1
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Neha N, Das P. Exploring G-quadruplex structure in PRCC-TFE3 fusion oncogene: Plausible use as anti cancer therapy for translocation Renal cell carcinoma (tRCC). J Biotechnol 2024; 390:39-49. [PMID: 38740306 DOI: 10.1016/j.jbiotec.2024.05.004] [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: 02/09/2024] [Revised: 04/26/2024] [Accepted: 05/08/2024] [Indexed: 05/16/2024]
Abstract
The TFE3 fusion gene, byproduct of Xp11.2 translocation, is the diagnostic marker for translocation renal cell carcinoma (tRCC). Absence of any clinically recognized therapy for tRCC, pressing a need to create novel and efficient therapeutic approaches. Previous studies shown that stabilization of the G-quadruplex structure in oncogenes suppresses their expression machinery. To combat the oncogenesis caused by fusion genes, our objective is to locate and stabilize the G-quadruplex structure within the PRCC-TFE3 fusion gene. Using the Quadruplex-forming G Rich Sequences (QGRS) mapper and the Non-B DNA motif search tool (nBMST) online server, we found putative G-quadruplex forming sequences (PQS) in the PRCC-TFE3 fusion gene. Circular dichroism demonstrating a parallel G-quadruplex in the targeted sequence. Fluorescence and UV-vis spectroscopy results suggest that pyridostatin binds to this newly discovered G-quadruplex. The PCR stop assay, as well as transcriptional or translational inhibition using real time PCR and Dual luciferase assay, revealed that stable G-quadruplex formation affects biological processes. Confocal microscopy of HEK293T cells transfected with the fusion transcript confirmed G-quadruplexes formation in cell. This investigation may shed light on G-quadruplex's functions in fusion genes and may help in the development of therapies specifically targeted against fusion oncogenes, which would enhance the capability of current tRCC therapy approach.
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Affiliation(s)
- Neha Neha
- Centre for Genetic Disorders, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh 221005, India
| | - Parimal Das
- Centre for Genetic Disorders, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh 221005, India.
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2
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Dai YX, Duan XL, Fu WT, Wang S, Liu NN, Li HH, Ai X, Guo HL, Navés CA, Bugnard E, Auguin D, Hou XM, Rety S, Xi XG. Stimulation of ATP Hydrolysis by ssDNA Provides the Necessary Mechanochemical Energy for G4 Unfolding. J Mol Biol 2024; 436:168373. [PMID: 37992890 DOI: 10.1016/j.jmb.2023.168373] [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: 08/13/2023] [Revised: 11/14/2023] [Accepted: 11/15/2023] [Indexed: 11/24/2023]
Abstract
The G-quadruplex (G4) is a distinct geometric and electrophysical structure compared to classical double-stranded DNA, and its stability can impede essential cellular processes such as replication, transcription, and translation. This study focuses on the BsPif1 helicase, revealing its ability to bind independently to both single-stranded DNA (ssDNA) and G4 structures. The unfolding activity of BsPif1 on G4 relies on the presence of a single tail chain, and the covalent continuity between the single tail chain and the G4's main chain is necessary for efficient G4 unwinding. This suggests that ATP hydrolysis-driven ssDNA translocation exerts a pull force on G4 unwinding. Molecular dynamics simulations identified a specific region within BsPif1 that contains five crucial amino acid sites responsible for G4 binding and unwinding. A "molecular wire stripper" model is proposed to explain BsPif1's mechanism of G4 unwinding. These findings provide a new theoretical foundation for further exploration of the G4 development mechanism in Pif1 family helicases.
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Affiliation(s)
- Yang-Xue Dai
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China; College of Basic Medicine, Zunyi Medical University, Zunyi 563000, China
| | - Xiao-Lei Duan
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China; Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi 563000, China
| | - Wen-Tong Fu
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Shan Wang
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Na-Nv Liu
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Hai-Hong Li
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Xia Ai
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Hai-Lei Guo
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Cel Areny Navés
- Université Paris-Saclay, ENS Paris-Saclay, CNRS, LBPA, 91190 Gif-sur-Yvette, France
| | - Elisabeth Bugnard
- Université Paris-Saclay, ENS Paris-Saclay, CNRS, LBPA, 91190 Gif-sur-Yvette, France
| | - Daniel Auguin
- Laboratoire de Physiologie, Ecologie et Environnement(P2E), UPRES EA 1207/USC INRAE-1328, UFR Sciences et Techniques, Université d'Orléans, Orléans, France
| | - Xi-Miao Hou
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China.
| | - Stephane Rety
- Université de Lyon, ENS de Lyon, Université Claude Bernard, CNRS UMR 5239, INSERM U1210, LBMC, 46 allée d'Italie, Site Jacques Monod, 69007 Lyon, France.
| | - Xu-Guang Xi
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China; Université Paris-Saclay, ENS Paris-Saclay, CNRS, LBPA, 91190 Gif-sur-Yvette, France.
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3
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Zhang ZH, Qian SH, Wei D, Chen ZX. In vivo dynamics and regulation of DNA G-quadruplex structures in mammals. Cell Biosci 2023; 13:117. [PMID: 37381029 DOI: 10.1186/s13578-023-01074-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Accepted: 06/19/2023] [Indexed: 06/30/2023] Open
Abstract
G-quadruplex (G4) is a four-stranded helical DNA secondary structure formed by guanine-rich sequence folding, and G4 has been computationally predicted to exist in a wide range of species. Substantial evidence has supported the formation of endogenous G4 (eG4) in living cells and revealed its regulatory dynamics and critical roles in several important biological processes, making eG4 a regulator of gene expression perturbation and a promising therapeutic target in disease biology. Here, we reviewed the methods for prediction of potential G4 sequences (PQS) and detection of eG4s. We also highlighted the factors affecting the dynamics of eG4s and the effects of eG4 dynamics. Finally, we discussed the future applications of eG4 dynamics in disease therapy.
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Affiliation(s)
- Ze-Hao Zhang
- Hubei Hongshan Laboratory, College of Life Science and Technology, College of Biomedicine and Health, Interdisciplinary Sciences Institute, Huazhong Agricultural University, Wuhan, 430070, China
| | - Sheng Hu Qian
- Hubei Hongshan Laboratory, College of Life Science and Technology, College of Biomedicine and Health, Interdisciplinary Sciences Institute, Huazhong Agricultural University, Wuhan, 430070, China
| | - Dengguo Wei
- College of Science, Huazhong Agricultural University, Wuhan, 430070, China
| | - Zhen-Xia Chen
- Hubei Hongshan Laboratory, College of Life Science and Technology, College of Biomedicine and Health, Interdisciplinary Sciences Institute, Huazhong Agricultural University, Wuhan, 430070, China.
- Shenzhen Institute of Nutrition and Health, Huazhong Agricultural University, Shenzhen, 518000, China.
- Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518000, China.
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4
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Vijay Kumar MJ, Morales R, Tsvetkov AS. G-quadruplexes and associated proteins in aging and Alzheimer's disease. FRONTIERS IN AGING 2023; 4:1164057. [PMID: 37323535 PMCID: PMC10267416 DOI: 10.3389/fragi.2023.1164057] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Accepted: 05/17/2023] [Indexed: 06/17/2023]
Abstract
Aging is a prominent risk factor for many neurodegenerative disorders, such as Alzheimer's disease (AD). Alzheimer's disease is characterized by progressive cognitive decline, memory loss, and neuropsychiatric and behavioral symptoms, accounting for most of the reported dementia cases. This disease is now becoming a major challenge and burden on modern society, especially with the aging population. Over the last few decades, a significant understanding of the pathophysiology of AD has been gained by studying amyloid deposition, hyperphosphorylated tau, synaptic dysfunction, oxidative stress, calcium dysregulation, and neuroinflammation. This review focuses on the role of non-canonical secondary structures of DNA/RNA G-quadruplexes (G4s, G4-DNA, and G4-RNA), G4-binding proteins (G4BPs), and helicases, and their roles in aging and AD. Being critically important for cellular function, G4s are involved in the regulation of DNA and RNA processes, such as replication, transcription, translation, RNA localization, and degradation. Recent studies have also highlighted G4-DNA's roles in inducing DNA double-strand breaks that cause genomic instability and G4-RNA's participation in regulating stress granule formation. This review emphasizes the significance of G4s in aging processes and how their homeostatic imbalance may contribute to the pathophysiology of AD.
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Affiliation(s)
- M. J. Vijay Kumar
- The Department of Neurology, The University of Texas McGovern Medical School at Houston, Houston, TX, United States
| | - Rodrigo Morales
- The Department of Neurology, The University of Texas McGovern Medical School at Houston, Houston, TX, United States
- Centro Integrativo de Biologia y Quimica Aplicada (CIBQA), Universidad Bernardo O’Higgins, Santiago, Chile
| | - Andrey S. Tsvetkov
- The Department of Neurology, The University of Texas McGovern Medical School at Houston, Houston, TX, United States
- The University of Texas Graduate School of Biomedical Sciences, Houston, TX, United States
- UTHealth Consortium on Aging, The University of Texas McGovern Medical School, Houston, TX, United States
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5
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Ngo K, Gittens TH, Gonzalez DI, Hatmaker EA, Plotkin S, Engle M, Friedman GA, Goldin M, Hoerr RE, Eichman BF, Rokas A, Benton ML, Friedman KL. A comprehensive map of hotspots of de novo telomere addition in Saccharomyces cerevisiae. Genetics 2023; 224:iyad076. [PMID: 37119805 PMCID: PMC10474931 DOI: 10.1093/genetics/iyad076] [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: 03/20/2023] [Revised: 04/15/2023] [Accepted: 04/18/2023] [Indexed: 05/01/2023] Open
Abstract
Telomere healing occurs when telomerase, normally restricted to chromosome ends, acts upon a double-strand break to create a new, functional telomere. De novo telomere addition (dnTA) on the centromere-proximal side of a break truncates the chromosome but, by blocking resection, may allow the cell to survive an otherwise lethal event. We previously identified several sequences in the baker's yeast, Saccharomyces cerevisiae, that act as hotspots of dnTA [termed Sites of Repair-associated Telomere Addition (SiRTAs)], but the distribution and functional relevance of SiRTAs is unclear. Here, we describe a high-throughput sequencing method to measure the frequency and location of telomere addition within sequences of interest. Combining this methodology with a computational algorithm that identifies SiRTA sequence motifs, we generate the first comprehensive map of telomere-addition hotspots in yeast. Putative SiRTAs are strongly enriched in subtelomeric regions where they may facilitate formation of a new telomere following catastrophic telomere loss. In contrast, outside of subtelomeres, the distribution and orientation of SiRTAs appears random. Since truncating the chromosome at most SiRTAs would be lethal, this observation argues against selection for these sequences as sites of telomere addition per se. We find, however, that sequences predicted to function as SiRTAs are significantly more prevalent across the genome than expected by chance. Sequences identified by the algorithm bind the telomeric protein Cdc13, raising the possibility that association of Cdc13 with single-stranded regions generated during the response to DNA damage may facilitate DNA repair more generally.
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Affiliation(s)
- Katrina Ngo
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232 USA
| | - Tristen H Gittens
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232 USA
| | - David I Gonzalez
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232 USA
| | - E Anne Hatmaker
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232 USA
- Evolutionary Studies Initiative, Vanderbilt University, Nashville, TN 37232 USA
| | - Simcha Plotkin
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232 USA
| | - Mason Engle
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232 USA
| | - Geofrey A Friedman
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232 USA
| | - Melissa Goldin
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232 USA
| | - Remington E Hoerr
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232 USA
| | - Brandt F Eichman
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232 USA
- Department of Biochemistry, Vanderbilt University, Nashville, TN 37232 USA
| | - Antonis Rokas
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232 USA
- Evolutionary Studies Initiative, Vanderbilt University, Nashville, TN 37232 USA
| | | | - Katherine L Friedman
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232 USA
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6
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Wang G, Vasquez KM. Dynamic alternative DNA structures in biology and disease. Nat Rev Genet 2023; 24:211-234. [PMID: 36316397 DOI: 10.1038/s41576-022-00539-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 51.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/27/2022] [Indexed: 11/06/2022]
Abstract
Repetitive elements in the human genome, once considered 'junk DNA', are now known to adopt more than a dozen alternative (that is, non-B) DNA structures, such as self-annealed hairpins, left-handed Z-DNA, three-stranded triplexes (H-DNA) or four-stranded guanine quadruplex structures (G4 DNA). These dynamic conformations can act as functional genomic elements involved in DNA replication and transcription, chromatin organization and genome stability. In addition, recent studies have revealed a role for these alternative structures in triggering error-generating DNA repair processes, thereby actively enabling genome plasticity. As a driving force for genetic variation, non-B DNA structures thus contribute to both disease aetiology and evolution.
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Affiliation(s)
- Guliang Wang
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Dell Paediatric Research Institute, Austin, TX, USA
| | - Karen M Vasquez
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Dell Paediatric Research Institute, Austin, TX, USA.
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7
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Ngo K, Gittens TH, Gonzalez DI, Hatmaker EA, Plotkin S, Engle M, Friedman GA, Goldin M, Hoerr RE, Eichman BF, Rokas A, Benton ML, Friedman KL. A comprehensive map of hotspots of de novo telomere addition in Saccharomyces cerevisiae. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.20.533556. [PMID: 36993206 PMCID: PMC10055226 DOI: 10.1101/2023.03.20.533556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Telomere healing occurs when telomerase, normally restricted to chromosome ends, acts upon a double-strand break to create a new, functional telomere. De novo telomere addition on the centromere-proximal side of a break truncates the chromosome but, by blocking resection, may allow the cell to survive an otherwise lethal event. We previously identified several sequences in the baker’s yeast, Saccharomyces cerevisiae , that act as hotspots of de novo telomere addition (termed Sites of Repair-associated Telomere Addition or SiRTAs), but the distribution and functional relevance of SiRTAs is unclear. Here, we describe a high-throughput sequencing method to measure the frequency and location of telomere addition within sequences of interest. Combining this methodology with a computational algorithm that identifies SiRTA sequence motifs, we generate the first comprehensive map of telomere-addition hotspots in yeast. Putative SiRTAs are strongly enriched in subtelomeric regions where they may facilitate formation of a new telomere following catastrophic telomere loss. In contrast, outside of subtelomeres, the distribution and orientation of SiRTAs appears random. Since truncating the chromosome at most SiRTAs would be lethal, this observation argues against selection for these sequences as sites of telomere addition per se. We find, however, that sequences predicted to function as SiRTAs are significantly more prevalent across the genome than expected by chance. Sequences identified by the algorithm bind the telomeric protein Cdc13, raising the possibility that association of Cdc13 with single-stranded regions generated during the response to DNA damage may facilitate DNA repair more generally.
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Affiliation(s)
- Katrina Ngo
- Department of Biological Sciences, Vanderbilt University
| | | | | | - E. Anne Hatmaker
- Department of Biological Sciences, Vanderbilt University
- Evolutionary Studies Initiative, Vanderbilt University
| | - Simcha Plotkin
- Department of Biological Sciences, Vanderbilt University
| | - Mason Engle
- Department of Biological Sciences, Vanderbilt University
| | | | - Melissa Goldin
- Department of Biological Sciences, Vanderbilt University
| | | | - Brandt F. Eichman
- Department of Biological Sciences, Vanderbilt University
- Department of Biochemistry, Vanderbilt University
| | - Antonis Rokas
- Department of Biological Sciences, Vanderbilt University
- Evolutionary Studies Initiative, Vanderbilt University
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8
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Chung WC, Ravichandran S, Park D, Lee GM, Kim YE, Choi Y, Song MJ, Kim KK, Ahn JH. G-quadruplexes formed by Varicella-Zoster virus reiteration sequences suppress expression of glycoprotein C and regulate viral cell-to-cell spread. PLoS Pathog 2023; 19:e1011095. [PMID: 36630443 PMCID: PMC9873165 DOI: 10.1371/journal.ppat.1011095] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 01/24/2023] [Accepted: 01/02/2023] [Indexed: 01/12/2023] Open
Abstract
G-quadruplex (G4) formed by repetitive guanosine-rich sequences plays important roles in diverse cellular processes; however, its roles in viral infection are not fully understood. In this study, we investigated the genome-wide distribution of G4-forming sequences (G4 motifs) in Varicella-Zoster virus (VZV) and found that G4 motifs are enriched in the internal repeat short and the terminal repeat short regions flanking the unique short region and also in some reiteration (R) sequence regions. A high density of G4 motifs in the R2 region was found on the template strand of ORF14, which encodes glycoprotein C (gC), a virulent factor for viral growth in skin. Analyses such as circular dichroism spectroscopy, thermal difference spectra, and native polyacrylamide gel electrophoresis with oligodeoxynucleotides demonstrated that several G4 motifs in ORF14 form stable G4 structures. In transfection assays, gC expression from the G4-disrupted ORF14 gene was increased at the transcriptional level and became more resistant to suppression by G4-ligand treatment. The recombinant virus containing the G4-disrupted ORF14 gene expressed a higher level of gC mRNA, while it showed a slightly reduced growth. This G4-disrupted ORF14 virus produced smaller plaques than the wild-type virus. Our results demonstrate that G4 formation via reiteration sequences suppresses gC expression during VZV infection and regulates viral cell-to-cell spread.
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Affiliation(s)
- Woo-Chang Chung
- Department of Microbiology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Subramaniyam Ravichandran
- Department of Precision Medicine, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Daegyu Park
- Department of Microbiology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Gwang Myeong Lee
- Department of Microbiology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Young-Eui Kim
- Department of Microbiology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Youngju Choi
- Department of Microbiology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Moon Jung Song
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea
| | - Kyeong Kyu Kim
- Department of Precision Medicine, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
- Biomedical Research Institute, Samsung Medical Center, Seoul, Republic of Korea
| | - Jin-Hyun Ahn
- Department of Microbiology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
- Biomedical Research Institute, Samsung Medical Center, Seoul, Republic of Korea
- * E-mail:
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9
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Li C, Yin Z, Xiao R, Huang B, Cui Y, Wang H, Xiang Y, Wang L, Lei L, Ye J, Li T, Zhong Y, Guo F, Xia Y, Fang P, Liang K. G-quadruplexes sense natural porphyrin metabolites for regulation of gene transcription and chromatin landscapes. Genome Biol 2022; 23:259. [PMID: 36522639 PMCID: PMC9753424 DOI: 10.1186/s13059-022-02830-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 12/02/2022] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND G-quadruplexes (G4s) are unique noncanonical nucleic acid secondary structures, which have been proposed to physically interact with transcription factors and chromatin remodelers to regulate cell type-specific transcriptome and shape chromatin landscapes. RESULTS Based on the direct interaction between G4 and natural porphyrins, we establish genome-wide approaches to profile where the iron-liganded porphyrin hemin can bind in the chromatin. Hemin promotes genome-wide G4 formation, impairs transcription initiation, and alters chromatin landscapes, including decreased H3K27ac and H3K4me3 modifications at promoters. Interestingly, G4 status is not involved in the canonical hemin-BACH1-NRF2-mediated enhancer activation process, highlighting an unprecedented G4-dependent mechanism for metabolic regulation of transcription. Furthermore, hemin treatment induces specific gene expression profiles in hepatocytes, underscoring the in vivo potential for metabolic control of gene transcription by porphyrins. CONCLUSIONS These studies demonstrate that G4 functions as a sensor for natural porphyrin metabolites in cells, revealing a G4-dependent mechanism for metabolic regulation of gene transcription and chromatin landscapes, which will deepen our knowledge of G4 biology and the contribution of cellular metabolites to gene regulation.
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Affiliation(s)
- Conghui Li
- School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Zhinang Yin
- School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Ruijing Xiao
- School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Beili Huang
- School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Yali Cui
- School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Honghong Wang
- School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Ying Xiang
- School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Lingrui Wang
- School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Lingyu Lei
- School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Jiaqin Ye
- School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Tianyu Li
- School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Youquan Zhong
- School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Fangteng Guo
- School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Yuchen Xia
- School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
- State Key Laboratory of Virology and Hubei Province Key Laboratory of Allergy and Immunology, Wuhan University, Wuhan, 430071, China
- TaiKang Center for Life and Medical Sciences, TaiKang Medical School, Wuhan University, Wuhan, 430071, China
| | - Pingping Fang
- School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China.
| | - Kaiwei Liang
- School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China.
- TaiKang Center for Life and Medical Sciences, TaiKang Medical School, Wuhan University, Wuhan, 430071, China.
- Hubei Province Key Laboratory of Allergy and Immunology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China.
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10
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Shitikov EA, Bespiatykh DA, Bodoev IN, Zaychikova MV. G-Quadruplex Structures in Bacteria: Functional Properties and Prospects for Use as Biotargets. BIOCHEMISTRY (MOSCOW), SUPPLEMENT SERIES B: BIOMEDICAL CHEMISTRY 2022. [DOI: 10.1134/s1990750822040084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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11
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Swafford K, Acharya B, Xu YZ, Raney T, McCrury M, Saha D, Frett B, Kendrick S. Targeting a Novel G-Quadruplex in the CARD11 Oncogene Promoter with Naptho(2,1-b)furan-1-ethanol,2-nitro- Requires the Nitro Group. Genes (Basel) 2022; 13:genes13071144. [PMID: 35885931 PMCID: PMC9321325 DOI: 10.3390/genes13071144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 06/17/2022] [Accepted: 06/21/2022] [Indexed: 02/04/2023] Open
Abstract
The aggressive nature of the activated B cell such as (ABC) subtype of diffuse large B cell (DLBCL) is frequently associated with altered B cell Receptor (BCR) signaling through the activation of key components including the scaffolding protein, CARD11. Most inhibitors, such as ibrutinib, target downstream BCR kinases with often modest and temporary responses for DLBCL patients. Here, we pursue an alternative strategy to target the BCR pathway by leveraging a novel DNA secondary structure to repress transcription. We discovered that a highly guanine (G)-rich element within the CARD11 promoter forms a stable G-quadruplex (G4) using circular dichroism and polymerase stop biophysical techniques. We then identified a small molecule, naptho(2,1-b)furan-1-ethanol,2-nitro- (NSC373981), from a fluorescence-resonance energy transfer-based screen that stabilized CARD11 G4 and inhibited CARD11 transcription in DLBCL cells. In generating and testing analogs of NSC373981, we determined that the nitro group is likely essential for the downregulation of CARD11 and interaction with CARD11 G4, and the removal of the ethanol side chain enhanced this activity. Of note, the expression of BCL2 and MYC, two other key oncogenes in DLBCL pathology with known promoter G4 structures, were often concurrently repressed with NSC373981 and the highly potent R158 analog. Our findings highlight a novel approach to treat aggressive DLBCL by silencing CARD11 gene expression that warrants further investigation.
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Affiliation(s)
- Kennith Swafford
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (K.S.); (Y.-Z.X.); (T.R.); (M.M.)
| | - Baku Acharya
- Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (B.A.); (D.S.)
| | - Ying-Zhi Xu
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (K.S.); (Y.-Z.X.); (T.R.); (M.M.)
| | - Thomas Raney
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (K.S.); (Y.-Z.X.); (T.R.); (M.M.)
| | - Mason McCrury
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (K.S.); (Y.-Z.X.); (T.R.); (M.M.)
| | - Debasmita Saha
- Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (B.A.); (D.S.)
| | - Brendan Frett
- Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (B.A.); (D.S.)
- Correspondence: (B.F.); (S.K.); Tel.: +1-501-526-0893 (B.F.); +1-501-526-6000 (ext. 25122) (S.K.)
| | - Samantha Kendrick
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (K.S.); (Y.-Z.X.); (T.R.); (M.M.)
- Correspondence: (B.F.); (S.K.); Tel.: +1-501-526-0893 (B.F.); +1-501-526-6000 (ext. 25122) (S.K.)
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12
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Shitikov EA, Bespiatykh DA, Bodoev IN, Zaychikova MV. [G-quadruplex structures in bacteria: functional properties and prospects for use as biotargets]. BIOMEDITSINSKAIA KHIMIIA 2022; 68:93-103. [PMID: 35485483 DOI: 10.18097/pbmc20226802093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
G-quadruplexes (G4), non-canonical secondary DNA structures, are intensively investigated for a long time. In eukaryotic organisms they play an important role in the regulation of gene expression and DNA repair. G4 have also been found in the genomes of numerous bacteria and archaea, but their functional role has not yet been fully explored. Nevertheless, their participation in the formation of antigenic variability, pathogenicity, antibiotic resistance and survival in extreme conditions has been established. Currently, many tools have been developed to detect potential G4 sequences and confirm their formation ability. Since the controlled formation and resolution of the quadruplex are significant means for the regulation of genes critical for survival, a promising direction is the search for ligands - compounds that can have a stabilizing effect on the quadruplex structure and thereby alter gene expression. Currently, a number of ligands are already known, their use stops the growth of pathogenic microorganisms. G4 ligands are of interest as potential antibiotics, which are extremely relevant due to the wide spread of drug resistant pathogens.
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Affiliation(s)
- E A Shitikov
- Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow, Russia
| | - D A Bespiatykh
- Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow, Russia
| | - I N Bodoev
- Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow, Russia
| | - M V Zaychikova
- Federal Research and Clinical Center of Physical-Chemical Medicine, Moscow, Russia
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13
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Noh B, Blasco-Conesa MP, Lai YJ, Ganesh BP, Urayama A, Moreno-Gonzalez I, Marrelli SP, McCullough LD, Moruno-Manchon JF. G-quadruplexes Stabilization Upregulates CCN1 and Accelerates Aging in Cultured Cerebral Endothelial Cells. FRONTIERS IN AGING 2022; 2:797562. [PMID: 35822045 PMCID: PMC9261356 DOI: 10.3389/fragi.2021.797562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 12/07/2021] [Indexed: 11/27/2022]
Abstract
Senescence in the cerebral endothelium has been proposed as a mechanism that can drive dysfunction of the cerebral vasculature, which precedes vascular dementia. Cysteine-rich angiogenic inducer 61 (Cyr61/CCN1) is a matricellular protein secreted by cerebral endothelial cells (CEC). CCN1 induces senescence in fibroblasts. However, whether CCN1 contributes to senescence in CEC and how this is regulated requires further study. Aging has been associated with the formation of four-stranded Guanine-quadruplexes (G4s) in G-rich motifs of DNA and RNA. Stabilization of the G4 structures regulates transcription and translation either by upregulation or downregulation depending on the gene target. Previously, we showed that aged mice treated with a G4-stabilizing compound had enhanced senescence-associated (SA) phenotypes in their brains, and these mice exhibited enhanced cognitive deficits. A sequence in the 3'-UTR of the human CCN1 mRNA has the ability to fold into G4s in vitro. We hypothesize that G4 stabilization regulates CCN1 in cultured primary CEC and induces endothelial senescence. We used cerebral microvessel fractions and cultured primary CEC from young (4-months old, m/o) and aged (18-m/o) mice to determine CCN1 levels. SA phenotypes were determined by high-resolution fluorescence microscopy in cultured primary CEC, and we used Thioflavin T to recognize RNA-G4s for fluorescence spectra. We found that cultured CEC from aged mice exhibited enhanced levels of SA phenotypes, and higher levels of CCN1 and G4 stabilization. In cultured CEC, CCN1 induced SA phenotypes, such as SA β-galactosidase activity, and double-strand DNA damage. Furthermore, CCN1 levels were upregulated by a G4 ligand, and a G-rich motif in the 3'-UTR of the Ccn1 mRNA was folded into a G4. In conclusion, we demonstrate that CCN1 can induce senescence in cultured primary CEC, and we provide evidence that G4 stabilization is a novel mechanism regulating the SASP component CCN1.
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Affiliation(s)
- Brian Noh
- Department of Neurology, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Maria P. Blasco-Conesa
- Department of Neurology, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Yun-Ju Lai
- Department of Neurology, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, TX, United States
- Solomont School of Nursing, Zuckerberg College of Health Sciences, University of Massachusetts Lowell, Lowell, MA, United States
| | - Bhanu Priya Ganesh
- Department of Neurology, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Akihiko Urayama
- Department of Neurology, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Ines Moreno-Gonzalez
- Department of Neurology, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, TX, United States
- Department of Cell Biology, Faculty of Sciences, Instituto de Investigacion Biomedica de Malaga-IBIMA, Malaga University, Malaga, Spain
- Networking Biomedical Research Networking Center on Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Sean P. Marrelli
- Department of Neurology, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Louise D. McCullough
- Department of Neurology, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Jose Felix Moruno-Manchon
- Department of Neurology, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, TX, United States
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14
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Kretzmann JA, Irving KL, Smith NM, Evans CW. Modulating gene expression in breast cancer via DNA secondary structure and the CRISPR toolbox. NAR Cancer 2022; 3:zcab048. [PMID: 34988459 PMCID: PMC8693572 DOI: 10.1093/narcan/zcab048] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 11/26/2021] [Accepted: 12/01/2021] [Indexed: 12/11/2022] Open
Abstract
Breast cancer is the most commonly diagnosed malignancy in women, and while the survival prognosis of patients with early-stage, non-metastatic disease is ∼75%, recurrence poses a significant risk and advanced and/or metastatic breast cancer is incurable. A distinctive feature of advanced breast cancer is an unstable genome and altered gene expression patterns that result in disease heterogeneity. Transcription factors represent a unique therapeutic opportunity in breast cancer, since they are known regulators of gene expression, including gene expression involved in differentiation and cell death, which are themselves often mutated or dysregulated in cancer. While transcription factors have traditionally been viewed as 'undruggable', progress has been made in the development of small-molecule therapeutics to target relevant protein-protein, protein-DNA and enzymatic active sites, with varying levels of success. However, non-traditional approaches such as epigenetic editing, transcriptional control via CRISPR/dCas9 systems, and gene regulation through non-canonical nucleic acid secondary structures represent new directions yet to be fully explored. Here, we discuss these new approaches and current limitations in light of new therapeutic opportunities for breast cancers.
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Affiliation(s)
- Jessica A Kretzmann
- Laboratory for Biomolecular Nanotechnology, Department of Physics, Technical University of Munich, Am Coulombwall 4a, 85748 Garching, Germany
| | - Kelly L Irving
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009, Australia
| | - Nicole M Smith
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009, Australia
| | - Cameron W Evans
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009, Australia
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15
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A fluorescent molecular rotor for the selective detection of the hybrid-conformation 22AG G-Quadruplex. Bioorg Med Chem Lett 2022; 55:128462. [PMID: 34813881 DOI: 10.1016/j.bmcl.2021.128462] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 11/09/2021] [Accepted: 11/12/2021] [Indexed: 01/07/2023]
Abstract
G-quadruplex (G4) DNA plays a vital role in myriad biological process and is linked to several human diseases, including Alzheimer's disease. Probing G4s with fluorescent probes can provide a better understanding their mechanisms of action and of their roles in Nature. In this study we developed a quinolinium-vinylaniline molecular rotor probe, featuring a diethylaminosalicylaldehyde unit that could discriminate the hybrid-22AG G4 sequence selectively amongst other G4 sequences. This probe underwent a significant red-shift upon binding to the target G4 (broad 575 nm → sharp 630 nm) with enhanced fluorescence (up to 14-fold). We suspect that the vinylaniline unit of the molecular rotor, when bound to the hybrid-22 A G4, experienced restricted rotation, thereby undergoing enhanced intramolecular charge transfer. The presence of the diethylaminosalicylaldehyde moiety appeared to play a major role in the enhanced selectivity toward the 22AG G4.
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16
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Ravichandran S, Razzaq M, Parveen N, Ghosh A, Kim KK. The effect of hairpin loop on the structure and gene expression activity of the long-loop G-quadruplex. Nucleic Acids Res 2021; 49:10689-10706. [PMID: 34450640 PMCID: PMC8501965 DOI: 10.1093/nar/gkab739] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 08/10/2021] [Accepted: 08/24/2021] [Indexed: 12/29/2022] Open
Abstract
G-quadruplex (G4), a four-stranded DNA or RNA structure containing stacks of guanine tetrads, plays regulatory roles in many cellular functions. So far, conventional G4s containing loops of 1–7 nucleotides have been widely studied. Increasing experimental evidence suggests that unconventional G4s, such as G4s containing long loops (long-loop G4s), play a regulatory role in the genome by forming a stable structure. Other secondary structures such as hairpins in the loop might thus contribute to the stability of long-loop G4s. Therefore, investigation of the effect of the hairpin-loops on the structure and function of G4s is required. In this study, we performed a systematic biochemical investigation of model G4s containing long loops with various sizes and structures. We found that the long-loop G4s are less stable than conventional G4s, but their stability increased when the loop forms a hairpin (hairpin-G4). We also verified the biological significance of hairpin-G4s by showing that hairpin-G4s present in the genome also form stable G4s and regulate gene expression as confirmed by in cellulo reporter assays. This study contributes to expanding the scope and diversity of G4s, thus facilitating future studies on the role of G4s in the human genome.
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Affiliation(s)
- Subramaniyam Ravichandran
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon 16419, Republic of Korea
| | - Maria Razzaq
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon 16419, Republic of Korea
| | - Nazia Parveen
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon 16419, Republic of Korea
| | - Ambarnil Ghosh
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon 16419, Republic of Korea
| | - Kyeong Kyu Kim
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon 16419, Republic of Korea
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17
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Yu G, Wu Y, Duan Z, Tang C, Xing H, Scharff MD, MacCarthy T. A Bayesian model based computational analysis of the relationship between bisulfite accessible single-stranded DNA in chromatin and somatic hypermutation of immunoglobulin genes. PLoS Comput Biol 2021; 17:e1009323. [PMID: 34491985 PMCID: PMC8462741 DOI: 10.1371/journal.pcbi.1009323] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 09/24/2021] [Accepted: 08/04/2021] [Indexed: 11/19/2022] Open
Abstract
The B cells in our body generate protective antibodies by introducing somatic hypermutations (SHM) into the variable region of immunoglobulin genes (IgVs). The mutations are generated by activation induced deaminase (AID) that converts cytosine to uracil in single stranded DNA (ssDNA) generated during transcription. Attempts have been made to correlate SHM with ssDNA using bisulfite to chemically convert cytosines that are accessible in the intact chromatin of mutating B cells. These studies have been complicated by using different definitions of "bisulfite accessible regions" (BARs). Recently, deep-sequencing has provided much larger datasets of such regions but computational methods are needed to enable this analysis. Here we leveraged the deep-sequencing approach with unique molecular identifiers and developed a novel Hidden Markov Model based Bayesian Segmentation algorithm to characterize the ssDNA regions in the IGHV4-34 gene of the human Ramos B cell line. Combining hierarchical clustering and our new Bayesian model, we identified recurrent BARs in certain subregions of both top and bottom strands of this gene. Using this new system, the average size of BARs is about 15 bp. We also identified potential G-quadruplex DNA structures in this gene and found that the BARs co-locate with G-quadruplex structures in the opposite strand. Using various correlation analyses, there is not a direct site-to-site relationship between the bisulfite accessible ssDNA and all sites of SHM but most of the highly AID mutated sites are within 15 bp of a BAR. In summary, we developed a novel platform to study single stranded DNA in chromatin at a base pair resolution that reveals potential relationships among BARs, SHM and G-quadruplexes. This platform could be applied to genome wide studies in the future.
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Affiliation(s)
- Guojun Yu
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Yingru Wu
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, New York, United States of America
| | - Zhi Duan
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Catherine Tang
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, New York, United States of America
| | - Haipeng Xing
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, New York, United States of America
| | - Matthew D. Scharff
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Thomas MacCarthy
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, New York, United States of America
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18
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Non-B DNA-Forming Motifs Promote Mfd-Dependent Stationary-Phase Mutagenesis in Bacillus subtilis. Microorganisms 2021; 9:microorganisms9061284. [PMID: 34204686 PMCID: PMC8231525 DOI: 10.3390/microorganisms9061284] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 06/08/2021] [Accepted: 06/09/2021] [Indexed: 02/07/2023] Open
Abstract
Transcription-induced mutagenic mechanisms limit genetic changes to times when expression happens and to coding DNA. It has been hypothesized that intrinsic sequences that have the potential to form alternate DNA structures, such as non-B DNA structures, influence these mechanisms. Non-B DNA structures are promoted by transcription and induce genome instability in eukaryotic cells, but their impact in bacterial genomes is less known. Here, we investigated if G4 DNA- and hairpin-forming motifs influence stationary-phase mutagenesis in Bacillus subtilis. We developed a system to measure the influence of non-B DNA on B. subtilis stationary-phase mutagenesis by deleting the wild-type argF at its chromosomal position and introducing IPTG-inducible argF alleles differing in their ability to form hairpin and G4 DNA structures into an ectopic locus. Using this system, we found that sequences predicted to form non-B DNA structures promoted mutagenesis in B. subtilis stationary-phase cells; such a response did not occur in growing conditions. We also found that the transcription-coupled repair factor Mfd promoted mutagenesis at these predicted structures. In summary, we showed that non-B DNA-forming motifs promote genetic instability, particularly in coding regions in stressed cells; therefore, non-B DNA structures may have a spatial and temporal mutagenic effect in bacteria. This study provides insights into mechanisms that prevent or promote mutagenesis and advances our understanding of processes underlying bacterial evolution.
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19
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G-Quadruplex Structures in Bacteria: Biological Relevance and Potential as an Antimicrobial Target. J Bacteriol 2021; 203:e0057720. [PMID: 33649149 DOI: 10.1128/jb.00577-20] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
DNA strands consisting of multiple runs of guanines can adopt a noncanonical, four-stranded DNA secondary structure known as G-quadruplex or G4 DNA. G4 DNA is thought to play an important role in transcriptional and translational regulation of genes, DNA replication, genome stability, and oncogene expression in eukaryotic genomes. In other organisms, including several bacterial pathogens and some plant species, the biological roles of G4 DNA and G4 RNA are starting to be explored. Recent investigations showed that G4 DNA and G4 RNA are generally conserved across plant species. In silico analyses of several bacterial genomes identified putative guanine-rich, G4 DNA-forming sequences in promoter regions. The sequences were particularly abundant in certain gene classes, suggesting that these highly diverse structures can be employed to regulate the expression of genes involved in secondary metabolite synthesis and signal transduction. Furthermore, in the pathogen Mycobacterium tuberculosis, the distribution of G4 motifs and their potential role in the regulation of gene transcription advocate for the use of G4 ligands to develop novel antitubercular therapies. In this review, we discuss the various roles of G4 structures in bacterial DNA and the application of G4 DNA as inhibitors or therapeutic agents to address bacterial pathogens.
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20
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Tang C, MacCarthy T. Characterization of DNA G-Quadruplex Structures in Human Immunoglobulin Heavy Variable (IGHV) Genes. Front Immunol 2021; 12:671944. [PMID: 34040612 PMCID: PMC8141862 DOI: 10.3389/fimmu.2021.671944] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 04/12/2021] [Indexed: 11/21/2022] Open
Abstract
Activation-induced deaminase (AID) is a key enzyme involved in antibody diversification by initiating somatic hypermutation (SHM) and class-switch recombination (CSR) of the Immunoglobulin (Ig) loci. AID preferentially targets WRC (W=A/T, R=A/G) hotspot motifs and avoids SYC (S=C/G, Y=C/T) coldspots. G-quadruplex (G4) structures are four-stranded DNA secondary structures with key functions in transcription, translation and replication. In vitro studies have shown G4s to form and bind AID in Ig switch (S) regions. Alterations in the gene encoding AID can further disrupt AID-G4 binding and reduce CSR in vivo. However, it is still unclear whether G4s form in the variable (V) region, or how they may affect SHM. To assess the possibility of G4 formation in human V regions, we analyzed germline human Ig heavy chain V (IGHV) sequences, using a pre-trained deep learning model that predicts G4 potential. This revealed that many genes from the IGHV3 and IGHV4 families are predicted to have high G4 potential in the top and bottom strand, respectively. Different IGHV alleles also showed variability in G4 potential. Using a high-resolution (G4-seq) dataset of biochemically confirmed potential G4s in IGHV genes, we validated our computational predictions. G4-seq also revealed variation between S and V regions in the distribution of potential G4s, with the V region having overall reduced G4 abundance compared to the S region. The density of AGCT motifs, where two AGC hotspots overlap on both strands, was roughly 2.6-fold greater in the V region than the Constant (C) region, which does not mutate despite having predicted G4s at similar levels. However, AGCT motifs in both V and C regions were less abundant than in S regions. In silico mutagenesis experiments showed that G4 potentials were generally robust to mutation, although large deviations from germline states were found, mostly in framework regions. G4 potential is also associated with higher mutability of certain WRC hotspots on the same strand. In addition, CCC coldspots opposite a predicted G4 were shown to be targeted significantly more for mutation. Our overall assessment reveals plausible evidence of functional G4s forming in the Ig V region.
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Affiliation(s)
- Catherine Tang
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, NY, United States
| | - Thomas MacCarthy
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, NY, United States.,Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, NY, United States
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21
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Dey U, Sarkar S, Teronpi V, Yella VR, Kumar A. G-quadruplex motifs are functionally conserved in cis-regulatory regions of pathogenic bacteria: An in-silico evaluation. Biochimie 2021; 184:40-51. [PMID: 33548392 DOI: 10.1016/j.biochi.2021.01.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 01/28/2021] [Accepted: 01/29/2021] [Indexed: 02/06/2023]
Abstract
The role of G-quadruplexes in the cellular physiology of human pathogenesis is an intriguing area of research. Nonetheless, their functional roles and evolutionary conservation have not been compared comprehensively in pathogenic forms of various bacterial genera and species. In the current in silico study, we addressed the role of G-quadruplex-forming sequences (G4 motifs) in the context of cis-regulation, expression variation, regulatory networks, gene orthology and ontology. Genome-wide screening across seven pathogenic genomes using the G4Hunter tool revealed the significant prevalence of G4 motifs in cis-regulatory regions compared to the intragenic regions. Significant conservation of G4 motifs was observed in the regulatory region of 300 orthologous genes. Further analysis of published ChIP-Seq data (Minch et al., 2015) of 91 DNA-binding proteins of the M. tuberculosis genome revealed significant links between G4 motifs and target sites of transcriptional regulators. Interestingly, the transcription factors entangled with virulence, in specific, CsoR, Rv0081, DevR/DosR, and TetR family are found to have G4 motifs in their target regulatory regions. Overall the current study applies positional-functional relationship computation to delve into the cis-regulation of G-quadruplex structures in the context of gene orthology in pathogenic bacteria.
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Affiliation(s)
- Upalabdha Dey
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, 784028, Assam, India
| | - Sharmilee Sarkar
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, 784028, Assam, India
| | - Valentina Teronpi
- Department of Zoology, Pandit Deendayal Upadhyaya Adarsha Mahavidyalaya, Behali, Biswanath, 784184, Assam, India
| | - Venkata Rajesh Yella
- Department of Biotechnology, Koneru Lakshmaiah Education Foundation, Guntur, 522502, Andhra Pradesh, India.
| | - Aditya Kumar
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, 784028, Assam, India.
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22
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Dhar S, Datta A, Brosh RM. DNA helicases and their roles in cancer. DNA Repair (Amst) 2020; 96:102994. [PMID: 33137625 DOI: 10.1016/j.dnarep.2020.102994] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 09/28/2020] [Indexed: 12/15/2022]
Abstract
DNA helicases, known for their fundamentally important roles in genomic stability, are high profile players in cancer. Not only are there monogenic helicase disorders with a strong disposition to cancer, it is well appreciated that helicase variants are associated with specific cancers (e.g., breast cancer). Flipping the coin, DNA helicases are frequently overexpressed in cancerous tissues and reduction in helicase gene expression results in reduced proliferation and growth capacity, as well as DNA damage induction and apoptosis of cancer cells. The seminal roles of helicases in the DNA damage and replication stress responses, as well as DNA repair pathways, validate their vital importance in cancer biology and suggest their potential values as targets in anti-cancer therapy. In recent years, many laboratories have characterized the specialized roles of helicase to resolve transcription-replication conflicts, maintain telomeres, mediate cell cycle checkpoints, remodel stalled replication forks, and regulate transcription. In vivo models, particularly mice, have been used to interrogate helicase function and serve as a bridge for preclinical studies that may lead to novel therapeutic approaches. In this review, we will summarize our current knowledge of DNA helicases and their roles in cancer, emphasizing the latest developments.
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Affiliation(s)
- Srijita Dhar
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Arindam Datta
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Robert M Brosh
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.
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23
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Shankar U, Jain N, Majee P, Kodgire P, Sharma TK, Kumar A. Exploring Computational and Biophysical Tools to Study the Presence of G-Quadruplex Structures: A Promising Therapeutic Solution for Drug-Resistant Vibrio cholerae. Front Genet 2020; 11:935. [PMID: 33101360 PMCID: PMC7545536 DOI: 10.3389/fgene.2020.00935] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 07/27/2020] [Indexed: 12/21/2022] Open
Abstract
Vibrio cholerae, a gram-negative bacterium that causes cholera, has already caused seven major pandemics across the world and infects roughly 1.3–4 million people every year. Cholera treatment primarily involves oral rehydration therapy supplemented with antibiotics. But recently, multidrug-resistant strains of V. cholerae have emerged. High genomic plasticity further enhances the pathogenesis of this human pathogen. Guanines in DNA or RNA assemble to form G-quadruplex (GQ) structures which have begun to be seen as potential drug targeting sites for different pathogenic bacteria and viruses. In this perspective, we carried out a genome-wide hunt in V. cholerae using a bio-informatics approach and observed ∼85 G-quadruplex forming motifs (VC-PGQs) in chromosome I and ∼45 putative G-quadruplexs (PGQs) in chromosome II. Ten putative G-quadruplex forming motifs (VC-PGQs) were selected on the basis of conservation throughout the genus and functional analysis displayed their location in the essential genes encoding bacterial proteins, for example, methyl-accepting chemotaxis protein, orotate phosphoribosyl transferase protein, amidase proteins, etc. The predicted VC-PGQs were validated using different bio-physical techniques, including Nuclear Magnetic Resonance spectroscopy, Circular Dichroism spectroscopy, and electrophoretic mobility shift assay, which demonstrated the formation of highly stable GQ structures in the bacteria. The interaction of these VC-PGQs with the known specific GQ ligand, TMPyP4, was analyzed using ITC and molecular dynamics studies that displayed the stabilization of the VC-PGQs by the GQ ligands and thus represents a potential therapeutic strategy against this enteric pathogen by inhibiting the PGQ harboring gene expression, thereby inhibiting the bacterial growth and virulence. In summary, this study reveals the presence of conserved GQ forming motifs in the V. cholerae genome that has the potential to be used to treat the multi-drug resistance problem of the notorious enteric pathogen.
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Affiliation(s)
- Uma Shankar
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, India
| | - Neha Jain
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, India
| | - Prativa Majee
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, India
| | - Prashant Kodgire
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, India
| | | | - Amit Kumar
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, India
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Varshney D, Spiegel J, Zyner K, Tannahill D, Balasubramanian S. The regulation and functions of DNA and RNA G-quadruplexes. Nat Rev Mol Cell Biol 2020; 21:459-474. [PMID: 32313204 PMCID: PMC7115845 DOI: 10.1038/s41580-020-0236-x] [Citation(s) in RCA: 619] [Impact Index Per Article: 154.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/11/2020] [Indexed: 02/06/2023]
Abstract
DNA and RNA can adopt various secondary structures. Four-stranded G-quadruplex (G4) structures form through self-recognition of guanines into stacked tetrads, and considerable biophysical and structural evidence exists for G4 formation in vitro. Computational studies and sequencing methods have revealed the prevalence of G4 sequence motifs at gene regulatory regions in various genomes, including in humans. Experiments using chemical, molecular and cell biology methods have demonstrated that G4s exist in chromatin DNA and in RNA, and have linked G4 formation with key biological processes ranging from transcription and translation to genome instability and cancer. In this Review, we first discuss the identification of G4s and evidence for their formation in cells using chemical biology, imaging and genomic technologies. We then discuss possible functions of DNA G4s and their interacting proteins, particularly in transcription, telomere biology and genome instability. Roles of RNA G4s in RNA biology, especially in translation, are also discussed. Furthermore, we consider the emerging relationships of G4s with chromatin and with RNA modifications. Finally, we discuss the connection between G4 formation and synthetic lethality in cancer cells, and recent progress towards considering G4s as therapeutic targets in human diseases.
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Affiliation(s)
- Dhaval Varshney
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, Cambridge, UK
| | - Jochen Spiegel
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, Cambridge, UK
| | - Katherine Zyner
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, Cambridge, UK
| | - David Tannahill
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, Cambridge, UK
| | - Shankar Balasubramanian
- Cancer Research UK Cambridge Institute, Li Ka Shing Centre, Cambridge, UK.
- Department of Chemistry, University of Cambridge, Cambridge, UK.
- School of Clinical Medicine, University of Cambridge, Cambridge, UK.
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R-loop induced G-quadruplex in non-template promotes transcription by successive R-loop formation. Nat Commun 2020; 11:3392. [PMID: 32636376 PMCID: PMC7341879 DOI: 10.1038/s41467-020-17176-7] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 06/17/2020] [Indexed: 01/06/2023] Open
Abstract
G-quadruplex (G4) is a noncanonical secondary structure of DNA or RNA which can enhance or repress gene expression, yet the underlying molecular mechanism remains uncertain. Here we show that when positioned downstream of transcription start site, the orientation of potential G4 forming sequence (PQS), but not the sequence alters transcriptional output. Ensemble in vitro transcription assays indicate that PQS in the non-template increases mRNA production rate and yield. Using sequential single molecule detection stages, we demonstrate that while binding and initiation of T7 RNA polymerase is unchanged, the efficiency of elongation and the final mRNA output is higher when PQS is in the non-template. Strikingly, the enhanced elongation arises from the transcription-induced R-loop formation, which in turn generates G4 structure in the non-template. The G4 stabilized R-loop leads to increased transcription by a mechanism involving successive rounds of R-loop formation. G-quadruplex (G4) forming sequences are highly enriched in the human genome and function as important regulators of diverse range of biological processes. Here the authors show that while G4 structures on template strand block transcription, folding on the non-template strand enhances transcription by means of successive R-loop formation.
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Shankar U, Jain N, Mishra SK, Sharma TK, Kumar A. Conserved G-Quadruplex Motifs in Gene Promoter Region Reveals a Novel Therapeutic Approach to Target Multi-Drug Resistance Klebsiella pneumoniae. Front Microbiol 2020; 11:1269. [PMID: 32714288 PMCID: PMC7344255 DOI: 10.3389/fmicb.2020.01269] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 05/19/2020] [Indexed: 11/22/2022] Open
Abstract
An opportunistic pathogen, Klebsiella pneumoniae is known to cause life-threating nosocomial infection with a high rate of morbidity and mortality. Evolutions of multi-drug-resistant and hyper-virulent strains of K. pneumoniae make the situation worse. Currently, there is no incisive drug molecule available for drug-resistant hyper-virulent K. pneumoniae infection that emphasizes the need for identification of novel and more promising drug targets in K. pneumoniae. Recently, various non-canonical structures of nucleic acids especially G-quadruplex (G4) motifs have been identified as potential therapeutic targets against several human pathogenic bacteria and viruses including Mycobacterium tuberculosis, Streptococcus pneumoniae, human immunodeficiency virus (HIV), Ebola, and Nipah. Therefore, in present study we screened the K. pneumoniae genomes for identification of evolutionary conserved G4 structure-forming motifs as promising anti-bacterial drug targets. Bioinformatics analysis revealed the presence of six highly conserved G4 motifs in the promoter region of five essential genes that play a critical role in nutrient transport and metabolism. Biophysical studies showed the formation of G4 structure by these conserved motifs. Circular Dichroism melting analysis showed the stabilization of these G4 motifs by a well-known G4-stabilizing agent, BRACO-19. The stabilization of these motifs by BRACO-19 was also able to stop the primer extension process, which is an essential phenomenon for expression of the G4-harboring gene. The addition of G4-specific ligand at low micromolar range was observed to be lethal for the growth of this bacteria and negatively controlled the expression of the G4-harboring genes via G4 structure stabilization. These observations strengthen the formation of G4 structures by the predicted G4 motif in vivo, which can be stabilized by G4 ligands like BRACO-19. This stabilization of G4 structures can attenuate the expression of G4-harboring essential genes and thus play a critical role in the regulation of gene expression. Thus, taking all given result in consideration, for the first time, this study showed the new therapeutic avenue for combating K. pneumoniae infection by characterizing the conserved G4 motifs as promising therapeutic targets.
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Affiliation(s)
- Uma Shankar
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, India
| | - Neha Jain
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, India
| | - Subodh Kumar Mishra
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, India
| | | | - Amit Kumar
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, India
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27
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Reina C, Cavalieri V. Epigenetic Modulation of Chromatin States and Gene Expression by G-Quadruplex Structures. Int J Mol Sci 2020; 21:E4172. [PMID: 32545267 PMCID: PMC7312119 DOI: 10.3390/ijms21114172] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 06/07/2020] [Accepted: 06/10/2020] [Indexed: 02/07/2023] Open
Abstract
G-quadruplexes are four-stranded helical nucleic acid structures formed by guanine-rich sequences. A considerable number of studies have revealed that these noncanonical structural motifs are widespread throughout the genome and transcriptome of numerous organisms, including humans. In particular, G-quadruplexes occupy strategic locations in genomic DNA and both coding and noncoding RNA molecules, being involved in many essential cellular and organismal functions. In this review, we first outline the fundamental structural features of G-quadruplexes and then focus on the concept that these DNA and RNA structures convey a distinctive layer of epigenetic information that is critical for the complex regulation, either positive or negative, of biological activities in different contexts. In this framework, we summarize and discuss the proposed mechanisms underlying the functions of G-quadruplexes and their interacting factors. Furthermore, we give special emphasis to the interplay between G-quadruplex formation/disruption and other epigenetic marks, including biochemical modifications of DNA bases and histones, nucleosome positioning, and three-dimensional organization of chromatin. Finally, epigenetic roles of RNA G-quadruplexes in post-transcriptional regulation of gene expression are also discussed. Undoubtedly, the issues addressed in this review take on particular importance in the field of comparative epigenetics, as well as in translational research.
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Affiliation(s)
- Chiara Reina
- Department of Health Promotion, Mother and Child Care, Internal Medicine and Medical Specialties (PROMISE), University of Palermo, 90127 Palermo, Italy;
| | - Vincenzo Cavalieri
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, 90128 Palermo, Italy
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Guanine Quadruplex DNA Regulates Gamma Radiation Response of Genome Functions in the Radioresistant Bacterium Deinococcus radiodurans. J Bacteriol 2019; 201:JB.00154-19. [PMID: 31235513 DOI: 10.1128/jb.00154-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 06/07/2019] [Indexed: 12/31/2022] Open
Abstract
Guanine quadruplex (G4) DNA/RNA are secondary structures that regulate the various cellular processes in both eukaryotes and bacteria. Deinococcus radiodurans, a Gram-positive bacterium known for its extraordinary radioresistance, shows a genomewide occurrence of putative G4 DNA-forming motifs in its GC-rich genome. N-Methyl mesoporphyrin (NMM), a G4 DNA structure-stabilizing drug, did not affect bacterial growth under normal conditions but inhibited the postirradiation recovery of gamma-irradiated cells. Transcriptome sequencing analysis of cells treated with both radiation and NMM showed repression of gamma radiation-responsive gene expression, which was observed in the absence of NMM. Notably, this effect of NMM on the expression of housekeeping genes involved in other cellular processes was not observed. Stabilization of G4 DNA structures mapped at the upstream of recA and in the encoding region of DR_2199 had negatively affected promoter activity in vivo, DNA synthesis in vitro and protein translation in Escherichia coli host. These results suggested that G4 DNA plays an important role in DNA damage response and in the regulation of expression of the DNA repair proteins required for radioresistance in D. radiodurans IMPORTANCE Deinococcus radiodurans can recover from extensive DNA damage caused by many genotoxic agents. It lacks LexA/RecA-mediated canonical SOS response. Therefore, the molecular mechanisms underlying the regulation of DNA damage response would be worth investigating in this bacterium. D. radiodurans genome is GC-rich and contains numerous islands of putative guanine quadruplex (G4) DNA structure-forming motifs. Here, we showed that in vivo stabilization of G4 DNA structures can impair DNA damage response processes in D. radiodurans Essential cellular processes such as transcription, DNA synthesis, and protein translation, which are also an integral part of the double-strand DNA break repair pathway, are affected by the arrest of G4 DNA structure dynamics. Thus, the role of DNA secondary structures in DNA damage response and radioresistance is demonstrated.
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Verma S, Ghuge SA, Ravichandiran V, Ranjan N. Spectroscopic studies of Thioflavin-T binding to c-Myc G-quadruplex DNA. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2019; 212:388-395. [PMID: 30703662 DOI: 10.1016/j.saa.2018.12.044] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 11/16/2018] [Accepted: 12/22/2018] [Indexed: 05/29/2023]
Abstract
G-quadruplexes are well-known DNA secondary structures which can be formed both within the DNA and the RNA sequences of the human genome. While many functions of G-quadruplex during cell regulatory events are still unknown, a number of reports have established their role in finding new cancer therapies. In this report, we provide a detailed account of Thioflavin T (ThT) interacting with a promoter gene (c-Myc) which has relevance in several types of human cancers. Using a variety of spectroscopic techniques, we have shown that the binding of ThT is selective to c-Myc G-quadruplex only, having poor interactions with the duplex DNA sequences. UV-Visible titration experiments show that binding involves stacking interactions which were further corroborated by CD experiments. Fluorescence studies showed that the binding of ThT to c-Myc G-quadruplex results in a large increase in the fluorescence emission spectrum of c-Myc G-quadruplex while the same to duplex DNAs was much poor. Binding of ThT to c-Myc G-quadruplex results in thermal stabilization of the quadruplex DNA by up to 7.4 °C and Job plot experiments demonstrated the presence of 1:1 and 2:1 ligand to quadruplex complexes. Finally, the docking study suggested that ThT stacks with the guanine bases in one of the grooves which is in agreement with the CD studies. These results are expected to provide leads into the design of new ThT analogs and derivatives for enhancing the stability and selectivity of new G-quadruplex targeting ligands.
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Affiliation(s)
- Smita Verma
- National Institute of Pharmaceutical Education and Research, ITI Compound, Raebareli 229010, India; National Institute of Pharmaceutical Education and Research, Kolkata, Maniktala Main Road, Kolkata 700054, India
| | - Sandip A Ghuge
- TERI-Deakin Nanobiotechnology Research Center, Sustainable Agriculture Division, The Energy and Resources Institute, New Delhi 110003, India
| | - V Ravichandiran
- National Institute of Pharmaceutical Education and Research, Kolkata, Maniktala Main Road, Kolkata 700054, India
| | - Nihar Ranjan
- National Institute of Pharmaceutical Education and Research, ITI Compound, Raebareli 229010, India.
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Fan J, Ding L. Single-system based discriminative optical sensors: different strategies and versatile applications. Analyst 2019; 143:3775-3788. [PMID: 29974083 DOI: 10.1039/c8an00235e] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Discriminative optical sensors with pattern recognition properties and high-throughput ability have been widely developed as they can distinguish multiple chemically similar analytes. Compared to traditional sensor arrays composed of a series of sensor elements, single-system based discriminative sensors using an array of optical changes at different wavelengths to provide input signals have drawn intensive attention recently. On the one hand, they can provide discrimination ability that is lack in using selective sensors; on the other hand, they can simplify the complex data acquisition process accompanied by multiple-element-based sensor arrays and reduce consumption of sensor samples. This tutorial review gives an overview of the development of single-system based discriminative optical sensors. Different strategies for the construction of single-system based discriminative sensors including dynamic combinatorial libraries, cross-reactive conjugated polymers, DNA G-quadruplex ensembles, combinatorial fluorescent molecular sensors, and fluorophore/surfactant aggregate ensembles are particularly introduced.
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Affiliation(s)
- Junmei Fan
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, 710062, PR China.
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Mishra SK, Jain N, Shankar U, Tawani A, Sharma TK, Kumar A. Characterization of highly conserved G-quadruplex motifs as potential drug targets in Streptococcus pneumoniae. Sci Rep 2019; 9:1791. [PMID: 30741996 PMCID: PMC6370756 DOI: 10.1038/s41598-018-38400-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 12/21/2018] [Indexed: 11/24/2022] Open
Abstract
Several G-quadruplex forming motifs have been reported to be highly conserved in the regulatory regions of the genome of different organisms and influence various biological processes like DNA replication, recombination and gene expression. Here, we report the highly conserved and three potentially G-quadruplex forming motifs (SP-PGQs) in the essential genes (hsdS, recD, and pmrA) of the Streptococcus pneumoniae genome. These genes were previously observed to play a vital role in providing the virulence to the bacteria, by participating in the host-pathogen interaction, drug-efflux system and recombination- repair system. However, the presence and importance of highly conserved G-quadruplex motifs in these genes have not been previously recognized. We employed the CD spectroscopy, NMR spectroscopy, and electrophoretic mobility shift assay to confirm the adaptation of the G-quadruplex structure by the SP-PGQs. Further, ITC and CD melting analysis revealed the energetically favorable and thermodynamically stable interaction between a candidate G4 binding small molecule TMPyP4 and SP-PGQs. Next, TFP reporter based assay confirmed the regulatory role of SP-PGQs in the expression of PGQ harboring genes. All these experiments together characterized the SP-PGQs as a promising drug target site for combating the Streptococcus pneumoniae infection.
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Affiliation(s)
- Subodh Kumar Mishra
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Simrol, Indore, 453552, India
| | - Neha Jain
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Simrol, Indore, 453552, India
| | - Uma Shankar
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Simrol, Indore, 453552, India
| | - Arpita Tawani
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Simrol, Indore, 453552, India
| | - Tarun Kumar Sharma
- Centre for Bio-design and Diagnostics, Translational Health Science and Technology Institute, Faridabad, Haryana, India
| | - Amit Kumar
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Simrol, Indore, 453552, India.
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Whole-Transcriptome Profiling of Canine and Human in Vitro Models Exposed to a G-Quadruplex Binding Small Molecule. Sci Rep 2018; 8:17107. [PMID: 30459395 PMCID: PMC6244004 DOI: 10.1038/s41598-018-35516-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 11/06/2018] [Indexed: 11/24/2022] Open
Abstract
G-quadruplexes (G4) are secondary nucleic acid structures that have been associated with genomic instability and cancer progression. When present in the promoter of some oncogenes, G4 structures can affect gene regulation and, hence, represent a possible therapeutic target. In this study, RNA-Seq was used to explore the effect of a G4-binding anthraquinone derivative, named AQ1, on the whole-transcriptome profiles of two common cell models for the study of KIT pathways; the human mast cell leukemia (HMC1.2) and the canine mast cell tumor (C2). The highest non-cytotoxic dose of AQ1 (2 µM) resulted in 5441 and 1201 differentially expressed genes in the HMC1.2 and C2 cells, respectively. In both cell lines, major pathways such as cell cycle progression, KIT- and MYC-related pathways were negatively enriched in the AQ1-treated group, while other pathways such as p53, apoptosis and hypoxia-related were positively enriched. These findings suggest that AQ1 treatment induces a similar functional response in the human and canine cell models, and provide news insights into using dogs as a reliable translational model for studying G4-binding compounds.
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Ogasawara S. Transcription Driven by Reversible Photocontrol of Hyperstable G-Quadruplexes. ACS Synth Biol 2018; 7:2507-2513. [PMID: 30350586 DOI: 10.1021/acssynbio.8b00216] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
G-quadruplexes occur in promoter regions, 5'-untranslated regions of mRNA and telomeric regions, and they function as regulatory elements for various key biological events, such as transcription, translation, and telomere elongation. As the stability of G-quadruplexes dramatically impacts these biological processes, controlling G-quadruplex stability via external stimuli such as light enables regulation of important biological phenomena with high spatial and temporal resolution. Here, we report a method for reversible photoregulation of transcription by controlling the stability of G-quadruplexes via cis- trans photoisomerization of photochromic nucleobase (PCN). Transcription was effectively inhibited when the PCN-modified G-quadruplex was in a hyperstable state, whereas transcription activity recovered markedly when the G-quadruplex changed to an unstable state induced by trans to cis PCN photoisomerization. Moreover, a reversibly photoactivatable plasmid was constructed by introducing PCN-modified G-quadruplexes downstream of the cytomegalovirus promoter of the pCS2 plasmid, which was used to demonstrate photoregulation of gene expression in zebrafish embryos.
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Affiliation(s)
- Shinzi Ogasawara
- PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
- Graduate School of Science, Hokkaido University, Kita 10, Nishi 8, Kita-ku, Sapporo 060-0810, Japan
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Yu H, Xue C, Long M, Jia H, Xue G, Du S, Coello Y, Ishibashi T. TEFM Enhances Transcription Elongation by Modifying mtRNAP Pausing Dynamics. Biophys J 2018; 115:2295-2300. [PMID: 30514634 DOI: 10.1016/j.bpj.2018.11.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 10/25/2018] [Accepted: 11/05/2018] [Indexed: 10/27/2022] Open
Abstract
Regulation of transcription elongation is one of the key mechanisms employed to control gene expression. The single-subunit mitochondrial RNA polymerase (mtRNAP) transcribes mitochondrial genes, such as those related to ATP synthesis. We investigated how mitochondrial transcription elongation factor (TEFM) enhances mtRNAP transcription elongation using a single-molecule optical-tweezers transcription assay, which follows transcription dynamics in real time and allows the separation of pause-free elongation from transcriptional pauses. We found that TEFM enhances the stall force of mtRNAP. Although TEFM does not change the pause-free elongation rate, it enhances mtRNAP transcription elongation by reducing the frequency of long-lived pauses and shortening their durations. Furthermore, we demonstrate how mtRNAP passes through the conserved sequence block II, which is the key sequence for the switch between DNA replication and transcription in mitochondria. Our findings elucidate how both TEFM and mitochondrial genomic DNA sequences directly control the transcription elongation dynamics of mtRNAP.
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Affiliation(s)
- Hongwu Yu
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, NT, Hong Kong, HKSAR, China
| | - Cheng Xue
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, NT, Hong Kong, HKSAR, China
| | - Mengping Long
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, NT, Hong Kong, HKSAR, China
| | - Huiqiang Jia
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, NT, Hong Kong, HKSAR, China
| | - Guosheng Xue
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, NT, Hong Kong, HKSAR, China; Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, NT, Hong Kong, HKSAR, China
| | - Shengwang Du
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, NT, Hong Kong, HKSAR, China; Department of Chemical and Biological Engineering, Hong Kong University of Science and Technology, Clear Water Bay, NT, Hong Kong, HKSAR, China
| | - Yves Coello
- Departamento de Ciencias, Sección Química, Pontificia Universidad Católica del Perú PUCP, Lima, Peru
| | - Toyotaka Ishibashi
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, NT, Hong Kong, HKSAR, China.
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G-quadruplex structure at intron 2 of TFE3 and its role in Xp11.2 translocation and splicing. Biochim Biophys Acta Gen Subj 2017; 1862:630-636. [PMID: 29138008 DOI: 10.1016/j.bbagen.2017.11.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Revised: 10/16/2017] [Accepted: 11/10/2017] [Indexed: 12/19/2022]
Abstract
Transcription Factor E3 (TFE3) translocation is found in a group of different type of cancers and most of the translocations are located in the 5' region of TFE3 which may be considered as Breakpoint Region (BR). In our In silico study by QGRS mapper and non BdB web servers we found a Potential G-quadruplex forming Sequence (PQS) in the intron 2 of TFE3 gene. In vitro G-quadruplex formation was shown by native PAGE in presence of Pyridostatin(PDS), which with inter molecular secondary structure caused reduced mobility to migrate slower. G-quadruplex formation was mapped at single base resolution by Sanger sequencing and Circular Dichroism showed the formation of parallel G-quadruplex. FRET analysis revealed increased and decreased formation of G-quadruplex in presence of PDS and antisense oligonucleotide respectively. PCR stop assay, transcriptional and translational inhibition by PQS showed stable G-quadruplex formation affecting the biological processes. TFE3 minigene splicing study showed the involvement of this G-quadruplex in TFE3 splicing too. Therefore, G-quadruplex is evident to be the reason behind TFE3 induced oncogenesis executed by translocation and also involved in the mRNA splicing.
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G-quadruplex unwinding helicases and their function in vivo. Biochem Soc Trans 2017; 45:1173-1182. [DOI: 10.1042/bst20170097] [Citation(s) in RCA: 105] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 07/31/2017] [Accepted: 08/10/2017] [Indexed: 12/21/2022]
Abstract
The concept that G-quadruplex (G4) structures can form within DNA or RNA in vitro has been long known and extensively discussed. In recent years, accumulating evidences imply that G-quadruplex structures form in vivo. Initially, inefficient regulation of G-quadruplex structures was mainly associated with genome instability. However, due to the location of G-quadruplex motifs and their evolutionary conservation, different cellular functions of these structures have been postulated (e.g. in telomere maintenance, DNA replication, transcription, and translation). Regardless of their function, efficient and controlled formation and unwinding are very important, because ‘mis’-regulated G-quadruplex structures are detrimental for a given process, causing genome instability and diseases. Several helicases have been shown to target and regulate specific G-quadruplex structures. This mini-review focuses on the biological consequences of G4 disruption by different helicases in vivo.
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Odorant Sensory Input Modulates DNA Secondary Structure Formation and Heterogeneous Ribonucleoprotein Recruitment on the Tyrosine Hydroxylase and Glutamic Acid Decarboxylase 1 Promoters in the Olfactory Bulb. J Neurosci 2017; 37:4778-4789. [PMID: 28411275 DOI: 10.1523/jneurosci.1363-16.2017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 03/15/2017] [Accepted: 03/16/2017] [Indexed: 12/25/2022] Open
Abstract
Adaptation of neural circuits to changes in sensory input can modify several cellular processes within neurons, including neurotransmitter biosynthesis levels. For a subset of olfactory bulb interneurons, activity-dependent changes in GABA are reflected by corresponding changes in Glutamate decarboxylase 1 (Gad1) expression levels. Mechanisms regulating Gad1 promoter activity are poorly understood, but here we show that a conserved G:C-rich region in the mouse Gad1 proximal promoter region both recruits heterogeneous nuclear ribonucleoproteins (hnRNPs) that facilitate transcription and forms single-stranded DNA secondary structures associated with transcriptional repression. This promoter architecture and function is shared with Tyrosine hydroxylase (Th), which is also modulated by odorant-dependent activity in the olfactory bulb. This study shows that the balance between DNA secondary structure formation and hnRNP binding on the mouse Th and Gad1 promoters in the olfactory bulb is responsive to changes in odorant-dependent sensory input. These findings reveal that Th and Gad1 share a novel transcription regulatory mechanism that facilitates sensory input-dependent regulation of dopamine and GABA expression.SIGNIFICANCE STATEMENT Adaptation of neural circuits to changes in sensory input can modify several cellular processes within neurons, including neurotransmitter biosynthesis levels. This study shows that transcription of genes encoding rate-limiting enzymes for GABA and dopamine biosynthesis (Gad1 and Th, respectively) in the mammalian olfactory bulb is regulated by G:C-rich regions that both recruit heterogeneous nuclear ribonucleoproteins (hnRNPs) to facilitate transcription and form single-stranded DNA secondary structures associated with repression. hnRNP binding and formation of DNA secondary structure on the Th and Gad1 promoters are mutually exclusive, and odorant sensory input levels regulate the balance between these regulatory features. These findings reveal that Th and Gad1 share a transcription regulatory mechanism that facilitates odorant-dependent regulation of dopamine and GABA expression levels.
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Dolinnaya NG, Ogloblina AM, Yakubovskaya MG. Structure, Properties, and Biological Relevance of the DNA and RNA G-Quadruplexes: Overview 50 Years after Their Discovery. BIOCHEMISTRY (MOSCOW) 2017; 81:1602-1649. [PMID: 28260487 PMCID: PMC7087716 DOI: 10.1134/s0006297916130034] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
G-quadruplexes (G4s), which are known to have important roles in regulation of key biological processes in both normal and pathological cells, are the most actively studied non-canonical structures of nucleic acids. In this review, we summarize the results of studies published in recent years that change significantly scientific views on various aspects of our understanding of quadruplexes. Modern notions on the polymorphism of DNA quadruplexes, on factors affecting thermodynamics and kinetics of G4 folding–unfolding, on structural organization of multiquadruplex systems, and on conformational features of RNA G4s and hybrid DNA–RNA G4s are discussed. Here we report the data on location of G4 sequence motifs in the genomes of eukaryotes, bacteria, and viruses, characterize G4-specific small-molecule ligands and proteins, as well as the mechanisms of their interactions with quadruplexes. New information on the structure and stability of G4s in telomeric DNA and oncogene promoters is discussed as well as proof being provided on the occurrence of G-quadruplexes in cells. Prominence is given to novel experimental techniques (single molecule manipulations, optical and magnetic tweezers, original chemical approaches, G4 detection in situ, in-cell NMR spectroscopy) that facilitate breakthroughs in the investigation of the structure and functions of G-quadruplexes.
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Affiliation(s)
- N G Dolinnaya
- Lomonosov Moscow State University, Department of Chemistry, Moscow, 119991, Russia.
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Rigo R, Palumbo M, Sissi C. G-quadruplexes in human promoters: A challenge for therapeutic applications. Biochim Biophys Acta Gen Subj 2016; 1861:1399-1413. [PMID: 28025083 DOI: 10.1016/j.bbagen.2016.12.024] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 12/21/2016] [Accepted: 12/22/2016] [Indexed: 12/19/2022]
Abstract
BACKGROUND G-rich sequences undergo unique structural equilibria to form G-quadruplexes (G4) both in vitro and in cell systems. Several pathologies emerged to be directly related to G4 occurrence at defined genomic portions. Additionally, G-rich sequences are significantly represented around transcription start sites (TSS) thus leading to the hypothesis of a gene regulatory function for G4. Thus, the tuning of G4 formation has been proposed as a new powerful tool to regulate gene expression to treat related pathologies. However, up-to date this approach did not provide any new really efficient treatment. SCOPE OF REVIEW Here, we summarize the most recent advances on the correlation between the structural features of G4 in human promoters and the role these systems physiologically exert. In particular we focus on the effect of G4 localization among cell compartments and along the promoters in correlation with protein interaction networks and epigenetic state. Finally the intrinsic structural features of G4 at promoters are discussed to unveil the contribution of different G4 structural modules in this complex architecture. MAJOR CONCLUSIONS It emerges that G4s play several roles in the intriguing and complex mechanism of gene expression, being able to produce opposite effects on the same target. This reflects the occurrence of a highly variegate network of several components working simultaneously. GENERAL SIGNIFICANCE The resulting picture is still fuzzy but some points of strength are definitely emerging, which prompts all of us to strengthen our efforts in view of a selective control of gene expression through G4 modulation. 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)
- Riccardo Rigo
- Dept. of Pharmaceutical and Pharmacological Sciences, University of Padova, v. Marzolo, 5, 35131 Padova, Italy
| | - Manlio Palumbo
- Dept. of Pharmaceutical and Pharmacological Sciences, University of Padova, v. Marzolo, 5, 35131 Padova, Italy
| | - Claudia Sissi
- Dept. of Pharmaceutical and Pharmacological Sciences, University of Padova, v. Marzolo, 5, 35131 Padova, Italy.
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Pinto B, Rusciano G, D'Errico S, Borbone N, Sasso A, Piccialli V, Mayol L, Oliviero G, Piccialli G. Synthesis and label free characterization of a bimolecular PNA homo quadruplex. Biochim Biophys Acta Gen Subj 2016; 1861:1222-1228. [PMID: 27913190 DOI: 10.1016/j.bbagen.2016.11.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 11/25/2016] [Accepted: 11/26/2016] [Indexed: 12/31/2022]
Abstract
BACKGROUND G-quadruplex DNA is involved in many physiological and pathological processes. Both clinical and experimental studies on DNA G-quadruplexes are slowed down by their enzymatic instability. In this frame, more stable chemically modified analogs are needed. METHODS The bis-end-linked-(gggt)2 PNA molecule (BEL-PNA) was synthesized using in solution and solid phase synthetic approaches. Quadruplex formation was assessed by circular dichroism (CD) and surface enhanced Raman scattering (SERS). RESULTS An unprecedented bimolecular PNA homo quadruplex is here reported. To achieve this goal, we developed a bifunctional linker that once functionalized with gggt PNA strands and annealed in K+ buffer allowed the obtainment of a PNA homo quadruplex. The identification of the strong SERS band at ~1481cm-1, attributable to vibrations involving the quadruplex diagnostic Hoogsteen type hydrogen bonds, confirmed the formation of the PNA homo quadruplex. CONCLUSIONS By tethering two G-rich PNA strands to the two ends of a suitable bifunctional linker it is possible to obtain bimolecular PNA homo quadruplexes after annealing in K+-containing buffers. The formation of such CD-unfriendly complexes can be monitored, even at low concentrations, by using the SERS technique. GENERAL SIGNIFICANCE Given the importance of DNA G-quadruplexes in medicine and nanotechnology, the obtainment of G-quadruplex analogs provided with enhanced enzymatic stability, and their monitoring by highly sensitive label-free techniques are of the highest importance. 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)
- Brunella Pinto
- Dipartimento di Farmacia, Università degli Studi di Napoli Federico II, 80131 Napoli, Italy
| | - Giulia Rusciano
- Dipartimento di Scienze Fisiche, Università degli Studi di Napoli Federico II, 80126 Napoli, Italy
| | - Stefano D'Errico
- Dipartimento di Farmacia, Università degli Studi di Napoli Federico II, 80131 Napoli, Italy
| | - Nicola Borbone
- Dipartimento di Farmacia, Università degli Studi di Napoli Federico II, 80131 Napoli, Italy
| | - Antonio Sasso
- Dipartimento di Scienze Fisiche, Università degli Studi di Napoli Federico II, 80126 Napoli, Italy
| | - Vincenzo Piccialli
- Dipartimento di Scienze Chimiche, Università degli Studi di Napoli Federico II, 80126 Napoli, Italy
| | - Luciano Mayol
- Dipartimento di Farmacia, Università degli Studi di Napoli Federico II, 80131 Napoli, Italy
| | - Giorgia Oliviero
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II, 80131 Napoli, Italy.
| | - Gennaro Piccialli
- Dipartimento di Farmacia, Università degli Studi di Napoli Federico II, 80131 Napoli, Italy; CNR, Institute of Protein Biochemistry, 80131 Napoli, Italy.
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Armas P, David A, Calcaterra NB. Transcriptional control by G-quadruplexes: In vivo roles and perspectives for specific intervention. Transcription 2016; 8:21-25. [PMID: 27696937 DOI: 10.1080/21541264.2016.1243505] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
G-quadruplexes are non-canonical DNA secondary structures involved in several genomic and molecular processes. Here, we summarize the main G-quadruplex features and evidences proving the in vivo role on the transcriptional regulation of genes required for zebrafish embryonic development. We also discuss alternative strategies for specifically interfering G-quadruplex in vivo.
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Affiliation(s)
- Pablo Armas
- a Instituto de Biología Molecular y Celular de Rosario (IBR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Ocampo y Esmeralda , Rosario , Argentina
| | - Aldana David
- a Instituto de Biología Molecular y Celular de Rosario (IBR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Ocampo y Esmeralda , Rosario , Argentina
| | - Nora B Calcaterra
- a Instituto de Biología Molecular y Celular de Rosario (IBR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Ocampo y Esmeralda , Rosario , Argentina
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Sherlock ME, Rumble CA, Kwok CK, Breffke J, Maroncelli M, Bevilacqua PC. Steady-State and Time-Resolved Studies into the Origin of the Intrinsic Fluorescence of G-Quadruplexes. J Phys Chem B 2016; 120:5146-58. [PMID: 27267433 DOI: 10.1021/acs.jpcb.6b03790] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Stretches of guanines in DNA and RNA can fold into guanine quadruplex structures (GQSs). These structures protect telomeres in DNA and regulate gene expression in RNA. GQSs have an intrinsic fluorescence that is sensitive to different parameters, including loop sequence and length. However, the dependence of GQS fluorescence on solution and sequence parameters and the origin of this fluorescence are poorly understood. Herein we examine effects of dangling nucleotides and cosolute conditions on GQS fluorescence using both steady-state and time-resolved fluorescence spectroscopy. The quantum yield of dGGGTGGGTGGGTGGG, termed "dG3T", is found to be modest at ∼2 × 10(-3). Nevertheless, dG3T and its variants are significantly brighter than the common nucleic acid fluorophore 2-aminopurine (2AP) largely due to their sizable extinction coefficients. Dangling 5'-end nucleotides generally reduce emission and blue-shift the resultant spectrum, whereas dangling 3'-end nucleotides slightly enhance fluorescence, particularly on the red side of the emission band. Time-resolved fluorescence decays are broadly distributed in time and require three exponential components for accurate fits. Time-resolved emission spectra suggest the presence of two emitting populations centered at ∼330 and ∼390 nm, with the redder component being a well-defined long-lived (∼1 ns) entity. Insights into GQS fluorescence obtained here should be useful in designing brighter intrinsic RNA and DNA quadruplexes for use in label-free biotechnological applications.
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Affiliation(s)
- Madeline E Sherlock
- Department of Chemistry, ‡Center for RNA Molecular Biology, and §Department of Biochemistry and Molecular Biology, Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Christopher A Rumble
- Department of Chemistry, ‡Center for RNA Molecular Biology, and §Department of Biochemistry and Molecular Biology, Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Chun Kit Kwok
- Department of Chemistry, ‡Center for RNA Molecular Biology, and §Department of Biochemistry and Molecular Biology, Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Jens Breffke
- Department of Chemistry, ‡Center for RNA Molecular Biology, and §Department of Biochemistry and Molecular Biology, Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Mark Maroncelli
- Department of Chemistry, ‡Center for RNA Molecular Biology, and §Department of Biochemistry and Molecular Biology, Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Philip C Bevilacqua
- Department of Chemistry, ‡Center for RNA Molecular Biology, and §Department of Biochemistry and Molecular Biology, Pennsylvania State University , University Park, Pennsylvania 16802, United States
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David AP, Margarit E, Domizi P, Banchio C, Armas P, Calcaterra NB. G-quadruplexes as novel cis-elements controlling transcription during embryonic development. Nucleic Acids Res 2016; 44:4163-73. [PMID: 26773060 PMCID: PMC4872077 DOI: 10.1093/nar/gkw011] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Accepted: 01/05/2016] [Indexed: 01/06/2023] Open
Abstract
G-quadruplexes are dynamic structures folded in G-rich single-stranded DNA regions. These structures have been recognized as a potential nucleic acid based mechanism for regulating multiple cellular processes such as replication, transcription and genomic maintenance. So far, their transcriptional role in vivo during vertebrate embryonic development has not yet been addressed. Here, we performed an in silico search to find conserved putative G-quadruplex sequences (PQSs) within proximal promoter regions of human, mouse and zebrafish developmental genes. Among the PQSs able to fold in vitro as G-quadruplex, those present in nog3, col2a1 and fzd5 promoters were selected for further studies. In cellulo studies revealed that the selected G-quadruplexes affected the transcription of luciferase controlled by the SV40 nonrelated promoter. G-quadruplex disruption in vivo by microinjection in zebrafish embryos of either small ligands or DNA oligonucleotides complementary to the selected PQSs resulted in lower transcription of the targeted genes. Moreover, zebrafish embryos and larvae phenotypes caused by the presence of complementary oligonucleotides fully resembled those ones reported for nog3, col2a1 and fzd5 morphants. To our knowledge, this is the first work revealing in vivo the role of conserved G-quadruplexes in the embryonic development, one of the most regulated processes of the vertebrates biology.
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Affiliation(s)
- Aldana P David
- Instituto de Biología Molecular y Celular de Rosario (IBR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Ocampo y Esmeralda, (S2000EZP) Rosario, Argentina
| | - Ezequiel Margarit
- Instituto de Biología Molecular y Celular de Rosario (IBR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Ocampo y Esmeralda, (S2000EZP) Rosario, Argentina
| | - Pablo Domizi
- Instituto de Biología Molecular y Celular de Rosario (IBR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Ocampo y Esmeralda, (S2000EZP) Rosario, Argentina
| | - Claudia Banchio
- Instituto de Biología Molecular y Celular de Rosario (IBR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Ocampo y Esmeralda, (S2000EZP) Rosario, Argentina
| | - Pablo Armas
- Instituto de Biología Molecular y Celular de Rosario (IBR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Ocampo y Esmeralda, (S2000EZP) Rosario, Argentina
| | - Nora B Calcaterra
- Instituto de Biología Molecular y Celular de Rosario (IBR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Ocampo y Esmeralda, (S2000EZP) Rosario, Argentina
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Holder IT, Hartig JS. A matter of location: influence of G-quadruplexes on Escherichia coli gene expression. ACTA ACUST UNITED AC 2015; 21:1511-21. [PMID: 25459072 DOI: 10.1016/j.chembiol.2014.09.014] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 08/13/2014] [Accepted: 09/17/2014] [Indexed: 01/01/2023]
Abstract
We provide important insights into secondary-structure-mediated regulation of gene expression in Escherichia coli. In a comprehensive survey, we show that the strand orientation and the exact position of a G-quadruplex sequence strongly influence its effect on transcription and translation. We generated a series of reporter gene constructs that contained systematically varied positions of quadruplexes and respective control sequences inserted into several positions within the promoter, 50-UTR, and 30-UTR regions. G-rich sequences at specific locations in the promoter and also in proximity to the ribosome-binding site (RBS) showed pronounced inhibitory effects. Additionally, we rationally designed a system where quadruplex formation showed a gene-activating behavior. Moreover, we characterized quadruplexes in proximity to the RBS that occur naturally in E. coli genes, demonstrating that some of these quadruplexes exert significant modulation of gene expression. Taken together, our data show strong position-dependent effects of quadruplex secondary structures on bacterial gene expression.
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Mosquera Orgueira A. Hidden among the crowd: differential DNA methylation-expression correlations in cancer occur at important oncogenic pathways. Front Genet 2015; 6:163. [PMID: 26029238 PMCID: PMC4429616 DOI: 10.3389/fgene.2015.00163] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2014] [Accepted: 04/10/2015] [Indexed: 12/31/2022] Open
Abstract
DNA methylation is a frequent epigenetic mechanism that participates in transcriptional repression. Variations in DNA methylation with respect to gene expression are constant, and, for unknown reasons, some genes with highly methylated promoters are sometimes overexpressed. In this study we have analyzed the expression and methylation patterns of thousands of genes in five groups of cancer and normal tissue samples in order to determine local and genome-wide differences. We observed significant changes in global methylation-expression correlation in all the neoplasms, which suggests that differential correlation events are frequent in cancer. A focused analysis in the breast cancer cohort identified 1662 genes whose correlation varies significantly between normal and cancerous breast, but whose DNA methylation and gene expression patterns do not change substantially. These genes were enriched in cancer-related pathways and repressive chromatin features across various model cell lines, such as PRC2 binding and H3K27me3 marks. Substantial changes in methylation-expression correlation indicate that these genes are subject to epigenetic remodeling, where the differential activity of other factors break the expected relationship between both variables. Our findings suggest a complex regulatory landscape where a redistribution of local and large-scale chromatin repressive domains at differentially correlated genes (DCGs) creates epigenetic hotspots that modulate cancer-specific gene expression.
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Pal N, Shweta H, Singh MK, Verma SD, Sen S. Power-Law Solvation Dynamics in G-Quadruplex DNA: Role of Hydration Dynamics on Ligand Solvation inside DNA. J Phys Chem Lett 2015; 6:1754-1760. [PMID: 26263345 DOI: 10.1021/acs.jpclett.5b00653] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
G-quadruplex DNA (GqDNA) structures act as promising anticancer targets for small-molecules (ligands). Solvation dynamics of a ligand (DAPI: 4',6-diamidino-2-phenylindole) inside antiparallel-GqDNA is studied through direct comparison of time-resolved experiments to molecular dynamics (MD) simulation. Dynamic Stokes shifts of DAPI in GqDNA prepared in H2O buffer and D2O are compared to find the effect of water on ligand solvation. Experimental dynamics (in H2O) is then directly compared with the dynamics computed from 65 ns simulation on the same DAPI-GqDNA complex. Ligand solvation follows power-law relaxation (summed with fast exponential relaxation) from ~100 fs to 10 ns. Simulation results show relaxation below ~5 ps is dominated by water motion, while both water and DNA contribute comparably to dictate long-time power-law dynamics. Ion contribution is, however, found to be negligible. Simulation results also suggest that anomalous solvation dynamics may have origin in subdiffusive motion of perturbed water near GqDNA.
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Affiliation(s)
- Nibedita Pal
- Spectroscopy Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Him Shweta
- Spectroscopy Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Moirangthem Kiran Singh
- Spectroscopy Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Sachin Dev Verma
- Spectroscopy Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Sobhan Sen
- Spectroscopy Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India
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