1
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Gu Y, Fan C, Yang H, Sun H, Wang X, Qiu X, Chen B, Li CM, Guo C. Fluorogenic RNA Aptamer-Based Amplification and Transcription Strategy for Label-free Sensing of Methyltransferase Activity in Complex Matrixes. Adv Biol (Weinh) 2024; 8:e2300668. [PMID: 38327153 DOI: 10.1002/adbi.202300668] [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: 12/29/2023] [Indexed: 02/09/2024]
Abstract
DNA methyltransferase is significant in cellular activities and gene expression, and its aberrant expression is closely linked to various cancers during initiation and progression. Currently, there is a great demand for reliable and label-free techniques for DNA methyltransferase evaluation in tumor diagnosis and cancer therapy. Herein, a low-background fluorescent RNA aptamer-based sensing approach for label-free quantification of cytosine-guanine (CpG) dinucleotides methyltransferase (M.SssI) is reported. The fluorogenic light-up RNA aptamers-based strategy exhibits high selectivity via restriction endonuclease, padlock-based recognition, and RNA transcription. By combining rolling circle amplification (RCA), and RNA transcription with fluorescence response of RNA aptamers of Spinach-dye compound, the proposed platform exhibited efficiently ultrahigh sensitivity toward M.SssI. Eventually, the detection can be achieved in a linear range of 0.02-100 U mL-1 with a detection limit of 1.6 × 10-3 U mL-1. Owing to these superior features, the method is further applied in serum samples spiked M.SssI, which delivers a recovery ranging from 92.0 to 107.0% and a relative standard deviation <7.0%, providing a promising and practical tool for determining M.SssI in complex biological matrices.
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Affiliation(s)
- Yu Gu
- Institute for Materials Science and Devices, School of Materials Science and Engineering, Suzhou University of Science and Technology, Kerui Road, Suzhou, 215009, P.R. China
| | - Cunxia Fan
- Institute for Materials Science and Devices, School of Materials Science and Engineering, Suzhou University of Science and Technology, Kerui Road, Suzhou, 215009, P.R. China
| | - Hongbin Yang
- Institute for Materials Science and Devices, School of Materials Science and Engineering, Suzhou University of Science and Technology, Kerui Road, Suzhou, 215009, P.R. China
| | - Huiping Sun
- Institute for Materials Science and Devices, School of Materials Science and Engineering, Suzhou University of Science and Technology, Kerui Road, Suzhou, 215009, P.R. China
| | - Xiaobao Wang
- Institute for Materials Science and Devices, School of Materials Science and Engineering, Suzhou University of Science and Technology, Kerui Road, Suzhou, 215009, P.R. China
| | - Xingchen Qiu
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Kerui Road, Suzhou, 215009, P.R. China
| | - Bo Chen
- Institute for Materials Science and Devices, School of Materials Science and Engineering, Suzhou University of Science and Technology, Kerui Road, Suzhou, 215009, P.R. China
- Jiangsu Key Laboratory for Biomaterials and Devices, Department of Biological Science and Medical Engineering, Southeast University, Nanjing, 210009, P. R. China
| | - Chang-Ming Li
- Institute for Materials Science and Devices, School of Materials Science and Engineering, Suzhou University of Science and Technology, Kerui Road, Suzhou, 215009, P.R. China
| | - Chunxian Guo
- Institute for Materials Science and Devices, School of Materials Science and Engineering, Suzhou University of Science and Technology, Kerui Road, Suzhou, 215009, P.R. China
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2
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Hwang HG, Ye DY, Jung GY. Biosensor-guided discovery and engineering of metabolic enzymes. Biotechnol Adv 2023; 69:108251. [PMID: 37690614 DOI: 10.1016/j.biotechadv.2023.108251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 09/04/2023] [Accepted: 09/05/2023] [Indexed: 09/12/2023]
Abstract
A variety of chemicals have been produced through metabolic engineering approaches, and enhancing biosynthesis performance can be achieved by using enzymes with high catalytic efficiency. Accordingly, a number of efforts have been made to discover enzymes in nature for various applications. In addition, enzyme engineering approaches have been attempted to suit specific industrial purposes. However, a significant challenge in enzyme discovery and engineering is the efficient screening of enzymes with the desired phenotype from extensive enzyme libraries. To overcome this bottleneck, genetically encoded biosensors have been developed to specifically detect target molecules produced by enzyme activity at the intracellular level. Especially, the biosensors facilitate high-throughput screening (HTS) of targeted enzymes, expanding enzyme discovery and engineering strategies with advances in systems and synthetic biology. This review examines biosensor-guided HTS systems and highlights studies that have utilized these tools to discover enzymes in diverse areas and engineer enzymes to enhance their properties, such as catalytic efficiency, specificity, and stability.
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Affiliation(s)
- Hyun Gyu Hwang
- Institute of Environmental and Energy Technology, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Dae-Yeol Ye
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Gyoo Yeol Jung
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, Republic of Korea; School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, Republic of Korea.
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3
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Ullah SF, Moreira G, Datta SPA, McLamore E, Vanegas D. An Experimental Framework for Developing Point-of-Need Biosensors: Connecting Bio-Layer Interferometry and Electrochemical Impedance Spectroscopy. BIOSENSORS 2022; 12:938. [PMID: 36354449 PMCID: PMC9688365 DOI: 10.3390/bios12110938] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 10/25/2022] [Accepted: 10/25/2022] [Indexed: 06/16/2023]
Abstract
Biolayer interferometry (BLI) is a well-established laboratory technique for studying biomolecular interactions important for applications such as drug development. Currently, there are interesting opportunities for expanding the use of BLI in other fields, including the development of rapid diagnostic tools. To date, there are no detailed frameworks for implementing BLI in target-recognition studies that are pivotal for developing point-of-need biosensors. Here, we attempt to bridge these domains by providing a framework that connects output(s) of molecular interaction studies with key performance indicators used in the development of point-of-need biosensors. First, we briefly review the governing theory for protein-ligand interactions, and we then summarize the approach for real-time kinetic quantification using various techniques. The 2020 PRISMA guideline was used for all governing theory reviews and meta-analyses. Using the information from the meta-analysis, we introduce an experimental framework for connecting outcomes from BLI experiments (KD, kon, koff) with electrochemical (capacitive) biosensor design. As a first step in the development of a larger framework, we specifically focus on mapping BLI outcomes to five biosensor key performance indicators (sensitivity, selectivity, response time, hysteresis, operating range). The applicability of our framework was demonstrated in a study of case based on published literature related to SARS-CoV-2 spike protein to show the development of a capacitive biosensor based on truncated angiotensin-converting enzyme 2 (ACE2) as the receptor. The case study focuses on non-specific binding and selectivity as research goals. The proposed framework proved to be an important first step toward modeling/simulation efforts that map molecular interactions to sensor design.
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Affiliation(s)
- Sadia Fida Ullah
- Division of Glycoscience, Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, 106 91 Stockholm, Sweden
- Department of Environmental Engineering and Earth Sciences, Clemson University, Clemson, SC 29634, USA
| | - Geisianny Moreira
- Department of Environmental Engineering and Earth Sciences, Clemson University, Clemson, SC 29634, USA
- Global Alliance for Rapid Diagnostics, Michigan State University, East Lancing, MI 48824, USA
| | - Shoumen Palit Austin Datta
- MIT Auto-ID Labs, Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, USA
- Medical Device (MDPnP) Interoperability and Cybersecurity Labs, Biomedical Engineering Program, Deparment of Anesthesiology, Massachusetts General Hospital, Harvard Medical School, 65 Landsdowne Street, Cambridge, MA 02139, USA
| | - Eric McLamore
- Department of Environmental Engineering and Earth Sciences, Clemson University, Clemson, SC 29634, USA
- Global Alliance for Rapid Diagnostics, Michigan State University, East Lancing, MI 48824, USA
- Agricultural Sciences, Clemson University, 821 McMillan Rd, Clemson, SC 29631, USA
| | - Diana Vanegas
- Department of Environmental Engineering and Earth Sciences, Clemson University, Clemson, SC 29634, USA
- Global Alliance for Rapid Diagnostics, Michigan State University, East Lancing, MI 48824, USA
- Interdisciplinary Group for Biotechnology Innovation and Ecosocial Change-BioNovo, Universidad del Valle, Cali 76001, Colombia
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4
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Giarimoglou N, Kouvela A, Maniatis A, Papakyriakou A, Zhang J, Stamatopoulou V, Stathopoulos C. A Riboswitch-Driven Era of New Antibacterials. Antibiotics (Basel) 2022; 11:antibiotics11091243. [PMID: 36140022 PMCID: PMC9495366 DOI: 10.3390/antibiotics11091243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 09/01/2022] [Accepted: 09/08/2022] [Indexed: 11/26/2022] Open
Abstract
Riboswitches are structured non-coding RNAs found in the 5′ UTR of important genes for bacterial metabolism, virulence and survival. Upon the binding of specific ligands that can vary from simple ions to complex molecules such as nucleotides and tRNAs, riboswitches change their local and global mRNA conformations to affect downstream transcription or translation. Due to their dynamic nature and central regulatory role in bacterial metabolism, riboswitches have been exploited as novel RNA-based targets for the development of new generation antibacterials that can overcome drug-resistance problems. During recent years, several important riboswitch structures from many bacterial representatives, including several prominent human pathogens, have shown that riboswitches are ideal RNA targets for new compounds that can interfere with their structure and function, exhibiting much reduced resistance over time. Most interestingly, mainstream antibiotics that target the ribosome have been shown to effectively modulate the regulatory behavior and capacity of several riboswitches, both in vivo and in vitro, emphasizing the need for more in-depth studies and biological evaluation of new antibiotics. Herein, we summarize the currently known compounds that target several main riboswitches and discuss the role of mainstream antibiotics as modulators of T-box riboswitches, in the dawn of an era of novel inhibitors that target important bacterial regulatory RNAs.
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Affiliation(s)
- Nikoleta Giarimoglou
- Department of Biochemistry, School of Medicine, University of Patras, 26504 Patras, Greece
| | - Adamantia Kouvela
- Department of Biochemistry, School of Medicine, University of Patras, 26504 Patras, Greece
| | - Alexandros Maniatis
- Department of Biochemistry, School of Medicine, University of Patras, 26504 Patras, Greece
| | - Athanasios Papakyriakou
- Institute of Biosciences & Applications, National Centre for Scientific Research “Demokritos”, Ag. Paraskevi, 15341 Athens, Greece
| | - Jinwei Zhang
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA
| | | | - Constantinos Stathopoulos
- Department of Biochemistry, School of Medicine, University of Patras, 26504 Patras, Greece
- Correspondence: ; Tel.: +30-2610-997932
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5
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Zhang M, Liu G, Zhang Y, Chen T, Feng S, Cai R, Lu C. The Second Class of Tetrahydrofolate (THF-II) Riboswitches Recognizes the Tetrahydrofolic Acid Ligand via Local Conformation Changes. Int J Mol Sci 2022; 23:ijms23115903. [PMID: 35682583 PMCID: PMC9180208 DOI: 10.3390/ijms23115903] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 05/02/2022] [Accepted: 05/06/2022] [Indexed: 02/05/2023] Open
Abstract
Riboswitches are regulatory noncoding RNAs found in bacteria, fungi and plants, that modulate gene expressions through structural changes in response to ligand binding. Understanding how ligands interact with riboswitches in solution can shed light on the molecular mechanisms of this ancient regulators. Previous studies showed that riboswitches undergo global conformation changes in response to ligand binding to relay information. Here, we report conformation switching models of the recently discovered tetrahydrofolic acid-responsive second class of tetrahydrofolate (THF-II) riboswitches in response to ligand binding. Using a combination of selective 2′-hydroxyl acylation, analyzed by primer extension (SHAPE) assay, 3D modeling and small-angle X-ray scattering (SAXS), we found that the ligand specifically recognizes and reshapes the THF-II riboswitch loop regions, but does not affect the stability of the P3 helix. Our results show that the THF-II riboswitch undergoes only local conformation changes in response to ligand binding, rearranging the Loop1-P3-Loop2 region and rotating Loop1 from a ~120° angle to a ~75° angle. This distinct conformation changes suggest a unique regulatory mechanism of the THF-II riboswitch, previously unseen in other riboswitches. Our findings may contribute to the fields of RNA sensors and drug design.
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Affiliation(s)
- Minmin Zhang
- College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, China; (M.Z.); (Y.Z.); (T.C.); (S.F.)
| | - Guangfeng Liu
- National Center for Protein Science Shanghai, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201204, China;
| | - Yunlong Zhang
- College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, China; (M.Z.); (Y.Z.); (T.C.); (S.F.)
| | - Ting Chen
- College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, China; (M.Z.); (Y.Z.); (T.C.); (S.F.)
| | - Shanshan Feng
- College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, China; (M.Z.); (Y.Z.); (T.C.); (S.F.)
| | - Rujie Cai
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
- Correspondence: (R.C.); (C.L.); Tel.: +86-21-6779-2740 (C.L.)
| | - Changrui Lu
- College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, China; (M.Z.); (Y.Z.); (T.C.); (S.F.)
- Correspondence: (R.C.); (C.L.); Tel.: +86-21-6779-2740 (C.L.)
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6
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Organelle-targeted imaging based on fluorogen-activating RNA aptamers in living cells. Anal Chim Acta 2022; 1209:339816. [DOI: 10.1016/j.aca.2022.339816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 04/04/2022] [Accepted: 04/05/2022] [Indexed: 11/21/2022]
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7
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Ryckelynck M. Development and Applications of Fluorogen/Light-Up RNA Aptamer Pairs for RNA Detection and More. Methods Mol Biol 2021; 2166:73-102. [PMID: 32710404 DOI: 10.1007/978-1-0716-0712-1_5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The central role of RNA in living systems made it highly desirable to have noninvasive and sensitive technologies allowing for imaging the synthesis and the location of these molecules in living cells. This need motivated the development of small pro-fluorescent molecules called "fluorogens" that become fluorescent upon binding to genetically encodable RNAs called "light-up aptamers." Yet, the development of these fluorogen/light-up RNA pairs is a long and thorough process starting with the careful design of the fluorogen and pursued by the selection of a specific and efficient synthetic aptamer. This chapter summarizes the main design and the selection strategies used up to now prior to introducing the main pairs. Then, the vast application potential of these molecules for live-cell RNA imaging and other applications is presented and discussed.
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Affiliation(s)
- Michael Ryckelynck
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, Strasbourg, France.
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8
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Swetha P, Fan Z, Wang F, Jiang JH. Genetically encoded light-up RNA aptamers and their applications for imaging and biosensing. J Mater Chem B 2021; 8:3382-3392. [PMID: 31984401 DOI: 10.1039/c9tb02668a] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Intracellular small ligands and biomacromolecules are playing crucial roles not only as executors but also as regulators. It is essential to develop tools to investigate their dynamics to interrogate their functions and reflect the cellular status. Light-up RNA aptamers are RNA sequences that can bind with their cognate nonfluorescent fluorogens and greatly activate their fluorescence. The emergence of genetically encoded light-up RNA aptamers has provided fascinating tools for studying intracellular small ligands and biomacromolecules owing to their high fluorescence activation degree and facile programmability. Here we review the burgeoning field of light-up RNA aptamers. We first briefly introduce light-up RNA aptamers with a focus on the photophysical properties of the fluorogens. Then design strategies of genetically encoded light-up RNA aptamer based sensors including turn-on, signal amplification and ratiometric rationales are emphasized.
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Affiliation(s)
- Puchakayala Swetha
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hu-nan University, Changsha, 410082, P. R. China.
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9
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Design and optimization of genetically encoded biosensors for high-throughput screening of chemicals. Curr Opin Biotechnol 2018; 54:18-25. [DOI: 10.1016/j.copbio.2018.01.011] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 01/08/2018] [Accepted: 01/11/2018] [Indexed: 02/07/2023]
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10
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Morse DP, Nevins CE, Aggrey-Fynn J, Bravo RJ, Pfaeffle HOI, Laney JE. Sensitive and specific detection of ligands using engineered riboswitches. J Biotechnol 2018. [PMID: 29518463 DOI: 10.1016/j.jbiotec.2018.03.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Riboswitches are RNA elements found in non-coding regions of messenger RNAs that regulate gene expression through a ligand-triggered conformational change. Riboswitches typically bind tightly and specifically to their ligands, so they have the potential to serve as highly effective sensors in vitro. In B. subtilis and other gram-positive bacteria, purine nucleotide synthesis is regulated by riboswitches that bind to guanine. We modified the xpt-pbuX guanine riboswitch for use in a fluorescence quenching assay that allowed us to specifically detect and quantify guanine in vitro. Using this assay, we reproducibly detected as little as 5 nM guanine. We then produced sensors for 2'-deoxyguanosine and cyclic diguanylate (c-diGMP) by appending the P1 stem of the guanine riboswitch to the ligand-binding domains of a 2'-deoxyguanosine riboswitch and a c-diGMP riboswitch. These hybrid sensors could detect 15 nM 2'-deoxyguanosine and 3 nM c-diGMP, respectively. Each sensor retained the ligand specificity of its corresponding natural riboswitch. In order to extend the utility of our approach, we developed a strategy for the in vitro selection of sensors with novel ligand specificity. Here we report a proof-of-principle experiment that demonstrated the feasibility of our selection strategy.
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Affiliation(s)
- Daniel P Morse
- Department of Chemistry, United States Naval Academy, Annapolis, MD 21402, USA.
| | - Colin E Nevins
- Department of Chemistry, United States Naval Academy, Annapolis, MD 21402, USA
| | - Joana Aggrey-Fynn
- Department of Biochemistry, Cell, and Molecular Biology, University of Ghana, Accra, Ghana
| | - Rick J Bravo
- Department of Chemistry, United States Naval Academy, Annapolis, MD 21402, USA
| | - Herman O I Pfaeffle
- Department of Chemistry, United States Naval Academy, Annapolis, MD 21402, USA
| | - Jess E Laney
- Department of Chemistry, United States Naval Academy, Annapolis, MD 21402, USA
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11
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Bouhedda F, Autour A, Ryckelynck M. Light-Up RNA Aptamers and Their Cognate Fluorogens: From Their Development to Their Applications. Int J Mol Sci 2017; 19:ijms19010044. [PMID: 29295531 PMCID: PMC5795994 DOI: 10.3390/ijms19010044] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 12/14/2017] [Accepted: 12/15/2017] [Indexed: 12/31/2022] Open
Abstract
An RNA-based fluorogenic module consists of a light-up RNA aptamer able to specifically interact with a fluorogen to form a fluorescent complex. Over the past decade, significant efforts have been devoted to the development of such modules, which now cover the whole visible spectrum, as well as to their engineering to serve in a wide range of applications. In this review, we summarize the different strategies used to develop each partner (the fluorogen and the light-up RNA aptamer) prior to giving an overview of their applications that range from live-cell RNA imaging to the set-up of high-throughput drug screening pipelines. We then conclude with a critical discussion on the current limitations of these modules and how combining in vitro selection with screening approaches may help develop even better molecules.
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Affiliation(s)
- Farah Bouhedda
- Architecture et Réactivité de l'ARN, CNRS, Université de Strasbourg, UPR 9002, F-67000 Strasbourg, France.
| | - Alexis Autour
- Architecture et Réactivité de l'ARN, CNRS, Université de Strasbourg, UPR 9002, F-67000 Strasbourg, France.
| | - Michael Ryckelynck
- Architecture et Réactivité de l'ARN, CNRS, Université de Strasbourg, UPR 9002, F-67000 Strasbourg, France.
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12
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Synthetic biological approaches for RNA labelling and imaging: design principles and future opportunities. Curr Opin Biotechnol 2017; 48:153-158. [DOI: 10.1016/j.copbio.2017.04.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 04/07/2017] [Accepted: 04/17/2017] [Indexed: 12/15/2022]
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13
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Findeiß S, Etzel M, Will S, Mörl M, Stadler PF. Design of Artificial Riboswitches as Biosensors. SENSORS 2017; 17:s17091990. [PMID: 28867802 PMCID: PMC5621056 DOI: 10.3390/s17091990] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 08/23/2017] [Accepted: 08/25/2017] [Indexed: 12/11/2022]
Abstract
RNA aptamers readily recognize small organic molecules, polypeptides, as well as other nucleic acids in a highly specific manner. Many such aptamers have evolved as parts of regulatory systems in nature. Experimental selection techniques such as SELEX have been very successful in finding artificial aptamers for a wide variety of natural and synthetic ligands. Changes in structure and/or stability of aptamers upon ligand binding can propagate through larger RNA constructs and cause specific structural changes at distal positions. In turn, these may affect transcription, translation, splicing, or binding events. The RNA secondary structure model realistically describes both thermodynamic and kinetic aspects of RNA structure formation and refolding at a single, consistent level of modelling. Thus, this framework allows studying the function of natural riboswitches in silico. Moreover, it enables rationally designing artificial switches, combining essentially arbitrary sensors with a broad choice of read-out systems. Eventually, this approach sets the stage for constructing versatile biosensors.
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Affiliation(s)
- Sven Findeiß
- Bioinformatics Group, Department of Computer Science, and Interdisciplinary Center for Bioinformatics, University Leipzig, Härtelstraße 16-18, 04107 Leipzig, Germany.
- Faculty of Computer Science, Research Group Bioinformatics and Computational Biology, University of Vienna, Währingerstraße 29, A-1090 Vienna, Austria.
- Faculty of Chemistry, Department of Theoretical Chemistry, University of Vienna, Währingerstraße 17, A-1090 Vienna, Austria.
| | - Maja Etzel
- Institute for Biochemistry, Leipzig University, Brüderstraße 34, 04103 Leipzig, Germany.
| | - Sebastian Will
- Bioinformatics Group, Department of Computer Science, and Interdisciplinary Center for Bioinformatics, University Leipzig, Härtelstraße 16-18, 04107 Leipzig, Germany.
- Faculty of Chemistry, Department of Theoretical Chemistry, University of Vienna, Währingerstraße 17, A-1090 Vienna, Austria.
- Institute for Biochemistry, Leipzig University, Brüderstraße 34, 04103 Leipzig, Germany.
| | - Mario Mörl
- Institute for Biochemistry, Leipzig University, Brüderstraße 34, 04103 Leipzig, Germany.
| | - Peter F Stadler
- Bioinformatics Group, Department of Computer Science, and Interdisciplinary Center for Bioinformatics, University Leipzig, Härtelstraße 16-18, 04107 Leipzig, Germany.
- Faculty of Chemistry, Department of Theoretical Chemistry, University of Vienna, Währingerstraße 17, A-1090 Vienna, Austria.
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, 04103 Leipzig, Germany.
- Max Planck Institute for Mathematics in the Sciences, Inselstraße 22, 04103 Leipzig, Germany.
- Fraunhofer Institute for Cell Therapy and Immunology, Perlickstrasse 1, 04103 Leipzig, Germany.
- Center for RNA in Technology and Health, University of Copenhagen, Grønnegårdsvej 3, 1870 Frederiksberg , Denmark.
- Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, NM 87501, USA.
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14
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Jones CP, Ferré-D'Amaré AR. Long-Range Interactions in Riboswitch Control of Gene Expression. Annu Rev Biophys 2017; 46:455-481. [PMID: 28375729 DOI: 10.1146/annurev-biophys-070816-034042] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Riboswitches are widespread RNA motifs that regulate gene expression in response to fluctuating metabolite concentrations. Known primarily from bacteria, riboswitches couple specific ligand binding and changes in RNA structure to mRNA expression in cis. Crystal structures of the ligand binding domains of most of the phylogenetically widespread classes of riboswitches, each specific to a particular metabolite or ion, are now available. Thus, the bound states-one end point-have been thoroughly characterized, but the unbound states have been more elusive. Consequently, it is less clear how the unbound, sensing riboswitch refolds into the ligand binding-induced output state. The ligand recognition mechanisms of riboswitches are diverse, but we find that they share a common structural strategy in positioning their binding sites at the point of the RNA three-dimensional fold where the residues farthest from one another in sequence meet. We review how riboswitch folds adhere to this fundamental strategy and propose future research directions for understanding and harnessing their ability to specifically control gene expression.
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Affiliation(s)
- Christopher P Jones
- Biochemistry and Biophysics Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20824;
| | - Adrian R Ferré-D'Amaré
- Biochemistry and Biophysics Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20824;
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15
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Hallberg ZF, Su Y, Kitto RZ, Hammond MC. Engineering and In Vivo Applications of Riboswitches. Annu Rev Biochem 2017; 86:515-539. [PMID: 28375743 DOI: 10.1146/annurev-biochem-060815-014628] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Riboswitches are common gene regulatory units mostly found in bacteria that are capable of altering gene expression in response to a small molecule. These structured RNA elements consist of two modular subunits: an aptamer domain that binds with high specificity and affinity to a target ligand and an expression platform that transduces ligand binding to a gene expression output. Significant progress has been made in engineering novel aptamer domains for new small molecule inducers of gene expression. Modified expression platforms have also been optimized to function when fused with both natural and synthetic aptamer domains. As this field expands, the use of these privileged scaffolds has permitted the development of tools such as RNA-based fluorescent biosensors. In this review, we summarize the methods that have been developed to engineer new riboswitches and highlight applications of natural and synthetic riboswitches in enzyme and strain engineering, in controlling gene expression and cellular physiology, and in real-time imaging of cellular metabolites and signals.
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Affiliation(s)
- Zachary F Hallberg
- Department of Chemistry, University of California, Berkeley, California 94720;
| | - Yichi Su
- Department of Chemistry, University of California, Berkeley, California 94720;
| | - Rebekah Z Kitto
- Department of Chemistry, University of California, Berkeley, California 94720;
| | - Ming C Hammond
- Department of Chemistry, University of California, Berkeley, California 94720; .,Department of Molecular and Cell Biology, University of California, Berkeley, California 94720
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Etzel M, Mörl M. Synthetic Riboswitches: From Plug and Pray toward Plug and Play. Biochemistry 2017; 56:1181-1198. [PMID: 28206750 DOI: 10.1021/acs.biochem.6b01218] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In synthetic biology, metabolic engineering, and gene therapy, there is a strong demand for orthogonal or externally controlled regulation of gene expression. Here, RNA-based regulatory devices represent a promising emerging alternative to proteins, allowing a fast and direct control of gene expression, as no synthesis of regulatory proteins is required. Besides programmable ribozyme elements controlling mRNA stability, regulatory RNA structures in untranslated regions are highly interesting for engineering approaches. Riboswitches are especially well suited, as they show a modular composition of sensor and response elements, allowing a free combination of different modules in a plug-and-play-like mode. The sensor or aptamer domain specifically interacts with a trigger molecule as a ligand, modulating the activity of the adjacent response domain that controls the expression of the genes located downstream, in most cases at the level of transcription or translation. In this review, we discuss the recent advances and strategies for designing such synthetic riboswitches based on natural or artificial components and readout systems, from trial-and-error approaches to rational design strategies. As the past several years have shown dramatic development in this fascinating field of research, we can give only a limited overview of the basic riboswitch design principles that is far from complete, and we apologize for not being able to consider every successful and interesting approach described in the literature.
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Affiliation(s)
- Maja Etzel
- Institute for Biochemistry, Leipzig University , Brüderstrasse 34, 04103 Leipzig, Germany
| | - Mario Mörl
- Institute for Biochemistry, Leipzig University , Brüderstrasse 34, 04103 Leipzig, Germany
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Recurrent RNA motifs as scaffolds for genetically encodable small-molecule biosensors. Nat Chem Biol 2017; 13:295-301. [PMID: 28092358 PMCID: PMC5310984 DOI: 10.1038/nchembio.2278] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 11/21/2016] [Indexed: 12/05/2022]
Abstract
Allosteric RNA devices are increasingly viewed as important tools capable of monitoring enzyme evolution, optimizing engineered metabolic pathways, facilitating gene discovery and regulators of nucleic acid-based therapeutics. A key bottleneck in the development of these platforms is the availability of small molecule binding RNA aptamers that robustly function in the cellular environment. While aptamers can be raised against nearly any desired target by in vitro selection, many cannot be easily integrated into devices or do not reliably function in a cellular context. Here, we describe a new approach using secondary and tertiary structural scaffolds derived from biologically active riboswitches and small ribozymes. Applied to neurotransmitter precursors 5-hydroxytryptophan and 3,4-dihydroxyphenylalanine, this approach yields easily identifiable and characterizable aptamers predisposed for coupling to readout domains to engineer nucleic acid sensory devices that function in vitro and in the cellular context.
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