1
|
Sahayasheela VJ, Sugiyama H. RNA G-quadruplex in functional regulation of noncoding RNA: Challenges and emerging opportunities. Cell Chem Biol 2024; 31:53-70. [PMID: 37909035 DOI: 10.1016/j.chembiol.2023.08.010] [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: 04/18/2023] [Revised: 07/12/2023] [Accepted: 08/22/2023] [Indexed: 11/02/2023]
Abstract
G-quadruplexes (G4s) are stable, noncanonical structures formed in guanine (G)-rich sequences of DNA/RNA. G4 structures are reported to play a regulatory role in various cellular processes and, recently, a considerable number of studies have attributed new biological functions to these structures, especially in RNA. Noncoding RNA (ncRNA), which does not translate into a functional protein, is widely expressed and has been shown to play a key role in shaping cellular activity. There has been growing evidence of G4 formation in several ncRNA classes, and it has been identified as a key part for diverse biological functions and physio-pathological contexts in neurodegenerative diseases and cancer. This review discusses RNA G4s (rG4s) in ncRNA, focusing on the molecular mechanism underlying its function. This review also aims to highlight potential and emerging opportunities to identify and target the rG4s in ncRNA to understand its function and, ultimately, treat many diseases.
Collapse
Affiliation(s)
- Vinodh J Sahayasheela
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-Ku, Kyoto 606-8502, Japan
| | - Hiroshi Sugiyama
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-Ku, Kyoto 606-8502, Japan; Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Yoshida-Ushinomaecho, Sakyo-Ku, Kyoto 606-8501, Japan.
| |
Collapse
|
2
|
Li F, Zhou J. G-quadruplexes from non-coding RNAs. J Mol Med (Berl) 2023:10.1007/s00109-023-02314-7. [PMID: 37069370 DOI: 10.1007/s00109-023-02314-7] [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: 08/31/2022] [Revised: 03/22/2023] [Accepted: 03/30/2023] [Indexed: 04/19/2023]
Abstract
Non-coding RNAs (ncRNAs) are significant regulators of gene expression in a wide range of biological processes, such as transcription, RNA maturation, or translation. ncRNAs interplay with proteins or other RNAs through not only classical sequence-based mechanisms but also unique higher-order structures such as RNA G-quadruplexes (rG4s). rG4s are predictably formed in guanine-rich sequences and are closely related to various human diseases, such as tumors, neurodegenerative diseases, and infections. This review focuses on the vital role of rG4s in ncRNAs, particularly lncRNAs and miRNAs. We outline the dynamic balance between rG4s and RNA stem-loop/hairpin structures and the interplay between ncRNAs and interactors, thereby modulating gene expression and disease progression. A complete understanding of the biological regulatory role and mechanism of rG4s in ncRNAs affirms the critical importance of folding into the appropriate three-dimensional structure in maintaining or modulating the functions of ncRNAs. It makes them novel therapeutic targets for adjusting potential-G4-containing-ncRNAs-associated diseases.
Collapse
Affiliation(s)
- Fangyuan Li
- Department Medical Research Central, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
- Clinical Biobank, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Jiang Zhou
- Beijing National Laboratory for Molecular Sciences, Analytical Instrumentation Center, College of Chemistry and Molecular Engineering, Peking University, Beijing, China.
| |
Collapse
|
3
|
G-Quadruplexes Regulate miRNA Biogenesis in Live Zebrafish Embryos. Int J Mol Sci 2023; 24:ijms24054828. [PMID: 36902262 PMCID: PMC10002522 DOI: 10.3390/ijms24054828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 02/16/2023] [Accepted: 02/20/2023] [Indexed: 03/06/2023] Open
Abstract
RNA guanine quadruplexes (G4s) regulate RNA functions, metabolism, and processing. G4s formed within precursors of microRNAs (pre-miRNAs) may impair pre-miRNAs maturation by Dicer, thus repressing mature miRNA biogenesis. As miRNAs are essential for proper embryonic development, we studied the role of G4s on miRNA biogenesis in vivo during zebrafish embryogenesis. We performed a computational analysis on zebrafish pre-miRNAs to find putative G4 forming sequences (PQSs). The precursor of the miRNA 150 (pre-miR-150) was found to contain an evolutionarily conserved PQS formed by three G-tetrads and able to fold in vitro as G4. MiR-150 controls the expression of myb, which shows a well-defined knock-down phenotype in zebrafish developing embryos. We microinjected zebrafish embryos with in vitro transcribed pre-miR-150 synthesized using either GTP (G-pre-miR-150) or 7-Deaza-GTP, a GTP analogue unable to form G4s (7DG-pre-miR-150). Compared to embryos injected with G-pre-miR-150, embryos injected with 7DG-pre-miR-150 showed higher levels of miRNA 150 (miR-150) and lower levels of myb mRNA and stronger phenotypes associated with myb knock-down. The incubation of pre-miR-150 prior to the injection with the G4 stabilizing ligand pyridostatin (PDS) reverted gene expression variations and rescued the phenotypes related to myb knock-down. Overall, results suggest that the G4 formed in pre-miR-150 functions in vivo as a conserved regulatory structure competing with the stem-loop structure necessary for miRNA biogenesis.
Collapse
|
4
|
Teng Y, Zhu M, Chi Y, Li L, Jin Y. Can G-quadruplex become a promising target in HBV therapy? Front Immunol 2022; 13:1091873. [PMID: 36591216 PMCID: PMC9797731 DOI: 10.3389/fimmu.2022.1091873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 11/28/2022] [Indexed: 12/23/2022] Open
Abstract
The chronic infection with hepatitis B virus (HBV) is an important health problem that affects millions of people worldwide. Current therapies for HBV always suffer from a poor response rate, common side effects, and the need for lifelong treatment. Novel therapeutic targets are expected. Interestingly, non-canonical structures of nucleic acids play crucial roles in the regulation of gene expression. Especially the formation of G-quadruplexes (G4s) in G-rich strands has been demonstrated to affect many bioprocesses including replication, transcription, and translation, showing great potential as targets in anticancer and antiviral therapies. In this review, we summarize recent antiviral studies about G4s and discuss the potential roles of G4 structures in antiviral therapy for HBV.
Collapse
Affiliation(s)
- Ye Teng
- School of Pharmacy, Changchun University of Chinese Medicine, Changchun, China
| | - Ming Zhu
- School of Pharmacy, Changchun University of Chinese Medicine, Changchun, China
| | - Yuan Chi
- Pharmaceutical Department, The Affiliated Hospital of Changchun University of Chinese Medicine, Changchun, China
| | - Lijing Li
- School of Pharmacy, Changchun University of Chinese Medicine, Changchun, China,*Correspondence: Lijing Li, ; Ye Jin,
| | - Ye Jin
- School of Pharmacy, Changchun University of Chinese Medicine, Changchun, China,*Correspondence: Lijing Li, ; Ye Jin,
| |
Collapse
|
5
|
Santos T, Miranda A, Imbert L, Monchaud D, Salgado GF, Cabrita EJ, Cruz C. Targeting a G-quadruplex from let-7e pre-miRNA with small molecules and nucleolin. J Pharm Biomed Anal 2022; 215:114757. [PMID: 35462282 DOI: 10.1016/j.jpba.2022.114757] [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: 12/12/2021] [Revised: 02/28/2022] [Accepted: 04/03/2022] [Indexed: 10/18/2022]
Abstract
Let-7e precursor microRNA has the potential to adopt a G-quadruplex (rG4) structure and recently, its roles in oncology have been the focus of much attention, as it is now known that let-7e pre-miRNA is frequently dysregulated in cancers. Therefore, it is crucial to unveil and fully characterize its ability to adopt a rG4 structure, which could be stabilized or destabilized by small molecules and proteins such as nucleolin, a protein that is deeply associated with miRNA biogenesis. Herein, by combining a set of different methods such as circular dichroism (CD), nuclear magnetic resonance (NMR), UV spectroscopy (thermal difference spectra (TDS) and isothermal difference spectra (IDS)) and polyacrylamide gel electrophoresis (PAGE), we demonstrate the formation of the rG4 structure found in let-7e pre-miRNA sequence in the presence of K+ (5'-GGGCUGAGGUAGGAGG-3'). The ability of eight small molecules (or ligands) to bind to and stabilize this rG4 structure was also fully assessed. The dissociation constants for each RNA G-quadruplex/ligand complex, determined by surface plasmon resonance (SPR), ranged in the 10-6 to 10-9 M range. Lastly, the binding of the rG4 structure to nucleolin in the presence and absence of ligands was evaluated via CD, SPR, PAGE and confocal microscopy. The small molecules 360 A and PDS demonstrated attractive properties to targetthe rG4 structure of let-7e pre-miRNA and control its biology. Our findings also highlighted that the interaction of TMPyP4 with the G-quadruplex of let-7e precursor miRNA could block the formation of the complex between the rG4 and nucleolin. Overall, this study introduces an approach to target the rG4 found in let-7e pre-miRNA which opens up a new opportunity to control the microRNA biogenesis.
Collapse
Affiliation(s)
- Tiago Santos
- CICS-UBI - Centro de Investigação em Ciências da Saúde, Universidade da Beira Interior, Av. Infante D. Henrique, Covilhã 6200-506, Portugal
| | - André Miranda
- CICS-UBI - Centro de Investigação em Ciências da Saúde, Universidade da Beira Interior, Av. Infante D. Henrique, Covilhã 6200-506, Portugal
| | - Lionel Imbert
- Univ. Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale (IBS), Grenoble, France; Univ. Grenoble Alpes, CNRS, CEA, EMBL Integrated Structural Biology Grenoble (ISBG), Grenoble, France
| | - David Monchaud
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB), CNRS UMR 6302, UBFC Dijon, Dijon 21078, France
| | - Gilmar F Salgado
- ARNA Laboratory, Université de Bordeaux, Inserm U1212, CNRS UMR 5320, IECB, Pessac 33607, France
| | - Eurico J Cabrita
- UCIBIO, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica 2829-516, Portugal; Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, Caparica 2819-516, Portugal
| | - Carla Cruz
- CICS-UBI - Centro de Investigação em Ciências da Saúde, Universidade da Beira Interior, Av. Infante D. Henrique, Covilhã 6200-506, Portugal.
| |
Collapse
|
6
|
Seneff S, Nigh G, Kyriakopoulos AM, McCullough PA. Innate immune suppression by SARS-CoV-2 mRNA vaccinations: The role of G-quadruplexes, exosomes, and MicroRNAs. Food Chem Toxicol 2022; 164:113008. [PMID: 35436552 PMCID: PMC9012513 DOI: 10.1016/j.fct.2022.113008] [Citation(s) in RCA: 71] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 04/03/2022] [Accepted: 04/08/2022] [Indexed: 12/12/2022]
Abstract
The mRNA SARS-CoV-2 vaccines were brought to market in response to the public health crises of Covid-19. The utilization of mRNA vaccines in the context of infectious disease has no precedent. The many alterations in the vaccine mRNA hide the mRNA from cellular defenses and promote a longer biological half-life and high production of spike protein. However, the immune response to the vaccine is very different from that to a SARS-CoV-2 infection. In this paper, we present evidence that vaccination induces a profound impairment in type I interferon signaling, which has diverse adverse consequences to human health. Immune cells that have taken up the vaccine nanoparticles release into circulation large numbers of exosomes containing spike protein along with critical microRNAs that induce a signaling response in recipient cells at distant sites. We also identify potential profound disturbances in regulatory control of protein synthesis and cancer surveillance. These disturbances potentially have a causal link to neurodegenerative disease, myocarditis, immune thrombocytopenia, Bell's palsy, liver disease, impaired adaptive immunity, impaired DNA damage response and tumorigenesis. We show evidence from the VAERS database supporting our hypothesis. We believe a comprehensive risk/benefit assessment of the mRNA vaccines questions them as positive contributors to public health.
Collapse
Affiliation(s)
- Stephanie Seneff
- Computer Science and Artificial Intelligence Laboratory, MIT, Cambridge, MA, USA, 02139.
| | - Greg Nigh
- Immersion Health, Portland, OR, 97214, USA.
| | - Anthony M Kyriakopoulos
- Research and Development, Nasco AD Biotechnology Laboratory, Department of Research and Development, Sachtouri 11, 18536, Piraeus, Greece.
| | | |
Collapse
|
7
|
Georgakopoulos-Soares I, Parada GE, Wong HY, Medhi R, Furlan G, Munita R, Miska EA, Kwok CK, Hemberg M. Alternative splicing modulation by G-quadruplexes. Nat Commun 2022; 13:2404. [PMID: 35504902 PMCID: PMC9065059 DOI: 10.1038/s41467-022-30071-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 03/30/2022] [Indexed: 12/14/2022] Open
Abstract
Alternative splicing is central to metazoan gene regulation, but the regulatory mechanisms are incompletely understood. Here, we show that G-quadruplex (G4) motifs are enriched ~3-fold near splice junctions. The importance of G4s in RNA is emphasised by a higher enrichment for the non-template strand. RNA-seq data from mouse and human neurons reveals an enrichment of G4s at exons that were skipped following depolarisation induced by potassium chloride. We validate the formation of stable RNA G4s for three candidate splice sites by circular dichroism spectroscopy, UV-melting and fluorescence measurements. Moreover, we find that sQTLs are enriched at G4s, and a minigene experiment provides further support for their role in promoting exon inclusion. Analysis of >1,800 high-throughput experiments reveals multiple RNA binding proteins associated with G4s. Finally, exploration of G4 motifs across eleven species shows strong enrichment at splice sites in mammals and birds, suggesting an evolutionary conserved splice regulatory mechanism. Here the authors shows that G-quadruplexes, non-canonical DNA/RNA structures, can have a direct impact on alternative splicing and that binding of splicing regulators is affected by their presence.
Collapse
Affiliation(s)
- Ilias Georgakopoulos-Soares
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, CB10 1SA, UK.,Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA, 94158, USA
| | - Guillermo E Parada
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, CB10 1SA, UK.,Wellcome Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN, UK.,Department of Genetics, University of Cambridge, Downing Street, Cambridge, CB2 3EH, UK.,Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, M5A 1A8, Canada
| | - Hei Yuen Wong
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
| | - Ragini Medhi
- Wellcome Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN, UK.,Department of Genetics, University of Cambridge, Downing Street, Cambridge, CB2 3EH, UK
| | - Giulia Furlan
- Wellcome Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN, UK.,Department of Genetics, University of Cambridge, Downing Street, Cambridge, CB2 3EH, UK
| | - Roberto Munita
- Division of Molecular Hematology, Department of Laboratory Medicine, Lund Stem Cell Center, Faculty of Medicine, Lund University, Lund, Sweden
| | - Eric A Miska
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, CB10 1SA, UK.,Wellcome Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN, UK.,Department of Genetics, University of Cambridge, Downing Street, Cambridge, CB2 3EH, UK
| | - Chun Kit Kwok
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China.,Shenzhen Research Institute of City University of Hong Kong, Shenzhen, China
| | - Martin Hemberg
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, CB10 1SA, UK. .,Wellcome Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN, UK. .,Evergrande Center for Immunologic Diseases, Harvard Medical School and Brigham and Women's Hospital, Boston, MA, 02115, USA.
| |
Collapse
|
8
|
Umar MI, Chan CY, Kwok CK. Development of RNA G-quadruplex (rG4)-targeting L-RNA aptamers by rG4-SELEX. Nat Protoc 2022; 17:1385-1414. [PMID: 35444329 DOI: 10.1038/s41596-022-00679-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 12/15/2021] [Indexed: 11/09/2022]
Abstract
RNA G-quadruplex (rG4)-SELEX is a method that generates L-RNA aptamers to target an rG4 structure of interest, which can be applied to inhibit G-quadruplex-mediated interactions that have important roles in gene regulation and function. Here we present a Protocol Extension substantially modifying an existing SELEX protocol to describe in detail the procedures involved in performing rG4-SELEX to identify rG4-specific binders that can effectively suppress rG4-peptide and rG4-protein associations. This Protocol Extension improves the speed of aptamer discovery and identification, offering a suite of techniques to characterize the aptamer secondary structure and monitor binding affinity and specificity, and demonstrating the utility of the L-RNA aptamer. The previous protocol mainly describes the identification of RNA aptamers against proteins of interest, whereas in this Protocol Extension we present the development of an unnatural RNA aptamer against an RNA structure of interest, with the potential to be applicable to other nucleic acid motifs or biomolecules. rG4-SELEX starts with a random D-RNA library incubated with the L-rG4 target of interest, followed by binding, washing and elution of the library. Enriched D-aptamer candidates are sequenced and structurally characterized. Then, the L-aptamer is synthesized and used for different applications. rG4-SELEX can be carried out by an experienced molecular biologist with a basic understanding of nucleic acids. The development of rG4-targeting L-RNA aptamers expands the current rG4 toolkit to explore innovative rG4-related applications, and opens new doors to discovering novel rG4 biology in the near future. The duration of each selection cycle as outlined in the protocol is ~2 d.
Collapse
Affiliation(s)
- Mubarak I Umar
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China.,RNA Molecular Biology Group, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health, Bethesda, MD, USA
| | - Chun-Yin Chan
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China.,Institut für Chemische Epigenetik München (ICEM), Ludwig-Maximilians-Universtität München, Munich, Germany
| | - Chun Kit Kwok
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China. .,Shenzhen Research Institute of City University of Hong Kong, Shenzhen, China.
| |
Collapse
|
9
|
Georgakopoulos-Soares I, Victorino J, Parada GE, Agarwal V, Zhao J, Wong HY, Umar MI, Elor O, Muhwezi A, An JY, Sanders SJ, Kwok CK, Inoue F, Hemberg M, Ahituv N. High-throughput characterization of the role of non-B DNA motifs on promoter function. CELL GENOMICS 2022; 2:100111. [PMID: 35573091 PMCID: PMC9105345 DOI: 10.1016/j.xgen.2022.100111] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 10/21/2021] [Accepted: 02/18/2022] [Indexed: 12/24/2022]
Abstract
lternative DNA conformations, termed non-B DNA structures, can affect transcription, but the underlying mechanisms and their functional impact have not been systematically characterized. Here, we used computational genomic analyses coupled with massively parallel reporter assays (MPRAs) to show that certain non-B DNA structures have a substantial effect on gene expression. Genomic analyses found that non-B DNA structures at promoters harbor an excess of germline variants. Analysis of multiple MPRAs, including a promoter library specifically designed to perturb non-B DNA structures, functionally validated that Z-DNA can significantly affect promoter activity. We also observed that biophysical properties of non-B DNA motifs, such as the length of Z-DNA motifs and the orientation of G-quadruplex structures relative to transcriptional direction, have a significant effect on promoter activity. Combined, their higher mutation rate and functional effect on transcription implicate a subset of non-B DNA motifs as major drivers of human gene-expression-associated phenotypes.
Collapse
Affiliation(s)
- Ilias Georgakopoulos-Soares
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA, USA
- Institute for Human Genetics, University of California San Francisco, San Francisco, CA, USA
| | - Jesus Victorino
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 28029 Madrid, Spain
- Departamento de Bioquímica, Facultad de Medicina, Universidad Autónoma de Madrid (UAM), 28029 Madrid, Spain
| | - Guillermo E. Parada
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton CB10 1SA, UK
- Wellcome Trust Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
| | | | - Jingjing Zhao
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA, USA
- Institute for Human Genetics, University of California San Francisco, San Francisco, CA, USA
| | - Hei Yuen Wong
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
| | - Mubarak Ishaq Umar
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
| | - Orry Elor
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA, USA
| | - Allan Muhwezi
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton CB10 1SA, UK
| | - Joon-Yong An
- Department of Psychiatry, UCSF Weill Institute for Neurosciences, University of California San Francisco, San Francisco, CA, USA
- School of Biosystem and Biomedical Science, College of Health Science, Korea University, Seoul, Republic of Korea
| | - Stephan J. Sanders
- Institute for Human Genetics, University of California San Francisco, San Francisco, CA, USA
- Department of Psychiatry, UCSF Weill Institute for Neurosciences, University of California San Francisco, San Francisco, CA, USA
| | - Chun Kit Kwok
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
- Shenzhen Research Institute of City University of Hong Kong, Shenzhen, China
| | - Fumitaka Inoue
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA, USA
- Institute for Human Genetics, University of California San Francisco, San Francisco, CA, USA
| | - Martin Hemberg
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton CB10 1SA, UK
- Wellcome Trust Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
| | - Nadav Ahituv
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA, USA
- Institute for Human Genetics, University of California San Francisco, San Francisco, CA, USA
| |
Collapse
|
10
|
Vannutelli A, Perreault JP, Ouangraoua A. G-quadruplex occurrence and conservation: more than just a question of guanine–cytosine content. NAR Genom Bioinform 2022; 4:lqac010. [PMID: 35261973 PMCID: PMC8896161 DOI: 10.1093/nargab/lqac010] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 12/06/2021] [Accepted: 02/25/2022] [Indexed: 12/14/2022] Open
Abstract
G-quadruplexes are motifs found in DNA and RNA that can fold into tertiary structures. Until now, they have been studied experimentally mainly in humans and a few other species. Recently, predictions have been made with bacterial and archaeal genomes. Nevertheless, a global comparison of predicted G4s (pG4s) across and within the three living kingdoms has not been addressed. In this study, we aimed to predict G4s in genes and transcripts of all kingdoms of living organisms and investigated the differences in their distributions. The relation of the predictions with GC content was studied. It appears that GC content is not the only parameter impacting G4 predictions and abundance. The distribution of pG4 densities varies depending on the class of transcripts and the group of species. Indeed, we have observed that, in coding transcripts, there are more predicted G4s than expected for eukaryotes but not for archaea and bacteria, while in noncoding transcripts, there are as many or fewer predicted G4s in all species groups. We even noticed that some species with the same GC content presented different pG4 profiles. For instance, Leishmania major and Chlamydomonas reinhardtii both have 60% of GC content, but the former has a pG4 density of 0.07 and the latter 1.16.
Collapse
Affiliation(s)
- Anaïs Vannutelli
- Department of Computer Science, Faculté des sciences, Université de Sherbrooke, QC, J1K 2R1, Canada
- Department of Biochemistry and Functional Genomics, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, QC J1E 4K8, Canada
| | - Jean-Pierre Perreault
- Department of Computer Science, Faculté des sciences, Université de Sherbrooke, QC, J1K 2R1, Canada
| | - Aïda Ouangraoua
- Department of Computer Science, Faculté des sciences, Université de Sherbrooke, QC, J1K 2R1, Canada
| |
Collapse
|
11
|
Mou X, Liew SW, Kwok CK. Identification and targeting of G-quadruplex structures in MALAT1 long non-coding RNA. Nucleic Acids Res 2022; 50:397-410. [PMID: 34904666 PMCID: PMC8754639 DOI: 10.1093/nar/gkab1208] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 10/07/2021] [Accepted: 11/24/2021] [Indexed: 12/11/2022] Open
Abstract
RNA G-quadruplexes (rG4s) have functional roles in many cellular processes in diverse organisms. While a number of rG4 examples have been reported in coding messenger RNAs (mRNA), so far only limited works have studied rG4s in non-coding RNAs (ncRNAs), especially in long non-coding RNAs (lncRNAs) that are of emerging interest and significance in biology. Herein, we report that MALAT1 lncRNA contains conserved rG4 motifs, forming thermostable rG4 structures with parallel topology. We also show that rG4s in MALAT1 lncRNA can interact with NONO protein with high specificity and affinity in vitro and in nuclear cell lysate, and we provide cellular data to support that NONO protein recognizes MALAT1 lncRNA via rG4 motifs. Notably, we demonstrate that rG4s in MALAT1 lncRNA can be targeted by the rG4-specific small molecule, peptide, and L-aptamer, leading to the dissociation of MALAT1 rG4-NONO protein interaction. Altogether, this study uncovers new and important rG4s in MALAT1 lncRNAs, reveals their specific interactions with NONO protein, offers multiple strategies for targeting MALAT1 and its RNA-protein complex via its rG4 structure and illustrates the prevalence and significance of rG4s in ncRNAs.
Collapse
Affiliation(s)
- Xi Mou
- Department of Chemistry and State Key Laboratory of Marine Pollution, City
University of Hong Kong, Kowloon Tong, Hong Kong
SAR, China
| | - Shiau Wei Liew
- Department of Chemistry and State Key Laboratory of Marine Pollution, City
University of Hong Kong, Kowloon Tong, Hong Kong
SAR, China
| | - Chun Kit Kwok
- Department of Chemistry and State Key Laboratory of Marine Pollution, City
University of Hong Kong, Kowloon Tong, Hong Kong
SAR, China
- Shenzhen Research Institute of City University of Hong Kong,
Shenzhen, China
| |
Collapse
|
12
|
Dumetz F, Chow EYC, Harris LM, Liew SW, Jensen A, Umar MI, Chung B, Chan TF, Merrick CJ, Kwok CK. G-quadruplex RNA motifs influence gene expression in the malaria parasite Plasmodium falciparum. Nucleic Acids Res 2021; 49:12486-12501. [PMID: 34792144 PMCID: PMC8643661 DOI: 10.1093/nar/gkab1095] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 10/15/2021] [Accepted: 10/21/2021] [Indexed: 11/12/2022] Open
Abstract
G-quadruplexes are non-helical secondary structures that can fold in vivo in both DNA and RNA. In human cells, they can influence replication, transcription and telomere maintenance in DNA, or translation, transcript processing and stability of RNA. We have previously showed that G-quadruplexes are detectable in the DNA of the malaria parasite Plasmodium falciparum, despite a very highly A/T-biased genome with unusually few guanine-rich sequences. Here, we show that RNA G-quadruplexes can also form in P. falciparum RNA, using rG4-seq for transcriptome-wide structure-specific RNA probing. Many of the motifs, detected here via the rG4seeker pipeline, have non-canonical forms and would not be predicted by standard in silico algorithms. However, in vitro biophysical assays verified formation of non-canonical motifs. The G-quadruplexes in the P. falciparum transcriptome are frequently clustered in certain genes and associated with regions encoding low-complexity peptide repeats. They are overrepresented in particular classes of genes, notably those that encode PfEMP1 virulence factors, stress response genes and DNA binding proteins. In vitro translation experiments and in vivo measures of translation efficiency showed that G-quadruplexes can influence the translation of P. falciparum mRNAs. Thus, the G-quadruplex is a novel player in post-transcriptional regulation of gene expression in this major human pathogen.
Collapse
Affiliation(s)
- Franck Dumetz
- Department of Pathology, Cambridge University, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Eugene Yui-Ching Chow
- School of Life Sciences and State Key Laboratory of Agrobiotechnology, Chinese University of Hong Kong, Shatin, NT, Hong Kong
| | - Lynne M Harris
- Centre for Applied Entomology and Parasitology, Faculty of Natural Sciences, Keele University, Keele, Staffordshire, ST5 5BG, UK
| | - Shiau Wei Liew
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
| | - Anders Jensen
- Department of Pathology, Cambridge University, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Mubarak I Umar
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
| | - Betty Chung
- Department of Pathology, Cambridge University, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Ting Fung Chan
- School of Life Sciences and State Key Laboratory of Agrobiotechnology, Chinese University of Hong Kong, Shatin, NT, Hong Kong
| | - Catherine J Merrick
- Department of Pathology, Cambridge University, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Chun Kit Kwok
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China.,Shenzhen Research Institute of City University of Hong Kong, Shenzhen, China
| |
Collapse
|
13
|
Figueiredo J, Santos T, Miranda A, Alexandre D, Teixeira B, Simões P, Lopes-Nunes J, Cruz C. Ligands as Stabilizers of G-Quadruplexes in Non-Coding RNAs. Molecules 2021; 26:6164. [PMID: 34684745 PMCID: PMC8540333 DOI: 10.3390/molecules26206164] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 10/03/2021] [Accepted: 10/06/2021] [Indexed: 11/16/2022] Open
Abstract
The non-coding RNAs (ncRNA) are RNA transcripts with different sizes, structures and biological functions that do not encode functional proteins. RNA G-quadruplexes (rG4s) have been found in small and long ncRNAs. The existence of an equilibrium between rG4 and stem-loop structures in ncRNAs and its effect on biological processes remains unexplored. For example, deviation from the stem-loop leads to deregulated mature miRNA levels, demonstrating that miRNA biogenesis can be modulated by ions or small molecules. In light of this, we report several examples of rG4s in certain types of ncRNAs, and the implications of G4 stabilization using small molecules, also known as G4 ligands, in the regulation of gene expression, miRNA biogenesis, and miRNA-mRNA interactions. Until now, different G4 ligands scaffolds were synthesized for these targets. The regulatory role of the above-mentioned rG4s in ncRNAs can be used as novel therapeutic approaches for adjusting miRNA levels.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - Carla Cruz
- CICS-UBI—Centro de Investigação em Ciências da Saúde, Universidade da Beira Interior, Av. Infante D. Hen-rique, 6200-506 Covilhã, Portugal; (J.F.); (T.S.); (A.M.); (D.A.); (B.T.); (P.S.); (J.L.-N.)
| |
Collapse
|
14
|
Translational control by DHX36 binding to 5'UTR G-quadruplex is essential for muscle stem-cell regenerative functions. Nat Commun 2021; 12:5043. [PMID: 34413292 PMCID: PMC8377060 DOI: 10.1038/s41467-021-25170-w] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 06/06/2021] [Indexed: 12/30/2022] Open
Abstract
Skeletal muscle has a remarkable ability to regenerate owing to its resident stem cells (also called satellite cells, SCs). SCs are normally quiescent; when stimulated by damage, they activate and expand to form new fibers. The mechanisms underlying SC proliferative progression remain poorly understood. Here we show that DHX36, a helicase that unwinds RNA G-quadruplex (rG4) structures, is essential for muscle regeneration by regulating SC expansion. DHX36 (initially named RHAU) is barely expressed at quiescence but is highly induced during SC activation and proliferation. Inducible deletion of Dhx36 in adult SCs causes defective proliferation and muscle regeneration after damage. System-wide mapping in proliferating SCs reveals DHX36 binding predominantly to rG4 structures at various regions of mRNAs, while integrated polysome profiling shows that DHX36 promotes mRNA translation via 5′-untranslated region (UTR) rG4 binding. Furthermore, we demonstrate that DHX36 specifically regulates the translation of Gnai2 mRNA by unwinding its 5′ UTR rG4 structures and identify GNAI2 as a downstream effector of DHX36 for SC expansion. Altogether, our findings uncover DHX36 as an indispensable post-transcriptional regulator of SC function and muscle regeneration acting through binding and unwinding rG4 structures at 5′ UTR of target mRNAs. Skeletal muscle stem cells (or satellite cells, SCs) are normally quiescent but activate and expand in response to injury. Here the authors show that induction of DHX36 helicase during SC activation promotes mRNA translation by binding to 5′UTR mRNA G-quadruplexes (rG4) in targets including Gnai2 and unwinding them.
Collapse
|
15
|
Lyu K, Chow EYC, Mou X, Chan TF, Kwok CK. RNA G-quadruplexes (rG4s): genomics and biological functions. Nucleic Acids Res 2021; 49:5426-5450. [PMID: 33772593 PMCID: PMC8191793 DOI: 10.1093/nar/gkab187] [Citation(s) in RCA: 79] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 03/02/2021] [Accepted: 03/24/2021] [Indexed: 02/07/2023] Open
Abstract
G-quadruplexes (G4s) are non-classical DNA or RNA secondary structures that have been first observed decades ago. Over the years, these four-stranded structural motifs have been demonstrated to have significant regulatory roles in diverse biological processes, but challenges remain in detecting them globally and reliably. Compared to DNA G4s (dG4s), the study of RNA G4s (rG4s) has received less attention until recently. In this review, we will summarize the innovative high-throughput methods recently developed to detect rG4s on a transcriptome-wide scale, highlight the many novel and important functions of rG4 being discovered in vivo across the tree of life, and discuss the key biological questions to be addressed in the near future.
Collapse
Affiliation(s)
- Kaixin Lyu
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
| | - Eugene Yui-Ching Chow
- School of Life Sciences, and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
| | - Xi Mou
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
| | - Ting-Fung Chan
- School of Life Sciences, and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
| | - Chun Kit Kwok
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China.,Shenzhen Research Institute of City University of Hong Kong, Shenzhen, China
| |
Collapse
|
16
|
Cave JW, Willis DE. G-quadruplex regulation of neural gene expression. FEBS J 2021; 289:3284-3303. [PMID: 33905176 DOI: 10.1111/febs.15900] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 03/24/2021] [Accepted: 04/23/2021] [Indexed: 12/11/2022]
Abstract
G-quadruplexes are four-stranded helical nucleic acid structures characterized by stacked tetrads of guanosine bases. These structures are widespread throughout mammalian genomic DNA and RNA transcriptomes, and prevalent across all tissues. The role of G-quadruplexes in cancer is well-established, but there has been a growing exploration of these structures in the development and homeostasis of normal tissue. In this review, we focus on the roles of G-quadruplexes in directing gene expression in the nervous system, including the regulation of gene transcription, mRNA processing, and trafficking, as well as protein translation. The role of G-quadruplexes and their molecular interactions in the pathology of neurological diseases is also examined. Outside of cancer, there has been only limited exploration of G-quadruplexes as potential intervention targets to treat disease or injury. We discuss studies that have used small-molecule ligands to manipulate G-quadruplex stability in order to treat disease or direct neural stem/progenitor cell proliferation and differentiation into therapeutically relevant cell types. Understanding the many roles that G-quadruplexes have in the nervous system not only provides critical insight into fundamental molecular mechanisms that control neurological function, but also provides opportunities to identify novel therapeutic targets to treat injury and disease.
Collapse
Affiliation(s)
- John W Cave
- InVitro Cell Research LLC, Englewood, NJ, USA
| | - Dianna E Willis
- Burke Neurological Institute, White Plains, NY, USA.,Feil Family Brain & Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| |
Collapse
|
17
|
Tassinari M, Richter SN, Gandellini P. Biological relevance and therapeutic potential of G-quadruplex structures in the human noncoding transcriptome. Nucleic Acids Res 2021; 49:3617-3633. [PMID: 33721024 PMCID: PMC8053107 DOI: 10.1093/nar/gkab127] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 02/10/2021] [Accepted: 02/15/2021] [Indexed: 12/11/2022] Open
Abstract
Noncoding RNAs are functional transcripts that are not translated into proteins. They represent the largest portion of the human transcriptome and have been shown to regulate gene expression networks in both physiological and pathological cell conditions. Research in this field has made remarkable progress in the comprehension of how aberrations in noncoding RNA drive relevant disease-associated phenotypes; however, the biological role and mechanism of action of several noncoding RNAs still need full understanding. Besides fulfilling its function through sequence-based mechanisms, RNA can form complex secondary and tertiary structures which allow non-canonical interactions with proteins and/or other nucleic acids. In this context, the presence of G-quadruplexes in microRNAs and long noncoding RNAs is increasingly being reported. This evidence suggests a role for RNA G-quadruplexes in controlling microRNA biogenesis and mediating noncoding RNA interaction with biological partners, thus ultimately regulating gene expression. Here, we review the state of the art of G-quadruplexes in the noncoding transcriptome, with their structural and functional characterization. In light of the existence and further possible development of G-quadruplex binders that modulate G-quadruplex conformation and protein interactions, we also discuss the therapeutic potential of G-quadruplexes as targets to interfere with disease-associated noncoding RNAs.
Collapse
Affiliation(s)
- Martina Tassinari
- Department of Biosciences, University of Milan, via G. Celoria 26, 20133 Milano, Italy
| | - Sara N Richter
- Department of Molecular Medicine, University of Padua, via A. Gabelli 63, 35121 Padova, Italy
| | - Paolo Gandellini
- Department of Biosciences, University of Milan, via G. Celoria 26, 20133 Milano, Italy
| |
Collapse
|
18
|
RNA and DNA G-quadruplexes bind to human dicer and inhibit its activity. Cell Mol Life Sci 2021; 78:3709-3724. [PMID: 33733306 PMCID: PMC8038994 DOI: 10.1007/s00018-021-03795-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 01/27/2021] [Accepted: 02/19/2021] [Indexed: 01/17/2023]
Abstract
Guanine (G)-rich single-stranded nucleic acids can adopt G-quadruplex structures. Accumulating evidence indicates that G-quadruplexes serve important regulatory roles in fundamental biological processes such as DNA replication, transcription, and translation, while aberrant G-quadruplex formation is linked to genome instability and cancer. Understanding the biological functions played by G-quadruplexes requires detailed knowledge of their protein interactome. Here, we report that both RNA and DNA G-quadruplexes are bound by human Dicer in vitro. Using in vitro binding assays, mutation studies, and computational modeling we demonstrate that G-quadruplexes can interact with the Platform-PAZ-Connector helix cassette of Dicer, the region responsible for anchoring microRNA precursors (pre-miRNAs). Consequently, we show that G-quadruplexes efficiently and stably inhibit the cleavage of pre-miRNA by Dicer. Our data highlight the potential of human Dicer for binding of G-quadruplexes and allow us to propose a G-quadruplex-driven sequestration mechanism of Dicer regulation.
Collapse
|
19
|
Dumas L, Herviou P, Dassi E, Cammas A, Millevoi S. G-Quadruplexes in RNA Biology: Recent Advances and Future Directions. Trends Biochem Sci 2020; 46:270-283. [PMID: 33303320 DOI: 10.1016/j.tibs.2020.11.001] [Citation(s) in RCA: 87] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 10/30/2020] [Accepted: 11/02/2020] [Indexed: 12/12/2022]
Abstract
RNA G-quadruplexes (RG4s) are four-stranded structures known to control gene expression mechanisms, from transcription to protein synthesis, and DNA-related processes. Their potential impact on RNA biology allows these structures to shape cellular processes relevant to disease development, making their targeting for therapeutic purposes an attractive option. We review here the current knowledge on RG4s, focusing on the latest breakthroughs supporting the notion of transient structures that fluctuate dynamically in cellulo, their interplay with RNA modifications, their role in cell compartmentalization, and their deregulation impacting the host immune response. We emphasize RG4-binding proteins as determinants of their transient conformation and effectors of their biological functions.
Collapse
Affiliation(s)
- Leïla Dumas
- Cancer Research Centre of Toulouse, INSERM UMR 1037, 31037 Toulouse, France; Université Toulouse III - Paul Sabatier, 31330 Toulouse, France
| | - Pauline Herviou
- Cancer Research Centre of Toulouse, INSERM UMR 1037, 31037 Toulouse, France; Université Toulouse III - Paul Sabatier, 31330 Toulouse, France
| | - Erik Dassi
- Laboratory of RNA Regulatory Networks, Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, 38123 Trento, (TN), Italy
| | - Anne Cammas
- Cancer Research Centre of Toulouse, INSERM UMR 1037, 31037 Toulouse, France; Université Toulouse III - Paul Sabatier, 31330 Toulouse, France
| | - Stefania Millevoi
- Cancer Research Centre of Toulouse, INSERM UMR 1037, 31037 Toulouse, France; Université Toulouse III - Paul Sabatier, 31330 Toulouse, France.
| |
Collapse
|
20
|
Umar MI, Kwok CK. Specific suppression of D-RNA G-quadruplex-protein interaction with an L-RNA aptamer. Nucleic Acids Res 2020; 48:10125-10141. [PMID: 32976590 PMCID: PMC7544233 DOI: 10.1093/nar/gkaa759] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 08/28/2020] [Accepted: 09/04/2020] [Indexed: 02/06/2023] Open
Abstract
G-quadruplexes (G4s) are nucleic acid structure motifs that are of significance in chemistry and biology. The function of G4s is often governed by their interaction with G4-binding proteins. Few categories of G4-specific tools have been developed to inhibit G4-protein interactions; however, until now there is no aptamer tool being developed to do so. Herein, we present a novel L-RNA aptamer that can generally bind to D-RNA G-quadruplex (rG4) structure, and interfere with rG4-protein interaction. Using hTERC rG4 as the target for in vitro selection, we report the shortest L-aptamer being developed so far, with only 25 nucleotides. Notably, this new aptamer, L-Apt.4-1c, adopts a stem-loop structure with the loop folding into an rG4 motif with two G-quartet, demonstrates preferential binding toward rG4s over non-G4s and DNA G-quadruplexes (dG4s), and suppresses hTERC rG4-nucleolin interactions. We also show that inhibition of rG4-protein interaction using L-RNA aptamer L-Apt.4-1c is comparable to or better than G4-specific ligands such as carboxypyridostatin and QUMA-1 respectively, highlighting that our approach and findings expand the current G4 toolbox, and open a new avenue for diverse applications.
Collapse
Affiliation(s)
- Mubarak I Umar
- Department of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong SAR, China
| | - Chun Kit Kwok
- Department of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong SAR, China
- Shenzhen Research Institute of City University of Hong Kong, Shenzhen, China
| |
Collapse
|
21
|
Miskiewicz J, Sarzynska J, Szachniuk M. How bioinformatics resources work with G4 RNAs. Brief Bioinform 2020; 22:5902714. [PMID: 32898859 PMCID: PMC8138894 DOI: 10.1093/bib/bbaa201] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 08/03/2020] [Accepted: 08/04/2020] [Indexed: 12/17/2022] Open
Abstract
Quadruplexes (G4s) are of interest, which increases with the number of identified G4 structures and knowledge about their biomedical potential. These unique motifs form in many organisms, including humans, where their appearance correlates with various diseases. Scientists store and analyze quadruplexes using recently developed bioinformatic tools—many of them focused on DNA structures. With an expanding collection of G4 RNAs, we check how existing tools deal with them. We review all available bioinformatics resources dedicated to quadruplexes and examine their usefulness in G4 RNA analysis. We distinguish the following subsets of resources: databases, tools to predict putative quadruplex sequences, tools to predict secondary structure with quadruplexes and tools to analyze and visualize quadruplex structures. We share the results obtained from processing specially created RNA datasets with these tools. Contact: mszachniuk@cs.put.poznan.pl Supplementary information: Supplementary data are available at Briefings in Bioinformatics online.
Collapse
Affiliation(s)
- Joanna Miskiewicz
- Institute of Computing Science and European Centre for Bioinformatics and Genomics, Poznan University of Technology, Piotrowo 2, 60-965 Poznan, Poland
| | - Joanna Sarzynska
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Marta Szachniuk
- Institute of Computing Science and European Centre for Bioinformatics and Genomics, Poznan University of Technology, Piotrowo 2, 60-965 Poznan, Poland
| |
Collapse
|
22
|
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.
Collapse
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.
| |
Collapse
|
23
|
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.
Collapse
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
| |
Collapse
|
24
|
Islam B, Stadlbauer P, Vorlíčková M, Mergny JL, Otyepka M, Šponer J. Stability of Two-Quartet G-Quadruplexes and Their Dimers in Atomistic Simulations. J Chem Theory Comput 2020; 16:3447-3463. [PMID: 32163706 DOI: 10.1021/acs.jctc.9b01068] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
G-quadruplexes (GQs) are four-stranded noncanonical DNA and RNA architectures that can be formed by guanine-rich sequences. The stability of GQs increases with the number of G-quartets, and three G-quartets generally form stable GQs. However, the stability of two-quartet GQs is an open issue. To understand the intrinsic stability of two-quartet GQ stems, we have carried out a series of unbiased molecular dynamics (MD) simulations (505 μs in total) of two- and four-quartet DNA and RNA GQs, with attention paid mainly to parallel-stranded arrangements. We used AMBER DNA parmOL15 and RNA parmOL3 force fields and tested different ion and water models. Two-quartet parallel-stranded DNA GQs unfolded in all the simulations, while the equivalent RNA GQ was stable in most of the simulations. GQs composed of two stacked units of two-quartet GQs were stable for both DNA and RNA. The simulations suggest that a minimum of three quartets are needed to form an intrinsically stable all-anti parallel-stranded DNA GQ. Parallel two-quartet DNA GQ may exist if substantially stabilized by another molecule or structural element, including multimerization. On the other hand, we predict that isolated RNA two-quartet parallel GQs may form, albeit being weakly stable. We also show that ionic parameters and water models should be chosen with caution because some parameter combinations can cause spurious instability of GQ stems. Some in-so-far unnoticed limitations of force-field description of multiple ions inside the GQs are discussed, which compromise the capability of simulations to fully capture the effect of increase in the number of quartets on the GQ stability.
Collapse
Affiliation(s)
- Barira Islam
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
| | - Petr Stadlbauer
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic.,Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacký University, tř. 17 listopadu 12, 771 46 Olomouc, Czech Republic
| | - Michaela Vorlíčková
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
| | - Jean-Louis Mergny
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
| | - Michal Otyepka
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic.,Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacký University, tř. 17 listopadu 12, 771 46 Olomouc, Czech Republic.,Department of Physical Chemistry, Faculty of Science, Palacký University, tř. 17 listopadu 12, 771 46 Olomouc, Czech Republic
| | - Jiří Šponer
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic
| |
Collapse
|
25
|
Self‐Assembly of DNA and RNA Building Blocks Explored by Nitrogen‐14 NMR Crystallography: Structure and Dynamics. Chemphyschem 2020; 21:1044-1051. [DOI: 10.1002/cphc.201901214] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 03/18/2020] [Indexed: 12/20/2022]
|
26
|
Chan C, Kwok CK. Specific Binding of a
d
‐RNA G‐Quadruplex Structure with an
l
‐RNA Aptamer. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201914955] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Chun‐Yin Chan
- Department of ChemistryCity University of Hong Kong Tat Chee Avenue Kowloon Tong, Hong Kong SAR China
| | - Chun Kit Kwok
- Department of ChemistryCity University of Hong Kong Tat Chee Avenue Kowloon Tong, Hong Kong SAR China
| |
Collapse
|
27
|
Chan CY, Kwok CK. Specific Binding of a d-RNA G-Quadruplex Structure with an l-RNA Aptamer. Angew Chem Int Ed Engl 2020; 59:5293-5297. [PMID: 31975549 DOI: 10.1002/anie.201914955] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Revised: 01/06/2020] [Indexed: 01/24/2023]
Abstract
G-quadruplex (G4) structures are of general importance in chemistry and biology, such as in biosensing, gene regulation, and cancers. Although a large repertoire of G4-binding tools has been developed, no aptamer has been developed to interact with G4. Moreover, the G4 selectivity of current toolkits is very limited. Herein, we report the first l-RNA aptamer that targets a d-RNA G-quadruplex (rG4). Using TERRA rG4 as an example, our results reveal that this l-RNA aptamer, Ap3-7, folds into a unique secondary structure, exhibits high G4 selectivity and effectively interferes with TERRA-rG4-RHAU53 binding. Our approach and findings open a new door in further developing G4-specific tools for diverse applications.
Collapse
Affiliation(s)
- Chun-Yin Chan
- Department of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong SAR, China
| | - Chun Kit Kwok
- Department of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong SAR, China
| |
Collapse
|
28
|
Abstract
Guanine (G)-rich sequences in RNA can fold into diverse RNA G-quadruplex (rG4) structures to mediate various biological functions and cellular processes in eukaryotic organisms. However, the presence, locations, and functions of rG4s in prokaryotes are still elusive. We used QUMA-1, an rG4-specific fluorescent probe, to detect rG4 structures in a wide range of bacterial species both in vitro and in live cells and found rG4 to be an abundant RNA secondary structure across those species. Subsequently, to identify bacterial rG4 sites in the transcriptome, the model Escherichia coli strain and a major human pathogen, Pseudomonas aeruginosa, were subjected to recently developed high-throughput rG4 structure sequencing (rG4-seq). In total, 168 and 161 in vitro rG4 sites were found in E. coli and P. aeruginosa, respectively. Genes carrying these rG4 sites were found to be involved in virulence, gene regulation, cell envelope synthesis, and metabolism. More importantly, biophysical assays revealed the formation of a group of rG4 sites in mRNAs (such as hemL and bswR), and they were functionally validated in cells by genetic (point mutation and lux reporter assays) and phenotypic experiments, providing substantial evidence for the formation and function of rG4s in bacteria. Overall, our study uncovers important regulatory functions of rG4s in bacterial pathogenicity and metabolic pathways and strongly suggests that rG4s exist and can be detected in a wide range of bacterial species.IMPORTANCE G-quadruplex in RNA (rG4) mediates various biological functions and cellular processes in eukaryotic organisms. However, the presence, locations, and functions of rG4 are still elusive in prokaryotes. Here, we found that rG4 is an abundant RNA secondary structure across a wide range of bacterial species. Subsequently, the transcriptome-wide rG4 structure sequencing (rG4-seq) revealed that the model E. coli strain and a major human pathogen, P. aeruginosa, have 168 and 161 in vitro rG4 sites, respectively, involved in virulence, gene regulation, cell envelope, and metabolism. We further verified the regulatory functions of two rG4 sites in bacteria (hemL and bswR). Overall, this finding strongly suggests that rG4s play key regulatory roles in a wide range of bacterial species.
Collapse
|
29
|
Lyu K, Chen SB, Chan CY, Tan JH, Kwok CK. Structural analysis and cellular visualization of APP RNA G-quadruplex. Chem Sci 2019; 10:11095-11102. [PMID: 32206258 PMCID: PMC7069244 DOI: 10.1039/c9sc02768h] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 10/21/2019] [Indexed: 12/15/2022] Open
Abstract
RNA G-quadruplexes (rG4s) are emerging structural motifs that are of pivotal importance in chemistry and biology; however, the current structural information of rG4s is limited, with their folding status and functions in cells remaining elusive. Here, we develop and employ a multi-disciplinary approach to characterize the structure, formation and function of an individual rG4 of interest in vitro and in cells. We apply this strategy to a biologically important rG4 in amyloid precursor protein (APP) transcript and reveal distinct structural features of APP rG4. Notably, we visualize the formation of APP rG4 in cells using an APP-specific G-quadruplex-triggered fluorogenic hybridization (GTFH) probe and report that the regulatory role of APP rG4 in translation is dependent on rG4 thermostability, providing evidence to the existence and significance of the stable rG4 structure in gene regulation.
Collapse
Affiliation(s)
- Kaixin Lyu
- Department of Chemistry , City University of Hong Kong , Kowloon Tong , Hong Kong SAR , China .
| | - Shuo-Bin Chen
- School of Pharmaceutical Sciences , Guangdong Provincial Key Laboratory of New Drug Design and Evaluation , Sun Yat-sen University , Guangzhou , 510006 China .
| | - Chun-Yin Chan
- Department of Chemistry , City University of Hong Kong , Kowloon Tong , Hong Kong SAR , China .
| | - Jia-Heng Tan
- School of Pharmaceutical Sciences , Guangdong Provincial Key Laboratory of New Drug Design and Evaluation , Sun Yat-sen University , Guangzhou , 510006 China .
| | - Chun Kit Kwok
- Department of Chemistry , City University of Hong Kong , Kowloon Tong , Hong Kong SAR , China .
| |
Collapse
|
30
|
Mitra J, Ha T. Nanomechanics and co-transcriptional folding of Spinach and Mango. Nat Commun 2019; 10:4318. [PMID: 31541108 PMCID: PMC6754394 DOI: 10.1038/s41467-019-12299-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 09/03/2019] [Indexed: 11/24/2022] Open
Abstract
Recent advances in fluorogen-binding “light-up” RNA aptamers have enabled protein-free detection of RNA in cells. Detailed biophysical characterization of folding of G-Quadruplex (GQ)-based light-up aptamers such as Spinach, Mango and Corn is still lacking despite the potential implications on their folding and function. In this work we employ single-molecule fluorescence-force spectroscopy to examine mechanical responses of Spinach2, iMangoIII and MangoIV. Spinach2 unfolds in four discrete steps as force is increased to 7 pN and refolds in reciprocal steps upon force relaxation. In contrast, GQ-core unfolding in iMangoIII and MangoIV occurs in one discrete step at forces >10 pN and refolding occurred at lower forces showing hysteresis. Co-transcriptional folding using superhelicases shows reduced misfolding propensity and allowed a folding pathway different from refolding. Under physiologically relevant pico-Newton levels of force, these aptamers may unfold in vivo and subsequently misfold. Understanding of the dynamics of RNA aptamers will aid engineering of improved fluorogenic modules for cellular applications. Light-up aptamers are widely used for fluorescence visualization of non-coding RNA in vivo. Here the authors employ single-molecule fluorescence-force spectroscopy to characterize the mechanical responses of the G-Quadruplex based light-up aptamers Spinach2, iMangoIII and MangoIV, which is of interest for the development of improved fluorogenic modules for imaging applications.
Collapse
Affiliation(s)
- Jaba Mitra
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.,Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Taekjip Ha
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, MD, 21205, USA. .,Department of Biophysics, Johns Hopkins University, Baltimore, MD, 21218, USA. .,Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA. .,Howard Hughes Medical Institute, Baltimore, MD, 21218, USA.
| |
Collapse
|
31
|
Enumeration of deregulated miRNAs in liquid and tissue biopsies of cervical cancer. Gynecol Oncol 2019; 155:135-143. [PMID: 31434614 DOI: 10.1016/j.ygyno.2019.08.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 07/18/2019] [Accepted: 08/11/2019] [Indexed: 12/18/2022]
Abstract
OBJECTIVE The altered miRNAs expression in cervical cancer tissue can be a critical player during tumorigenesis, may contribute to tumor cell heterogeneity and may determine distinct phenotypes within the tumor. Recent studies have highlighted the role of circulating miRNAs as a minimally-invasive biomarker and its potential as biosignature to complement routine tissue-based procedures. METHODS In order to determine whether miRNAs in serum can indicate changes in cervical tissue specimens, we performed small RNA sequencing and selected miRNAs were validated using qRT-PCR in serum and tissue specimens (n = 115). Further, luciferase assay were performed to investigate the interactions between hsa-miR-409-3p and hsa-miR-454-3p binding sites on 3'UTR region of MTF2 and ST18 respectively. RESULTS We have identified a total of 14 differentially expressed miRNAs common in serum and tissue specimens. Among them, hsa-miR-17-5p, hsa-miR-32-5p and hsa-miR-454-3p were upregulated while, hsa-miR-409-3p was downregulated in serum and tissue of cervical cancer subjects. Our in-silico small RNA sequencing data analysis identified isomiRs and classified miRNA into clusters and subtypes (exonic, intronic and intergenic) with respect to the expression status in serum and tissue specimens. Expression level of hsa-miR-409-3p and hsa-miR-454-3p were inversely correlated with their target genes MTF2 and ST18 levels respectively in human cervical cancer specimens. Luciferase assay demonstrated that hsa-miR-409-3p and hsa-miR-454-3p functionally interacts with 3'-UTR of MTF2 and ST18 respectively to decrease their activity. CONCLUSION Our results support the significant role of circulating miRNAs in disease dissemination and their potential utility as biosignatures of clinical relevance.
Collapse
|
32
|
Lightfoot HL, Hagen T, Tatum NJ, Hall J. The diverse structural landscape of quadruplexes. FEBS Lett 2019; 593:2083-2102. [PMID: 31325371 DOI: 10.1002/1873-3468.13547] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Revised: 07/09/2019] [Accepted: 07/15/2019] [Indexed: 12/15/2022]
Abstract
G-quadruplexes are secondary structures formed in G-rich sequences in DNA and RNA. Considerable research over the past three decades has led to in-depth insight into these unusual structures in DNA. Since the more recent exploration into RNA G-quadruplexes, such structures have demonstrated their in cellulo existence, function and roles in pathology. In comparison to Watson-Crick-based secondary structures, most G-quadruplexes display highly redundant structural characteristics. However, numerous reports of G-quadruplex motifs/structures with unique features (e.g. bulges, long loops, vacancy) have recently surfaced, expanding the repertoire of G-quadruplex scaffolds. This review addresses G-quadruplex formation and structure, including recent reports of non-canonical G-quadruplex structures. Improved methods of detection will likely further expand this collection of novel structures and ultimately change the face of quadruplex-RNA targeting as a therapeutic strategy.
Collapse
Affiliation(s)
- Helen L Lightfoot
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, ETH Zurich, Switzerland
| | - Timo Hagen
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, ETH Zurich, Switzerland
| | - Natalie J Tatum
- Newcastle Cancer Centre, Northern Institute for Cancer Research, Medical School, Newcastle University, Newcastle upon Tyne, UK
| | - Jonathan Hall
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, ETH Zurich, Switzerland
| |
Collapse
|
33
|
Umar MI, Ji D, Chan CY, Kwok CK. G-Quadruplex-Based Fluorescent Turn-On Ligands and Aptamers: From Development to Applications. Molecules 2019; 24:E2416. [PMID: 31262059 PMCID: PMC6650947 DOI: 10.3390/molecules24132416] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Revised: 06/17/2019] [Accepted: 06/24/2019] [Indexed: 02/08/2023] Open
Abstract
Guanine (G)-quadruplexes (G4s) are unique nucleic acid structures that are formed by stacked G-tetrads in G-rich DNA or RNA sequences. G4s have been reported to play significant roles in various cellular events in both macro- and micro-organisms. The identification and characterization of G4s can help to understand their different biological roles and potential applications in diagnosis and therapy. In addition to biophysical and biochemical methods to interrogate G4 formation, G4 fluorescent turn-on ligands can be used to target and visualize G4 formation both in vitro and in cells. Here, we review several representative classes of G4 fluorescent turn-on ligands in terms of their interaction mechanism and application perspectives. Interestingly, G4 structures are commonly identified in DNA and RNA aptamers against targets that include proteins and small molecules, which can be utilized as G4 tools for diverse applications. We therefore also summarize the recent development of G4-containing aptamers and highlight their applications in biosensing, bioimaging, and therapy. Moreover, we discuss the current challenges and future perspectives of G4 fluorescent turn-on ligands and G4-containing aptamers.
Collapse
Affiliation(s)
- Mubarak I Umar
- Department of Chemistry, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
| | - Danyang Ji
- Department of Chemistry, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
| | - Chun-Yin Chan
- Department of Chemistry, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
| | - Chun Kit Kwok
- Department of Chemistry, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China.
| |
Collapse
|
34
|
Sengupta A, Ganguly A, Chowdhury S. Promise of G-Quadruplex Structure Binding Ligands as Epigenetic Modifiers with Anti-Cancer Effects. Molecules 2019; 24:E582. [PMID: 30736345 PMCID: PMC6384772 DOI: 10.3390/molecules24030582] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 01/31/2019] [Accepted: 02/01/2019] [Indexed: 11/16/2022] Open
Abstract
Evidences from more than three decades of work support the function of non-duplex DNA structures called G-quadruplex (G4) in important processes like transcription and replication. In addition, G4 structures have been studied in connection with DNA base modifications and chromatin/nucleosome arrangements. Recent work, interestingly, shows promise of G4 structures, through interaction with G4 structure-interacting proteins, in epigenetics-in both DNA and histone modification. Epigenetic changes are found to be intricately associated with initiation as well as progression of cancer. Multiple oncogenes have been reported to harbor the G4 structure at regulatory regions. In this context, G4 structure-binding ligands attain significance as molecules with potential to modify the epigenetic state of chromatin. Here, using examples from recent studies we discuss the emerging role of G4 structures in epigenetic modifications and, therefore, the promise of G4 structure-binding ligands in epigenetic therapy.
Collapse
Affiliation(s)
- Antara Sengupta
- Integrative and Functional Biology Unit, CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi-110025, India.
- Academy of Scientific and Innovative Research, Rafi Marg, New Delhi-110001, India.
| | - Akansha Ganguly
- Integrative and Functional Biology Unit, CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi-110025, India.
| | - Shantanu Chowdhury
- Integrative and Functional Biology Unit, CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi-110025, India.
- Academy of Scientific and Innovative Research, Rafi Marg, New Delhi-110001, India.
- GNR Knowledge Centre for Genome Informatics, CSIR Institute of Genomics and Integrative Biology, Mathura Road, New Delhi-110025, India.
| |
Collapse
|