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Xia C, Colognori D, Jiang X, Xu K, Doudna JA. Single-molecule live-cell RNA imaging with CRISPR-Csm. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.14.603457. [PMID: 39071319 PMCID: PMC11275710 DOI: 10.1101/2024.07.14.603457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
High-resolution, real-time imaging of RNA is essential for understanding the diverse, dynamic behaviors of individual RNA molecules in single cells. However, single-molecule live-cell imaging of unmodified endogenous RNA has not yet been achieved. Here, we present single-molecule live-cell fluorescence in situ hybridization (smLiveFISH), a robust approach that combines the programmable RNA-guided, RNA-targeting CRISPR-Csm complex with multiplexed guide RNAs for efficient, direct visualization of single RNA molecules in a range of cell types, including primary cells. Using smLiveFISH, we tracked individual endogenous NOTCH2 and MAP1B mRNA transcripts in living cells and identified two distinct localization mechanisms: co-translational translocation of NOTCH2 mRNA at the endoplasmic reticulum, and directional transport of MAP1B mRNA toward the cell periphery. This method has the potential to unlock principles governing the spatiotemporal organization of native transcripts in health and disease.
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Abstract
The translation of messenger RNA (mRNA) into proteins represents the culmination of gene expression. Recent technological advances have revolutionized our ability to investigate this process with unprecedented precision, enabling the study of translation at the single-molecule level in real time within live cells. In this review, we provide an overview of single-mRNA translation reporters. We focus on the core technology, as well as the rapid development of complementary probes, tags, and accessories that enable the visualization and quantification of a wide array of translation dynamics. We then highlight notable studies that have utilized these reporters in model systems to address key biological questions. The high spatiotemporal resolution of these studies is shedding light on previously unseen phenomena, uncovering the full heterogeneity and complexity of translational regulation.
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Affiliation(s)
- Tatsuya Morisaki
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, USA;
| | - O'Neil Wiggan
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, USA;
| | - Timothy J Stasevich
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, USA;
- Cell Biology Center and World Research Hub Initiative, Tokyo Institute of Technology, Yokohama, Japan
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3
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Hwang DW, Maekiniemi A, Singer RH, Sato H. Real-time single-molecule imaging of transcriptional regulatory networks in living cells. Nat Rev Genet 2024; 25:272-285. [PMID: 38195868 DOI: 10.1038/s41576-023-00684-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/27/2023] [Indexed: 01/11/2024]
Abstract
Gene regulatory networks drive the specific transcriptional programmes responsible for the diversification of cell types during the development of multicellular organisms. Although our knowledge of the genes involved in these dynamic networks has expanded rapidly, our understanding of how transcription is spatiotemporally regulated at the molecular level over a wide range of timescales in the small volume of the nucleus remains limited. Over the past few decades, advances in the field of single-molecule fluorescence imaging have enabled real-time behaviours of individual transcriptional components to be measured in living cells and organisms. These efforts are now shedding light on the dynamic mechanisms of transcription, revealing not only the temporal rules but also the spatial coordination of underlying molecular interactions during various biological events.
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Affiliation(s)
- Dong-Woo Hwang
- Department of Cell Biology, Albert Einstein College of Medicine, New York, NY, USA
| | - Anna Maekiniemi
- Department of Cell Biology, Albert Einstein College of Medicine, New York, NY, USA
| | - Robert H Singer
- Department of Cell Biology, Albert Einstein College of Medicine, New York, NY, USA
| | - Hanae Sato
- Department of Cell Biology, Albert Einstein College of Medicine, New York, NY, USA.
- Nano Life Science Institute (WPI-Nano LSI), Kanazawa University, Kakuma-machi, Kanazawa, Japan.
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4
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Blake LA, Watkins L, Liu Y, Inoue T, Wu B. A rapid inducible RNA decay system reveals fast mRNA decay in P-bodies. Nat Commun 2024; 15:2720. [PMID: 38548718 PMCID: PMC10979015 DOI: 10.1038/s41467-024-46943-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 03/14/2024] [Indexed: 04/01/2024] Open
Abstract
RNA decay is vital for regulating mRNA abundance and gene expression. Existing technologies lack the spatiotemporal precision or transcript specificity to capture the stochastic and transient decay process. We devise a general strategy to inducibly recruit protein factors to modulate target RNA metabolism. Specifically, we introduce a Rapid Inducible Decay of RNA (RIDR) technology to degrade target mRNAs within minutes. The fast and synchronous induction enables direct visualization of mRNA decay dynamics in cells. Applying RIDR to endogenous ACTB mRNA reveals rapid formation and dissolution of RNA granules in pre-existing P-bodies. Time-resolved RNA distribution measurements demonstrate rapid RNA decay inside P-bodies, which is further supported by knocking down P-body constituent proteins. Light and oxidative stress modulate P-body behavior, potentially reconciling the contradictory literature about P-body function. This study reveals compartmentalized RNA decay kinetics, establishing RIDR as a pivotal tool for exploring the spatiotemporal RNA metabolism in cells.
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Affiliation(s)
- Lauren A Blake
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- The Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Leslie Watkins
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- The Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Yang Liu
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- The Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Department of Biochemistry, University of Utah, Salt Lake City, UT, 84112, USA
| | - Takanari Inoue
- The Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Bin Wu
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
- The Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
- The Solomon H Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
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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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Liu Z, Jillette N, Robson P, Cheng AW. Simultaneous multifunctional transcriptome engineering by CRISPR RNA scaffold. Nucleic Acids Res 2023; 51:e77. [PMID: 37395412 PMCID: PMC10415119 DOI: 10.1093/nar/gkad547] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 06/06/2023] [Accepted: 06/15/2023] [Indexed: 07/04/2023] Open
Abstract
RNA processing and metabolism are subjected to precise regulation in the cell to ensure integrity and functions of RNA. Though targeted RNA engineering has become feasible with the discovery and engineering of the CRISPR-Cas13 system, simultaneous modulation of different RNA processing steps remains unavailable. In addition, off-target events resulting from effectors fused with dCas13 limit its application. Here we developed a novel platform, Combinatorial RNA Engineering via Scaffold Tagged gRNA (CREST), which can simultaneously execute multiple RNA modulation functions on different RNA targets. In CREST, RNA scaffolds are appended to the 3' end of Cas13 gRNA and their cognate RNA binding proteins are fused with enzymatic domains for manipulation. Taking RNA alternative splicing, A-to-G and C-to-U base editing as examples, we developed bifunctional and tri-functional CREST systems for simultaneously RNA manipulation. Furthermore, by fusing two split fragments of the deaminase domain of ADAR2 to dCas13 and/or PUFc respectively, we reconstituted its enzyme activity at target sites. This split design can reduce nearly 99% of off-target events otherwise induced by a full-length effector. The flexibility of the CREST framework will enrich the transcriptome engineering toolbox for the study of RNA biology.
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Affiliation(s)
- Zukai Liu
- The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032, USA
- Department of Genetics and Genome Sciences, University of Connecticut Health Center, Farmington, CT 06030, USA
| | | | - Paul Robson
- The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032, USA
- Department of Genetics and Genome Sciences, University of Connecticut Health Center, Farmington, CT 06030, USA
- The Jackson Laboratory Cancer Center, Bar Harbor, ME 04609, USA
- Institute for Systems Genomics, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Albert Wu Cheng
- The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032, USA
- Department of Genetics and Genome Sciences, University of Connecticut Health Center, Farmington, CT 06030, USA
- The Jackson Laboratory Cancer Center, Bar Harbor, ME 04609, USA
- Institute for Systems Genomics, University of Connecticut Health Center, Farmington, CT 06030, USA
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ 85281, USA
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Gerber A, van Otterdijk S, Bruggeman FJ, Tutucci E. Understanding spatiotemporal coupling of gene expression using single molecule RNA imaging technologies. Transcription 2023; 14:105-126. [PMID: 37050882 PMCID: PMC10807504 DOI: 10.1080/21541264.2023.2199669] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 03/30/2023] [Accepted: 04/01/2023] [Indexed: 04/14/2023] Open
Abstract
Across all kingdoms of life, gene regulatory mechanisms underlie cellular adaptation to ever-changing environments. Regulation of gene expression adjusts protein synthesis and, in turn, cellular growth. Messenger RNAs are key molecules in the process of gene expression. Our ability to quantitatively measure mRNA expression in single cells has improved tremendously over the past decades. This revealed an unexpected coordination between the steps that control the life of an mRNA, from transcription to degradation. Here, we provide an overview of the state-of-the-art imaging approaches for measurement and quantitative understanding of gene expression, starting from the early visualizations of single genes by electron microscopy to current fluorescence-based approaches in single cells, including live-cell RNA-imaging approaches to FISH-based spatial transcriptomics across model organisms. We also highlight how these methods have shaped our current understanding of the spatiotemporal coupling between transcriptional and post-transcriptional events in prokaryotes. We conclude by discussing future challenges of this multidisciplinary field.Abbreviations: mRNA: messenger RNA; rRNA: ribosomal rDNA; tRNA: transfer RNA; sRNA: small RNA; FISH: fluorescence in situ hybridization; RNP: ribonucleoprotein; smFISH: single RNA molecule FISH; smiFISH: single molecule inexpensive FISH; HCR-FISH: Hybridization Chain-Reaction-FISH; RCA: Rolling Circle Amplification; seqFISH: Sequential FISH; MERFISH: Multiplexed error robust FISH; UTR: Untranslated region; RBP: RNA binding protein; FP: fluorescent protein; eGFP: enhanced GFP, MCP: MS2 coat protein; PCP: PP7 coat protein; MB: Molecular beacons; sgRNA: single guide RNA.
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Affiliation(s)
- Alan Gerber
- Amsterdam UMC, Location Vrije Universiteit Amsterdam, Department of Neurosurgery, Amsterdam, The Netherlands
- Cancer Center Amsterdam, Brain Tumor Center Amsterdam, Amsterdam, The Netherlands
| | - Sander van Otterdijk
- Systems Biology Lab, A-LIFE department, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Frank J. Bruggeman
- Systems Biology Lab, A-LIFE department, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Evelina Tutucci
- Systems Biology Lab, A-LIFE department, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
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8
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Liang Y, Willey S, Chung YC, Lo YM, Miao S, Rundell S, Tu LC, Bong D. Intracellular RNA and DNA tracking by uridine-rich internal loop tagging with fluorogenic bPNA. Nat Commun 2023; 14:2987. [PMID: 37225690 DOI: 10.1038/s41467-023-38579-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 05/05/2023] [Indexed: 05/26/2023] Open
Abstract
The most widely used method for intracellular RNA fluorescence labeling is MS2 labeling, which generally relies on the use of multiple protein labels targeted to multiple RNA (MS2) hairpin structures installed on the RNA of interest (ROI). While effective and conveniently applied in cell biology labs, the protein labels add significant mass to the bound RNA, which potentially impacts steric accessibility and native RNA biology. We have previously demonstrated that internal, genetically encoded, uridine-rich internal loops (URILs) comprised of four contiguous UU pairs (8 nt) in RNA may be targeted with minimal structural perturbation by triplex hybridization with 1 kD bifacial peptide nucleic acids (bPNAs). A URIL-targeting strategy for RNA and DNA tracking would avoid the use of cumbersome protein fusion labels and minimize structural alterations to the RNA of interest. Here we show that URIL-targeting fluorogenic bPNA probes in cell media can penetrate cell membranes and effectively label RNAs and RNPs in fixed and live cells. This method, which we call fluorogenic U-rich internal loop (FLURIL) tagging, was internally validated through the use of RNAs bearing both URIL and MS2 labeling sites. Notably, a direct comparison of CRISPR-dCas labeled genomic loci in live U2OS cells revealed that FLURIL-tagged gRNA yielded loci with signal to background up to 7X greater than loci targeted by guide RNA modified with an array of eight MS2 hairpins. Together, these data show that FLURIL tagging provides a versatile scope of intracellular RNA and DNA tracking while maintaining a light molecular footprint and compatibility with existing methods.
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Affiliation(s)
- Yufeng Liang
- Department of Chemistry & Biochemistry, The Ohio State University, Columbus, OH, USA
- Center for RNA Biology, The Ohio State University, Columbus, OH, USA
| | - Sydney Willey
- Center for RNA Biology, The Ohio State University, Columbus, OH, USA
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, USA
- The Ohio State University Comprehensive Cancer Center, The Ohio State University, Columbus, OH, USA
| | - Yu-Chieh Chung
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, USA
| | - Yi-Meng Lo
- Department of Chemistry & Biochemistry, The Ohio State University, Columbus, OH, USA
- Center for RNA Biology, The Ohio State University, Columbus, OH, USA
| | - Shiqin Miao
- Department of Chemistry & Biochemistry, The Ohio State University, Columbus, OH, USA
- Center for RNA Biology, The Ohio State University, Columbus, OH, USA
| | - Sarah Rundell
- Department of Chemistry & Biochemistry, The Ohio State University, Columbus, OH, USA
- Center for RNA Biology, The Ohio State University, Columbus, OH, USA
| | - Li-Chun Tu
- Center for RNA Biology, The Ohio State University, Columbus, OH, USA.
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, USA.
- The Ohio State University Comprehensive Cancer Center, The Ohio State University, Columbus, OH, USA.
| | - Dennis Bong
- Department of Chemistry & Biochemistry, The Ohio State University, Columbus, OH, USA.
- Center for RNA Biology, The Ohio State University, Columbus, OH, USA.
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9
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Huang Y, Gao BQ, Meng Q, Yang LZ, Ma XK, Wu H, Pan YH, Yang L, Li D, Chen LL. CRISPR-dCas13-tracing reveals transcriptional memory and limited mRNA export in developing zebrafish embryos. Genome Biol 2023; 24:15. [PMID: 36658633 PMCID: PMC9854193 DOI: 10.1186/s13059-023-02848-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 01/04/2023] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Understanding gene transcription and mRNA-protein (mRNP) dynamics in single cells in a multicellular organism has been challenging. The catalytically dead CRISPR-Cas13 (dCas13) system has been used to visualize RNAs in live cells without genetic manipulation. We optimize this system to track developmentally expressed mRNAs in zebrafish embryos and to understand features of endogenous transcription kinetics and mRNP export. RESULTS We report that zygotic microinjection of purified CRISPR-dCas13-fluorescent proteins and modified guide RNAs allows single- and dual-color tracking of developmentally expressed mRNAs in zebrafish embryos from zygotic genome activation (ZGA) until early segmentation period without genetic manipulation. Using this approach, we uncover non-synchronized de novo transcription between inter-alleles, synchronized post-mitotic re-activation in pairs of alleles, and transcriptional memory as an extrinsic noise that potentially contributes to synchronized post-mitotic re-activation. We also reveal rapid dCas13-engaged mRNP movement in the nucleus with a corralled and diffusive motion, but a wide varying range of rate-limiting mRNP export, which can be shortened by Alyref and Nxf1 overexpression. CONCLUSIONS This optimized dCas13-based toolkit enables robust spatial-temporal tracking of endogenous mRNAs and uncovers features of transcription and mRNP motion, providing a powerful toolkit for endogenous RNA visualization in a multicellular developmental organism.
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Affiliation(s)
- Youkui Huang
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, China
| | - Bao-Qing Gao
- CAS Key Laboratory of Computational Biology, Shanghai Institute of Nutrition and Health, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Quan Meng
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Liang-Zhong Yang
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, China
| | - Xu-Kai Ma
- Center for Molecular Medicine, Children's Hospital, Fudan University and Shanghai Key Laboratory of Medical Epigenetics, International Laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Hao Wu
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, China
| | - Yu-Hang Pan
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, China
| | - Li Yang
- Center for Molecular Medicine, Children's Hospital, Fudan University and Shanghai Key Laboratory of Medical Epigenetics, International Laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Dong Li
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Ling-Ling Chen
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, China.
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China.
- School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, China.
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10
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Kukhtevich IV, Rivero-Romano M, Rakesh N, Bheda P, Chadha Y, Rosales-Becerra P, Hamperl S, Bureik D, Dornauer S, Dargemont C, Kirmizis A, Schmoller KM, Schneider R. Quantitative RNA imaging in single live cells reveals age-dependent asymmetric inheritance. Cell Rep 2022; 41:111656. [DOI: 10.1016/j.celrep.2022.111656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 08/31/2022] [Accepted: 10/20/2022] [Indexed: 11/18/2022] Open
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Tingey M, Schnell SJ, Yu W, Saredy J, Junod S, Patel D, Alkurdi AA, Yang W. Technologies Enabling Single-Molecule Super-Resolution Imaging of mRNA. Cells 2022; 11:3079. [PMID: 36231040 PMCID: PMC9564294 DOI: 10.3390/cells11193079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 09/22/2022] [Accepted: 09/28/2022] [Indexed: 11/16/2022] Open
Abstract
The transient nature of RNA has rendered it one of the more difficult biological targets for imaging. This difficulty stems both from the physical properties of RNA as well as the temporal constraints associated therewith. These concerns are further complicated by the difficulty in imaging endogenous RNA within a cell that has been transfected with a target sequence. These concerns, combined with traditional concerns associated with super-resolution light microscopy has made the imaging of this critical target difficult. Recent advances have provided researchers the tools to image endogenous RNA in live cells at both the cellular and single-molecule level. Here, we review techniques used for labeling and imaging RNA with special emphases on various labeling methods and a virtual 3D super-resolution imaging technique.
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Affiliation(s)
| | | | | | | | | | | | | | - Weidong Yang
- Department of Biology, Temple University, Philadelphia, PA 19122, USA
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12
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Sun P, Zou W. Research progress of live-cell RNA imaging techniques. Zhejiang Da Xue Xue Bao Yi Xue Ban 2022; 51:362-372. [PMID: 36207827 PMCID: PMC9511491 DOI: 10.3724/zdxbyxb-2022-0017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Accepted: 04/12/2022] [Indexed: 06/16/2023]
Abstract
RNA molecules play diverse roles in many physiological and pathological processes as they interact with various nucleic acids and proteins. The various biological processes of RNA are highly dynamic. Tracking RNA dynamics in living cells is crucial for a better understanding of the spatiotemporal control of gene expression and the regulatory roles of RNA. Genetically encoded RNA-tagging systems include MS2/MCP, PP7/PCP, boxB/λN22 and CRISPR-Cas. The MS2/MCP system is the most widely applied, and it has the advantages of stable binding and high signal-to-noise ratio, while the realization of RNA imaging requires gene editing of the target RNA, which may change the characteristics of the target RNA. Recently developed CRISPR-dCas13 system does not require RNA modification, but the uncertainty in CRISPR RNA (crRNA) efficiency and low signal-to-noise ratio are its limitations. Fluorescent dye-based RNA-tagging systems include molecular beacons and fluorophore-binding aptamers. The molecular beacons have high specificity and high signal-to-noise ratio; Mango and Peppers outperform the other RNA-tagging system in signal-to-noise, but they also need gene editing. Live-cell RNA imaging allows us to visualize critical steps of RNA activities, including transcription, splicing, transport, translation (for message RNA only) and subcellular localization. It will contribute to studying biological processes such as cell differentiation and the transcriptional regulation mechanism when cells adapt to the external environment, and it improves our understanding of the pathogenic mechanism of various diseases caused by abnormal RNA behavior and helps to find potential therapeutic targets. This review provides an overview of current progress of live-cell RNA imaging techniques and highlights their major strengths and limitations.
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Affiliation(s)
- Pingping Sun
- 1. The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu 322000, Zhejiang Province, China
- 2. Institute of Translational Medicine, Zhejiang University, Hangzhou 310058, China
| | - Wei Zou
- 1. The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu 322000, Zhejiang Province, China
- 2. Institute of Translational Medicine, Zhejiang University, Hangzhou 310058, China
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13
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Cañonero L, Pautasso C, Galello F, Sigaut L, Pietrasanta L, Arroyo J, Bermúdez-Moretti M, Portela P, Rossi S. Heat stress regulates the expression of TPK1 gene at transcriptional and post-transcriptional levels in Saccharomyces cerevisiae. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2022; 1869:119209. [PMID: 34999138 DOI: 10.1016/j.bbamcr.2021.119209] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/16/2021] [Accepted: 12/28/2021] [Indexed: 12/11/2022]
Abstract
In Saccharomyces cerevisiae cAMP regulates different cellular processes through PKA. The specificity of the response of the cAMP-PKA pathway is highly regulated. Here we address the mechanism through which the cAMP-PKA pathway mediates its response to heat shock and thermal adaptation in yeast. PKA holoenzyme is composed of a regulatory subunit dimer (Bcy1) and two catalytic subunits (Tpk1, Tpk2, or Tpk3). PKA subunits are differentially expressed under certain growth conditions. Here we demonstrate the increased abundance and half-life of TPK1 mRNA and the assembly of this mRNA in cytoplasmic foci during heat shock at 37 °C. The resistance of the foci to cycloheximide-induced disassembly along with the polysome profiling analysis suggest that TPK1 mRNA is impaired for entry into translation. TPK1 expression was also evaluated during a recurrent heat shock and thermal adaptation. Tpk1 protein level is significantly increased during the recovery periods. The crosstalk of cAMP-PKA pathway and CWI signalling was also studied. Wsc3 sensor and some components of the CWI pathway are necessary for the TPK1 expression upon heat shock. The assembly in foci upon thermal stress depends on Wsc3. Tpk1 expression is lower in a wsc3∆ mutant than in WT strain during thermal adaptation and thus the PKA levels are also lower. An increase in Tpk1 abundance in the PKA holoenzyme in response to heat shock is presented, suggesting that a recurrent stress enhanced the fitness for the coming favourable conditions. Therefore, the regulation of TPK1 expression by thermal stress contributes to the specificity of cAMP-PKA signalling.
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Affiliation(s)
- Luciana Cañonero
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento Química Biológica, Buenos Aires, Argentina; CONICET Universidad de Buenos Aires, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Buenos Aires, Argentina
| | - Constanza Pautasso
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento Química Biológica, Buenos Aires, Argentina; CONICET Universidad de Buenos Aires, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Buenos Aires, Argentina
| | - Fiorella Galello
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento Química Biológica, Buenos Aires, Argentina; CONICET Universidad de Buenos Aires, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Buenos Aires, Argentina
| | - Lorena Sigaut
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento Física, Buenos Aires, Argentina; CONICET Universidad de Buenos Aires, Instituto de Física de Buenos Aires (IFIBA), Buenos Aires, Argentina
| | - Lia Pietrasanta
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento Física, Buenos Aires, Argentina; CONICET Universidad de Buenos Aires, Instituto de Física de Buenos Aires (IFIBA), Buenos Aires, Argentina
| | - Javier Arroyo
- Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad Complutense de Madrid, IRYCIS, Madrid, Spain
| | - Mariana Bermúdez-Moretti
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento Química Biológica, Buenos Aires, Argentina; CONICET Universidad de Buenos Aires, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Buenos Aires, Argentina
| | - Paula Portela
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento Química Biológica, Buenos Aires, Argentina; CONICET Universidad de Buenos Aires, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Buenos Aires, Argentina
| | - Silvia Rossi
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento Química Biológica, Buenos Aires, Argentina; CONICET Universidad de Buenos Aires, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Buenos Aires, Argentina.
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14
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Cao H, Wang Y, Zhang N, Xia S, Tian P, Lu L, Du J, Du Y. Progress of CRISPR-Cas13 Mediated Live-Cell RNA Imaging and Detection of RNA-Protein Interactions. Front Cell Dev Biol 2022; 10:866820. [PMID: 35356276 PMCID: PMC8959342 DOI: 10.3389/fcell.2022.866820] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 02/21/2022] [Indexed: 12/26/2022] Open
Abstract
Ribonucleic acid (RNA) and proteins play critical roles in gene expression and regulation. The relevant study increases the understanding of various life processes and contributes to the diagnosis and treatment of different diseases. RNA imaging and mapping RNA-protein interactions expand the understanding of RNA biology. However, the existing methods have some limitations. Recently, precise RNA targeting of CRISPR-Cas13 in cells has been reported, which is considered a new promising platform for RNA imaging in living cells and recognition of RNA-protein interactions. In this review, we first described the current findings on Cas13. Furthermore, we introduced current tools of RNA real-time imaging and mapping RNA-protein interactions and highlighted the latest advances in Cas13-mediated tools. Finally, we discussed the advantages and disadvantages of Cas13-based methods, providing a set of new ideas for the optimization of Cas13-mediated methods.
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Affiliation(s)
- Huake Cao
- School of Basic Medical Sciences, Anhui Medical University, Hefei, China
- First School of Clinical Medicine, Anhui Medical University, Hefei, China
| | - Yuechen Wang
- School of Basic Medical Sciences, Anhui Medical University, Hefei, China
- Second School of Clinical Medicine, Anhui Medical University, Hefei, China
| | - Ning Zhang
- School of Basic Medical Sciences, Anhui Medical University, Hefei, China
- First School of Clinical Medicine, Anhui Medical University, Hefei, China
- First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Siyuan Xia
- School of Basic Medical Sciences, Anhui Medical University, Hefei, China
- Second School of Clinical Medicine, Anhui Medical University, Hefei, China
| | - Pengfei Tian
- School of Basic Medical Sciences, Anhui Medical University, Hefei, China
- First School of Clinical Medicine, Anhui Medical University, Hefei, China
- First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Li Lu
- School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Juan Du
- School of Medicine, The Chinese University of Hong Kong, Shenzhen, China
- Longgang District People’s Hospital of Shenzhen & The Second Affiliated Hospital, The Chinese University of Hong Kong, Shenzhen, China
- *Correspondence: Yinan Du, ; Juan Du,
| | - Yinan Du
- School of Basic Medical Sciences, Anhui Medical University, Hefei, China
- *Correspondence: Yinan Du, ; Juan Du,
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15
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Cawte AD, Iino H, Unrau PJ, Rueda DS. Single-Molecule RNA Imaging Using Mango II Arrays. Methods Mol Biol 2022; 2404:267-280. [PMID: 34694614 DOI: 10.1007/978-1-0716-1851-6_14] [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] [Indexed: 06/13/2023]
Abstract
In recent years, fluorogenic RNA aptamers, such as Spinach, Broccoli, Corn, Mango, Coral, and Pepper have gathered traction as an efficient alternative labeling strategy for background-free imaging of cellular RNAs. However, their application has been somewhat limited by relatively inefficient folding and fluorescent stability. With the recent advent of novel RNA-Mango variants which are improved in both fluorescence intensity and folding stability in tandem arrays, it is now possible to image RNAs with single-molecule sensitivity. Here we discuss the protocol for imaging Mango II tagged RNAs in both fixed and live cells.
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Affiliation(s)
- Adam D Cawte
- Single Molecule Imaging Group, MRC London Institute of Medical Sciences, London, UK
- Section of Virology, Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, UK
- Developmental Epigenetics, Department of Biochemistry, University of Oxford, Oxford, UK
| | - Haruki Iino
- Single Molecule Imaging Group, MRC London Institute of Medical Sciences, London, UK
- Section of Virology, Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, UK
| | - Peter J Unrau
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada.
| | - David S Rueda
- Single Molecule Imaging Group, MRC London Institute of Medical Sciences, London, UK.
- Section of Virology, Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, UK.
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16
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Rombouts S, Nollmann M. RNA imaging in bacteria. FEMS Microbiol Rev 2021; 45:5917984. [PMID: 33016325 DOI: 10.1093/femsre/fuaa051] [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] [Received: 01/15/2020] [Accepted: 10/01/2020] [Indexed: 12/25/2022] Open
Abstract
The spatiotemporal regulation of gene expression plays an essential role in many biological processes. Recently, several imaging-based RNA labeling and detection methods, both in fixed and live cells, were developed and now enable the study of transcript abundance, localization and dynamics. Here, we review the main single-cell techniques for RNA visualization with fluorescence microscopy and describe their applications in bacteria.
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Affiliation(s)
- Sara Rombouts
- Centre de Biochimie Structurale, CNRS UMR 5048, INSERM U1054, Université de Montpellier, 60 Rue de Navacelles, 34090, Montpellier, France
| | - Marcelo Nollmann
- Centre de Biochimie Structurale, CNRS UMR 5048, INSERM U1054, Université de Montpellier, 60 Rue de Navacelles, 34090, Montpellier, France
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17
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Escalante LE, Gasch AP. The role of stress-activated RNA-protein granules in surviving adversity. RNA (NEW YORK, N.Y.) 2021; 27:rna.078738.121. [PMID: 33931500 PMCID: PMC8208049 DOI: 10.1261/rna.078738.121] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 04/28/2021] [Indexed: 05/17/2023]
Abstract
Severe environmental stress can trigger a plethora of physiological changes and, in the process, significant cytoplasmic reorganization. Stress-activated RNA-protein granules have been implicated in this cellular overhaul by sequestering pre-existing mRNAs and influencing their fates during and after stress acclimation. While the composition and dynamics of stress-activated granule formation has been well studied, their function and impact on RNA-cargo has remained murky. Several recent studies challenge the view that these granules degrade and silence mRNAs present at the onset of stress and instead suggest new roles for these structures in mRNA storage, transit, and inheritance. Here we discuss recent evidence for revised models of stress-activated granule functions and the role of these granules in stress survival and recovery.
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18
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Morales-Polanco F, Bates C, Lui J, Casson J, Solari CA, Pizzinga M, Forte G, Griffin C, Garner KEL, Burt HE, Dixon HL, Hubbard S, Portela P, Ashe MP. Core Fermentation (CoFe) granules focus coordinated glycolytic mRNA localization and translation to fuel glucose fermentation. iScience 2021; 24:102069. [PMID: 33554071 PMCID: PMC7859310 DOI: 10.1016/j.isci.2021.102069] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 12/16/2020] [Accepted: 01/12/2021] [Indexed: 12/24/2022] Open
Abstract
Glycolysis is a fundamental metabolic pathway for glucose catabolism across biology, and glycolytic enzymes are among the most abundant proteins in cells. Their expression at such levels provides a particular challenge. Here we demonstrate that the glycolytic mRNAs are localized to granules in yeast and human cells. Detailed live cell and smFISH studies in yeast show that the mRNAs are actively translated in granules, and this translation appears critical for the localization. Furthermore, this arrangement is likely to facilitate the higher level organization and control of the glycolytic pathway. Indeed, the degree of fermentation required by cells is intrinsically connected to the extent of mRNA localization to granules. On this basis, we term these granules, core fermentation (CoFe) granules; they appear to represent translation factories, allowing high-level coordinated enzyme synthesis for a critical metabolic pathway.
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Affiliation(s)
- Fabian Morales-Polanco
- School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Christian Bates
- School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Jennifer Lui
- School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Joseph Casson
- School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Clara A Solari
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IQUIBICEN-CONICET, Buenos Aires, Argentina
| | - Mariavittoria Pizzinga
- School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Gabriela Forte
- School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Claire Griffin
- School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Kirsten E L Garner
- School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Harriet E Burt
- School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Hannah L Dixon
- School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Simon Hubbard
- School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Paula Portela
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IQUIBICEN-CONICET, Buenos Aires, Argentina
| | - Mark P Ashe
- School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
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19
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Irastortza-Olaziregi M, Amster-Choder O. RNA localization in prokaryotes: Where, when, how, and why. WILEY INTERDISCIPLINARY REVIEWS-RNA 2020; 12:e1615. [PMID: 32851805 DOI: 10.1002/wrna.1615] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/27/2020] [Accepted: 06/02/2020] [Indexed: 12/27/2022]
Abstract
Only recently has it been recognized that the transcriptome of bacteria and archaea can be spatiotemporally regulated. All types of prokaryotic transcripts-rRNAs, tRNAs, mRNAs, and regulatory RNAs-may acquire specific localization and these patterns can be temporally regulated. In some cases bacterial RNAs reside in the vicinity of the transcription site, but in many others, transcripts show distinct localizations to the cytoplasm, the inner membrane, or the pole of rod-shaped species. This localization, which often overlaps with that of the encoded proteins, can be achieved either in a translation-dependent or translation-independent fashion. The latter implies that RNAs carry sequence-level features that determine their final localization with the aid of RNA-targeting factors. Localization of transcripts regulates their posttranscriptional fate by affecting their degradation and processing, translation efficiency, sRNA-mediated regulation, and/or propensity to undergo RNA modifications. By facilitating complex assembly and liquid-liquid phase separation, RNA localization is not only a consequence but also a driver of subcellular spatiotemporal complexity. We foresee that in the coming years the study of RNA localization in prokaryotes will produce important novel insights regarding the fundamental understanding of membrane-less subcellular organization and lead to practical outputs with biotechnological and therapeutic implications. This article is categorized under: RNA Export and Localization > RNA Localization Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications.
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Affiliation(s)
- Mikel Irastortza-Olaziregi
- Department of Microbiology and Molecular Genetics, IMRIC, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Orna Amster-Choder
- Department of Microbiology and Molecular Genetics, IMRIC, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
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20
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Braselmann E, Rathbun C, Richards EM, Palmer AE. Illuminating RNA Biology: Tools for Imaging RNA in Live Mammalian Cells. Cell Chem Biol 2020; 27:891-903. [PMID: 32640188 PMCID: PMC7595133 DOI: 10.1016/j.chembiol.2020.06.010] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 05/30/2020] [Accepted: 06/15/2020] [Indexed: 01/06/2023]
Abstract
The central dogma teaches us that DNA makes RNA, which in turn makes proteins, the main building blocks of the cell. But this over simplified linear transmission of information overlooks the vast majority of the genome produces RNAs that do not encode proteins and the myriad ways that RNA regulates cellular functions. Historically, one of the challenges in illuminating RNA biology has been the lack of tools for visualizing RNA in live cells. But clever approaches for exploiting RNA binding proteins, in vitro RNA evolution, and chemical biology have resulted in significant advances in RNA visualization tools in recent years. This review provides an overview of current tools for tagging RNA with fluorescent probes and tracking their dynamics, localization andfunction in live mammalian cells.
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Affiliation(s)
- Esther Braselmann
- Department of Biochemistry, BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Avenue, Boulder, CO 80309, USA
| | - Colin Rathbun
- Department of Biochemistry, BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Avenue, Boulder, CO 80309, USA
| | - Erin M Richards
- Department of Biochemistry, BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Avenue, Boulder, CO 80309, USA
| | - Amy E Palmer
- Department of Biochemistry, BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Avenue, Boulder, CO 80309, USA.
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21
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Dave P, Chao JA. Insights into mRNA degradation from single-molecule imaging in living cells. Curr Opin Struct Biol 2020; 65:89-95. [PMID: 32659634 DOI: 10.1016/j.sbi.2020.06.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 05/15/2020] [Accepted: 06/02/2020] [Indexed: 10/23/2022]
Abstract
Single-molecule fluorescence microscopy techniques have enabled the lifecycle of individual RNA transcripts to be quantitatively measured in living cells. The application of these approaches to monitor mRNA degradation, however, has presented a challenge to unequivocally detect these events due to the inherent loss-of-signal resulting from decay of a transcript. Here, we highlight the recent technological developments that have enabled the spatial and temporal dynamics of mRNA degradation of individual transcripts to be visualized within living cells.
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Affiliation(s)
- Pratik Dave
- Friedrich Miescher Institute for Biomedical Research, CH-4058 Basel, Switzerland
| | - Jeffrey A Chao
- Friedrich Miescher Institute for Biomedical Research, CH-4058 Basel, Switzerland.
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22
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Vera M, Tutucci E, Singer RH. Imaging Single mRNA Molecules in Mammalian Cells Using an Optimized MS2-MCP System. Methods Mol Biol 2020; 2038:3-20. [PMID: 31407274 DOI: 10.1007/978-1-4939-9674-2_1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Visualization of single mRNAs in their native cellular environment provides key information to study gene expression regulation. This fundamental biological question triggered the development of the MS2-MCP (MS2-Capsid Protein) system to tag mRNAs and image their life cycle using widefield fluorescence microscopy. The last two decades have evolved toward improving the qualitative and quantitative characteristics of the MS2-MCP system. Here, we provide a protocol to use the latest versions, MS2V6 and MS2V7, to tag and visualize mRNAs in mammalian cells in culture. The motivation behind engineering MS2V6 and MS2V7 was to overcome a degradation caveat observed in S. cerevisiae with the previous MS2-MCP systems. While for yeast we recommend the use of MS2V6, we found that for live-cell imaging experiments in mammalian cells, the MS2V7 has improved reporter properties.
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Affiliation(s)
- Maria Vera
- Department of Biochemistry, McGill University, Montreal, Canada
| | - Evelina Tutucci
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Robert H Singer
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY, USA. .,Janelia Research Campus of the HHMI, Ashburn, Virginia, USA.
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23
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Sato H, Das S, Singer RH, Vera M. Imaging of DNA and RNA in Living Eukaryotic Cells to Reveal Spatiotemporal Dynamics of Gene Expression. Annu Rev Biochem 2020; 89:159-187. [PMID: 32176523 DOI: 10.1146/annurev-biochem-011520-104955] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
This review focuses on imaging DNA and single RNA molecules in living cells to define eukaryotic functional organization and dynamic processes. The latest advances in technologies to visualize individual DNA loci and RNAs in real time are discussed. Single-molecule fluorescence microscopy provides the spatial and temporal resolution to reveal mechanisms regulating fundamental cell functions. Novel insights into the regulation of nuclear architecture, transcription, posttranscriptional RNA processing, and RNA localization provided by multicolor fluorescence microscopy are reviewed. A perspective on the future use of live imaging technologies and overcoming their current limitations is provided.
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Affiliation(s)
- Hanae Sato
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA; , ,
| | - Sulagna Das
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA; , ,
| | - Robert H Singer
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA; , , .,Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia 20147, USA
| | - Maria Vera
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA; , , .,Department of Biochemistry, McGill University, Montreal, Quebec H3G 1Y6, Canada;
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24
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Cawte AD, Unrau PJ, Rueda DS. Live cell imaging of single RNA molecules with fluorogenic Mango II arrays. Nat Commun 2020; 11:1283. [PMID: 32152311 PMCID: PMC7062757 DOI: 10.1038/s41467-020-14932-7] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 01/30/2020] [Indexed: 01/19/2023] Open
Abstract
RNA molecules play vital roles in many cellular processes. Visualising their dynamics in live cells at single-molecule resolution is essential to elucidate their role in RNA metabolism. RNA aptamers, such as Spinach and Mango, have recently emerged as a powerful background-free technology for live-cell RNA imaging due to their fluorogenic properties upon ligand binding. Here, we report a novel array of Mango II aptamers for RNA imaging in live and fixed cells with high contrast and single-molecule sensitivity. Direct comparison of Mango II and MS2-tdMCP-mCherry dual-labelled mRNAs show marked improvements in signal to noise ratio using the fluorogenic Mango aptamers. Using both coding (β-actin mRNA) and long non-coding (NEAT1) RNAs, we show that the Mango array does not affect cellular localisation. Additionally, we can track single mRNAs for extended time periods, likely due to bleached fluorophore replacement. This property makes the arrays readily compatible with structured illumination super-resolution microscopy.
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Affiliation(s)
- Adam D Cawte
- Single Molecule Imaging Group, MRC London Institute of Medical Sciences, Du Cane Rd, London, UK
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, Du Cane Rd, London, UK
| | - Peter J Unrau
- Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, Canada.
| | - David S Rueda
- Single Molecule Imaging Group, MRC London Institute of Medical Sciences, Du Cane Rd, London, UK.
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, Du Cane Rd, London, UK.
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25
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Park SY, Moon HC, Park HY. Live-cell imaging of single mRNA dynamics using split superfolder green fluorescent proteins with minimal background. RNA (NEW YORK, N.Y.) 2020; 26:101-109. [PMID: 31641028 PMCID: PMC6913125 DOI: 10.1261/rna.067835.118] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 10/20/2019] [Indexed: 06/10/2023]
Abstract
The MS2 system, with an MS2 binding site (MBS) and an MS2 coat protein fused to a fluorescent protein (MCP-FP), has been widely used to fluorescently label mRNA in live cells. However, one of its limitations is the constant background fluorescence signal generated from free MCP-FPs. To overcome this obstacle, we used a superfolder GFP (sfGFP) split into two or three nonfluorescent fragments that reassemble and emit fluorescence only when bound to the target mRNA. Using the high-affinity interactions of bacteriophage coat proteins with their corresponding RNA binding motifs, we showed that the nonfluorescent sfGFP fragments were successfully brought close to each other to reconstitute a complete sfGFP. Furthermore, real-time mRNA dynamics inside the nucleus as well as the cytoplasm were observed by using the split sfGFPs with the MS2-PP7 hybrid system. Our results demonstrate that the split sfGFP systems are useful tools for background-free imaging of mRNA with high spatiotemporal resolution.
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Affiliation(s)
- Sung Young Park
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Korea
- Center for RNA Research, Institute for Basic Science, Seoul, 08826, Korea
| | - Hyungseok C Moon
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Korea
| | - Hye Yoon Park
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Korea
- Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul, 08826, Korea
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26
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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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27
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Kim SH, Vieira M, Shim JY, Choi H, Park HY. Recent progress in single-molecule studies of mRNA localization in vivo. RNA Biol 2019; 16:1108-1118. [PMID: 30336727 PMCID: PMC6693552 DOI: 10.1080/15476286.2018.1536592] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 08/28/2018] [Accepted: 10/08/2018] [Indexed: 12/26/2022] Open
Abstract
From biogenesis to degradation, mRNA goes through diverse types of regulation and interaction with other biomolecules. Uneven distribution of mRNA transcripts and the diverse isoforms and modifications of mRNA make us wonder how cells manage the complexity and keep the functional integrity for the normal development of cells and organisms. Single-molecule microscopy tools have expanded the scope of RNA research with unprecedented spatiotemporal resolution. In this review, we highlight the recent progress in the methods for labeling mRNA targets and analyzing the quantitative information from fluorescence images of single mRNA molecules. In particular, the MS2 system and its various applications are the main focus of this article. We also review how recent studies have addressed biological questions related to the significance of mRNA localization in vivo. Efforts to visualize the dynamics of single mRNA molecules in live cells will push forward our knowledge on the nature of heterogeneity in RNA sequence, structure, and distribution as well as their molecular function and coordinated interaction with RNA binding proteins.
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Affiliation(s)
- Songhee H. Kim
- Department of Physics and Astronomy, Seoul National University, Seoul, Korea
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul, Korea
| | - Melissa Vieira
- Interdisciplinary Program in Neuroscience, Seoul National University, Seoul, Korea
| | - Jae Youn Shim
- Department of Physics and Astronomy, Seoul National University, Seoul, Korea
| | - Hongyoung Choi
- Department of Physics and Astronomy, Seoul National University, Seoul, Korea
| | - Hye Yoon Park
- Department of Physics and Astronomy, Seoul National University, Seoul, Korea
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul, Korea
- Interdisciplinary Program in Neuroscience, Seoul National University, Seoul, Korea
- Institute of Applied Physics, Seoul National University, Seoul, Korea
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28
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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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29
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Pizzinga M, Bates C, Lui J, Forte G, Morales-Polanco F, Linney E, Knotkova B, Wilson B, Solari CA, Berchowitz LE, Portela P, Ashe MP. Translation factor mRNA granules direct protein synthetic capacity to regions of polarized growth. J Cell Biol 2019; 218:1564-1581. [PMID: 30877141 PMCID: PMC6504908 DOI: 10.1083/jcb.201704019] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 11/12/2018] [Accepted: 02/28/2019] [Indexed: 12/22/2022] Open
Abstract
mRNA localization serves key functions in localized protein production, making it critical that the translation machinery itself is present at these locations. Here we show that translation factor mRNAs are localized to distinct granules within yeast cells. In contrast to many messenger RNP granules, such as processing bodies and stress granules, which contain translationally repressed mRNAs, these granules harbor translated mRNAs under active growth conditions. The granules require Pab1p for their integrity and are inherited by developing daughter cells in a She2p/She3p-dependent manner. These results point to a model where roughly half the mRNA for certain translation factors is specifically directed in granules or translation factories toward the tip of the developing daughter cell, where protein synthesis is most heavily required, which has particular implications for filamentous forms of growth. Such a feedforward mechanism would ensure adequate provision of the translation machinery where it is to be needed most over the coming growth cycle.
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Affiliation(s)
- Mariavittoria Pizzinga
- Division of Molecular and Cellular Function, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Christian Bates
- Division of Molecular and Cellular Function, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Jennifer Lui
- Division of Molecular and Cellular Function, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Gabriella Forte
- Division of Molecular and Cellular Function, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Fabián Morales-Polanco
- Division of Molecular and Cellular Function, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Emma Linney
- Division of Molecular and Cellular Function, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Barbora Knotkova
- Division of Molecular and Cellular Function, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Beverley Wilson
- Division of Molecular and Cellular Function, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Clara A Solari
- Universidad de Buenos Aires, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales-Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Luke E Berchowitz
- Department of Genetics and Development, Hammer Health Sciences Center, Columbia University Medical Center, New York, NY
| | - Paula Portela
- Universidad de Buenos Aires, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales-Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Mark P Ashe
- Division of Molecular and Cellular Function, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
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30
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Taliaferro JM. Classical and emerging techniques to identify and quantify localized RNAs. WILEY INTERDISCIPLINARY REVIEWS-RNA 2019; 10:e1542. [PMID: 31044542 DOI: 10.1002/wrna.1542] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 04/05/2019] [Accepted: 04/08/2019] [Indexed: 12/12/2022]
Abstract
In essentially every cell, proteins are asymmetrically distributed according to their function. For many genes, this protein sorting problem is solved by transporting RNA molecules encoding the protein, rather than the protein itself, to the desired subcellular location. The protein is then translated on-site to immediately produce a correctly localized protein. This strategy is widely used as thousands of RNAs localize to distinct locations across diverse cell types and species. One of the fundamental challenges to study this process is the determination of the subcellular spatial distribution of any given RNA. The number of tools available for the study of RNA localization, from classical and state-of-the-art methods for the visualization of individual RNA molecules within cells to the profiling of localized transcriptomes, is rapidly growing. These include imaging-based approaches, a variety of biochemical and mechanical fractionation techniques, and proximity-labeling methods. These procedures allow for both the detailed study of the molecular requirements for the localization of individual RNA molecules and computational studies of RNA transport on a genomic scale. Together, they have the ability to allow insight into the regulatory principles that govern the localization of diverse RNAs. These new techniques provide the framework for integrating our knowledge of the regulation of RNA localization with that of other posttranscriptional processes. This article is categorized under: RNA Export and Localization > RNA Localization RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications RNA Methods > RNA Analyses in Cells.
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Affiliation(s)
- J Matthew Taliaferro
- Department of Biochemistry and Molecular Genetics, RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, Colorado
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31
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Kim SH, Vieira M, Kim HJ, Kesawat MS, Park HY. MS2 Labeling of Endogenous Beta-Actin mRNA Does Not Result in Stabilization of Degradation Intermediates. Mol Cells 2019; 42:356-362. [PMID: 30841028 PMCID: PMC6530646 DOI: 10.14348/molcells.2019.2398] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 01/17/2019] [Accepted: 02/05/2019] [Indexed: 11/27/2022] Open
Abstract
The binding of MS2 bacteriophage coat protein (MCP) to MS2 binding site (MBS) RNA stem-loop sequences has been widely used to label mRNA for live-cell imaging at single-molecule resolution. However, concerns have been raised recently from studies with budding yeast showing aberrant mRNA metabolism following the MS2-GFP labeling. To investigate the degradation pattern of MS2-GFP-labeled mRNA in mammalian cells and tissues, we used Northern blot analysis of β-actin mRNA extracted from the Actb-MBS knock-in and MBS×MCP hybrid mouse models. In the immortalized mouse embryonic cell lines and various organ tissues derived from the mouse models, we found no noticeable accumulation of decay products of β-actin mRNA compared with the wild-type mice. Our results suggest that accumulation of MBS RNA decay fragments does not always happen depending on the mRNA species and the model organisms used.
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Affiliation(s)
- Songhee H. Kim
- Department of Physics and Astronomy, Seoul National University, Seoul 08826,
Korea
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul 08826,
Korea
| | - Melissa Vieira
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul 08826,
Korea
- Interdisciplinary Program in Neuroscience, Seoul National University, Seoul 08826,
Korea
| | - Hye-Jin Kim
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul 08826,
Korea
| | - Mahipal Singh Kesawat
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul 08826,
Korea
| | - Hye Yoon Park
- Department of Physics and Astronomy, Seoul National University, Seoul 08826,
Korea
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul 08826,
Korea
- Interdisciplinary Program in Neuroscience, Seoul National University, Seoul 08826,
Korea
- Institute of Applied Physics, Seoul National University, Seoul 08826,
Korea
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32
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Hughes SC, Simmonds AJ. Drosophila mRNA Localization During Later Development: Past, Present, and Future. Front Genet 2019; 10:135. [PMID: 30899273 PMCID: PMC6416162 DOI: 10.3389/fgene.2019.00135] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 02/11/2019] [Indexed: 12/12/2022] Open
Abstract
Multiple mechanisms tightly regulate mRNAs during their transcription, translation, and degradation. Of these, the physical localization of mRNAs to specific cytoplasmic regions is relatively easy to detect; however, linking localization to functional regulatory roles has been more difficult to establish. Historically, Drosophila melanogaster is a highly effective model to identify localized mRNAs and has helped identify roles for this process by regulating various cell activities. The majority of the well-characterized functional roles for localizing mRNAs to sub-regions of the cytoplasm have come from the Drosophila oocyte and early syncytial embryo. At present, relatively few functional roles have been established for mRNA localization within the relatively smaller, differentiated somatic cell lineages characteristic of later development, beginning with the cellular blastoderm, and the multiple cell lineages that make up the gastrulating embryo, larva, and adult. This review is divided into three parts—the first outlines past evidence for cytoplasmic mRNA localization affecting aspects of cellular activity post-blastoderm development in Drosophila. The majority of these known examples come from highly polarized cell lineages such as differentiating neurons. The second part considers the present state of affairs where we now know that many, if not most mRNAs are localized to discrete cytoplasmic regions in one or more somatic cell lineages of cellularized embryos, larvae or adults. Assuming that the phenomenon of cytoplasmic mRNA localization represents an underlying functional activity, and correlation with the encoded proteins suggests that mRNA localization is involved in far more than neuronal differentiation. Thus, it seems highly likely that past-identified examples represent only a small fraction of localization-based mRNA regulation in somatic cells. The last part highlights recent technological advances that now provide an opportunity for probing the role of mRNA localization in Drosophila, moving beyond cataloging the diversity of localized mRNAs to a similar understanding of how localization affects mRNA activity.
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Affiliation(s)
- Sarah C Hughes
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.,Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Andrew J Simmonds
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
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33
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Abstract
Diverse mechanisms and functions of posttranscriptional regulation by small regulatory RNAs and RNA-binding proteins have been described in bacteria. In contrast, little is known about the spatial organization of RNAs in bacterial cells. In eukaryotes, subcellular localization and transport of RNAs play important roles in diverse physiological processes, such as embryonic patterning, asymmetric cell division, epithelial polarity, and neuronal plasticity. It is now clear that bacterial RNAs also can accumulate at distinct sites in the cell. However, due to the small size of bacterial cells, RNA localization and localization-associated functions are more challenging to study in bacterial cells, and the underlying molecular mechanisms of transcript localization are less understood. Here, we review the emerging examples of RNAs localized to specific subcellular locations in bacteria, with indications that subcellular localization of transcripts might be important for gene expression and regulatory processes. Diverse mechanisms for bacterial RNA localization have been suggested, including close association to their genomic site of transcription, or to the localizations of their protein products in translation-dependent or -independent processes. We also provide an overview of the state of the art of technologies to visualize and track bacterial RNAs, ranging from hybridization-based approaches in fixed cells to in vivo imaging approaches using fluorescent protein reporters and/or RNA aptamers in single living bacterial cells. We conclude with a discussion of open questions in the field and ongoing technological developments regarding RNA imaging in eukaryotic systems that might likewise provide novel insights into RNA localization in bacteria.
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34
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Tutucci E, Vera M, Singer RH. Single-mRNA detection in living S. cerevisiae using a re-engineered MS2 system. Nat Protoc 2018; 13:2268-2296. [DOI: 10.1038/s41596-018-0037-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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35
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Abstract
An essential feature of protein expression is the tight regulation of when and where a protein is translated from its cognate mRNA. This spatiotemporal expression is particularly important in guaranteeing the correct and efficient targeting of proteins to defined subcellular sites. In order to achieve local translation, mRNAs must be deposited at specific locations. A common mechanism is the active transport of mRNAs along the actin or microtubule cytoskeleton. To study such dynamic transport processes in vivo RNA live imaging is the method of choice. This method is based on the principle that defined binding sites for a heterologous RNA-binding protein (RBP) are inserted in the 3' UTR of target mRNAs. Coexpression of the RBP fused to a fluorescent protein enables mRNA detection in vivo using fluorescence microscopy techniques. In this chapter we describe the well-established method of studying microtubule-dependent mRNA transport in the eukaryotic model microorganism Ustilago maydis. The presented experimental design and the microscopic techniques are applicable to a broad range of other organisms.
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Affiliation(s)
- Sabrina Zander
- Heinrich-Heine University Düsseldorf, Institute for Microbiology, Cluster of Excellence on Plant Sciences (CEPLAS), Universitätsstr. 1, Geb. 26.12, 40225, Düsseldorf, Germany
| | - Kira Müntjes
- Heinrich-Heine University Düsseldorf, Institute for Microbiology, Cluster of Excellence on Plant Sciences (CEPLAS), Universitätsstr. 1, Geb. 26.12, 40225, Düsseldorf, Germany
| | - Michael Feldbrügge
- Heinrich-Heine University Düsseldorf, Institute for Microbiology, Cluster of Excellence on Plant Sciences (CEPLAS), Universitätsstr. 1, Geb. 26.12, 40225, Düsseldorf, Germany.
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36
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An improved MS2 system for accurate reporting of the mRNA life cycle. Nat Methods 2017; 15:81-89. [PMID: 29131164 PMCID: PMC5843578 DOI: 10.1038/nmeth.4502] [Citation(s) in RCA: 206] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 10/04/2017] [Indexed: 12/19/2022]
Abstract
The MS2-MCP system enables researchers to image multiple steps of the mRNA life cycle with high temporal and spatial resolution. However, for short-lived mRNAs, the tight binding of the MS2 coat protein (MCP) to the MS2 binding sites (MBS) protects the RNA from being efficiently degraded, and this confounds the study of mRNA regulation. Here, we describe a reporter system (MBSV6) with reduced affinity for the MCP, which allows mRNA degradation while preserving single-molecule detection determined by single-molecule FISH (smFISH) or live imaging. Constitutive mRNAs (MDN1 and DOA1) and highly-regulated mRNAs (GAL1 and ASH1) endogenously tagged with MBSV6 in Saccharomyces cerevisiae degrade normally. As a result, short-lived mRNAs were imaged throughout their complete life cycle. The MBSV6 reporter revealed that, in contrast to previous findings, coordinated recruitment of mRNAs at specialized structures such as P-bodies during stress did not occur, and mRNA degradation was heterogeneously distributed in the cytoplasm.
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37
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Loll-Krippleber R, Brown GW. P-body proteins regulate transcriptional rewiring to promote DNA replication stress resistance. Nat Commun 2017; 8:558. [PMID: 28916784 PMCID: PMC5601920 DOI: 10.1038/s41467-017-00632-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 07/12/2017] [Indexed: 12/12/2022] Open
Abstract
mRNA-processing (P-) bodies are cytoplasmic granules that form in eukaryotic cells in response to numerous stresses to serve as sites of degradation and storage of mRNAs. Functional P-bodies are critical for the DNA replication stress response in yeast, yet the repertoire of P-body targets and the mechanisms by which P-bodies promote replication stress resistance are unknown. In this study we identify the complete complement of mRNA targets of P-bodies during replication stress induced by hydroxyurea treatment. The key P-body protein Lsm1 controls the abundance of HHT1, ACF4, ARL3, TMA16, RRS1 and YOX1 mRNAs to prevent their toxic accumulation during replication stress. Accumulation of YOX1 mRNA causes aberrant downregulation of a network of genes critical for DNA replication stress resistance and leads to toxic acetaldehyde accumulation. Our data reveal the scope and the targets of regulation by P-body proteins during the DNA replication stress response. P-bodies form in response to stress and act as sites of mRNA storage and degradation. Here the authors identify the mRNA targets of P-bodies during DNA replication stress, and show that P-body proteins act to prevent toxic accumulation of these target transcripts.
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Affiliation(s)
- Raphael Loll-Krippleber
- Department of Biochemistry and Donnelly Centre, University of Toronto, 160 College Street, Toronto, ON, Canada, M5S 3E1
| | - Grant W Brown
- Department of Biochemistry and Donnelly Centre, University of Toronto, 160 College Street, Toronto, ON, Canada, M5S 3E1.
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38
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Trachman RJ, Truong L, Ferré-D'Amaré AR. Structural Principles of Fluorescent RNA Aptamers. Trends Pharmacol Sci 2017; 38:928-939. [PMID: 28728963 DOI: 10.1016/j.tips.2017.06.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 06/21/2017] [Accepted: 06/21/2017] [Indexed: 11/26/2022]
Abstract
Several aptamer RNAs have been selected in vitro that bind to otherwise weakly fluorescent small molecules and enhance their fluorescence several thousand-fold. By genetically tagging cellular RNAs of interest with these aptamers and soaking cells in their cell-permeable cognate small-molecule fluorophores, it is possible to use them to study RNA localization and trafficking. These aptamers have also been fused to metabolite-binding RNAs to generate fluorescent biosensors. The 3D structures of three unrelated fluorogenic RNAs have been determined, and reveal a shared reliance on base quadruples (tetrads) to constrain the photo-excited chromophore. The structural diversity of fluorogenic RNAs and the chemical diversity of potential fluorophores to be activated are likely to yield a variety of future fluorogenic RNA tags that are optimized for different applications in RNA imaging and in the design of fluorescent RNA biosensors.
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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
| | - Lynda Truong
- Biochemistry and Biophysics Center, National Heart, Lung and Blood Institute, 50 South Drive MSC 8012, Bethesda, MD 20892-8012, USA
| | - 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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39
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Donlin-Asp PG, Rossoll W, Bassell GJ. Spatially and temporally regulating translation via mRNA-binding proteins in cellular and neuronal function. FEBS Lett 2017; 591:1508-1525. [PMID: 28295262 DOI: 10.1002/1873-3468.12621] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 03/02/2017] [Accepted: 03/03/2017] [Indexed: 12/20/2022]
Abstract
Coordinated regulation of mRNA localization and local translation are essential steps in cellular asymmetry and function. It is increasingly evident that mRNA-binding proteins play critical functions in controlling the fate of mRNA, including when and where translation occurs. In this review, we discuss the robust and complex roles that mRNA-binding proteins play in the regulation of local translation that impact cellular function in vertebrates. First, we discuss the role of local translation in cellular polarity and possible links to vertebrate development and patterning. Next, we discuss the expanding role for local protein synthesis in neuronal development and function, with special focus on how a number of neurological diseases have given us insight into the importance of translational regulation. Finally, we discuss the ever-increasing set of tools to study regulated translation and how these tools will be vital in pushing forward and addressing the outstanding questions in the field.
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Affiliation(s)
- Paul G Donlin-Asp
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, USA
| | - Wilfried Rossoll
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, USA.,Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA, USA
| | - Gary J Bassell
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, USA.,Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA, USA.,Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA
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40
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An mRNA decapping mutant deficient in P body assembly limits mRNA stabilization in response to osmotic stress. Sci Rep 2017; 7:44395. [PMID: 28290514 PMCID: PMC5349606 DOI: 10.1038/srep44395] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 02/07/2017] [Indexed: 01/19/2023] Open
Abstract
Yeast is exposed to changing environmental conditions and must adapt its genetic program to provide a homeostatic intracellular environment. An important stress for yeast in the wild is high osmolarity. A key response to this stress is increased mRNA stability primarily by the inhibition of deadenylation. We previously demonstrated that mutations in decapping activators (edc3∆ lsm4∆C), which result in defects in P body assembly, can destabilize mRNA under unstressed conditions. We wished to examine whether mRNA would be destabilized in the edc3∆ lsm4∆C mutant as compared to the wild-type in response to osmotic stress, when P bodies are intense and numerous. Our results show that the edc3∆ lsm4∆C mutant limits the mRNA stability in response to osmotic stress, while the magnitude of stabilization was similar as compared to the wild-type. The reduced mRNA stability in the edc3∆ lsm4∆C mutant was correlated with a shorter PGK1 poly(A) tail. Similarly, the MFA2 mRNA was more rapidly deadenylated as well as significantly stabilized in the ccr4∆ deadenylation mutant in the edc3∆ lsm4∆C background. These results suggest a role for these decapping factors in stabilizing mRNA and may implicate P bodies as sites of reduced mRNA degradation.
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41
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Heinrich S, Sidler CL, Azzalin CM, Weis K. Stem-loop RNA labeling can affect nuclear and cytoplasmic mRNA processing. RNA (NEW YORK, N.Y.) 2017; 23:134-141. [PMID: 28096443 PMCID: PMC5238788 DOI: 10.1261/rna.057786.116] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 11/03/2016] [Indexed: 05/17/2023]
Abstract
The binding of sequence-specific RNA-interacting proteins, such as the bacteriophage MS2 or PP7 coat proteins, to their corresponding target sequences has been extremely useful and widely used to visualize single mRNAs in vivo. However, introduction of MS2 stem-loops into yeast mRNAs has recently been shown to lead to the accumulation of RNA fragments, suggesting that the loops impair mRNA decay. This result was questioned, because fragment occurrence was mainly assessed using ensemble methods, and their cellular localization and its implications had not been addressed on a single transcript level. Here, we demonstrate that the introduction of either MS2 stem-loops (MS2SL) or PP7 stem-loops (PP7SL) can affect the processing and subcellular localization of mRNA. We use single-molecule fluorescence in situ hybridization (smFISH) to determine the localization of three independent mRNAs tagged with the stem-loop labeling systems in glucose-rich and glucose starvation conditions. Transcripts containing MS2SL or PP7SL display aberrant localization in both the nucleus and the cytoplasm. These defects are most prominent in glucose starvation conditions, with nuclear mRNA processing being altered and stem-loop fragments abnormally enriching in processing bodies (PBs). The mislocalization of SL-containing RNAs is independent of the presence of the MS2 or PP7 coat protein (MCP or PCP).
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Affiliation(s)
| | | | - Claus M Azzalin
- Institute of Biochemistry, ETH Zurich, 8093 Zurich, Switzerland
| | - Karsten Weis
- Institute of Biochemistry, ETH Zurich, 8093 Zurich, Switzerland
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42
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Heinrich S, Derrer CP, Lari A, Weis K, Montpetit B. Temporal and spatial regulation of mRNA export: Single particle RNA-imaging provides new tools and insights. Bioessays 2017; 39. [PMID: 28052353 DOI: 10.1002/bies.201600124] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The transport of messenger RNAs (mRNAs) from the nucleus to cytoplasm is an essential step in the gene expression program of all eukaryotes. Recent technological advances in the areas of RNA-labeling, microscopy, and sequencing are leading to novel insights about mRNA biogenesis and export. This includes quantitative single molecule imaging (SMI) of RNA molecules in live cells, which is providing knowledge of the spatial and temporal dynamics of the export process. As this information becomes available, it leads to new questions, the reinterpretation of previous findings, and revised models of mRNA export. In this review, we will briefly highlight some of these recent findings and discuss how live cell SMI approaches may be used to further our current understanding of mRNA export and gene expression.
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Affiliation(s)
| | | | - Azra Lari
- Department of Cell Biology, University of Alberta, Edmonton, Canada
| | - Karsten Weis
- Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
| | - Ben Montpetit
- Department of Cell Biology, University of Alberta, Edmonton, Canada.,Department of Viticulture and Enology, University of California, Davis, CA, USA
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43
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Mugler CF, Hondele M, Heinrich S, Sachdev R, Vallotton P, Koek AY, Chan LY, Weis K. ATPase activity of the DEAD-box protein Dhh1 controls processing body formation. eLife 2016; 5. [PMID: 27692063 PMCID: PMC5096884 DOI: 10.7554/elife.18746] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 09/28/2016] [Indexed: 12/22/2022] Open
Abstract
Translational repression and mRNA degradation are critical mechanisms of posttranscriptional gene regulation that help cells respond to internal and external cues. In response to certain stress conditions, many mRNA decay factors are enriched in processing bodies (PBs), cellular structures involved in degradation and/or storage of mRNAs. Yet, how cells regulate assembly and disassembly of PBs remains poorly understood. Here, we show that in budding yeast, mutations in the DEAD-box ATPase Dhh1 that prevent ATP hydrolysis, or that affect the interaction between Dhh1 and Not1, the central scaffold of the CCR4-NOT complex and an activator of the Dhh1 ATPase, prevent PB disassembly in vivo. Intriguingly, this process can be recapitulated in vitro, since recombinant Dhh1 and RNA, in the presence of ATP, phase-separate into liquid droplets that rapidly dissolve upon addition of Not1. Our results identify the ATPase activity of Dhh1 as a critical regulator of PB formation. DOI:http://dx.doi.org/10.7554/eLife.18746.001 Most cells and organisms live in changeable environments. Adapting to environmental changes means that organisms must quickly alter which of their genes they express. Varying which genes are switched on or off is not enough; cells must also degrade existing messenger RNAs (or mRNAs for short), which contain the genetic instructions of the previously active genes. Therefore, cells must tightly regulate the machinery needed to degrade mRNAs. When Baker’s yeast (also known as budding yeast) cells experience certain stressful conditions, the proteins that break down mRNAs localize into specific structures inside the cell known as ‘processing bodies’. These structures are found in many other organisms across evolution, from yeast to human. Processing bodies also form in a variety of biological contexts, such as in nerve cells and developing embryos. Still, why cells form processing bodies, and how their assembly is regulated, is not well understood. One essential component of processing bodies is an enzyme called Dhh1. This enzyme has been conserved throughout evolution and is known to promote the decay of mRNAs as well as to repress their translation into proteins. Now, Mugler, Hondele et al. show that Dhh1’s must break down molecules of the energy carrier ATP (referred to as its “ATPase activity”) in order to regulate the dynamic nature of processing bodies. Mutant Dhh1 proteins that lack ATPase activity form permanent processing bodies in non-stressed yeast cells. This shows that that the breakdown of ATP by Dhh1 is required for the disassembly of processing bodies. Similar results were seen for mutant Dhh1 proteins that cannot interact with Not1, a protein which enhances the ATPase activity of Dhh1. Next Mugler, Hondele et al. mixed purified Dhh1 with ATP and RNA molecules and saw that the mixture underwent a “liquid-liquid phase separation” and formed observable granules, similar to oil droplets in water. These granules dissolved when Not1 was added to stimulate the Dhh1 enzyme to turnover ATP. This showed that several important biochemical and biophysical aspects of processing bodies seen within living cells could be recreated outside of a cell. Armed with a greater understanding of the rules that govern the formation of processing bodies, future work can now address how important processing bodies are for regulating gene expression. Another challenge for the future will be to examine the specific roles that processing bodies play in yeast and other cells, like human egg cells or nerve cells. DOI:http://dx.doi.org/10.7554/eLife.18746.002
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Affiliation(s)
| | | | | | | | | | - Adriana Y Koek
- University of California, Berkeley, Berkeley, United States
| | - Leon Y Chan
- University of California, Berkeley, Berkeley, United States
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Laprade H, Lalonde M, Guérit D, Chartrand P. Live-cell imaging of budding yeast telomerase RNA and TERRA. Methods 2016; 114:46-53. [PMID: 27474163 DOI: 10.1016/j.ymeth.2016.07.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 07/11/2016] [Accepted: 07/23/2016] [Indexed: 02/02/2023] Open
Abstract
In most eukaryotes, the ribonucleoprotein complex telomerase is responsible for maintaining telomere length. In recent years, single-cell microscopy techniques such as fluorescent in situ hybridization and live-cell imaging have been developed to image the RNA subunit of the telomerase holoenzyme. These techniques are now becoming important tools for the study of telomerase biogenesis, its association with telomeres and its regulation. Here, we present detailed protocols for live-cell imaging of the Saccharomyces cerevisiae telomerase RNA subunit, called TLC1, and also of the non-coding telomeric repeat-containing RNA TERRA. We describe the approach used for genomic integration of MS2 stem-loops in these transcripts, and provide information for optimal live-cell imaging of these non-coding RNAs.
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Affiliation(s)
- Hadrien Laprade
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Qc H3C 3J7, Canada
| | - Maxime Lalonde
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Qc H3C 3J7, Canada
| | - David Guérit
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Qc H3C 3J7, Canada
| | - Pascal Chartrand
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Qc H3C 3J7, Canada.
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Haimovich G, Zabezhinsky D, Haas B, Slobodin B, Purushothaman P, Fan L, Levin JZ, Nusbaum C, Gerst JE. Use of the MS2 aptamer and coat protein for RNA localization in yeast: A response to "MS2 coat proteins bound to yeast mRNAs block 5' to 3' degradation and trap mRNA decay products: implications for the localization of mRNAs by MS2-MCP system". RNA (NEW YORK, N.Y.) 2016; 22:660-6. [PMID: 26968626 PMCID: PMC4836641 DOI: 10.1261/rna.055095.115] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 02/09/2016] [Indexed: 05/17/2023]
Abstract
The MS2 system has been extensively used to visualize single mRNA molecules in live cells and follow their localization and behavior. In their Letter to the Editor recently published, Garcia and Parker suggest that use of the MS2 system may yield erroneous mRNA localization results due to the accumulation of 3' decay products. Here we cite published works and provide new data which demonstrate that this is not a phenomenon general to endogenously expressed MS2-tagged transcripts, and that some of the results obtained in their study could have arisen from artifacts of gene expression.
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Affiliation(s)
- Gal Haimovich
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Dmitry Zabezhinsky
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Brian Haas
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA
| | - Boris Slobodin
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | | | - Lin Fan
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA
| | - Joshua Z Levin
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA
| | - Chad Nusbaum
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA
| | - Jeffrey E Gerst
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
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