in vitro selection experiment, reveals that although the two DNAzymes comparably accelerate the rate of thymine dimer repair, Sero1C has a substantially broader substrate repertoire, as it can repair many more kinds of pyrimidine dimers than UV1C. Therefore, the co-opting of an amino acid-like cofactor by a nucleic acid enzyme in this case contributes functional versatility rather than a greater rate enhancement. In recent work on UV1C, we have succeeded in shifting its action spectrum from the UVB into the blue region of the spectrum and determined that although it catalyzes both repair and de novo formation of thymine dimers, UV1C is primarily a catalyst for thymine dimer repair. Our work on photolyase DNAzymes has stimulated broader questions about whether analogous, purely nucleotide-based photoreactivation also occurs in double-helical DNA, the dominant form of DNA in living cells. Recently, a number of different groups have reported that this kind of repair is indeed operational in DNA duplexes, i.e., that there exist nucleotide sequences that actively protect, by way of photoreactivation (rather than by simply preventing their formation), pyrimidine dimers located proximal to them. Nucleotide-based photoreactivation thus appears to be a salient, if unanticipated, property of DNA and RNA. The phenomenon also offers pointers in the direction of how in primordial evolution-in an RNA world-early nucleic acids may have protected themselves from structural and functional damage wrought by ultraviolet light.
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Affiliation(s)
- Adam Barlev
- Department
of Chemistry and ‡Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Dipankar Sen
- Department
of Chemistry and ‡Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
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45
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Mixed guanine, adenine base quartets: possible roles of protons and metal ions in their stabilization. J Biol Inorg Chem 2017; 23:41-49. [PMID: 29218641 PMCID: PMC5756560 DOI: 10.1007/s00775-017-1507-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 10/18/2017] [Indexed: 11/17/2022]
Abstract
Structural variations of the well-known guanine quartet (G4) motif in nucleic acid structures, namely substitution of two guanine bases (G) by two adenine (A) nucleobases in mutual trans positions, are discussed and studied by density functional theory (DFT) methods. This work was initiated by three findings, namely (1) that GA mismatches are compatible with complementary pairing patterns in duplex-DNA structures and can, in principle, be extended to quartet structures, (2) that GA pairs can come in several variations, including with a N1 protonated adeninium moiety (AH), and (3) that cross-linking of the major donor sites of purine nucleobases (N1 and N7) by transition metal ions of linear coordination geometries produces planar purine quartets, as demonstrated by some of us in the past. Here, possible structures of mixed AGAG quartets both in the presence of protons and alkali metal ions are discussed, and in particular, the existence of a putative four-purine, two-metal motif.
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46
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A novel G-quadruplex motif in the Human MET promoter region. Biosci Rep 2017; 37:BSR20171128. [PMID: 29054971 PMCID: PMC5705779 DOI: 10.1042/bsr20171128] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 10/15/2017] [Accepted: 10/17/2017] [Indexed: 12/11/2022] Open
Abstract
It is known that the guanine-rich strands in proto-oncogene promoters can fold into G-quadruplex structures to regulate gene expression. An intramolecular parallel G-quadruplex has been identified in MET promoter. It acts as a repressor in regulating MET expression. However, the full guanine-rich region in MET promoter forms a hybrid parallel/antiparallel G-quadruplex structure under physiological conditions, which means there are some antiparallel and hybrid parallel/antiparallel G-quadruplex structures in this region. In the present study, our data indicate that g3-5 truncation adopts an intramolecular hybrid parallel/antiparallel G-quadruplex under physiological conditions in vitro The g3-5 G-quadruplex structure significantly stops polymerization by Klenow fragment in K+ buffer. Furthermore, the results of circular dichroism (CD) spectra and polymerase stop assay directly demonstrate that the G-quadruplex structure in g3-5 fragment can be stabilized by the G-quadruplex ligand TMPyP4 (5,10,15,20-tetra-(N-methyl-4-pyridyl) porphine). But the dual luciferase assay indicates TMPyP4 has no effect on the formation of g3-5 G-quadruplex in HepG2 cells. The findings in the present study will enrich our understanding of the G-quadruplex formation in proto-oncogene promoters and the mechanisms of gene expression regulation.
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47
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Lech CJ, Phan AT. Ball with hair: modular functionalization of highly stable G-quadruplex DNA nano-scaffolds through N2-guanine modification. Nucleic Acids Res 2017; 45:6265-6274. [PMID: 28499037 PMCID: PMC5499775 DOI: 10.1093/nar/gkx243] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 05/10/2017] [Indexed: 12/13/2022] Open
Abstract
Functionalized nanoparticles have seen valuable applications, particularly in the delivery of therapeutic and diagnostic agents in biological systems. However, the manufacturing of such nano-scale systems with the consistency required for biological application can be challenging, as variation in size and shape have large influences in nanoparticle behavior in vivo. We report on the development of a versatile nano-scaffold based on the modular functionalization of a DNA G-quadruplex. DNA sequences are functionalized in a modular fashion using well-established phosphoramidite chemical synthesis with nucleotides containing modification of the amino (N2) position of the guanine base. In physiological conditions, these sequences fold into well-defined G-quadruplex structures. The resulting DNA nano-scaffolds are thermally stable, consistent in size, and functionalized in a manner that allows for control over the density and relative orientation of functional chemistries on the nano-scaffold surface. Various chemistries including small modifications (N2-methyl-guanine), bulky aromatic modifications (N2-benzyl-guanine), and long chain-like modifications (N2-6-amino-hexyl-guanine) are tested and are found to be generally compatible with G-quadruplex formation. Furthermore, these modifications stabilize the G-quadruplex scaffold by 2.0–13.3 °C per modification in the melting temperature, with concurrent modifications producing extremely stable nano-scaffolds. We demonstrate the potential of this approach by functionalizing nano-scaffolds for use within the biotin–avidin conjugation approach.
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Affiliation(s)
- Christopher Jacques Lech
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371
| | - Anh Tuân Phan
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371
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48
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Sagi J. In What Ways Do Synthetic Nucleotides and Natural Base Lesions Alter the Structural Stability of G-Quadruplex Nucleic Acids? J Nucleic Acids 2017; 2017:1641845. [PMID: 29181193 PMCID: PMC5664352 DOI: 10.1155/2017/1641845] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 08/15/2017] [Indexed: 01/03/2023] Open
Abstract
Synthetic analogs of natural nucleotides have long been utilized for structural studies of canonical and noncanonical nucleic acids, including the extensively investigated polymorphic G-quadruplexes (GQs). Dependence on the sequence and nucleotide modifications of the folding landscape of GQs has been reviewed by several recent studies. Here, an overview is compiled on the thermodynamic stability of the modified GQ folds and on how the stereochemical preferences of more than 70 synthetic and natural derivatives of nucleotides substituting for natural ones determine the stability as well as the conformation. Groups of nucleotide analogs only stabilize or only destabilize the GQ, while the majority of analogs alter the GQ stability in both ways. This depends on the preferred syn or anti N-glycosidic linkage of the modified building blocks, the position of substitution, and the folding architecture of the native GQ. Natural base lesions and epigenetic modifications of GQs explored so far also stabilize or destabilize the GQ assemblies. Learning the effect of synthetic nucleotide analogs on the stability of GQs can assist in engineering a required stable GQ topology, and exploring the in vitro action of the single and clustered natural base damage on GQ architectures may provide indications for the cellular events.
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Affiliation(s)
- Janos Sagi
- Rimstone Laboratory, RLI, Carlsbad, CA 92010, USA
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49
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Liao JY, Anosova I, Bala S, Van Horn WD, Chaput JC. A parallel stranded G-quadruplex composed of threose nucleic acid (TNA). Biopolymers 2017; 107. [PMID: 27718227 DOI: 10.1002/bip.22999] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 09/26/2016] [Accepted: 10/05/2016] [Indexed: 11/08/2022]
Abstract
G-rich sequences can adopt four-stranded helical structures, called G-quadruplexes, that self-assemble around monovalent cations like sodium (Na+ ) and potassium (K+ ). Whether similar structures can be formed from xeno-nucleic acid (XNA) polymers with a shorter backbone repeat unit is an unanswered question with significant implications on the fold space of functional XNA polymers. Here, we examine the potential for TNA (α-l-threofuranosyl nucleic acid) to adopt a four-stranded helical structure based on a planar G-quartet motif. Using native polyacrylamide gel electrophoresis (PAGE), circular dichroism (CD) and solution-state nuclear magnetic resonance (NMR) spectroscopy, we show that despite a backbone repeat unit that is one atom shorter than the backbone repeat unit found in DNA and RNA, TNA can self-assemble into stable G-quadruplex structures that are similar in thermal stability to equivalent DNA structures. However, unlike DNA, TNA does not appear to discriminate between Na+ and K+ ions, as G-quadruplex structures form equally well in the presence of either ion. Together, these findings demonstrate that despite a shorter backbone repeat unit, TNA is capable of self-assembling into stable G-quadruplex structures.
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Affiliation(s)
- Jen-Yu Liao
- Department of Pharmaceutical Sciences, University of California, Irvine, CA, 92697
| | - Irina Anosova
- School of Molecular Sciences and the Biodesign Institute, Arizona State University. Tempe, AZ, 85287
| | - Saikat Bala
- Department of Pharmaceutical Sciences, University of California, Irvine, CA, 92697
| | - Wade D Van Horn
- School of Molecular Sciences and the Biodesign Institute, Arizona State University. Tempe, AZ, 85287
| | - John C Chaput
- Department of Pharmaceutical Sciences, University of California, Irvine, CA, 92697
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50
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Lecours MJ, Marchand A, Anwar A, Guetta C, Hopkins WS, Gabelica V. What stoichiometries determined by mass spectrometry reveal about the ligand binding mode to G-quadruplex nucleic acids. Biochim Biophys Acta Gen Subj 2017; 1861:1353-1361. [PMID: 28087374 DOI: 10.1016/j.bbagen.2017.01.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2016] [Revised: 01/06/2017] [Accepted: 01/09/2017] [Indexed: 11/27/2022]
Abstract
G-quadruplexes (G4s) have become important drug targets to regulate gene expression and telomere maintenance. Many studies on G4 ligand binding focus on determining the ligand binding affinities and selectivities. Ligands, however, can also affect the G4 conformation. Here we explain how to use electrospray ionization mass spectrometry (ESI-MS) to monitor simultaneously ligand binding and cation binding stoichiometries. The changes in potassium binding stoichiometry upon ligand binding hint at ligand-induced conformational changes involving a modification of the number of G-quartets. We investigated the interaction of three quadruplex ligands (PhenDC3, 360A and Pyridostatin) with a variety of G4s. Electrospray mass spectrometry makes it easy to detect K+ displacement (interpreted as quartet disruption) upon ligand binding, and to determine how many ligand molecules must be bound for the quartet opening to occur. The reasons for ligand-induced conversion to antiparallel structures with fewer quartets are discussed. Conversely, K+ intake (hence quartet formation) was detected upon ligand binding to G-rich sequences that did not form quadruplexes in 1mM K+ alone. This demonstrates the value of mass spectrometry for assessing not only ligand binding, but also ligand-induced rearrangements in the target sequence. This article is part of a Special Issue entitled "G-quadruplex" Guest Editor: Dr. Concetta Giancola and Dr. Daniela Montesarchio.
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Affiliation(s)
- Michael J Lecours
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Adrien Marchand
- INSERM, CNRS, Université de Bordeaux, Laboratoire Acides Nucléiques: Régulations Naturelle et Artificielle (ARNA, U1212, UMR5320), IECB, 2 rue Robert Escarpit, 33607 Pessac, France
| | - Ahdia Anwar
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Corinne Guetta
- Institut Curie, CNRS, INSERM, Univ. Paris Sud, Laboratoire de Chimie, modélisation et imagerie pour la biologie (CMIB, U1196, UMR9187), Orsay, France
| | - W Scott Hopkins
- Department of Chemistry, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Valérie Gabelica
- INSERM, CNRS, Université de Bordeaux, Laboratoire Acides Nucléiques: Régulations Naturelle et Artificielle (ARNA, U1212, UMR5320), IECB, 2 rue Robert Escarpit, 33607 Pessac, France.
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