1
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Lu X, Passalacqua LFM, Nodwell M, Kong KYS, Caballero-García G, Dolgosheina EV, Ferré-D'Amaré AR, Britton R, Unrau PJ. Symmetry breaking of fluorophore binding to a G-quadruplex generates an RNA aptamer with picomolar KD. Nucleic Acids Res 2024:gkae493. [PMID: 38945550 DOI: 10.1093/nar/gkae493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 05/21/2024] [Accepted: 06/12/2024] [Indexed: 07/02/2024] Open
Abstract
Fluorogenic RNA aptamer tags with high affinity enable RNA purification and imaging. The G-quadruplex (G4) based Mango (M) series of aptamers were selected to bind a thiazole orange based (TO1-Biotin) ligand. Using a chemical biology and reselection approach, we have produced a MII.2 aptamer-ligand complex with a remarkable set of properties: Its unprecedented KD of 45 pM, formaldehyde resistance (8% v/v), temperature stability and ligand photo-recycling properties are all unusual to find simultaneously within a small RNA tag. Crystal structures demonstrate how MII.2, which differs from MII by a single A23U mutation, and modification of the TO1-Biotin ligand to TO1-6A-Biotin achieves these results. MII binds TO1-Biotin heterogeneously via a G4 surface that is surrounded by a stadium of five adenosines. Breaking this pseudo-rotational symmetry results in a highly cooperative and homogeneous ligand binding pocket: A22 of the G4 stadium stacks on the G4 binding surface while the TO1-6A-Biotin ligand completely fills the remaining three quadrants of the G4 ligand binding face. Similar optimization attempts with MIII.1, which already binds TO1-Biotin in a homogeneous manner, did not produce such marked improvements. We use the novel features of the MII.2 complex to demonstrate a powerful optically-based RNA purification system.
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Affiliation(s)
- Xiaocen Lu
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Luiz F M Passalacqua
- Laboratory of Nucleic Acids, National Heart, Lung and Blood Institute, Bethesda, MD 20892, USA
| | - Matthew Nodwell
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Kristen Y S Kong
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | | | - Elena V Dolgosheina
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Adrian R Ferré-D'Amaré
- Laboratory of Nucleic Acids, National Heart, Lung and Blood Institute, Bethesda, MD 20892, USA
| | - Robert Britton
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Peter J Unrau
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
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2
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Sathyan D, Sunbul M. A bright green tag for RNA imaging. Nat Chem Biol 2024:10.1038/s41589-024-01637-x. [PMID: 38831038 DOI: 10.1038/s41589-024-01637-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2024]
Affiliation(s)
- Dhrisya Sathyan
- Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Heidelberg, Germany
| | - Murat Sunbul
- Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Heidelberg, Germany.
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3
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Zuo F, Jiang L, Su N, Zhang Y, Bao B, Wang L, Shi Y, Yang H, Huang X, Li R, Zeng Q, Chen Z, Lin Q, Zhuang Y, Zhao Y, Chen X, Zhu L, Yang Y. Imaging the dynamics of messenger RNA with a bright and stable green fluorescent RNA. Nat Chem Biol 2024:10.1038/s41589-024-01629-x. [PMID: 38783134 DOI: 10.1038/s41589-024-01629-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 04/19/2024] [Indexed: 05/25/2024]
Abstract
Fluorescent RNAs (FRs) provide an attractive approach to visualizing RNAs in live cells. Although the color palette of FRs has been greatly expanded recently, a green FR with high cellular brightness and photostability is still highly desired. Here we develop a fluorogenic RNA aptamer, termed Okra, that can bind and activate the fluorophore ligand ACE to emit bright green fluorescence. Okra has an order of magnitude enhanced cellular brightness than currently available green FRs, allowing the robust imaging of messenger RNA in both live bacterial and mammalian cells. We further demonstrate the usefulness of Okra for time-resolved measurements of ACTB mRNA trafficking to stress granules, as well as live-cell dual-color superresolution imaging of RNA in combination with Pepper620, revealing nonuniform and distinct distributions of different RNAs throughout the granules. The favorable properties of Okra make it a versatile tool for the study of RNA dynamics and subcellular localization.
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Affiliation(s)
- Fangting Zuo
- Optogenetics & Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
- Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism, School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Li Jiang
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Ni Su
- Optogenetics & Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
- Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism, School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Yaqiang Zhang
- Optogenetics & Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
- Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism, School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Bingkun Bao
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Limei Wang
- Optogenetics & Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
- Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism, School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Yajie Shi
- Optogenetics & Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Huimin Yang
- Optogenetics & Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
- Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism, School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Xinyi Huang
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Ruilong Li
- Optogenetics & Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Qingmei Zeng
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Zhengda Chen
- Optogenetics & Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
- Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism, School of Pharmacy, East China University of Science and Technology, Shanghai, China
| | - Qiuning Lin
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Yingping Zhuang
- School of Bioengineering, East China University of Science and Technology, Shanghai, China
| | - Yuzheng Zhao
- Optogenetics & Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
- Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism, School of Pharmacy, East China University of Science and Technology, Shanghai, China
- Research Unit of New Techniques for Live-cell Metabolic Imaging, Chinese Academy of Medical Sciences, Beijing, China
| | - Xianjun Chen
- Optogenetics & Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China.
- Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism, School of Pharmacy, East China University of Science and Technology, Shanghai, China.
- Research Unit of New Techniques for Live-cell Metabolic Imaging, Chinese Academy of Medical Sciences, Beijing, China.
| | - Linyong Zhu
- Optogenetics & Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China.
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.
| | - Yi Yang
- Optogenetics & Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China.
- Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism, School of Pharmacy, East China University of Science and Technology, Shanghai, China.
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4
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Zhang Y, Xu Z, Xiao Y, Jiang H, Zuo X, Li X, Fang X. Structural mechanisms for binding and activation of a contact-quenched fluorophore by RhoBAST. Nat Commun 2024; 15:4206. [PMID: 38760339 PMCID: PMC11101630 DOI: 10.1038/s41467-024-48478-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Accepted: 04/29/2024] [Indexed: 05/19/2024] Open
Abstract
The fluorescent light-up aptamer RhoBAST, which binds and activates the fluorophore-quencher conjugate tetramethylrhodamine-dinitroaniline with high affinity, super high brightness, remarkable photostability, and fast exchange kinetics, exhibits excellent performance in super-resolution RNA imaging. Here we determine the co-crystal structure of RhoBAST in complex with tetramethylrhodamine-dinitroaniline to elucidate the molecular basis for ligand binding and fluorescence activation. The structure exhibits an asymmetric "A"-like architecture for RhoBAST with a semi-open binding pocket harboring the xanthene of tetramethylrhodamine at the tip, while the dinitroaniline quencher stacks over the phenyl of tetramethylrhodamine instead of being fully released. Molecular dynamics simulations show highly heterogeneous conformational ensembles with the contact-but-unstacked fluorophore-quencher conformation for both free and bound tetramethylrhodamine-dinitroaniline being predominant. The simulations also show that, upon RNA binding, the fraction of xanthene-dinitroaniline stacked conformation significantly decreases in free tetramethylrhodamine-dinitroaniline. This highlights the importance of releasing dinitroaniline from xanthene tetramethylrhodamine to unquench the RhoBAST-tetramethylrhodamine-dinitroaniline complex. Using SAXS and ITC, we characterized the magnesium dependency of the folding and binding mode of RhoBAST in solution and indicated its strong structural robustness. The structures and binding modes of relevant fluorescent light-up aptamers are compared, providing mechanistic insights for rational design and optimization of this important fluorescent light-up aptamer-ligand system.
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Affiliation(s)
- Yufan Zhang
- Key Laboratory of RNA Science and Engineering, Institute of Biophysics Chinese Academy of Sciences, Beijing, China
| | - Zhonghe Xu
- Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing, China
| | - Yu Xiao
- Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing, China
| | - Haodong Jiang
- Institute of Zoology, Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, China
| | - Xiaobing Zuo
- X-ray Science Division, Argonne National Laboratory, Lemont, IL, USA
| | - Xing Li
- Institute of Zoology, Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, China.
| | - Xianyang Fang
- Key Laboratory of RNA Science and Engineering, Institute of Biophysics Chinese Academy of Sciences, Beijing, China.
- Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing, China.
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5
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Pham TG, Wu J. Recent advances in methods for live-cell RNA imaging. NANOSCALE 2024; 16:5537-5545. [PMID: 38414383 DOI: 10.1039/d4nr00129j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Abstract
As one of the most fundamental building blocks of life, RNA plays critical roles in diverse biological processes, from X chromosome inactivation, genome stability maintenance, to embryo development. Being able to visualize the localization and dynamics of RNA can provide critical insights into these fundamental processes. In this review, we provide an overview of current methods for live-cell RNA imaging with a focus on methods for visualizing RNA in living mammalian cells with single-molecule resolution.
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Affiliation(s)
- Tien G Pham
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, USA.
| | - Jiahui Wu
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, USA.
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6
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Zhang Z, Wei W, Chen S, Yang J, Song D, Chen Y, Zhao Z, Chen J, Wang F, Wang J, Li Z, Liang Y, Yu H. Chemoenzymatic Installation of Site-Specific Chemical Groups on DNA Enhances the Catalytic Activity. J Am Chem Soc 2024; 146:7052-7062. [PMID: 38427585 DOI: 10.1021/jacs.4c00484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2024]
Abstract
Functional DNAs are valuable molecular tools in chemical biology and analytical chemistry but suffer from low activities due to their limited chemical functionalities. Here, we present a chemoenzymatic method for site-specific installation of diverse functional groups on DNA, and showcase the application of this method to enhance the catalytic activity of a DNA catalyst. Through chemoenzymatic introduction of distinct chemical groups, such as hydroxyl, carboxyl, and benzyl, at specific positions, we achieve significant enhancements in the catalytic activity of the RNA-cleaving deoxyribozyme 10-23. A single carboxyl modification results in a 100-fold increase, while dual modifications (carboxyl and benzyl) yield an approximately 700-fold increase in activity when an RNA cleavage reaction is catalyzed on a DNA-RNA chimeric substrate. The resulting dually modified DNA catalyst, CaBn, exhibits a kobs of 3.76 min-1 in the presence of 1 mM Mg2+ and can be employed for fluorescent imaging of intracellular magnesium ions. Molecular dynamics simulations reveal the superior capability of CaBn to recruit magnesium ions to metal-ion-binding site 2 and adopt a catalytically competent conformation. Our work provides a broadly accessible strategy for DNA functionalization with diverse chemical modifications, and CaBn offers a highly active DNA catalyst with immense potential in chemistry and biotechnology.
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Affiliation(s)
- Ze Zhang
- State Key Laboratory of Coordination Chemistry, Department of Biomedical Engineering, College of Engineering and Applied Sciences, Chemistry and Biomedicine Innovation Center (ChemBIC), Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210023, China
| | - Wanqing Wei
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China
| | - Siqi Chen
- State Key Laboratory of Coordination Chemistry, Department of Biomedical Engineering, College of Engineering and Applied Sciences, Chemistry and Biomedicine Innovation Center (ChemBIC), Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210023, China
| | - Jintao Yang
- State Key Laboratory of Coordination Chemistry, Department of Biomedical Engineering, College of Engineering and Applied Sciences, Chemistry and Biomedicine Innovation Center (ChemBIC), Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210023, China
| | - Dongfan Song
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Yinghan Chen
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Zerun Zhao
- School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Jiawen Chen
- State Key Laboratory of Coordination Chemistry, Department of Biomedical Engineering, College of Engineering and Applied Sciences, Chemistry and Biomedicine Innovation Center (ChemBIC), Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210023, China
| | - Fulong Wang
- State Key Laboratory of Coordination Chemistry, Department of Biomedical Engineering, College of Engineering and Applied Sciences, Chemistry and Biomedicine Innovation Center (ChemBIC), Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210023, China
| | - Jiahuan Wang
- State Key Laboratory of Coordination Chemistry, Department of Biomedical Engineering, College of Engineering and Applied Sciences, Chemistry and Biomedicine Innovation Center (ChemBIC), Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210023, China
| | - Zhe Li
- State Key Laboratory of Analytical Chemistry for Life Science, Department of Biomedical Engineering, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210023, China
| | - Yong Liang
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Hanyang Yu
- State Key Laboratory of Coordination Chemistry, Department of Biomedical Engineering, College of Engineering and Applied Sciences, Chemistry and Biomedicine Innovation Center (ChemBIC), Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210023, China
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7
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Ji R, Wang L, Shang Y, Du S, Xiao Y, Dong W, Cui L, Gao R, Ren K. RNA Condensate as a Versatile Platform for Improving Fluorogenic RNA Aptamer Properties and Cell Imaging. J Am Chem Soc 2024; 146:4402-4411. [PMID: 38329936 DOI: 10.1021/jacs.3c09162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2024]
Abstract
Fluorogenic RNA aptamers are valuable tools for cell imaging, but they still suffer from shortcomings such as easy degradation, limited photostability, and low fluorescence enhancement. Molecular crowding conditions enable the stabilization of the structure, promotion of folding, and improvement of activity of functional RNA. Based on artificial RNA condensates, here we present a versatile platform to improve fluorogenic RNA aptamer properties and develop sensors for target analyte imaging in living cells. Using the CUG repeat as a general tag to drive phase separation, various fluorogenic aptamer-based RNA condensates (FLARE) were prepared. We show that the molecular crowding of FLARE can improve the enzymatic resistance, thermostability, photostability, and binding affinity of fluorogenic RNA aptamers. Moreover, the FLARE systems can be modularly engineered into sensors (FLARES), which demonstrate enhanced brightness and sensitivity compared to free sensors dispersed in homogeneous solution. This scalable design principle provides new insights into RNA aptamer property regulation and cellular imaging.
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Affiliation(s)
- Ruoyang Ji
- School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, P.R. China
| | - Long Wang
- School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, P.R. China
| | - Yuzhe Shang
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, P.R. China
| | - Songyuan Du
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, P.R. China
| | - Yang Xiao
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, P.R. China
| | - Wei Dong
- School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, P.R. China
| | - Lin Cui
- College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, P.R. China
| | - Ruru Gao
- School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, P.R. China
| | - Kewei Ren
- School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, P.R. China
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8
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Bühler B, Sunbul M. Single-Molecule RNA Imaging in Live Cells with an Avidity-Based Fluorescent Light-Up Aptamer biRhoBAST. Methods Mol Biol 2024; 2822:87-100. [PMID: 38907914 DOI: 10.1007/978-1-0716-3918-4_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/24/2024]
Abstract
Observing individual RNA molecules provides valuable insights into their regulation, interactions with other cellular components, organization, and functions. Although fluorescent light-up aptamers (FLAPs) have recently shown promise for RNA imaging, their wider applications have been mostly hindered by poor brightness and photostability. We recently developed an avidity-based FLAP known as biRhoBAST that allows for single-molecule RNA imaging in live or fixed cells and tracking individual mRNA molecules in living cells due to its excellent photostability and high brightness. Here, we present step-by-step detailed protocols starting from cloning biRhoBAST repeats into the target RNA sequence, to imaging dynamics of single mRNA molecules. Additionally, we address the validation of single-molecule imaging experiments through single-molecule fluorescence in situ hybridization (smFISH) and colocalization studies.
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Affiliation(s)
- Bastian Bühler
- Department of Chemical Biology, Max Planck Institute for Medical Research, Heidelberg, Germany
| | - Murat Sunbul
- Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Heidelberg, Germany.
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9
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Yin P, Ge M, Xie S, Zhang L, Kuang S, Nie Z. A universal orthogonal imaging platform for living-cell RNA detection using fluorogenic RNA aptamers. Chem Sci 2023; 14:14131-14139. [PMID: 38098702 PMCID: PMC10717586 DOI: 10.1039/d3sc04957d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 11/21/2023] [Indexed: 12/17/2023] Open
Abstract
MicroRNAs (miRNAs) are crucial regulators of gene expression at the post-transcriptional level, offering valuable insights into disease mechanisms and prospects for targeted therapeutic interventions. Herein, we present a class of miRNA-induced light-up RNA sensors (miLS) that are founded on the toehold mediated principle and employ the fluorogenic RNA aptamers Pepper and Squash as imaging modules. By incorporating a sensor switch to disrupt the stabilizing stem of these aptamers, our design offers enhanced flexibility and convertibility for different target miRNAs and aptamers. These sensors detect multiple miRNA targets (miR-21 and miR-122) with detection limits of 0.48 and 0.2 nM, respectively, while achieving a robust signal-to-noise ratio of up to 44 times. Capitalizing on the distinct fluorescence imaging channels afforded by Pepper-HBC620 (red) and Squash-DFHBI-1T (green), we establish an orthogonal miRNA activation imaging platform, enabling the simultaneous visualization of different intracellular miRNAs in living cells. Our dual-color orthogonal miLS imaging platform provides a powerful tool for sequence-specific miRNA imaging in different cells, opening up new avenues for studying the intricate functions of RNA in living cells.
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Affiliation(s)
- Peng Yin
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan Provincial Key Laboratory of Biomacromolecular Chemical Biology, Hunan University Changsha 410082 China
| | - Mingmin Ge
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan Provincial Key Laboratory of Biomacromolecular Chemical Biology, Hunan University Changsha 410082 China
| | - Shiyi Xie
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan Provincial Key Laboratory of Biomacromolecular Chemical Biology, Hunan University Changsha 410082 China
| | - Li Zhang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan Provincial Key Laboratory of Biomacromolecular Chemical Biology, Hunan University Changsha 410082 China
| | - Shi Kuang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan Provincial Key Laboratory of Biomacromolecular Chemical Biology, Hunan University Changsha 410082 China
| | - Zhou Nie
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan Provincial Key Laboratory of Biomacromolecular Chemical Biology, Hunan University Changsha 410082 China
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10
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Si D, Li Q, Bao Y, Zhang J, Wang L. Fluorogenic and Cell-Permeable Rhodamine Dyes for High-Contrast Live-Cell Protein Labeling in Bioimaging and Biosensing. Angew Chem Int Ed Engl 2023; 62:e202307641. [PMID: 37483077 DOI: 10.1002/anie.202307641] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 07/21/2023] [Accepted: 07/21/2023] [Indexed: 07/25/2023]
Abstract
The advancement of fluorescence microscopy techniques has opened up new opportunities for visualizing proteins and unraveling their functions in living biological systems. Small-molecule organic dyes, which possess exceptional photophysical properties, small size, and high photostability, serve as powerful fluorescent reporters in protein imaging. However, achieving high-contrast live-cell labeling of target proteins with conventional organic dyes remains a considerable challenge in bioimaging and biosensing due to their inadequate cell permeability and high background signal. Over the past decade, a novel generation of fluorogenic and cell-permeable dyes has been developed, which have substantially improved live-cell protein labeling by fine-tuning the reversible equilibrium between a cell-permeable, nonfluorescent spirocyclic state (unbound) and a fluorescent zwitterion (protein-bound) of rhodamines. In this review, we present the mechanism and design strategies of these fluorogenic and cell-permeable rhodamines, as well as their applications in bioimaging and biosensing.
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Affiliation(s)
- Dongjuan Si
- School of Pharmacy, Endoscopy Center and Endoscopy Research Institute, Zhongshan Hospital, Fudan University, Zhangheng Road 826, Shanghai, China
| | - Quanlin Li
- School of Pharmacy, Endoscopy Center and Endoscopy Research Institute, Zhongshan Hospital, Fudan University, Zhangheng Road 826, Shanghai, China
| | - Yifan Bao
- School of Pharmacy, Endoscopy Center and Endoscopy Research Institute, Zhongshan Hospital, Fudan University, Zhangheng Road 826, Shanghai, China
| | - Jingye Zhang
- School of Pharmacy, Endoscopy Center and Endoscopy Research Institute, Zhongshan Hospital, Fudan University, Zhangheng Road 826, Shanghai, China
| | - Lu Wang
- School of Pharmacy, Endoscopy Center and Endoscopy Research Institute, Zhongshan Hospital, Fudan University, Zhangheng Road 826, Shanghai, China
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11
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Bühler B, Schokolowski J, Jäschke A, Sunbul M. Programmable, Structure-Switching RhoBAST for Hybridization-Mediated mRNA Imaging in Living Cells. ACS Chem Biol 2023; 18:1838-1845. [PMID: 37530071 DOI: 10.1021/acschembio.3c00258] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/03/2023]
Abstract
The development of fluorescent probes for visualizing endogenous RNAs in living cells is crucial to understand their complex biochemical roles. Recently, we developed RhoBAST, one of the most photostable and brightest fluorescence light-up aptamers (FLAPs), as a genetically encoded tag for imaging messenger RNAs (mRNAs). Here, we describe programmable RhoBAST sequences flanked by target-binding hybridization arms that light up only when bound to the untagged target RNA in trans. As part of the hybridization arm, we introduced a modular transducer sequence that switches the secondary structure of RhoBAST and renders it incapable of binding to its fluorogenic ligand TMR-DN. Only the specific binding of the hybridization arms to the target RNA triggers the correct folding of RhoBAST and fluorescence light-up after binding to TMR-DN. We characterized the structural switching of programmable RhoBAST sequences extensively in vitro and applied them to visualize untagged mRNAs in live bacteria.
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Affiliation(s)
- Bastian Bühler
- Institute of Pharmacy and Molecular Biotechnology (IPMB), Heidelberg University, 69120 Heidelberg, Germany
| | - Janin Schokolowski
- Institute of Pharmacy and Molecular Biotechnology (IPMB), Heidelberg University, 69120 Heidelberg, Germany
| | - Andres Jäschke
- Institute of Pharmacy and Molecular Biotechnology (IPMB), Heidelberg University, 69120 Heidelberg, Germany
| | - Murat Sunbul
- Institute of Pharmacy and Molecular Biotechnology (IPMB), Heidelberg University, 69120 Heidelberg, Germany
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Englert D, Burger EM, Grün F, Verma MS, Lackner J, Lampe M, Bühler B, Schokolowski J, Nienhaus GU, Jäschke A, Sunbul M. Fast-exchanging spirocyclic rhodamine probes for aptamer-based super-resolution RNA imaging. Nat Commun 2023; 14:3879. [PMID: 37391423 PMCID: PMC10313827 DOI: 10.1038/s41467-023-39611-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 06/22/2023] [Indexed: 07/02/2023] Open
Abstract
Live-cell RNA imaging with high spatial and temporal resolution remains a major challenge. Here we report the development of RhoBAST:SpyRho, a fluorescent light-up aptamer (FLAP) system ideally suited for visualizing RNAs in live or fixed cells with various advanced fluorescence microscopy modalities. Overcoming problems associated with low cell permeability, brightness, fluorogenicity, and signal-to-background ratio of previous fluorophores, we design a novel probe, SpyRho (Spirocyclic Rhodamine), which tightly binds to the RhoBAST aptamer. High brightness and fluorogenicity is achieved by shifting the equilibrium between spirolactam and quinoid. With its high affinity and fast ligand exchange, RhoBAST:SpyRho is a superb system for both super-resolution SMLM and STED imaging. Its excellent performance in SMLM and the first reported super-resolved STED images of specifically labeled RNA in live mammalian cells represent significant advances over other FLAPs. The versatility of RhoBAST:SpyRho is further demonstrated by imaging endogenous chromosomal loci and proteins.
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Affiliation(s)
- Daniel Englert
- Institute of Pharmacy and Molecular Biotechnology (IPMB), Heidelberg University, Heidelberg, Germany
| | - Eva-Maria Burger
- Institute of Pharmacy and Molecular Biotechnology (IPMB), Heidelberg University, Heidelberg, Germany
| | - Franziska Grün
- Institute of Pharmacy and Molecular Biotechnology (IPMB), Heidelberg University, Heidelberg, Germany
| | - Mrigank S Verma
- Institute of Applied Physics (APH), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Jens Lackner
- Institute of Applied Physics (APH), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Marko Lampe
- Advanced Light Microscopy Facility, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Bastian Bühler
- Institute of Pharmacy and Molecular Biotechnology (IPMB), Heidelberg University, Heidelberg, Germany
| | - Janin Schokolowski
- Institute of Pharmacy and Molecular Biotechnology (IPMB), Heidelberg University, Heidelberg, Germany
| | - G Ulrich Nienhaus
- Institute of Applied Physics (APH), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany.
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany.
- Institute of Biological and Chemical Systems (IBCS), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany.
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
| | - Andres Jäschke
- Institute of Pharmacy and Molecular Biotechnology (IPMB), Heidelberg University, Heidelberg, Germany.
| | - Murat Sunbul
- Institute of Pharmacy and Molecular Biotechnology (IPMB), Heidelberg University, Heidelberg, Germany.
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