51
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Iyer A, Baranov M, Foster AJ, Chordia S, Roelfes G, Vlijm R, van den Bogaart G, Poolman B. Chemogenetic Tags with Probe Exchange for Live-Cell Fluorescence Microscopy. ACS Chem Biol 2021; 16:891-904. [PMID: 33913682 PMCID: PMC8154248 DOI: 10.1021/acschembio.1c00100] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 04/15/2021] [Indexed: 11/29/2022]
Abstract
Fluorogenic protein tagging systems have been less developed for prokaryotes than for eukaryotic cell systems. Here, we extend the concept of noncovalent fluorogenic protein tags in bacteria by introducing transcription factor-based tags, namely, LmrR and RamR, for probe binding and fluorescence readout under aerobic and anaerobic conditions. We developed two chemogenetic protein tags that impart fluorogenicity and a longer fluorescence lifetime to reversibly bound organic fluorophores, hence the name Chemogenetic Tags with Probe Exchange (CTPEs). We present an extensive characterization of 30 fluorophores reversibly interacting with the two different CTPEs and conclude that aromatic planar structures bind with high specificity to the hydrophobic pockets of these tags. The reversible binding of organic fluorophores to the CTPEs and the superior photophysical properties of organic fluorophores enable long-term fluorescence microscopy of living bacterial cells. Our protein tags provide a general tool for investigating (sub)cellular protein localization and dynamics, protein-protein interactions, and prolonged live-cell microscopy, even under oxygen-free conditions.
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Affiliation(s)
- Aditya Iyer
- Department
of Biochemistry, Groningen Biomolecular Sciences and Biotechnology
Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Maxim Baranov
- Department
of Molecular Immunology, Groningen Biomolecular Sciences and Biotechnology
Institute, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Alexander J. Foster
- Department
of Biochemistry, Groningen Biomolecular Sciences and Biotechnology
Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Shreyans Chordia
- Stratingh
Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Gerard Roelfes
- Stratingh
Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Rifka Vlijm
- Molecular
Biophysics, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Geert van den Bogaart
- Department
of Molecular Immunology, Groningen Biomolecular Sciences and Biotechnology
Institute, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Bert Poolman
- Department
of Biochemistry, Groningen Biomolecular Sciences and Biotechnology
Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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52
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Chen C, Tachibana SR, Baleeva NS, Myasnyanko IN, Bogdanov AM, Gavrikov AS, Mishin AS, Malyshevskaya KK, Baranov MS, Fang C. Developing Bright Green Fluorescent Protein (GFP)-like Fluorogens for Live-Cell Imaging with Nonpolar Protein-Chromophore Interactions. Chemistry 2021; 27:8946-8950. [PMID: 33938061 DOI: 10.1002/chem.202101250] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Indexed: 11/09/2022]
Abstract
Fluorescence-activating proteins (FAPs) that bind a chromophore and activate its fluorescence have gained popularity in bioimaging. The fluorescence-activating and absorption-shifting tag (FAST) is a light-weight FAP that enables fast reversible fluorogen binding, thus advancing multiplex and super-resolution imaging. However, the rational design of FAST-specific fluorogens with large fluorescence enhancement (FE) remains challenging. Herein, a new fluorogen directly engineered from green fluorescent protein (GFP) chromophore by a unique double-donor-one-acceptor strategy, which exhibits an over 550-fold FE upon FAST binding and a high extinction coefficient of approximately 100,000 M-1 cm-1 , is reported. Correlation analysis of the excited state nonradiative decay rates and environmental factors reveal that the large FE is caused by nonpolar protein-fluorogen interactions. Our deep insights into structure-function relationships could guide the rational design of bright fluorogens for live-cell imaging with extended spectral properties such as redder emissions.
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Affiliation(s)
- Cheng Chen
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR 97331-4003, USA
| | - Sean R Tachibana
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR 97331-4003, USA
| | - Nadezhda S Baleeva
- Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow, 117997, Russia
| | - Ivan N Myasnyanko
- Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow, 117997, Russia
| | - Alexey M Bogdanov
- Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow, 117997, Russia
| | - Alexey S Gavrikov
- Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow, 117997, Russia
| | - Alexander S Mishin
- Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow, 117997, Russia
| | - Kseniya K Malyshevskaya
- Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow, 117997, Russia
| | - Mikhail S Baranov
- Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow, 117997, Russia.,Pirogov Russian National Research Medical University, Ostrovitianov 1, Moscow, 117997, Russia
| | - Chong Fang
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR 97331-4003, USA
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53
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Single-Molecule Imaging in Living Plant Cells: A Methodological Review. Int J Mol Sci 2021; 22:ijms22105071. [PMID: 34064786 PMCID: PMC8151321 DOI: 10.3390/ijms22105071] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 05/06/2021] [Accepted: 05/09/2021] [Indexed: 12/23/2022] Open
Abstract
Single-molecule imaging is emerging as a revolutionary approach to studying fundamental questions in plants. However, compared with its use in animals, the application of single-molecule imaging in plants is still underexplored. Here, we review the applications, advantages, and challenges of single-molecule fluorescence imaging in plant systems from the perspective of methodology. Firstly, we provide a general overview of single-molecule imaging methods and their principles. Next, we summarize the unprecedented quantitative details that can be obtained using single-molecule techniques compared to bulk assays. Finally, we discuss the main problems encountered at this stage and provide possible solutions.
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54
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Yu Q, Ren K, You M. Genetically encoded RNA nanodevices for cellular imaging and regulation. NANOSCALE 2021; 13:7988-8003. [PMID: 33885099 PMCID: PMC8122502 DOI: 10.1039/d0nr08301a] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Nucleic acid-based nanodevices have been widely used in the fields of biosensing and nanomedicine. Traditionally, the majority of these nanodevices were first constructed in vitro using synthetic DNA or RNA oligonucleotides and then delivered into cells. Nowadays, the emergence of genetically encoded RNA nanodevices has provided a promising alternative approach for intracellular analysis and regulation. These genetically encoded RNA-based nanodevices can be directly transcribed and continuously produced inside living cells. A variety of highly precise and programmable nanodevices have been constructed in this way during the last decade. In this review, we will summarize the recent advances in the design and function of these artificial genetically encoded RNA nanodevices. In particular, we will focus on their applications in regulating cellular gene expression, imaging, logic operation, structural biology, and optogenetics. We believe these versatile RNA-based nanodevices will be broadly used in the near future to probe and program cells and other biological systems.
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Affiliation(s)
- Qikun Yu
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, USA.
| | - Kewei Ren
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, USA.
| | - Mingxu You
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, USA.
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55
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Biocompatible and noncytotoxic nucleoside-based AIEgens sensor for lighting-up nucleic acids. CHINESE CHEM LETT 2021. [DOI: 10.1016/j.cclet.2021.02.038] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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56
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Abstract
Technologies for RNA imaging in live cells play an important role in understanding the function and regulatory process of RNAs. One approach for genetically encoded fluorescent RNA imaging involves fluorescent light-up aptamers (FLAPs), which are short RNA sequences that can bind cognate fluorogens and activate their fluorescence greatly. Over the past few years, FLAPs have emerged as genetically encoded RNA-based fluorescent biosensors for the cellular imaging and detection of various targets of interest. In this review, we first give a brief overview of the development of the current FLAPs based on various fluorogens. Then we further discuss on the photocycles of the reversibly photoswitching properties in FLAPs and their photostability. Finally, we focus on the applications of FLAPs as genetically encoded RNA-based fluorescent biosensors in biosensing and bioimaging, including RNA, non-nucleic acid molecules, metal ions imaging and quantitative imaging. Their design strategies and recent cellular applications are emphasized and summarized in detail.
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Affiliation(s)
- Huangmei Zhou
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China
| | - Sanjun Zhang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China.,Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi, China.,NYU-ECNU Institute of Physics at NYU Shanghai, Shanghai, China
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57
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Jeng SCY, Trachman RJ, Weissenboeck F, Truong L, Link KA, Jepsen MDE, Knutson JR, Andersen ES, Ferré-D'Amaré AR, Unrau PJ. Fluorogenic aptamers resolve the flexibility of RNA junctions using orientation-dependent FRET. RNA (NEW YORK, N.Y.) 2021; 27:433-444. [PMID: 33376189 PMCID: PMC7962493 DOI: 10.1261/rna.078220.120] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 12/20/2020] [Indexed: 05/26/2023]
Abstract
To further understand the transcriptome, new tools capable of measuring folding, interactions, and localization of RNA are needed. Although Förster resonance energy transfer (FRET) is an angle- and distance-dependent phenomenon, the majority of FRET measurements have been used to report distances, by assuming rotationally averaged donor-acceptor pairs. Angle-dependent FRET measurements have proven challenging for nucleic acids due to the difficulties in incorporating fluorophores rigidly into local substructures in a biocompatible manner. Fluorescence turn-on RNA aptamers are genetically encodable tags that appear to rigidly confine their cognate fluorophores, and thus have the potential to report angular-resolved FRET. Here, we use the fluorescent aptamers Broccoli and Mango-III as donor and acceptor, respectively, to measure the angular dependence of FRET. Joining the two fluorescent aptamers by a helix of variable length allowed systematic rotation of the acceptor fluorophore relative to the donor. FRET oscillated in a sinusoidal manner as a function of helix length, consistent with simulated data generated from models of oriented fluorophores separated by an inflexible helix. Analysis of the orientation dependence of FRET allowed us to demonstrate structural rigidification of the NiCo riboswitch upon transition metal-ion binding. This application of fluorescence turn-on aptamers opens the way to improved structural interpretation of ensemble and single-molecule FRET measurements of RNA.
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Affiliation(s)
- Sunny C Y Jeng
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
| | - Robert J Trachman
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, Bethesda, Maryland 20892-8012, USA
| | - Florian Weissenboeck
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
| | - Lynda Truong
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, Bethesda, Maryland 20892-8012, USA
| | - Katie A Link
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, Bethesda, Maryland 20892-8012, USA
| | - Mette D E Jepsen
- Interdisciplinary Nanoscience Center, Aarhus University, 8000 Aarhus C, Denmark
| | - Jay R Knutson
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, Bethesda, Maryland 20892-8012, USA
| | - Ebbe S Andersen
- Interdisciplinary Nanoscience Center, Aarhus University, 8000 Aarhus C, Denmark
| | - Adrian R Ferré-D'Amaré
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, Bethesda, Maryland 20892-8012, USA
| | - Peter J Unrau
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
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58
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Abstract
The discovery of the GFP-type dye DFHBI that becomes fluorescent upon binding to an RNA aptamer, termed Spinach, led to the development of a variety of fluorogenic RNA systems that enable genetic encoding of living cells. In view of increasing interest in small RNA aptamers and the scarcity of their photophysical characterisation, this paper is a model study on Baby Spinach, a truncated Spinach aptamer with half its sequence. Fluorescence and fluorescence excitation spectra of DFHBI complexes of Spinach and Baby Spinach are known to be similar. Surprisingly, a significant divergence between absorption and fluorescence excitation spectra of the DFHBI/RNA complex was observed on conditions of saturation at large excess of RNA over DFHBI. Since absorption spectra were not reported for any Spinach-type aptamer, this effect is new. Quantitative modelling of the absorption spectrum based on competing dark and fluorescent binding sites could explain it. However, following reasoning of fluorescence lifetimes of bound DFHBI, femtosecond-fluorescence lifetime profiles would be more supportive of the notion that the abnormal absorption spectrum is largely caused by trans-isomers formed within the cis-bound DFHBI/RNA complex. Independent of the origin, the unexpected discrepancy between absorption and fluorescence excitation spectra allows for easily accessed screening and insight into the efficiency of a fluorogenic dye/RNA system.
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59
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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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60
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Manna S, Truong J, Hammond MC. Guanidine Biosensors Enable Comparison of Cellular Turn-on Kinetics of Riboswitch-Based Biosensor and Reporter. ACS Synth Biol 2021; 10:566-578. [PMID: 33646758 PMCID: PMC7985839 DOI: 10.1021/acssynbio.0c00583] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Indexed: 12/30/2022]
Abstract
Cell-based sensors are useful for many synthetic biology applications, including regulatory circuits, metabolic engineering, and diagnostics. While considerable research efforts have been made toward recognizing new target ligands and increasing sensitivity, the analysis and optimization of turn-on kinetics is often neglected. For example, to our knowledge there has been no systematic study that compared the performance of a riboswitch-based biosensor versus reporter for the same ligand. In this study, we show the development of RNA-based fluorescent (RBF) biosensors for guanidine, a common chaotropic agent that is a precursor to both fertilizer and explosive compounds. Guanidine is cell permeable and nontoxic to E. coli at millimolar concentrations, which in contrast to prior studies enabled direct activation of the riboswitch-based biosensor and corresponding reporter with ligand addition to cells. Our results reveal that the biosensors activate fluorescence in the cell within 4 min of guanidine treatment, which is at least 15 times faster than a reporter derived from the same riboswitch, and this rapid sensing activity is maintained for up to 1.6 weeks. Together, this study describes the design of two new biosensor topologies and showcases the advantages of RBF biosensors for monitoring dynamic processes in cell biology, biotechnology, and synthetic biology.
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Affiliation(s)
- Sudeshna Manna
- Department
of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
- Henry
Eyring Center for Cell & Genome Science, University of Utah, Salt Lake
City, Utah 84112, United States
| | - Johnny Truong
- Department
of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
- Henry
Eyring Center for Cell & Genome Science, University of Utah, Salt Lake
City, Utah 84112, United States
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
| | - Ming C. Hammond
- Department
of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
- Henry
Eyring Center for Cell & Genome Science, University of Utah, Salt Lake
City, Utah 84112, United States
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
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61
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Shanaa OA, Rumyantsev A, Sambuk E, Padkina M. In Vivo Production of RNA Aptamers and Nanoparticles: Problems and Prospects. Molecules 2021; 26:molecules26051422. [PMID: 33800717 PMCID: PMC7961669 DOI: 10.3390/molecules26051422] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 03/04/2021] [Accepted: 03/04/2021] [Indexed: 12/26/2022] Open
Abstract
RNA aptamers are becoming increasingly attractive due to their superior properties. This review discusses the early stages of aptamer research, the main developments in this area, and the latest technologies being developed. The review also highlights the advantages of RNA aptamers in comparison to antibodies, considering the great potential of RNA aptamers and their applications in the near future. In addition, it is shown how RNA aptamers can form endless 3-D structures, giving rise to various structural and functional possibilities. Special attention is paid to the Mango, Spinach and Broccoli fluorescent RNA aptamers, and the advantages of split RNA aptamers are discussed. The review focuses on the importance of creating a platform for the synthesis of RNA nanoparticles in vivo and examines yeast, namely Saccharomyces cerevisiae, as a potential model organism for the production of RNA nanoparticles on a large scale.
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Affiliation(s)
- Ousama Al Shanaa
- Department of Genetics and Biotechnology, Saint Petersburg State University, 199034 Saint Petersburg, Russia; (A.R.); (E.S.)
- Atomic Energy Commission of Syria, Damascus P.O.B 6091, Syria
- Correspondence: (O.A.S.); (M.P.); Tel.: +7-812-328-2822 (O.A.S.); +7-812-327-9827 (M.P.)
| | - Andrey Rumyantsev
- Department of Genetics and Biotechnology, Saint Petersburg State University, 199034 Saint Petersburg, Russia; (A.R.); (E.S.)
| | - Elena Sambuk
- Department of Genetics and Biotechnology, Saint Petersburg State University, 199034 Saint Petersburg, Russia; (A.R.); (E.S.)
| | - Marina Padkina
- Department of Genetics and Biotechnology, Saint Petersburg State University, 199034 Saint Petersburg, Russia; (A.R.); (E.S.)
- Correspondence: (O.A.S.); (M.P.); Tel.: +7-812-328-2822 (O.A.S.); +7-812-327-9827 (M.P.)
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62
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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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63
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Kolpashchikov DM, Spelkov AA. Binary (Split) Light‐up Aptameric Sensors. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.201914919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Dmitry M. Kolpashchikov
- Chemistry Department University of Central Florida Orlando FL 32816-2366 USA
- Burnett School of Biomedical Sciences University of Central Florida Orlando FL 32816 USA
| | - Alexander A. Spelkov
- Laboratory of Solution Chemistry of Advanced Materials and Technologies ITMO University 9 Lomonosova Str. St. Petersburg 191002 Russian Federation
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64
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Incorporation of sensing modalities into de novo designed fluorescence-activating proteins. Nat Commun 2021; 12:856. [PMID: 33558528 PMCID: PMC7870846 DOI: 10.1038/s41467-020-18911-w] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 08/10/2020] [Indexed: 01/07/2023] Open
Abstract
Through the efforts of many groups, a wide range of fluorescent protein reporters and sensors based on green fluorescent protein and its relatives have been engineered in recent years. Here we explore the incorporation of sensing modalities into de novo designed fluorescence-activating proteins, called mini-fluorescence-activating proteins (mFAPs), that bind and stabilize the fluorescent cis-planar state of the fluorogenic compound DFHBI. We show through further design that the fluorescence intensity and specificity of mFAPs for different chromophores can be tuned, and the fluorescence made sensitive to pH and Ca2+ for real-time fluorescence reporting. Bipartite split mFAPs enable real-time monitoring of protein-protein association and (unlike widely used split GFP reporter systems) are fully reversible, allowing direct readout of association and dissociation events. The relative ease with which sensing modalities can be incorporated and advantages in smaller size and photostability make de novo designed fluorescence-activating proteins attractive candidates for optical sensor engineering.
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65
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Savage JC, Shinde P, Yao Y, Davare MA, Shinde U. A Broccoli aptamer chimera yields a fluorescent K + sensor spanning physiological concentrations. Chem Commun (Camb) 2021; 57:1344-1347. [PMID: 33432937 DOI: 10.1039/d0cc07042d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The RNA aptamer Broccoli accepts 2'fluorinated (2'F) pyrimidine nucleotide incorporation without perturbation of structure or fluorescence in the presence of potassium and DFHBI. However, the modification decreases Broccoli's apparent affinity for K+ >30-fold. A chimera of Broccoli RNAs with mixed chemistries displays linear fluorescent gain spanning physiological K+ concentrations, yielding an effective RNA-based fluorescent K+ sensor.
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Affiliation(s)
- Jonathan C Savage
- Department of Chemical Physiology & Biochemistry, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd, Portland, OR 97239, USA.
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66
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Kitto RZ, Christiansen KE, Hammond MC. RNA-based fluorescent biosensors for live cell detection of bacterial sRNA. Biopolymers 2021; 112:e23394. [PMID: 32786000 PMCID: PMC7856060 DOI: 10.1002/bip.23394] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 07/11/2020] [Accepted: 07/13/2020] [Indexed: 01/21/2023]
Abstract
Bacteria contain a diverse set of RNAs to provide tight regulation of gene expression in response to environmental stimuli. Bacterial small RNAs (sRNAs) work in conjunction with protein cofactors to bind complementary mRNA sequences in the cell, leading to up- or downregulation of protein synthesis. In vivo imaging of sRNAs can aid in understanding their spatiotemporal dynamics in real time, which inspires new ways to manipulate these systems for a variety of applications including synthetic biology and therapeutics. Current methods for sRNA imaging are quite limited in vivo and do not provide real-time information about fluctuations in sRNA levels. Herein, we describe our efforts toward the development of an RNA-based fluorescent biosensor for bacterial sRNA both in vitro and in vivo. We validated these sensors for three different bacterial sRNAs in Escherichia coli and demonstrated that the designs provide a bright, sequence-specific signal output in response to exogenous and endogenous RNA targets.
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Affiliation(s)
- Rebekah Z Kitto
- Department of Chemistry, University of California, Berkeley, California, USA
- Department of Chemistry and Henry Eyring Center for Cell and Genome Sciences, University of Utah, Salt Lake City, Utah, USA
| | - Kylee E Christiansen
- Department of Chemistry and Henry Eyring Center for Cell and Genome Sciences, University of Utah, Salt Lake City, Utah, USA
| | - Ming C Hammond
- Department of Chemistry, University of California, Berkeley, California, USA
- Department of Chemistry and Henry Eyring Center for Cell and Genome Sciences, University of Utah, Salt Lake City, Utah, USA
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67
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Live Cell Imaging Using Riboswitch-Spinach tRNA Fusions as Metabolite-Sensing Fluorescent Biosensors. Methods Mol Biol 2021; 2323:121-140. [PMID: 34086278 DOI: 10.1007/978-1-0716-1499-0_10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
The development of fluorescent biosensors is motivated by the desire to monitor cellular metabolite levels in real time. Most genetically encodable fluorescent biosensors are based on receptor proteins fused to fluorescent protein domains. More recently, small molecule-binding riboswitches have been adapted for use as fluorescent biosensors through fusion to the in vitro selected Spinach aptamer, which binds a profluorescent, cell-permeable small molecule mimic of the GFP chromophore, DFHBI. Here we describe methods to prepare and analyze riboswitch-Spinach tRNA fusions for ligand-dependent activation of fluorescence in vivo. Example procedures describe the use of the Vc2-Spinach tRNA biosensor to monitor perturbations in cellular levels of cyclic di-GMP using either fluorescence microscopy or flow cytometry. In this updated chapter, we have added procedures on using biosensors in flow cytometry to detect exogenously added compounds. The relative ease of cloning and imaging of these biosensors, as well as their modular nature, should make this method appealing to other researchers interested in utilizing riboswitch-based biosensors for metabolite sensing.
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68
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Al Mazid MF, Shkel O, Kharkivska Y, Lee JS. Application of fluorescent turn-on aptamers in RNA studies. Mol Omics 2021; 17:483-491. [PMID: 34137415 DOI: 10.1039/d1mo00085c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
RNA is an intermediate player between DNA transcription and protein translation. RNAs also interact with other macromolecules and metabolites and regulate their fate. The emerging number of RNA identifications expanded new areas of study to determine their applicability and functional analysis. Recently, extensive research has been focused on visualizing RNA in living biological samples and a method has been developed by the evolution of specific fluorophore-binding aptamers through the Systematic Evolution of Ligands by Exponential Enrichment (SELEX) method. Several promising fluorescent turn-on aptamers are currently available, and they can detect RNA-RNA, RNA-protein, ligand binding, small molecule, and metabolite interactions in vitro and under live-cell conditions. Here we review the currently available fluorescent turn-on aptamers and discuss their applicability for analyzing the fate of targeted RNAs in in vitro and in vivo systems.
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Affiliation(s)
| | - Olha Shkel
- Bio-Med Program KIST-School UST, Seoul, 02792, Republic of Korea
| | | | - Jun-Seok Lee
- Department of Pharmacology, Korea University College of Medicine, Seoul, 02841, Republic of Korea.
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69
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Cambré A, Aertsen A. Bacterial Vivisection: How Fluorescence-Based Imaging Techniques Shed a Light on the Inner Workings of Bacteria. Microbiol Mol Biol Rev 2020; 84:e00008-20. [PMID: 33115939 PMCID: PMC7599038 DOI: 10.1128/mmbr.00008-20] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The rise in fluorescence-based imaging techniques over the past 3 decades has improved the ability of researchers to scrutinize live cell biology at increased spatial and temporal resolution. In microbiology, these real-time vivisections structurally changed the view on the bacterial cell away from the "watery bag of enzymes" paradigm toward the perspective that these organisms are as complex as their eukaryotic counterparts. Capitalizing on the enormous potential of (time-lapse) fluorescence microscopy and the ever-extending pallet of corresponding probes, initial breakthroughs were made in unraveling the localization of proteins and monitoring real-time gene expression. However, later it became clear that the potential of this technique extends much further, paving the way for a focus-shift from observing single events within bacterial cells or populations to obtaining a more global picture at the intra- and intercellular level. In this review, we outline the current state of the art in fluorescence-based vivisection of bacteria and provide an overview of important case studies to exemplify how to use or combine different strategies to gain detailed information on the cell's physiology. The manuscript therefore consists of two separate (but interconnected) parts that can be read and consulted individually. The first part focuses on the fluorescent probe pallet and provides a perspective on modern methodologies for microscopy using these tools. The second section of the review takes the reader on a tour through the bacterial cell from cytoplasm to outer shell, describing strategies and methods to highlight architectural features and overall dynamics within cells.
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Affiliation(s)
- Alexander Cambré
- KU Leuven, Department of Microbial and Molecular Systems, Faculty of Bioscience Engineering, Leuven, Belgium
| | - Abram Aertsen
- KU Leuven, Department of Microbial and Molecular Systems, Faculty of Bioscience Engineering, Leuven, Belgium
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70
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Kolpashchikov DM, Spelkov AA. Binary (Split) Light-up Aptameric Sensors. Angew Chem Int Ed Engl 2020; 60:4988-4999. [PMID: 32208549 DOI: 10.1002/anie.201914919] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Indexed: 12/12/2022]
Abstract
This Minireview discusses the design and applications of binary (also known as split) light-up aptameric sensors (BLAS). BLAS consist of two RNA or DNA strands and a fluorogenic organic dye added as a buffer component. When associated, the two strands form a dye-binding site, followed by an increase in fluorescence of the aptamer-bound dye. The design is cost-efficient because it uses short oligonucleotides and does not require conjugation of organic dyes with nucleic acids. In some applications, BLAS design is preferable over monolithic sensors because of simpler assay optimization and improved selectivity. RNA-based BLAS can be expressed in cells and used for the intracellular monitoring of biological molecules. BLAS have been used as reporters of nucleic acid association events in RNA nanotechnology and nucleic-acid-based molecular computation. Other applications of BLAS include the detection of nucleic acids, proteins, and cancer cells, and potentially they can be tailored to report a broad range of biological analytes.
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Affiliation(s)
- Dmitry M Kolpashchikov
- Chemistry Department, University of Central Florida, Orlando, FL, 32816-2366, USA.,Burnett School of Biomedical Sciences, University of Central Florida, Orlando, FL, 32816, USA
| | - Alexander A Spelkov
- Laboratory of Solution Chemistry of Advanced Materials and Technologies, ITMO University, 9 Lomonosova Str., St. Petersburg, 191002, Russian Federation
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71
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Aissa HB, Gautier A. Engineering Glowing Chemogenetic Hybrids for Spying on Cells. European J Org Chem 2020. [DOI: 10.1002/ejoc.202000340] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Hela Ben Aissa
- École normale supérieure PSL University CNRS, Laboratoire des biomolécules, LBM Sorbonne Université 75005 Paris France
| | - Arnaud Gautier
- École normale supérieure PSL University CNRS, Laboratoire des biomolécules, LBM Sorbonne Université 75005 Paris France
- Institut Universitaire de France Paris France
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72
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Bai J, Luo Y, Wang X, Li S, Luo M, Yin M, Zuo Y, Li G, Yao J, Yang H, Zhang M, Wei W, Wang M, Wang R, Fan C, Zhao Y. A protein-independent fluorescent RNA aptamer reporter system for plant genetic engineering. Nat Commun 2020; 11:3847. [PMID: 32737299 PMCID: PMC7395781 DOI: 10.1038/s41467-020-17497-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Accepted: 07/02/2020] [Indexed: 02/05/2023] Open
Abstract
Reporter systems are routinely used in plant genetic engineering and functional genomics research. Most such plant reporter systems cause accumulation of foreign proteins. Here, we demonstrate a protein-independent reporter system, 3WJ-4 × Bro, based on a fluorescent RNA aptamer. Via transient expression assays in both Escherichia coli and Nicotiana benthamiana, we show that 3WJ-4 × Bro is suitable for transgene identification and as an mRNA reporter for expression pattern analysis. Following stable transformation in Arabidopsis thaliana, 3WJ-4 × Bro co-segregates and co-expresses with target transcripts and is stably inherited through multiple generations. Further, 3WJ-4 × Bro can be used to visualize virus-mediated RNA delivery in plants. This study demonstrates a protein-independent reporter system that can be used for transgene identification and in vivo dynamic analysis of mRNA.
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Affiliation(s)
- Jiuyuan Bai
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Yao Luo
- State Key Laboratory and Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Xin Wang
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Shi Li
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Mei Luo
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Meng Yin
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Yuanli Zuo
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Guolin Li
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Junyu Yao
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Hua Yang
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Mingdi Zhang
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Wei Wei
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Maolin Wang
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Rui Wang
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China.
| | - Chunhai Fan
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Institute of Translational Medicine, Shanghai Jiao Tong University, Shanghai, 200240, China.
- Institute of Molecular Medicine, Shanghai Key Laboratory for Nucleic Acids Chemistry and Nanomedicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, China.
| | - Yun Zhao
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China.
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73
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Broch F, Gautier A. Illuminating Cellular Biochemistry: Fluorogenic Chemogenetic Biosensors for Biological Imaging. Chempluschem 2020; 85:1487-1497. [PMID: 32644262 DOI: 10.1002/cplu.202000413] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 06/18/2020] [Indexed: 12/19/2022]
Abstract
Cellular activity is defined by the precise spatiotemporal regulation of various components, such as ions, small molecules, or proteins. Studying cell physiology consequently requires the optical recording of these processes, notably by using fluorescent biosensors. The recent development of various fluorogenic systems greatly expanded the palette of reporters to be included in these sensors design. Fluorogenic reporters consist of a protein or RNA tag that can complex either an endogenous or a synthetic fluorogenic dye (so-called fluorogen). The intrinsic nature of these tags, along with the high tunability of their cognate chromophore provide interesting features such as far-red to near-infrared emission, oxygen independence, or unprecedented color versatility. These engineered photoreceptors, self-labelling proteins, or noncovalent aptamers and protein tags were rapidly identified as promising reporters to observe biological events. This Minireview focuses on the new perspectives they offer to design unique and innovative biosensors, thus pushing the boundaries of cellular imaging.
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Affiliation(s)
- Fanny Broch
- Sorbonne Université, École normale supérieure, PSL University, CNRS Laboratoire des biomolécules, LBM, 75005, Paris, France
| | - Arnaud Gautier
- Sorbonne Université, École normale supérieure, PSL University, CNRS Laboratoire des biomolécules, LBM, 75005, Paris, France.,Institut Universitaire de France, France
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74
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Endoh T, Sugimoto N. Signaling Aptamer Optimization through Selection Using RNA-Capturing Microsphere Particles. Anal Chem 2020; 92:7955-7963. [PMID: 32363852 DOI: 10.1021/acs.analchem.0c01338] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An RNA signaling aptamer is composed of two units: a sensing aptamer that binds the input target molecule and a working aptamer that binds the output target molecule to result in a detectable signal. A conformational change of the signaling aptamer that induces an allosteric interaction with the output target molecule in response to the input target molecule depends on a junction region, which connects the two aptamer units. Efficient and effective optimization of the junction region remains a technical challenge. In this study, we demonstrate a simple strategy for optimizing the junction region through functional RNA selection using RNA-capturing microsphere particles. From approximately 0.2 million sequence variants, a signaling aptamer that enabled intracellular detection of S-adenosyl methionine with a high signal-to-noise ratio, which is approximately 2-fold higher relative fluorescence increment compared to the previously reported signaling aptamer, was obtained after single round of selection. The technology demonstrated here can be used to select RNA sequences that carry out specific functions in response to particular stimuli.
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Affiliation(s)
- Tamaki Endoh
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20 Minatojima-Minamimachi, Kobe 650-0047, Japan
| | - Naoki Sugimoto
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20 Minatojima-Minamimachi, Kobe 650-0047, Japan.,Graduate School of Frontiers of Innovative Research in Science and Technology (FIRST), Konan University, 7-1-20 Minatojima-Minamimachi, Kobe 650-0047, Japan
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75
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Steinmetzger C, Bessi I, Lenz AK, Höbartner C. Structure-fluorescence activation relationships of a large Stokes shift fluorogenic RNA aptamer. Nucleic Acids Res 2020; 47:11538-11550. [PMID: 31740962 PMCID: PMC7145527 DOI: 10.1093/nar/gkz1084] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 10/13/2019] [Accepted: 11/01/2019] [Indexed: 12/21/2022] Open
Abstract
The Chili RNA aptamer is a 52 nt long fluorogen-activating RNA aptamer (FLAP) that confers fluorescence to structurally diverse derivatives of fluorescent protein chromophores. A key feature of Chili is the formation of highly stable complexes with different ligands, which exhibit bright, highly Stokes-shifted fluorescence emission. In this work, we have analyzed the interactions between the Chili RNA and a family of conditionally fluorescent ligands using a variety of spectroscopic, calorimetric and biochemical techniques to reveal key structure–fluorescence activation relationships (SFARs). The ligands under investigation form two categories with emission maxima of ∼540 or ∼590 nm, respectively, and bind with affinities in the nanomolar to low-micromolar range. Isothermal titration calorimetry was used to elucidate the enthalpic and entropic contributions to binding affinity for a cationic ligand that is unique to the Chili aptamer. In addition to fluorescence activation, ligand binding was also observed by NMR spectroscopy, revealing characteristic signals for the formation of a G-quadruplex only upon ligand binding. These data shed light on the molecular features required and responsible for the large Stokes shift and the strong fluorescence enhancement of red and green emitting RNA–chromophore complexes.
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Affiliation(s)
- Christian Steinmetzger
- Institute of Organic Chemistry, Julius-Maximilians-University Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Irene Bessi
- Institute of Organic Chemistry, Julius-Maximilians-University Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Ann-Kathrin Lenz
- Institute of Organic Chemistry, Julius-Maximilians-University Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Claudia Höbartner
- Institute of Organic Chemistry, Julius-Maximilians-University Würzburg, Am Hubland, 97074 Würzburg, Germany
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76
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Trachman RJ, Cojocaru R, Wu D, Piszczek G, Ryckelynck M, Unrau PJ, Ferré-D'Amaré AR. Structure-Guided Engineering of the Homodimeric Mango-IV Fluorescence Turn-on Aptamer Yields an RNA FRET Pair. Structure 2020; 28:776-785.e3. [PMID: 32386573 DOI: 10.1016/j.str.2020.04.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 04/06/2020] [Accepted: 04/11/2020] [Indexed: 10/24/2022]
Abstract
Fluorescent RNA aptamers have been used in cells as biosensor reporters and tags for tracking transcripts. Recently, combined SELEX and microfluidic fluorescence sorting yielded three aptamers that activate fluorescence of TO1-Biotin: Mango-II, Mango-III, and Mango-IV. Of these, Mango-IV was best at imaging RNAs in both fixed and live mammalian cells. To understand how Mango-IV achieves activity in cells, we determined its crystal structure complexed with TO1-Biotin. The structure reveals a domain-swapped homodimer with two independent G-quadruplex fluorophore binding pockets. Structure-based analyses indicate that the Mango-IV core has relaxed fluorophore specificity, and a tendency to reorganize binding pocket residues. These molecular properties may endow it with robustness in the cellular milieu. Based on the domain-swapped structure, heterodimers between Mango-IV and the fluorescent aptamer iSpinach, joined by Watson-Crick base pairing, were constructed. These exhibited FRET between their respective aptamer-activated fluorophores, advancing fluorescent aptamer technology toward multi-color, RNA-based imaging of RNA coexpression and colocalization.
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Affiliation(s)
- Robert J Trachman
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, 50 South Drive MSC 8012, Bethesda, MD 20892-8012, USA
| | - Razvan Cojocaru
- Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
| | - Di Wu
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, 50 South Drive MSC 8012, Bethesda, MD 20892-8012, USA
| | - Grzegorz Piszczek
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, 50 South Drive MSC 8012, Bethesda, MD 20892-8012, USA
| | - Michael Ryckelynck
- Architecture et Réactivité de l'ARN, Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire du CNRS, 15 rue René Descartes, 67084 Strasbourg, France
| | - Peter J Unrau
- Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
| | - Adrian R Ferré-D'Amaré
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, 50 South Drive MSC 8012, Bethesda, MD 20892-8012, USA.
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Abstract
Iron is essential for nearly every organism, and mismanagement of its intracellular concentrations (either deficiency or excess) contributes to diminished virulence in human pathogens, necessitating intricate metalloregulatory mechanisms. To date, although several metal-responsive riboswitches have been identified in bacteria, none has been shown to respond to FeII. The czcD riboswitch, present in numerous human gut microbiota and pathogens, was recently shown to respond to NiII and CoII but thought not to respond to FeII, on the basis of aerobic, in vitro assays; its function in vivo is not well understood. We constructed a fluorescent sensor using this riboswitch fused to the RNA aptamer, Spinach2. When assayed anaerobically, the resulting sensor responds in vitro to FeII, as well as to MnII, CoII, NiII, and ZnII, but only in the cases of FeII and MnII do the apparent Kd values (0.4 and 11 μM, respectively) fall within the range of labile metal concentrations maintained by known metalloregulators. We also show that the sensor-which is, to the best of our knowledge, the first reversible genetically encoded fluorescent sensor for FeII-responds to iron in Escherichia coli cells. Finally, we demonstrate that the putative metal exporters directly downstream of two czcD riboswitches efficiently rescue iron toxicity in a heterologous expression system. Together, our results indicate that iron merits consideration as a plausible physiological ligand for czcD riboswitches, although a response to general metal stress cannot be ruled out at present.
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Affiliation(s)
- Jiansong Xu
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Joseph A Cotruvo
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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78
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Chen C, Fang C. Devising Efficient Red-Shifting Strategies for Bioimaging: A Generalizable Donor-Acceptor Fluorophore Prototype. Chem Asian J 2020; 15:1514-1523. [PMID: 32216076 DOI: 10.1002/asia.202000175] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 03/26/2020] [Indexed: 11/06/2022]
Abstract
Long emission wavelengths, high fluorescence quantum yields (FQYs), and large Stokes shifts are highly desirable features for fluorescent probes in biological imaging. However, the current development of many fluorescent probes remains largely trial-and-error and lacks efficiency. Moreover, to achieve far-red/near-infrared emission, a significant extension in the π -conjugation is usually adopted but accompanied by other drawbacks such as fluorescence loss. In this review, we discuss an effective red-shifting strategy built upon the green fluorescent protein chromophore, which enables a synergistic tuning of both the electronic ground and excited states. This approach could shorten the path toward redder emission in comparison to the conventional intramolecular charge transfer (ICT) strategy. We envision that this spectroscopy and computation-aided strategy may advance the noncanonical fluorescent protein design and be generalized to various fluorophore scaffolds for redder emission while preserving other superior properties such as high FQYs.
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Affiliation(s)
- Cheng Chen
- Department of Chemistry, Oregon State University 153 Gilbert Hall, Corvallis, OR, 97331, USA
| | - Chong Fang
- Department of Chemistry, Oregon State University 153 Gilbert Hall, Corvallis, OR, 97331, USA
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79
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Samanta D, Ebrahimi SB, Mirkin CA. Nucleic-Acid Structures as Intracellular Probes for Live Cells. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1901743. [PMID: 31271253 PMCID: PMC6942251 DOI: 10.1002/adma.201901743] [Citation(s) in RCA: 93] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 05/08/2019] [Indexed: 05/02/2023]
Abstract
The chemical composition of cells at the molecular level determines their growth, differentiation, structure, and function. Probing this composition is powerful because it provides invaluable insight into chemical processes inside cells and in certain cases allows disease diagnosis based on molecular profiles. However, many techniques analyze fixed cells or lysates of bulk populations, in which information about dynamics and cellular heterogeneity is lost. Recently, nucleic-acid-based probes have emerged as a promising platform for the detection of a wide variety of intracellular analytes in live cells with single-cell resolution. Recent advances in this field are described and common strategies for probe design, types of targets that can be identified, current limitations, and future directions are discussed.
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Affiliation(s)
- Devleena Samanta
- Department of Chemistry and International Institute for Nanotechnology, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA
| | - Sasha B Ebrahimi
- Department of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA
| | - Chad A Mirkin
- Department of Chemistry and International Institute for Nanotechnology, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA
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80
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Development of encoded Broccoli RNA aptamers for live cell imaging of alphavirus genomic and subgenomic RNAs. Sci Rep 2020; 10:5233. [PMID: 32251299 PMCID: PMC7090087 DOI: 10.1038/s41598-020-61573-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 02/03/2020] [Indexed: 11/26/2022] Open
Abstract
Sindbis virus (SINV) can infect neurons and cause encephalomyelitis in mice. Nonstructural proteins are translated from genomic RNA and structural proteins from subgenomic RNA. While visualization of viral proteins in living cells is well developed, imaging of viral RNAs has been challenging. RNA aptamers that bind and activate conditional fluorophores provide a tool for RNA visualization. We incorporated cassettes of two F30-scaffolded dimers of the Broccoli aptamer into a SINV cDNA clone using sites in nsP3 (genomic RNA), the 3′UTR (genomic and subgenomic RNAs) and after a second subgenomic promoter resulting in 4–28 Broccoli copies. After addition of the cell-permeable 3,5-difluoro-4-hydroxybenzylidene imidazolinone (DFHBI-1T) conditional fluorophore and laser excitation, infected cells emitted green fluorescence that correlated with Broccoli copy numbers. All recombinant viruses replicated well in BHK and undifferentiated neural cells but viruses with 14 or more Broccoli copies were attenuated in differentiated neurons and mice. The signal survived fixation and allowed visualization of viral RNAs in differentiated neurons and mouse brain, as well as BHK cells. Subgenomic RNA was diffusely distributed in the cytoplasm with genomic RNA also in perinuclear vesicle-like structures near envelope glycoproteins or mitochondria. Broccoli aptamer-tagging provides a valuable tool for live cell imaging of viral RNA.
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81
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Masoud S, Mihan P, Hamed M, Mehdi M, Mohamad RM. The presence of mycobacterial antigens in sarcoidosis associated granulomas. SARCOIDOSIS VASCULITIS AND DIFFUSE LUNG DISEASES 2020; 34:236-241. [PMID: 32476851 PMCID: PMC7170105 DOI: 10.36141/svdld.v34i3.5739] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 12/22/2016] [Indexed: 01/30/2023]
Abstract
Background: Sarcoidosis is a multi-organ disorder with unknown etiology. The role of bacteria in pathogenesis of sarcoidosis is still controversial. This study analyses new aspects of Mycobacterium Tuberculosis (MTB) presence in sarcoidosis diseases. Objectives: To find MTB in paraffin embedded tissues of sarcoidosis patients, samples of 10 sarcoidosis, 12 confirmed pulmonary tuberculosis (PTB) and 5 controls associated with granulomatous tissues were analysed. Methods: The paraffin embedded tissue specimens of the selected patients from the pathology archive of a subspecialty pulmonary hospital in IRAN were evaluated by Real Time PCR for MTB DNA using IS6110. Immunohistochemistry (IHC) method using MTB purified protein derivative (PPD) antibody was used to detect mycobacterial antigens. Results: All sarcoidosis patients had negative MTB DNA results in Real time PCR analysis. This analysis resulted in 10 (83.3%) positive cases for TB patients. The IHC analysis for MTB anti-PPD antibody showed positive diffused cytoplasmic staining for all TB patients whereas this staining was positive for 3 sarcoidosis patients (30%). Conclusion: Amplification of the IS6110 DNA sequence that is the most common target used for MTB diagnosis is not sensitive method to detect MTB in sarcoidosis granuloma. However, tissue IHC for anti-PPD antibody shows higher performance to detect MTB in sarcoidal granulomas reveals a mycobacterial signature in sarcoidosis tissue with negative IS6110 assay. This finding supports Mycobacterium tuberculosis may have an etiologic role in sarcoidosis. (Sarcoidosis Vasc Diffuse Lung Dis 2017; 34: 236-241)
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Affiliation(s)
- Shamaei Masoud
- Clinical Tuberculosis and Epidemiology Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Pourabdollah Mihan
- Chronic Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mousaei Hamed
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, NE2 4AX, UK
| | - Mirsaeidi Mehdi
- Division of Pulmonary and Critical Care, Department of Medicine, University of Miami, FL, US
| | - Reza Masjedi Mohamad
- Tobacco Prevention and Control Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences,Tehran, Iran
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82
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Li X, Kim H, Litke JL, Wu J, Jaffrey SR. Fluorophore‐Promoted RNA Folding and Photostability Enables Imaging of Single Broccoli‐Tagged mRNAs in Live Mammalian Cells. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201914576] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Xing Li
- Department of PharmacologyWeill Cornell MedicineCornell University New York NY 10065 USA
| | - Hyaeyeong Kim
- Department of PharmacologyWeill Cornell MedicineCornell University New York NY 10065 USA
| | - Jacob L. Litke
- Department of PharmacologyWeill Cornell MedicineCornell University New York NY 10065 USA
| | - Jiahui Wu
- Department of PharmacologyWeill Cornell MedicineCornell University New York NY 10065 USA
| | - Samie R. Jaffrey
- Department of PharmacologyWeill Cornell MedicineCornell University New York NY 10065 USA
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83
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RNA-based fluorescent biosensors for live cell imaging of small molecules and RNAs. Curr Opin Biotechnol 2020; 63:157-166. [PMID: 32086101 DOI: 10.1016/j.copbio.2020.01.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Revised: 12/23/2019] [Accepted: 01/03/2020] [Indexed: 12/23/2022]
Abstract
Genetically encodable fluorescent biosensors provide spatiotemporal information on their target analytes in a label-free manner, which has enabled the study of cell biology and signaling in living cells. Over the past three decades, fueled by the development of a wide palette of fluorescent proteins, protein-based fluorescent biosensors against a broad array of targets have been developed. Recently, with the development of fluorogenic RNA aptamer-dye pairs that function in live cells, RNA-based fluorescent (RBF) biosensors have emerged as a complementary class of biosensors. Here we review the current state-of-the-art for fluorogenic RNA aptamers and RBF biosensors for imaging small molecules and RNAs, and highlight some emerging opportunities.
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84
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Li X, Kim H, Litke JL, Wu J, Jaffrey SR. Fluorophore-Promoted RNA Folding and Photostability Enables Imaging of Single Broccoli-Tagged mRNAs in Live Mammalian Cells. Angew Chem Int Ed Engl 2020; 59:4511-4518. [PMID: 31850609 DOI: 10.1002/anie.201914576] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Indexed: 11/11/2022]
Abstract
Spinach and Broccoli are fluorogenic RNA aptamers that bind DFHBI, a mimic of the chromophore in green fluorescent protein, and activate its fluorescence. Spinach/Broccoli-DFHBI complexes exhibit high fluorescence in vitro, but they exhibit lower fluorescence in mammalian cells. Here, computational screening was used to identify BI, a DFHBI derivative that binds Broccoli with higher affinity and leads to markedly higher fluorescence in cells compared to previous ligands. BI prevents thermal unfolding of Broccoli at 37 °C, leading to more folded Broccoli and thus more fluorescent Broccoli-BI complexes in cells. Broccoli-BI complexes are more photostable owing to impaired photoisomerization and rapid unbinding of photoisomerized cis-BI. These properties enable single mRNA containing 24 Broccoli aptamers to be imaged in live mammalian cells treated with BI. Small molecule ligands can thus promote RNA folding in cells, and thus allow single mRNA imaging with fluorogenic aptamers.
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Affiliation(s)
- Xing Li
- Department of Pharmacology, Weill Cornell Medicine, Cornell University, New York, NY, 10065, USA
| | - Hyaeyeong Kim
- Department of Pharmacology, Weill Cornell Medicine, Cornell University, New York, NY, 10065, USA
| | - Jacob L Litke
- Department of Pharmacology, Weill Cornell Medicine, Cornell University, New York, NY, 10065, USA
| | - Jiahui Wu
- Department of Pharmacology, Weill Cornell Medicine, Cornell University, New York, NY, 10065, USA
| | - Samie R Jaffrey
- Department of Pharmacology, Weill Cornell Medicine, Cornell University, New York, NY, 10065, USA
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85
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Yuan SF, Alper HS. Improving Spinach2-and Broccoli-based biosensors for single and double analytes. ACTA ACUST UNITED AC 2020. [DOI: 10.1016/j.biotno.2020.01.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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86
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Gao T, Luo Y, Li W, Cao Y, Pei R. Progress in the isolation of aptamers to light-up the dyes and the applications. Analyst 2020; 145:701-718. [DOI: 10.1039/c9an01825e] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The progress in the selection of aptamers to light-up the dyes and the related applications are reviewed.
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Affiliation(s)
- Tian Gao
- CAS Key Laboratory of Nano-Bio Interface
- Suzhou Institute of Nano-Tech and Nano-Bionics
- Chinese Academy of Sciences
- Suzhou
- China
| | - Yu Luo
- CAS Key Laboratory of Nano-Bio Interface
- Suzhou Institute of Nano-Tech and Nano-Bionics
- Chinese Academy of Sciences
- Suzhou
- China
| | - Wenjing Li
- CAS Key Laboratory of Nano-Bio Interface
- Suzhou Institute of Nano-Tech and Nano-Bionics
- Chinese Academy of Sciences
- Suzhou
- China
| | - Yanwei Cao
- CAS Key Laboratory of Nano-Bio Interface
- Suzhou Institute of Nano-Tech and Nano-Bionics
- Chinese Academy of Sciences
- Suzhou
- China
| | - Renjun Pei
- CAS Key Laboratory of Nano-Bio Interface
- Suzhou Institute of Nano-Tech and Nano-Bionics
- Chinese Academy of Sciences
- Suzhou
- China
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87
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Deng H, Yan S, Huang Y, Lei C, Nie Z. Design strategies for fluorescent proteins/mimics and their applications in biosensing and bioimaging. Trends Analyt Chem 2020. [DOI: 10.1016/j.trac.2019.115757] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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88
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Péresse T, Gautier A. Next-Generation Fluorogen-Based Reporters and Biosensors for Advanced Bioimaging. Int J Mol Sci 2019; 20:E6142. [PMID: 31817528 PMCID: PMC6940837 DOI: 10.3390/ijms20246142] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 12/04/2019] [Accepted: 12/04/2019] [Indexed: 12/17/2022] Open
Abstract
Our ability to observe biochemical events with high spatial and temporal resolution is essential for understanding the functioning of living systems. Intrinsically fluorescent proteins such as the green fluorescent protein (GFP) have revolutionized the way biologists study cells and organisms. The fluorescence toolbox has been recently extended with new fluorescent reporters composed of a genetically encoded tag that binds endogenously present or exogenously applied fluorogenic chromophores (so-called fluorogens) and activates their fluorescence. This review presents the toolbox of fluorogen-based reporters and biosensors available to biologists. Various applications are detailed to illustrate the possible uses and opportunities offered by this new generation of fluorescent probes and sensors for advanced bioimaging.
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Affiliation(s)
- Tiphaine Péresse
- Sorbonne Université, École Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules, LBM, 75005 Paris, France;
| | - Arnaud Gautier
- Sorbonne Université, École Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules, LBM, 75005 Paris, France;
- Institut Universitaire de France (IUF), 1 rue Descartes, 75005 Paris, France
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89
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Xu F, Fan M, Kang S, Duan X. A genetically encoded fluorescent biosensor for detecting nitroreductase activity in living cancer cells. Anal Chim Acta 2019; 1088:131-136. [DOI: 10.1016/j.aca.2019.08.058] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 08/16/2019] [Accepted: 08/25/2019] [Indexed: 01/19/2023]
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90
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Panigaj M, Johnson MB, Ke W, McMillan J, Goncharova EA, Chandler M, Afonin KA. Aptamers as Modular Components of Therapeutic Nucleic Acid Nanotechnology. ACS NANO 2019; 13:12301-12321. [PMID: 31664817 PMCID: PMC7382785 DOI: 10.1021/acsnano.9b06522] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Nucleic acids play a central role in all domains of life, either as genetic blueprints or as regulators of various biochemical pathways. The chemical makeup of ribonucleic acid (RNA) or deoxyribonucleic acid (DNA), generally represented by a sequence of four monomers, also provides precise instructions for folding and higher-order assembly of these biopolymers that, in turn, dictate biological functions. The sequence-based specific 3D structures of nucleic acids led to the development of the directed evolution of oligonucleotides, SELEX (systematic evolution of ligands by exponential enrichment), against a chosen target molecule. Among the variety of functions, selected oligonucleotides named aptamers also allow targeting of cell-specific receptors with antibody-like precision and can deliver functional RNAs without a transfection agent. The advancements in the field of customizable nucleic acid nanoparticles (NANPs) opened avenues for the design of nanoassemblies utilizing aptamers for triggering or blocking cell signaling pathways or using aptamer-receptor combinations to activate therapeutic functionalities. A recent selection of fluorescent aptamers enables real-time tracking of NANP formation and interactions. The aptamers are anticipated to contribute to the future development of technologies, enabling an efficient assembly of functional NANPs in mammalian cells or in vivo. These research topics are of top importance for the field of therapeutic nucleic acid nanotechnology with the promises to scale up mass production of NANPs suitable for biomedical applications, to control the intracellular organization of biological materials to enhance the efficiency of biochemical pathways, and to enhance the therapeutic potential of NANP-based therapeutics while minimizing undesired side effects and toxicities.
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Affiliation(s)
- Martin Panigaj
- Nanoscale Science Program, Department of Chemistry, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
- Institute of Biology and Ecology, Faculty of Science, Pavol Jozef Safarik University in Kosice, Kosice 04154, Slovak Republic
| | - M. Brittany Johnson
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
| | - Weina Ke
- Nanoscale Science Program, Department of Chemistry, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
| | - Jessica McMillan
- Nanoscale Science Program, Department of Chemistry, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
| | - Ekaterina A. Goncharova
- Nanoscale Science Program, Department of Chemistry, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
- Laboratory of Solution Chemistry of Advanced Materials and Technologies, ITMO University, St. Petersburg 191002, Russian Federation
| | - Morgan Chandler
- Nanoscale Science Program, Department of Chemistry, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
| | - Kirill A. Afonin
- Nanoscale Science Program, Department of Chemistry, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, United States
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91
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Wright TA, Jiang L, Park JJ, Anderson WA, Chen G, Hallberg ZF, Nan B, Hammond MC. Second messengers and divergent HD-GYP phosphodiesterases regulate 3',3'-cGAMP signaling. Mol Microbiol 2019; 113:222-236. [PMID: 31665539 DOI: 10.1111/mmi.14412] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/28/2019] [Indexed: 12/16/2022]
Abstract
3',3'-cyclic GMP-AMP (cGAMP) is the third cyclic dinucleotide (CDN) to be discovered in bacteria. No activators of cGAMP signaling have yet been identified, and the signaling pathways for cGAMP have been inferred to display a narrow distribution based upon the characterized synthases, DncV and Hypr GGDEFs. Here, we report that the ubiquitous second messenger cyclic AMP (cAMP) is an activator of the Hypr GGDEF enzyme GacB from Myxococcus xanthus. Furthermore, we show that GacB is inhibited directly by cyclic di-GMP, which provides evidence for cross-regulation between different CDN pathways. Finally, we reveal that the HD-GYP enzyme PmxA is a cGAMP-specific phosphodiesterase (GAP) that promotes resistance to osmotic stress in M. xanthus. A signature amino acid change in PmxA was found to reprogram substrate specificity and was applied to predict the presence of non-canonical HD-GYP phosphodiesterases in many bacterial species, including phyla previously not known to utilize cGAMP signaling.
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Affiliation(s)
- Todd A Wright
- Department of Chemistry, University of California, Berkeley, CA, 94720, USA.,Department of Chemistry and Henry Eyring Center for Cell and Genome Science, University of Utah, Salt Lake City, UT, 84112, USA
| | - Lucy Jiang
- Department of Chemistry, University of California, Berkeley, CA, 94720, USA
| | - James J Park
- Department of Chemistry, University of California, Berkeley, CA, 94720, USA
| | - Wyatt A Anderson
- Department of Chemistry, University of California, Berkeley, CA, 94720, USA.,Department of Chemistry and Henry Eyring Center for Cell and Genome Science, University of Utah, Salt Lake City, UT, 84112, USA
| | - Ge Chen
- Department of Biology, Texas A&M University, College Station, TX, 77843, USA
| | - Zachary F Hallberg
- Department of Chemistry, University of California, Berkeley, CA, 94720, USA
| | - Beiyan Nan
- Department of Biology, Texas A&M University, College Station, TX, 77843, USA
| | - Ming C Hammond
- Department of Chemistry and Henry Eyring Center for Cell and Genome Science, University of Utah, Salt Lake City, UT, 84112, USA
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92
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A dimerization-based fluorogenic dye-aptamer module for RNA imaging in live cells. Nat Chem Biol 2019; 16:69-76. [PMID: 31636432 PMCID: PMC6920041 DOI: 10.1038/s41589-019-0381-8] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Accepted: 08/22/2019] [Indexed: 01/19/2023]
Abstract
Live-cell imaging of RNA has remained a challenge because of the lack of naturally fluorescent RNAs. Recently developed RNA aptamers that can light-up small fluorogenic dyes could overcome this limitation, but they still suffer from poor brightness and photostability. Here, we propose a concept of cell-permeable fluorogenic dimer of sulforhodamine B dyes (Gemini-561) and corresponding dimerized aptamer (o-Coral) that can drastically enhance performance of the current RNA imaging method. The unprecedented brightness and photostability together with high affinity of this complex allowed, for the first time, direct fluorescence imaging in live mammalian cells of RNA polymerase-III transcription products as well as messenger RNAs labelled with a single copy of the aptamer, i.e. without tag multimerization. The developed fluorogenic module enables fast and sensitive detection of RNA inside live cells, while the proposed design concept opens the route to new generation of ultrabright RNA probes.
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93
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Kim H, Jaffrey SR. A Fluorogenic RNA-Based Sensor Activated by Metabolite-Induced RNA Dimerization. Cell Chem Biol 2019; 26:1725-1731.e6. [PMID: 31631009 DOI: 10.1016/j.chembiol.2019.09.013] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 08/02/2019] [Accepted: 09/26/2019] [Indexed: 11/30/2022]
Abstract
Corn is a fluorogenic RNA aptamer that forms a high-affinity quasi-symmetric homodimer. The Corn dimer interface binds DFHO, resulting in highly photostable yellow fluorescence. Because of its photostability, Corn would be useful in RNA-based small-molecule biosensors, where quantitative accuracy would be affected by photobleaching. Here we describe a strategy for converting the constitutive Corn dimer into a small-molecule-regulated fluorescent biosensor that detects S-adenosylmethionine (SAM) in vitro and in living cells. We fused the Corn aptamer into a helical stem that was engineered by circularly permuting the SAM aptamer from the SAM-III riboswitch. In the absence of SAM, the Corn portion of this fusion RNA is unable to dimerize. However, upon binding SAM, the RNA dimerizes and binds DFHO. This RNA-based biosensor enables detection of SAM dynamics in living mammalian cells. Together, these data describe a class of RNA-based biosensor based on small-molecule-regulated dimerization of Corn.
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Affiliation(s)
- Hyaeyeong Kim
- Department of Pharmacology, Weill Cornell Medicine, Cornell University, New York, NY 10065, USA
| | - Samie R Jaffrey
- Department of Pharmacology, Weill Cornell Medicine, Cornell University, New York, NY 10065, USA.
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94
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Chen X, Zhang D, Su N, Bao B, Xie X, Zuo F, Yang L, Wang H, Jiang L, Lin Q, Fang M, Li N, Hua X, Chen Z, Bao C, Xu J, Du W, Zhang L, Zhao Y, Zhu L, Loscalzo J, Yang Y. Visualizing RNA dynamics in live cells with bright and stable fluorescent RNAs. Nat Biotechnol 2019; 37:1287-1293. [PMID: 31548726 DOI: 10.1038/s41587-019-0249-1] [Citation(s) in RCA: 183] [Impact Index Per Article: 36.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2018] [Accepted: 08/02/2019] [Indexed: 12/15/2022]
Abstract
Fluorescent RNAs (FRs), aptamers that bind and activate fluorescent dyes, have been used to image abundant cellular RNA species. However, limitations such as low brightness and limited availability of dye/aptamer combinations with different spectral characteristics have limited use of these tools in live mammalian cells and in vivo. Here, we develop Peppers, a series of monomeric, bright and stable FRs with a broad range of emission maxima spanning from cyan to red. Peppers allow simple and robust imaging of diverse RNA species in live cells with minimal perturbation of the target RNA's transcription, localization and translation. Quantification of the levels of proteins and their messenger RNAs in single cells suggests that translation is governed by normal enzyme kinetics but with marked heterogeneity. We further show that Peppers can be used for imaging genomic loci with CRISPR display, for real-time tracking of protein-RNA tethering, and for super-resolution imaging. We believe these FRs will be useful tools for live imaging of cellular RNAs.
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Affiliation(s)
- Xianjun Chen
- Optogenetics and Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, Shanghai, China.,CAS Center for Excellence in Brain Science and Intelligence Technology, Institute of Neuroscience, Chinese Academy of Sciences, Shanghai, China.,School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Dasheng Zhang
- Optogenetics and Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, Shanghai, China.,School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, China
| | - Ni Su
- Optogenetics and Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, Shanghai, China.,School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Bingkun Bao
- Optogenetics and Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, Shanghai, China.,School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, China
| | - Xin Xie
- Optogenetics and Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, Shanghai, China.,School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Fangting Zuo
- Optogenetics and Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, Shanghai, China.,School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Lipeng Yang
- Optogenetics and Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, Shanghai, China.,School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, China
| | - Hui Wang
- Optogenetics and Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, Shanghai, China.,School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Li Jiang
- Optogenetics and Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, Shanghai, China.,School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, China
| | - Qiuning Lin
- Optogenetics and Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, Shanghai, China.,School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, China
| | - Mengyue Fang
- Optogenetics and Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, Shanghai, China.,School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Ningfeng Li
- Optogenetics and Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, Shanghai, China.,School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, China
| | - Xin Hua
- Optogenetics and Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, Shanghai, China.,School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, China
| | - Zhengda Chen
- Optogenetics and Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, Shanghai, China.,School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Chunyan Bao
- Optogenetics and Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, Shanghai, China.,School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, China
| | - Jinjin Xu
- Key Laboratory of Advanced Control and Optimization for Chemical Processed of Ministry of Education, School of information Science and Engineering, East China University of Science and Technology, Shanghai, China
| | - Wenli Du
- Key Laboratory of Advanced Control and Optimization for Chemical Processed of Ministry of Education, School of information Science and Engineering, East China University of Science and Technology, Shanghai, China
| | - Lixin Zhang
- Optogenetics and Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, Shanghai, China
| | - Yuzheng Zhao
- Optogenetics and Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, Shanghai, China.,School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Linyong Zhu
- Optogenetics and Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, Shanghai, China. .,School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, China.
| | - Joseph Loscalzo
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Yi Yang
- Optogenetics and Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, Shanghai, China. .,CAS Center for Excellence in Brain Science and Intelligence Technology, Institute of Neuroscience, Chinese Academy of Sciences, Shanghai, China. .,School of Pharmacy, East China University of Science and Technology, Shanghai, China.
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95
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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.
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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.
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96
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Yesselman JD, Eiler D, Carlson ED, Gotrik MR, d'Aquino AE, Ooms AN, Kladwang W, Carlson PD, Shi X, Costantino DA, Herschlag D, Lucks JB, Jewett MC, Kieft JS, Das R. Computational design of three-dimensional RNA structure and function. NATURE NANOTECHNOLOGY 2019; 14:866-873. [PMID: 31427748 PMCID: PMC7324284 DOI: 10.1038/s41565-019-0517-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 06/24/2019] [Indexed: 05/30/2023]
Abstract
RNA nanotechnology seeks to create nanoscale machines by repurposing natural RNA modules. The field is slowed by the current need for human intuition during three-dimensional structural design. Here, we demonstrate that three distinct problems in RNA nanotechnology can be reduced to a pathfinding problem and automatically solved through an algorithm called RNAMake. First, RNAMake discovers highly stable single-chain solutions to the classic problem of aligning a tetraloop and its sequence-distal receptor, with experimental validation from chemical mapping, gel electrophoresis, solution X-ray scattering and crystallography with 2.55 Å resolution. Second, RNAMake automatically generates structured tethers that integrate 16S and 23S ribosomal RNAs into single-chain ribosomal RNAs that remain uncleaved by ribonucleases and assemble onto messenger RNA. Third, RNAMake enables the automated stabilization of small-molecule binding RNAs, with designed tertiary contacts that improve the binding affinity of the ATP aptamer and improve the fluorescence and stability of the Spinach RNA in cell extracts and in living Escherichia coli cells.
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Affiliation(s)
- Joseph D Yesselman
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, USA
| | - Daniel Eiler
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver School of Medicine, Aurora, CO, USA
| | - Erik D Carlson
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA
- Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, USA
| | - Michael R Gotrik
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, USA
| | - Anne E d'Aquino
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, USA
- Interdisciplinary Biological Sciences Graduate Program, Northwestern University, Evanston, IL, USA
| | - Alexandra N Ooms
- Department of Cancer Genetics & Genomics, Stanford University School of Medicine, Stanford, CA, USA
| | - Wipapat Kladwang
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, USA
| | - Paul D Carlson
- Robert F. Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY, USA
| | - Xuesong Shi
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, USA
| | - David A Costantino
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver School of Medicine, Aurora, CO, USA
| | - Daniel Herschlag
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, USA
- Department of Chemistry, Stanford University School of Medicine, Stanford, CA, USA
- Stanford ChEM-H (Chemistry, Engineering, and Medicine for Human Health), Stanford University, Stanford, CA, USA
| | - Julius B Lucks
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA
- Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, USA
- Interdisciplinary Biological Sciences Graduate Program, Northwestern University, Evanston, IL, USA
| | - Michael C Jewett
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA
- Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, USA
- Interdisciplinary Biological Sciences Graduate Program, Northwestern University, Evanston, IL, USA
| | - Jeffrey S Kieft
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver School of Medicine, Aurora, CO, USA
| | - Rhiju Das
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, USA.
- Department of Physics, Stanford University, Stanford, CA, USA.
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97
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Saha R, Chen IA. Effect of UV Radiation on Fluorescent RNA Aptamers' Functional and Templating Ability. Chembiochem 2019; 20:2609-2617. [PMID: 31125512 PMCID: PMC6899979 DOI: 10.1002/cbic.201900261] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Indexed: 12/25/2022]
Abstract
Damage from ultraviolet (UV) radiation was likely to be an important selection pressure during the origin of life. RNA is believed to have been central to the origin of life and might form the basis for simple synthetic cells. Although photodamage of DNA has been extensively studied, photodamage is highly dependent on local molecular context, and damage to functional RNAs has been relatively under‐studied. We irradiated two fluorescent RNA aptamers and monitored the loss of activity, folding, and the kinetics of lesion accumulation. The loss of activity differed depending on the aptamer, with the Spinach2 aptamer retaining substantial activity after long exposure times. The binding pocket was particularly susceptible to damage, and melting of the duplex regions increased susceptibility; this is consistent with the view that duplex formation is protective. At the same time, susceptibility varied greatly depending on context, thus emphasizing the importance of studying many different RNAs to understand UV hardiness.
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Affiliation(s)
- Ranajay Saha
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, 93106, USA
| | - Irene A Chen
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, 93106, USA.,Program in Biomolecular Sciences and Engineering, University of California, Santa Barbara, CA, 93106, USA.,Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA, 90095, USA
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98
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Tracking RNA with light: selection, structure, and design of fluorescence turn-on RNA aptamers. Q Rev Biophys 2019; 52:e8. [PMID: 31423956 DOI: 10.1017/s0033583519000064] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Fluorescence turn-on aptamers, in vitro evolved RNA molecules that bind conditional fluorophores and activate their fluorescence, have emerged as RNA counterparts of the fluorescent proteins. Turn-on aptamers have been selected to bind diverse fluorophores, and they achieve varying degrees of specificity and affinity. These RNA-fluorophore complexes, many of which exceed the brightness of green fluorescent protein and their variants, can be used as tags for visualizing RNA localization and transport in live cells. Structure determination of several fluorescent RNAs revealed that they have diverse, unrelated overall architectures. As most of these RNAs activate the fluorescence of their ligands by restraining their photoexcited states into a planar conformation, their fluorophore binding sites have in common a planar arrangement of several nucleobases, most commonly a G-quartet. Nonetheless, each turn-on aptamer has developed idiosyncratic structural solutions to achieve specificity and efficient fluorescence turn-on. The combined structural diversity of fluorophores and turn-on RNA aptamers has already produced combinations that cover the visual spectrum. Further molecular evolution and structure-guided engineering is likely to produce fluorescent tags custom-tailored to specific applications.
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99
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Chia HE, Marsh ENG, Biteen JS. Extending fluorescence microscopy into anaerobic environments. Curr Opin Chem Biol 2019; 51:98-104. [DOI: 10.1016/j.cbpa.2019.05.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Revised: 04/22/2019] [Accepted: 05/13/2019] [Indexed: 12/01/2022]
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100
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Endoh T, Ohyama T, Sugimoto N. RNA-Capturing Microsphere Particles (R-CAMPs) for Optimization of Functional Aptamers. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2019; 15:e1805062. [PMID: 30773785 DOI: 10.1002/smll.201805062] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 01/23/2019] [Indexed: 06/09/2023]
Abstract
RNA aptamers are useful building blocks for constructing functional nucleic acid-based nanoarchitectures. The abilities of aptamers to recognize specific ligands have also been utilized for various biotechnological applications. Solution conditions, which can differ depending on the application, impact the affinity of the aptamers, and thus it is important to optimize the aptamers for the solution conditions to be employed. To simplify the aptamer optimization process, an efficient method that enables re-selection of an aptamer from a partially randomized library is developed. The process relies on RNA-capturing microsphere particles (R-CAMPs): each particle displays different clones of identical DNA and RNA sequences. Using a fluorescence-activated cell sorter, the R-CAMPs that are linked to functional aptamers are sorted. It is demonstrated that after a single round of reselection, several functional aptamers, including the wild-type, are selected from a library of 16 384 sequences. The selection using R-CAMPs is further performed under the solution containing high concentration of ethylene glycol, suggesting applicability in various conditions to optimize an aptamer for a particular application. As any type of RNA clone can be displayed on the microspheres, the technology demonstrated here will be useful for the selection of RNAs based on diverse functions.
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Affiliation(s)
- Tamaki Endoh
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20, Minatojima-minamimachi, Chuo-ku, Kobe, 650-0047, Japan
| | - Tatsuya Ohyama
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20, Minatojima-minamimachi, Chuo-ku, Kobe, 650-0047, Japan
| | - Naoki Sugimoto
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20, Minatojima-minamimachi, Chuo-ku, Kobe, 650-0047, Japan
- Graduate School of Frontiers of Innovative Research in Science and Technology (FIRST), Konan University, 7-1-20, Minatojima-minamimachi, Chuo-ku, Kobe, 650-0047, Japan
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