1
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Smart A, Gilmer O, Caliskan N. Translation Inhibition Mediated by Interferon-Stimulated Genes during Viral Infections. Viruses 2024; 16:1097. [PMID: 39066259 PMCID: PMC11281336 DOI: 10.3390/v16071097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 07/04/2024] [Accepted: 07/04/2024] [Indexed: 07/28/2024] Open
Abstract
Viruses often pose a significant threat to the host through the exploitation of cellular machineries for their own benefit. In the context of immune responses, myriad host factors are deployed to target viral RNAs and inhibit viral protein translation, ultimately hampering viral replication. Understanding how "non-self" RNAs interact with the host translation machinery and trigger immune responses would help in the development of treatment strategies for viral infections. In this review, we explore how interferon-stimulated gene products interact with viral RNA and the translation machinery in order to induce either global or targeted translation inhibition.
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Affiliation(s)
- Alexandria Smart
- Helmholtz Institute for RNA-Based Infection Research, Helmholtz Centre for Infection Research (HIRI-HZI), Josef-Schneider-Strasse 2, 97080 Würzburg, Germany; (A.S.); (O.G.)
| | - Orian Gilmer
- Helmholtz Institute for RNA-Based Infection Research, Helmholtz Centre for Infection Research (HIRI-HZI), Josef-Schneider-Strasse 2, 97080 Würzburg, Germany; (A.S.); (O.G.)
| | - Neva Caliskan
- Helmholtz Institute for RNA-Based Infection Research, Helmholtz Centre for Infection Research (HIRI-HZI), Josef-Schneider-Strasse 2, 97080 Würzburg, Germany; (A.S.); (O.G.)
- Regensburg Center for Biochemistry (RCB), University of Regensburg, 93053 Regensburg, Germany
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2
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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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Zhang D, Gao Y, Zhu L, Wang Y, Li P. Advances and opportunities in methods to study protein translation - A review. Int J Biol Macromol 2024; 259:129150. [PMID: 38171441 DOI: 10.1016/j.ijbiomac.2023.129150] [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: 08/02/2023] [Revised: 12/27/2023] [Accepted: 12/28/2023] [Indexed: 01/05/2024]
Abstract
It is generally believed that the regulation of gene expression involves protein translation occurring before RNA transcription. Therefore, it is crucial to investigate protein translation and its regulation. Recent advancements in biological sciences, particularly in the field of omics, have revolutionized protein translation research. These studies not only help characterize changes in protein translation during specific biological or pathological processes but also have significant implications in disease prevention and treatment. In this review, we summarize the latest methods in ribosome-based translation omics. We specifically focus on the application of fluorescence imaging technology and omics technology in studying overall protein translation. Additionally, we analyze the advantages, disadvantages, and application of these experimental methods, aiming to provide valuable insights and references to researchers studying translation.
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Affiliation(s)
- Dejiu Zhang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Yanyan Gao
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Lei Zhu
- College of Basic Medical, Qingdao Binhai University, Qingdao, China
| | - Yin Wang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China.
| | - Peifeng Li
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China.
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4
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Abstract
Protein synthesis by the ribosome is the final stage of biological information transfer and represents an irreversible commitment to gene expression. Accurate translation of messenger RNA is therefore essential to all life, and spontaneous errors by the translational machinery are highly infrequent (∼1/100,000 codons). Programmed -1 ribosomal frameshifting (-1PRF) is a mechanism in which the elongating ribosome is induced at high frequency to slip backward by one nucleotide at a defined position and to continue translation in the new reading frame. This is exploited as a translational regulation strategy by hundreds of RNA viruses, which rely on -1PRF during genome translation to control the stoichiometry of viral proteins. While early investigations of -1PRF focused on virological and biochemical aspects, the application of X-ray crystallography and cryo-electron microscopy (cryo-EM), and the advent of deep sequencing and single-molecule approaches have revealed unexpected structural diversity and mechanistic complexity. Molecular players from several model systems have now been characterized in detail, both in isolation and, more recently, in the context of the elongating ribosome. Here we provide a summary of recent advances and discuss to what extent a general model for -1PRF remains a useful way of thinking.
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Affiliation(s)
- Chris H Hill
- York Structural Biology Laboratory, York Biomedical Research Institute, Department of Biology, University of York, York, United Kingdom;
| | - Ian Brierley
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom;
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5
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Gao G, Walter NG. Critical Assessment of Condensate Boundaries in Dual-Color Single Particle Tracking. J Phys Chem B 2023; 127:7694-7707. [PMID: 37669232 DOI: 10.1021/acs.jpcb.3c03776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/07/2023]
Abstract
Biomolecular condensates are membraneless cellular compartments generated by phase separation that regulate a broad variety of cellular functions by enriching some biomolecules while excluding others. Live-cell single particle tracking of individual fluorophore-labeled condensate components has provided insights into a condensate's mesoscopic organization and biological functions, such as revealing the recruitment, translation, and decay of RNAs within ribonucleoprotein (RNP) granules. Specifically, during dual-color tracking, one imaging channel provides a time series of individual biomolecule locations, while the other channel monitors the location of the condensate relative to these molecules. Therefore, an accurate assessment of a condensate's boundary is critical for combined live-cell single particle-condensate tracking. Despite its importance, a quantitative benchmarking and objective comparison of the various available boundary detection methods is missing due to the lack of an absolute ground truth for condensate images. Here, we use synthetic data of defined ground truth to generate noise-overlaid images of condensates with realistic phase separation parameters to benchmark the most commonly used methods for condensate boundary detection, including an emerging machine-learning method. We find that it is critical to carefully choose an optimal boundary detection method for a given dataset to obtain accurate measurements of single particle-condensate interactions. The criteria proposed in this study to guide the selection of an optimal boundary detection method can be broadly applied to imaging-based studies of condensates.
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Affiliation(s)
- Guoming Gao
- Biophysics Graduate Program, University of Michigan, Ann Arbor, Michigan 48109, United States
- Center for RNA Biomedicine, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Nils G Walter
- Center for RNA Biomedicine, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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6
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Latallo MJ, Wang S, Dong D, Nelson B, Livingston NM, Wu R, Zhao N, Stasevich TJ, Bassik MC, Sun S, Wu B. Single-molecule imaging reveals distinct elongation and frameshifting dynamics between frames of expanded RNA repeats in C9ORF72-ALS/FTD. Nat Commun 2023; 14:5581. [PMID: 37696852 PMCID: PMC10495369 DOI: 10.1038/s41467-023-41339-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Accepted: 08/30/2023] [Indexed: 09/13/2023] Open
Abstract
C9ORF72 hexanucleotide repeat expansion is the most common genetic cause of both amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). One pathogenic mechanism is the accumulation of toxic dipeptide repeat (DPR) proteins like poly-GA, GP and GR, produced by the noncanonical translation of the expanded RNA repeats. However, how different DPRs are synthesized remains elusive. Here, we use single-molecule imaging techniques to directly measure the translation dynamics of different DPRs. Besides initiation, translation elongation rates vary drastically between different frames, with GP slower than GA and GR the slowest. We directly visualize frameshift events using a two-color single-molecule translation assay. The repeat expansion enhances frameshifting, but the overall frequency is low. There is a higher chance of GR-to-GA shift than in the reversed direction. Finally, the ribosome-associated protein quality control (RQC) factors ZNF598 and Pelota modulate the translation dynamics, and the repeat RNA sequence is important for invoking the RQC pathway. This study reveals that multiple translation steps modulate the final DPR production. Understanding repeat RNA translation is critically important to decipher the DPR-mediated pathogenesis and identify potential therapeutic targets in C9ORF72-ALS/FTD.
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Affiliation(s)
- Malgorzata J Latallo
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Shaopeng Wang
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Daoyuan Dong
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Blake Nelson
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Nathan M Livingston
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Rong Wu
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Ning Zhao
- Department of Biochemistry and Molecular Genetics, University of Colorado-Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Timothy J Stasevich
- Department of Biochemistry and Molecular Genetics, University of Colorado-Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Michael C Bassik
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Shuying Sun
- Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
- Department of Pathology, 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.
- Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
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7
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Wang S, Sun S. Translation dysregulation in neurodegenerative diseases: a focus on ALS. Mol Neurodegener 2023; 18:58. [PMID: 37626421 PMCID: PMC10464328 DOI: 10.1186/s13024-023-00642-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 07/21/2023] [Indexed: 08/27/2023] Open
Abstract
RNA translation is tightly controlled in eukaryotic cells to regulate gene expression and maintain proteome homeostasis. RNA binding proteins, translation factors, and cell signaling pathways all modulate the translation process. Defective translation is involved in multiple neurological diseases including amyotrophic lateral sclerosis (ALS). ALS is a progressive neurodegenerative disorder and poses a major public health challenge worldwide. Over the past few years, tremendous advances have been made in the understanding of the genetics and pathogenesis of ALS. Dysfunction of RNA metabolisms, including RNA translation, has been closely associated with ALS. Here, we first introduce the general mechanisms of translational regulation under physiological and stress conditions and review well-known examples of translation defects in neurodegenerative diseases. We then focus on ALS-linked genes and discuss the recent progress on how translation is affected by various mutant genes and the repeat expansion-mediated non-canonical translation in ALS.
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Affiliation(s)
- Shaopeng Wang
- Department of Physiology and Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Shuying Sun
- Department of Physiology and Brain Science Institute, 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.
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
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8
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Livingston NM, Kwon J, Valera O, Saba JA, Sinha NK, Reddy P, Nelson B, Wolfe C, Ha T, Green R, Liu J, Wu B. Bursting translation on single mRNAs in live cells. Mol Cell 2023; 83:2276-2289.e11. [PMID: 37329884 PMCID: PMC10330622 DOI: 10.1016/j.molcel.2023.05.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 03/27/2023] [Accepted: 05/14/2023] [Indexed: 06/19/2023]
Abstract
Stochasticity has emerged as a mechanism of gene regulation. Much of this so-called "noise" has been attributed to bursting transcription. Although bursting transcription has been studied extensively, the role of stochasticity in translation has not been fully investigated due to the lack of enabling imaging technology. In this study, we developed techniques to track single mRNAs and their translation in live cells for hours, allowing the measurement of previously uncharacterized translation dynamics. We applied genetic and pharmacological perturbations to control translation kinetics and found that, like transcription, translation is not a constitutive process but instead cycles between inactive and active states, or "bursts." However, unlike transcription, which is largely frequency-modulated, complex structures in the 5'-untranslated region alter burst amplitudes. Bursting frequency can be controlled through cap-proximal sequences and trans-acting factors such as eIF4F. We coupled single-molecule imaging with stochastic modeling to quantitatively determine the kinetic parameters of translational bursting.
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Affiliation(s)
- Nathan M Livingston
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Jiwoong Kwon
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Oliver Valera
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - James A Saba
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Niladri K Sinha
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Pranav Reddy
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Blake Nelson
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Clara Wolfe
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Taekjip Ha
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Rachel Green
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Jian Liu
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Center for Cell Dynamics, 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; Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Solomon H Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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9
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Khan D, Terenzi F, Liu G, Ghosh PK, Ye F, Nguyen K, China A, Ramachandiran I, Chakraborty S, Stefan J, Khan K, Vasu K, Dong F, Willard B, Karn J, Gack MU, Fox PL. A viral pan-end RNA element and host complex define a SARS-CoV-2 regulon. Nat Commun 2023; 14:3385. [PMID: 37296097 PMCID: PMC10250186 DOI: 10.1038/s41467-023-39091-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Accepted: 05/25/2023] [Indexed: 06/12/2023] Open
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19, generates multiple protein-coding, subgenomic RNAs (sgRNAs) from a longer genomic RNA, all bearing identical termini with poorly understood roles in regulating viral gene expression. Insulin and interferon-gamma, two host-derived, stress-related agents, and virus spike protein, induce binding of glutamyl-prolyl-tRNA synthetase (EPRS1), within an unconventional, tetra-aminoacyl-tRNA synthetase complex, to the sgRNA 3'-end thereby enhancing sgRNA expression. We identify an EPRS1-binding sarbecoviral pan-end activating RNA (SPEAR) element in the 3'-end of viral RNAs driving agonist-induction. Translation of another co-terminal 3'-end feature, ORF10, is necessary for SPEAR-mediated induction, independent of Orf10 protein expression. The SPEAR element enhances viral programmed ribosomal frameshifting, thereby expanding its functionality. By co-opting noncanonical activities of a family of essential host proteins, the virus establishes a post-transcriptional regulon stimulating global viral RNA translation. A SPEAR-targeting strategy markedly reduces SARS-CoV-2 titer, suggesting a pan-sarbecoviral therapeutic modality.
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Affiliation(s)
- Debjit Khan
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, 44195, USA
| | - Fulvia Terenzi
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, 44195, USA
| | - GuanQun Liu
- Florida Research and Innovation Center, Cleveland Clinic Foundation, Port St. Lucie, FL, 34987, USA
| | - Prabar K Ghosh
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, 44195, USA
| | - Fengchun Ye
- Department of Molecular Biology and Microbiology, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Kien Nguyen
- Department of Molecular Biology and Microbiology, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Arnab China
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, 44195, USA
| | - Iyappan Ramachandiran
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, 44195, USA
| | - Shruti Chakraborty
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, 44195, USA
| | - Jennifer Stefan
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, 44195, USA
| | - Krishnendu Khan
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, 44195, USA
| | - Kommireddy Vasu
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, 44195, USA
| | - Franklin Dong
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, 44195, USA
| | - Belinda Willard
- Lerner Research Institute Proteomics and Metabolomics Core, Cleveland Clinic Foundation, Cleveland, OH, 44195, USA
| | - Jonathan Karn
- Department of Molecular Biology and Microbiology, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Michaela U Gack
- Florida Research and Innovation Center, Cleveland Clinic Foundation, Port St. Lucie, FL, 34987, USA
| | - Paul L Fox
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, 44195, USA.
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10
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Raymond WS, Ghaffari S, Aguilera LU, Ron E, Morisaki T, Fox ZR, May MP, Stasevich TJ, Munsky B. Using mechanistic models and machine learning to design single-color multiplexed nascent chain tracking experiments. Front Cell Dev Biol 2023; 11:1151318. [PMID: 37325568 PMCID: PMC10267835 DOI: 10.3389/fcell.2023.1151318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 05/09/2023] [Indexed: 06/17/2023] Open
Abstract
mRNA translation is the ubiquitous cellular process of reading messenger-RNA strands into functional proteins. Over the past decade, large strides in microscopy techniques have allowed observation of mRNA translation at a single-molecule resolution for self-consistent time-series measurements in live cells. Dubbed Nascent chain tracking (NCT), these methods have explored many temporal dynamics in mRNA translation uncaptured by other experimental methods such as ribosomal profiling, smFISH, pSILAC, BONCAT, or FUNCAT-PLA. However, NCT is currently restricted to the observation of one or two mRNA species at a time due to limits in the number of resolvable fluorescent tags. In this work, we propose a hybrid computational pipeline, where detailed mechanistic simulations produce realistic NCT videos, and machine learning is used to assess potential experimental designs for their ability to resolve multiple mRNA species using a single fluorescent color for all species. Our simulation results show that with careful application this hybrid design strategy could in principle be used to extend the number of mRNA species that could be watched simultaneously within the same cell. We present a simulated example NCT experiment with seven different mRNA species within the same simulated cell and use our ML labeling to identify these spots with 90% accuracy using only two distinct fluorescent tags. We conclude that the proposed extension to the NCT color palette should allow experimentalists to access a plethora of new experimental design possibilities, especially for cell Signaling applications requiring simultaneous study of multiple mRNAs.
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Affiliation(s)
- William S Raymond
- School of Biomedical Engineering, Colorado State University, Fort Collins, CO, United States
| | - Sadaf Ghaffari
- Department of Computer Science, Colorado State University, Fort Collins, CO, United States
| | - Luis U Aguilera
- Department of Chemical and Biological Engineering, Colorado State University, Fort Collins, CO, United States
| | - Eric Ron
- School of Biomedical Engineering, Colorado State University, Fort Collins, CO, United States
| | - Tatsuya Morisaki
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, United States
| | - Zachary R Fox
- School of Biomedical Engineering, Colorado State University, Fort Collins, CO, United States
- Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Michael P May
- School of Biomedical Engineering, Colorado State University, Fort Collins, CO, United States
| | - Timothy J Stasevich
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, United States
- World Research Hub Initiative and Cell Biology Unit, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Brian Munsky
- School of Biomedical Engineering, Colorado State University, Fort Collins, CO, United States
- Department of Chemical and Biological Engineering, Colorado State University, Fort Collins, CO, United States
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11
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Raymond WS, Ghaffari S, Aguilera LU, Ron E, Morisaki T, Fox ZR, May MP, Stasevich TJ, Munsky B. Using Mechanistic Models and Machine Learning to Design Single-Color Multiplexed Nascent Chain Tracking Experiments. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.25.525583. [PMID: 36747627 PMCID: PMC9900927 DOI: 10.1101/2023.01.25.525583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
mRNA translation is the ubiquitous cellular process of reading messenger-RNA strands into functional proteins. Over the past decade, large strides in microscopy techniques have allowed observation of mRNA translation at a single-molecule resolution for self-consistent time-series measurements in live cells. Dubbed Nascent chain tracking (NCT), these methods have explored many temporal dynamics in mRNA translation uncaptured by other experimental methods such as ribosomal profiling, smFISH, pSILAC, BONCAT, or FUNCAT-PLA. However, NCT is currently restricted to the observation of one or two mRNA species at a time due to limits in the number of resolvable fluorescent tags. In this work, we propose a hybrid computational pipeline, where detailed mechanistic simulations produce realistic NCT videos, and machine learning is used to assess potential experimental designs for their ability to resolve multiple mRNA species using a single fluorescent color for all species. Through simulation, we show that with careful application, this hybrid design strategy could in principle be used to extend the number of mRNA species that could be watched simultaneously within the same cell. We present a simulated example NCT experiment with seven different mRNA species within the same simulated cell and use our ML labeling to identify these spots with 90% accuracy using only two distinct fluorescent tags. The proposed extension to the NCT color palette should allow experimentalists to access a plethora of new experimental design possibilities, especially for cell signalling applications requiring simultaneous study of multiple mRNAs.
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Affiliation(s)
- William S. Raymond
- School of Biomedical Engineering, Colorado State University, Fort Collins, Colorado, USA
| | - Sadaf Ghaffari
- Department of Computer Science, Colorado State University, Fort Collins, Colorado, USA
| | - Luis U. Aguilera
- Department of Chemical and Biological Engineering, Colorado State University, Fort Collins, Colorado, USA
| | - Eric Ron
- School of Biomedical Engineering, Colorado State University, Fort Collins, Colorado, USA
| | - Tatsuya Morisaki
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, USA
| | - Zachary R. Fox
- School of Biomedical Engineering, Colorado State University, Fort Collins, Colorado, USA,Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Michael P. May
- School of Biomedical Engineering, 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 Unit, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta-cho 4259, Midori-ku, Yokohama, Japan
| | - Brian Munsky
- School of Biomedical Engineering, Colorado State University, Fort Collins, Colorado, USA,Department of Chemical and Biological Engineering, Colorado State University, Fort Collins, Colorado, USA,Corresponding Author: Brian Munsky -
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12
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Cialek CA, Galindo G, Morisaki T, Zhao N, Montgomery TA, Stasevich TJ. Imaging translational control by Argonaute with single-molecule resolution in live cells. Nat Commun 2022; 13:3345. [PMID: 35688806 PMCID: PMC9187665 DOI: 10.1038/s41467-022-30976-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 05/24/2022] [Indexed: 11/29/2022] Open
Abstract
A major challenge to our understanding of translational control has been deconvolving the individual impact specific regulatory factors have on the complex dynamics of mRNA translation. MicroRNAs (miRNAs), for example, guide Argonaute and associated proteins to target mRNAs, where they direct gene silencing in multiple ways that are not well understood. To better deconvolve these dynamics, we have developed technology to directly visualize and quantify the impact of human Argonaute2 (Ago2) on the translation and subcellular localization of individual reporter mRNAs in living cells. We show that our combined translation and Ago2 tethering sensor reflects endogenous miRNA-mediated gene silencing. Using the sensor, we find that Ago2 association leads to progressive silencing of translation at individual mRNA. Silencing was occasionally interrupted by brief bursts of translational activity and took 3–4 times longer than a single round of translation, consistent with a gradual increase in the inhibition of translation initiation. At later time points, Ago2-tethered mRNAs cluster and coalesce with P-bodies, where a translationally silent state is maintained. These results provide a framework for exploring miRNA-mediated gene regulation in live cells at the single-molecule level. Furthermore, our tethering-based, single-molecule reporter system will likely have wide-ranging application in studying RNA-protein interactions. Guided by miRNA, Argonaute proteins silence mRNA in multiple ways that are not well understood. Here, the authors develop live-cell biosensors to image the impact tethered regulatory factors, such as Argonaute, have on single-mRNA translation dynamics.
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Affiliation(s)
- Charlotte A Cialek
- Department of Biochemistry & Molecular Biology, Colorado State University, Fort Collins, CO, 80523, USA
| | - Gabriel Galindo
- Department of Biochemistry & Molecular Biology, Colorado State University, Fort Collins, CO, 80523, USA
| | - Tatsuya Morisaki
- Department of Biochemistry & Molecular Biology, Colorado State University, Fort Collins, CO, 80523, USA
| | - Ning Zhao
- Department of Biochemistry & Molecular Biology, Colorado State University, Fort Collins, CO, 80523, USA
| | - Taiowa A Montgomery
- Department of Biology, Colorado State University, Fort Collins, CO, 80523, USA.
| | - Timothy J Stasevich
- Department of Biochemistry & Molecular Biology, Colorado State University, Fort Collins, CO, 80523, USA. .,Cell Biology Center and World Research Hub Initiative, Tokyo Institute of Technology, Yokohama, Japan.
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13
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Feng Y, Wang Z, Chien KY, Chen HL, Liang YH, Hua X, Chiu CH. "Pseudo-pseudogenes" in bacterial genomes: Proteogenomics reveals a wide but low protein expression of pseudogenes in Salmonella enterica. Nucleic Acids Res 2022; 50:5158-5170. [PMID: 35489061 PMCID: PMC9122581 DOI: 10.1093/nar/gkac302] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 04/11/2022] [Accepted: 04/14/2022] [Indexed: 12/03/2022] Open
Abstract
Pseudogenes (genes disrupted by frameshift or in-frame stop codons) are ubiquitously present in the bacterial genome and considered as nonfunctional fossil. Here, we used RNA-seq and mass-spectrometry technologies to measure the transcriptomes and proteomes of Salmonella enterica serovars Paratyphi A and Typhi. All pseudogenes’ mRNA sequences remained disrupted, and were present at comparable levels to their intact homologs. At the protein level, however, 101 out of 161 pseudogenes suggested successful translation, with their low expression regardless of growth conditions, genetic background and pseudogenization causes. The majority of frameshifting detected was compensatory for -1 frameshift mutations. Readthrough of in-frame stop codons primarily involved UAG; and cytosine was the most frequent base adjacent to the codon. Using a fluorescence reporter system, fifteen pseudogenes were confirmed to express successfully in vivo in Escherichia coli. Expression of the intact copy of the fifteen pseudogenes in S. Typhi affected bacterial pathogenesis as revealed in human macrophage and epithelial cell infection models. The above findings suggest the need to revisit the nonstandard translation mechanism as well as the biological role of pseudogenes in the bacterial genome.
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Affiliation(s)
- Ye Feng
- Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, People's Republic of China.,Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, People's Republic of China
| | - Zeyu Wang
- Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, People's Republic of China.,Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, People's Republic of China
| | - Kun-Yi Chien
- Graduate Institute of Biomedical Sciences, Chang Gung University College of Medicine, Taoyuan, Republic of China
| | - Hsiu-Ling Chen
- Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Taoyuan, Republic of China
| | - Yi-Hua Liang
- Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Taoyuan, Republic of China
| | - Xiaoting Hua
- Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, People's Republic of China
| | - Cheng-Hsun Chiu
- Graduate Institute of Biomedical Sciences, Chang Gung University College of Medicine, Taoyuan, Republic of China.,Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Taoyuan, Republic of China.,Division of Pediatric Infectious Diseases, Department of Pediatrics, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Republic of China
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14
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Evans EL, Pocock GM, Einsdorf G, Behrens RT, Dobson ETA, Wiedenmann M, Birkhold C, Ahlquist P, Eliceiri KW, Sherer NM. HIV RGB: Automated Single-Cell Analysis of HIV-1 Rev-Dependent RNA Nuclear Export and Translation Using Image Processing in KNIME. Viruses 2022; 14:903. [PMID: 35632645 PMCID: PMC9145009 DOI: 10.3390/v14050903] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/21/2022] [Accepted: 04/23/2022] [Indexed: 01/27/2023] Open
Abstract
Single-cell imaging has emerged as a powerful means to study viral replication dynamics and identify sites of virus−host interactions. Multivariate aspects of viral replication cycles yield challenges inherent to handling large, complex imaging datasets. Herein, we describe the design and implementation of an automated, imaging-based strategy, “Human Immunodeficiency Virus Red-Green-Blue” (HIV RGB), for deriving comprehensive single-cell measurements of HIV-1 unspliced (US) RNA nuclear export, translation, and bulk changes to viral RNA and protein (HIV-1 Rev and Gag) subcellular distribution over time. Differentially tagged fluorescent viral RNA and protein species are recorded using multicolor long-term (>24 h) time-lapse video microscopy, followed by image processing using a new open-source computational imaging workflow dubbed “Nuclear Ring Segmentation Analysis and Tracking” (NR-SAT) based on ImageJ plugins that have been integrated into the Konstanz Information Miner (KNIME) analytics platform. We describe a typical HIV RGB experimental setup, detail the image acquisition and NR-SAT workflow accompanied by a step-by-step tutorial, and demonstrate a use case wherein we test the effects of perturbing subcellular localization of the Rev protein, which is essential for viral US RNA nuclear export, on the kinetics of HIV-1 late-stage gene regulation. Collectively, HIV RGB represents a powerful platform for single-cell studies of HIV-1 post-transcriptional RNA regulation. Moreover, we discuss how similar NR-SAT-based design principles and open-source tools might be readily adapted to study a broad range of dynamic viral or cellular processes.
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Affiliation(s)
- Edward L. Evans
- McArdle Laboratory for Cancer Research (Department of Oncology), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI 53706, USA; (E.L.E.III); (G.M.P.); (R.T.B.)
- Laboratory for Optical and Computational Instrumentation, Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, WI 53706, USA; (G.E.); (E.T.A.D.); (M.W.)
- Morgridge Institute for Research, Madison, WI 53715, USA
| | - Ginger M. Pocock
- McArdle Laboratory for Cancer Research (Department of Oncology), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI 53706, USA; (E.L.E.III); (G.M.P.); (R.T.B.)
- Laboratory for Optical and Computational Instrumentation, Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, WI 53706, USA; (G.E.); (E.T.A.D.); (M.W.)
- Morgridge Institute for Research, Madison, WI 53715, USA
| | - Gabriel Einsdorf
- Laboratory for Optical and Computational Instrumentation, Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, WI 53706, USA; (G.E.); (E.T.A.D.); (M.W.)
- KNIME GmbH, 78467 Konstanz, Germany;
| | - Ryan T. Behrens
- McArdle Laboratory for Cancer Research (Department of Oncology), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI 53706, USA; (E.L.E.III); (G.M.P.); (R.T.B.)
| | - Ellen T. A. Dobson
- Laboratory for Optical and Computational Instrumentation, Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, WI 53706, USA; (G.E.); (E.T.A.D.); (M.W.)
| | - Marcel Wiedenmann
- Laboratory for Optical and Computational Instrumentation, Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, WI 53706, USA; (G.E.); (E.T.A.D.); (M.W.)
- KNIME GmbH, 78467 Konstanz, Germany;
| | | | - Paul Ahlquist
- McArdle Laboratory for Cancer Research (Department of Oncology), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI 53706, USA; (E.L.E.III); (G.M.P.); (R.T.B.)
- Morgridge Institute for Research, Madison, WI 53715, USA
- John and Jeanne Rowe Center for Research in Virology, Madison, WI 53715, USA
| | - Kevin W. Eliceiri
- Laboratory for Optical and Computational Instrumentation, Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, WI 53706, USA; (G.E.); (E.T.A.D.); (M.W.)
- Morgridge Institute for Research, Madison, WI 53715, USA
| | - Nathan M. Sherer
- McArdle Laboratory for Cancer Research (Department of Oncology), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI 53706, USA; (E.L.E.III); (G.M.P.); (R.T.B.)
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15
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Riegger RJ, Caliskan N. Thinking Outside the Frame: Impacting Genomes Capacity by Programmed Ribosomal Frameshifting. Front Mol Biosci 2022; 9:842261. [PMID: 35281266 PMCID: PMC8915115 DOI: 10.3389/fmolb.2022.842261] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 01/26/2022] [Indexed: 01/08/2023] Open
Abstract
Translation facilitates the transfer of the genetic information stored in the genome via messenger RNAs to a functional protein and is therefore one of the most fundamental cellular processes. Programmed ribosomal frameshifting is a ubiquitous alternative translation event that is extensively used by viruses to regulate gene expression from overlapping open reading frames in a controlled manner. Recent technical advances in the translation field enabled the identification of precise mechanisms as to how and when ribosomes change the reading frame on mRNAs containing cis-acting signals. Several studies began also to illustrate that trans-acting RNA modulators can adjust the timing and efficiency of frameshifting illuminating that frameshifting can be a dynamically regulated process in cells. Here, we intend to summarize these new findings and emphasize how it fits in our current understanding of PRF mechanisms as previously described.
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Affiliation(s)
- Ricarda J. Riegger
- Helmholtz Centre for Infection Research (HZI), Helmholtz Institute for RNA-Based Infection Research (HIRI), Würzburg, Germany
- Graduate School of Life Sciences (GSLS), University of Würzburg, Würzburg, Germany
| | - Neva Caliskan
- Helmholtz Centre for Infection Research (HZI), Helmholtz Institute for RNA-Based Infection Research (HIRI), Würzburg, Germany
- Medical Faculty, University of Würzburg, Würzburg, Germany
- *Correspondence: Neva Caliskan,
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16
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Ha T, Kaiser C, Myong S, Wu B, Xiao J. Next generation single-molecule techniques: Imaging, labeling, and manipulation in vitro and in cellulo. Mol Cell 2022; 82:304-314. [PMID: 35063098 DOI: 10.1016/j.molcel.2021.12.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 12/14/2021] [Accepted: 12/14/2021] [Indexed: 12/24/2022]
Abstract
Owing to their unique abilities to manipulate, label, and image individual molecules in vitro and in cellulo, single-molecule techniques provide previously unattainable access to elementary biological processes. In imaging, single-molecule fluorescence resonance energy transfer (smFRET) and protein-induced fluorescence enhancement in vitro can report on conformational changes and molecular interactions, single-molecule pull-down (SiMPull) can capture and analyze the composition and function of native protein complexes, and single-molecule tracking (SMT) in live cells reveals cellular structures and dynamics. In labeling, the abilities to specifically label genomic loci, mRNA, and nascent polypeptides in cells have uncovered chromosome organization and dynamics, transcription and translation dynamics, and gene expression regulation. In manipulation, optical tweezers, integration of single-molecule fluorescence with force measurements, and single-molecule force probes in live cells have transformed our mechanistic understanding of diverse biological processes, ranging from protein folding, nucleic acids-protein interactions to cell surface receptor function.
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Affiliation(s)
- Taekjip Ha
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, 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 21205, USA.
| | - Christian Kaiser
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Sua Myong
- Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Bin Wu
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Jie Xiao
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
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17
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Benner BE, Bruce JW, Kentala JR, Murray M, Becker JT, Garcia-Miranda P, Ahlquist P, Butcher SE, Sherer NM. Perturbing HIV-1 Ribosomal Frameshifting Frequency Reveals a cis Preference for Gag-Pol Incorporation into Assembling Virions. J Virol 2022; 96:e0134921. [PMID: 34643428 PMCID: PMC8754204 DOI: 10.1128/jvi.01349-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 09/30/2021] [Indexed: 12/29/2022] Open
Abstract
HIV-1 virion production is driven by Gag and Gag-Pol (GP) proteins, with Gag forming the bulk of the capsid and driving budding, while GP binds Gag to deliver the essential virion enzymes protease, reverse transcriptase, and integrase. Virion GP levels are traditionally thought to reflect the relative abundances of GP and Gag in cells (∼1:20), dictated by the frequency of a -1 programmed ribosomal frameshifting (PRF) event occurring in gag-pol mRNAs. Here, we exploited a panel of PRF mutant viruses to show that mechanisms in addition to PRF regulate GP incorporation into virions. First, we show that GP is enriched ∼3-fold in virions relative to cells, with viral infectivity being better maintained at subphysiological levels of GP than when GP levels are too high. Second, we report that GP is more efficiently incorporated into virions when Gag and GP are synthesized in cis (i.e., from the same gag-pol mRNA) than in trans, suggesting that Gag/GP translation and assembly are spatially coupled processes. Third, we show that, surprisingly, virions exhibit a strong upper limit to trans-delivered GP incorporation; an adaptation that appears to allow the virus to temper defects to GP/Gag cleavage that may negatively impact reverse transcription. Taking these results together, we propose a "weighted Goldilocks" scenario for HIV-1 GP incorporation, wherein combined mechanisms of GP enrichment and exclusion buffer virion infectivity over a broad range of local GP concentrations. These results provide new insights into the HIV-1 virion assembly pathway relevant to the anticipated efficacy of PRF-targeted antiviral strategies. IMPORTANCE HIV-1 infectivity requires incorporation of the Gag-Pol (GP) precursor polyprotein into virions during the process of virus particle assembly. Mechanisms dictating GP incorporation into assembling virions are poorly defined, with GP levels in virions traditionally thought to solely reflect relative levels of Gag and GP expressed in cells, dictated by the frequency of a -1 programmed ribosomal frameshifting (PRF) event that occurs in gag-pol mRNAs. Herein, we provide experimental support for a "weighted Goldilocks" scenario for GP incorporation, wherein the virus exploits both random and nonrandom mechanisms to buffer infectivity over a wide range of GP expression levels. These mechanistic data are relevant to ongoing efforts to develop antiviral strategies targeting PRF frequency and/or HIV-1 virion maturation.
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Affiliation(s)
- Bayleigh E. Benner
- Department of Oncology (McArdle Laboratory for Cancer Research), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin—Madison, Madison, Wisconsin, USA
- UW—Madison Microbiology Doctoral Training Program, Madison, Wisconsin, USA
| | - James W. Bruce
- Department of Oncology (McArdle Laboratory for Cancer Research), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin—Madison, Madison, Wisconsin, USA
- John and Jeanne Rowe Center for Research in Virology, Morgridge Institute for Research, Madison, Wisconsin, USA
| | - Jacob R. Kentala
- Department of Oncology (McArdle Laboratory for Cancer Research), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin—Madison, Madison, Wisconsin, USA
| | - Magdalena Murray
- Department of Oncology (McArdle Laboratory for Cancer Research), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin—Madison, Madison, Wisconsin, USA
| | - Jordan T. Becker
- Department of Oncology (McArdle Laboratory for Cancer Research), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin—Madison, Madison, Wisconsin, USA
| | - Pablo Garcia-Miranda
- Department of Oncology (McArdle Laboratory for Cancer Research), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin—Madison, Madison, Wisconsin, USA
- Department of Biochemistry, University of Wisconsin—Madison, Madison, Wisconsin, USA
| | - Paul Ahlquist
- Department of Oncology (McArdle Laboratory for Cancer Research), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin—Madison, Madison, Wisconsin, USA
- John and Jeanne Rowe Center for Research in Virology, Morgridge Institute for Research, Madison, Wisconsin, USA
| | - Samuel E. Butcher
- Department of Biochemistry, University of Wisconsin—Madison, Madison, Wisconsin, USA
| | - Nathan M. Sherer
- Department of Oncology (McArdle Laboratory for Cancer Research), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin—Madison, Madison, Wisconsin, USA
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18
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Morisaki T, Stasevich TJ. Single-Molecule Imaging of mRNA Interactions with Stress Granules. Methods Mol Biol 2022; 2428:349-360. [PMID: 35171490 PMCID: PMC9191879 DOI: 10.1007/978-1-0716-1975-9_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Single-molecule imaging in living cells enables the investigation of molecular dynamics and interactions underlying the physiology of a cell. We recently developed a method to visualize translation events at single-mRNA resolution in living cells. Here we describe how we apply this method to visualize mRNA interactions with stress granules in the context of translational activity during cell stress.
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Affiliation(s)
- Tatsuya Morisaki
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA
| | - Timothy J Stasevich
- World Research Hub Initiative, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Kanagawa, Japan
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19
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Structural dynamics of single SARS-CoV-2 pseudoknot molecules reveal topologically distinct conformers. Nat Commun 2021; 12:4749. [PMID: 34362921 PMCID: PMC8346527 DOI: 10.1038/s41467-021-25085-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Accepted: 07/21/2021] [Indexed: 11/08/2022] Open
Abstract
The RNA pseudoknot that stimulates programmed ribosomal frameshifting in SARS-CoV-2 is a possible drug target. To understand how it responds to mechanical tension applied by ribosomes, thought to play a key role during frameshifting, we probe its structural dynamics using optical tweezers. We find that it forms multiple structures: two pseudoknotted conformers with different stability and barriers, and alternative stem-loop structures. The pseudoknotted conformers have distinct topologies, one threading the 5′ end through a 3-helix junction to create a knot-like fold, the other with unthreaded 5′ end, consistent with structures observed via cryo-EM and simulations. Refolding of the pseudoknotted conformers starts with stem 1, followed by stem 3 and lastly stem 2; Mg2+ ions are not required, but increase pseudoknot mechanical rigidity and favor formation of the knot-like conformer. These results resolve the SARS-CoV-2 frameshift signal folding mechanism and highlight its conformational heterogeneity, with important implications for structure-based drug-discovery efforts. The RNA pseudoknot of SARS-CoV-2 promotes -1 programmed ribosomal frameshifting. Here the authors use single molecule force spectroscopy to study the folding of this pseudoknot, showing that it forms at least two different pseudoknot conformers with distinct fold topologies.
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20
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Atkins JF, O’Connor KM, Bhatt PR, Loughran G. From Recoding to Peptides for MHC Class I Immune Display: Enriching Viral Expression, Virus Vulnerability and Virus Evasion. Viruses 2021; 13:1251. [PMID: 34199077 PMCID: PMC8310308 DOI: 10.3390/v13071251] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 06/11/2021] [Accepted: 06/19/2021] [Indexed: 01/02/2023] Open
Abstract
Many viruses, especially RNA viruses, utilize programmed ribosomal frameshifting and/or stop codon readthrough in their expression, and in the decoding of a few a UGA is dynamically redefined to specify selenocysteine. This recoding can effectively increase viral coding capacity and generate a set ratio of products with the same N-terminal domain(s) but different C-terminal domains. Recoding can also be regulatory or generate a product with the non-universal 21st directly encoded amino acid. Selection for translation speed in the expression of many viruses at the expense of fidelity creates host immune defensive opportunities. In contrast to host opportunism, certain viruses, including some persistent viruses, utilize recoding or adventitious frameshifting as part of their strategy to evade an immune response or specific drugs. Several instances of recoding in small intensively studied viruses escaped detection for many years and their identification resolved dilemmas. The fundamental importance of ribosome ratcheting is consistent with the initial strong view of invariant triplet decoding which however did not foresee the possibility of transitory anticodon:codon dissociation. Deep level dynamics and structural understanding of recoding is underway, and a high level structure relevant to the frameshifting required for expression of the SARS CoV-2 genome has just been determined.
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Affiliation(s)
- John F. Atkins
- Schools of Biochemistry and Microbiology, University College Cork, T12 XF62 Cork, Ireland; (K.M.O.); (P.R.B.); (G.L.)
| | - Kate M. O’Connor
- Schools of Biochemistry and Microbiology, University College Cork, T12 XF62 Cork, Ireland; (K.M.O.); (P.R.B.); (G.L.)
| | - Pramod R. Bhatt
- Schools of Biochemistry and Microbiology, University College Cork, T12 XF62 Cork, Ireland; (K.M.O.); (P.R.B.); (G.L.)
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, 8093 Zurich, Switzerland
| | - Gary Loughran
- Schools of Biochemistry and Microbiology, University College Cork, T12 XF62 Cork, Ireland; (K.M.O.); (P.R.B.); (G.L.)
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21
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Kharod SC, Hwang DW, Das S, Yoon YJ. Spatiotemporal Insights Into RNA-Organelle Interactions in Neurons. Front Cell Dev Biol 2021; 9:663367. [PMID: 34178987 PMCID: PMC8222803 DOI: 10.3389/fcell.2021.663367] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 05/04/2021] [Indexed: 01/03/2023] Open
Abstract
Neurons exhibit spatial compartmentalization of gene expression where localization of messenger RNAs (mRNAs) to distal processes allows for site-specific distribution of proteins through local translation. Recently, there have been reports of coordination between mRNA transport with vesicular and organellar trafficking. In this review, we will highlight the latest literature on axonal and dendritic local protein synthesis with links to mRNA-organelle cotransport followed by emerging technologies necessary to study these phenomena. Recent high-resolution imaging studies have led to insights into the dynamics of RNA-organelle interactions, and we can now peer into these intricate interactions within subcellular compartments of neurons.
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Affiliation(s)
- Shivani C. Kharod
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY, United States
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Dong-Woo Hwang
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Sulagna Das
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Young J. Yoon
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY, United States
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, United States
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22
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Kowalczyk GJ, Cruz JA, Guo Y, Zhang Q, Sauerwald N, Lee REC. dNEMO: a tool for quantification of mRNA and punctate structures in time-lapse images of single cells. Bioinformatics 2021; 37:677-683. [PMID: 33051642 DOI: 10.1093/bioinformatics/btaa874] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 03/20/2020] [Accepted: 09/28/2020] [Indexed: 11/14/2022] Open
Abstract
MOTIVATION Many biological processes are regulated by single molecules and molecular assemblies within cells that are visible by microscopy as punctate features, often diffraction limited. Here, we present detecting-NEMO (dNEMO), a computational tool optimized for accurate and rapid measurement of fluorescent puncta in fixed-cell and time-lapse images. RESULTS The spot detection algorithm uses the à trous wavelet transform, a computationally inexpensive method that is robust to imaging noise. By combining automated with manual spot curation in the user interface, fluorescent puncta can be carefully selected and measured against their local background to extract high-quality single-cell data. Integrated into the workflow are segmentation and spot-inspection tools that enable almost real-time interaction with images without time consuming pre-processing steps. Although the software is agnostic to the type of puncta imaged, we demonstrate dNEMO using smFISH to measure transcript numbers in single cells in addition to the transient formation of IKK/NEMO puncta from time-lapse images of cells exposed to inflammatory stimuli. We conclude that dNEMO is an ideal user interface for rapid and accurate measurement of fluorescent molecular assemblies in biological imaging data. AVAILABILITY AND IMPLEMENTATION The data and software are freely available online at https://github.com/recleelab. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Gabriel J Kowalczyk
- Department of Computational and Systems Biology, School of Medicine, Pittsburgh, PA 15213, USA
| | - J Agustin Cruz
- Department of Computational and Systems Biology, School of Medicine, Pittsburgh, PA 15213, USA
| | - Yue Guo
- Department of Computational and Systems Biology, School of Medicine, Pittsburgh, PA 15213, USA.,Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Qiuhong Zhang
- Department of Computational and Systems Biology, School of Medicine, Pittsburgh, PA 15213, USA
| | - Natalie Sauerwald
- Department of Computational Biology, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Robin E C Lee
- Department of Computational and Systems Biology, School of Medicine, Pittsburgh, PA 15213, USA
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23
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Cialek CA, Galindo G, Koch AL, Saxton MN, Stasevich TJ. Bead Loading Proteins and Nucleic Acids into Adherent Human Cells. J Vis Exp 2021:10.3791/62559. [PMID: 34152325 PMCID: PMC9074699 DOI: 10.3791/62559] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Many live-cell imaging experiments use exogenous particles (e.g., peptides, antibodies, beads) to label or function within cells. However, introducing proteins into a cell across its membrane is difficult. The limited selection of current methods struggles with low efficiency, requires expensive and technically demanding equipment, or functions within narrow parameters. Here, we describe a relatively simple and cost-effective technique for loading DNA, RNA, and proteins into live human cells. Bead loading induces a temporary mechanical disruption to the cell membrane, allowing macromolecules to enter adherent, live mammalian cells. At less than 0.01 USD per experiment, bead loading is the least expensive cell loading method available. Moreover, bead loading does not substantially stress cells or impact their viability or proliferation. This manuscript describes the steps of the bead loading procedure, adaptations, variations, and technical limitations. This methodology is especially suited for live-cell imaging but provides a practical solution for other applications requiring the introduction of proteins, beads, RNA, or plasmids into living, adherent mammalian cells.
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Affiliation(s)
| | - Gabriel Galindo
- Department of Biochemistry and Molecular Biology, Colorado State University
| | - Amanda Lynn Koch
- Department of Biochemistry and Molecular Biology, Colorado State University
| | | | - Timothy John Stasevich
- Department of Biochemistry and Molecular Biology, Colorado State University; World Research Hub Initiative, Institute of Innovative Research, Tokyo Institute of Technology;
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24
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Ho JJD, Man JHS, Schatz JH, Marsden PA. Translational remodeling by RNA-binding proteins and noncoding RNAs. WILEY INTERDISCIPLINARY REVIEWS-RNA 2021; 12:e1647. [PMID: 33694288 DOI: 10.1002/wrna.1647] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/09/2021] [Accepted: 02/10/2021] [Indexed: 12/14/2022]
Abstract
Responsible for generating the proteome that controls phenotype, translation is the ultimate convergence point for myriad upstream signals that influence gene expression. System-wide adaptive translational reprogramming has recently emerged as a pillar of cellular adaptation. As classic regulators of mRNA stability and translation efficiency, foundational studies established the concept of collaboration and competition between RNA-binding proteins (RBPs) and noncoding RNAs (ncRNAs) on individual mRNAs. Fresh conceptual innovations now highlight stress-activated, evolutionarily conserved RBP networks and ncRNAs that increase the translation efficiency of populations of transcripts encoding proteins that participate in a common cellular process. The discovery of post-transcriptional functions for long noncoding RNAs (lncRNAs) was particularly intriguing given their cell-type-specificity and historical definition as nuclear-functioning epigenetic regulators. The convergence of RBPs, lncRNAs, and microRNAs on functionally related mRNAs to enable adaptive protein synthesis is a newer biological paradigm that highlights their role as "translatome (protein output) remodelers" and reinvigorates the paradigm of "RNA operons." Together, these concepts modernize our understanding of cellular stress adaptation and strategies for therapeutic development. This article is categorized under: RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications Translation > Translation Regulation Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs.
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Affiliation(s)
- J J David Ho
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, Florida, USA.,Division of Hematology, Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Jeffrey H S Man
- Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada.,Department of Medicine, University of Toronto, Toronto, Ontario, Canada.,Department of Respirology, University Health Network, Latner Thoracic Research Laboratories, University of Toronto, Toronto, Ontario, Canada
| | - Jonathan H Schatz
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, Florida, USA.,Division of Hematology, Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Philip A Marsden
- Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada.,Department of Medicine, University of Toronto, Toronto, Ontario, Canada
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25
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Neelagandan N, Lamberti I, Carvalho HJF, Gobet C, Naef F. What determines eukaryotic translation elongation: recent molecular and quantitative analyses of protein synthesis. Open Biol 2020; 10:200292. [PMID: 33292102 PMCID: PMC7776565 DOI: 10.1098/rsob.200292] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 11/10/2020] [Indexed: 12/14/2022] Open
Abstract
Protein synthesis from mRNA is an energy-intensive and tightly controlled cellular process. Translation elongation is a well-coordinated, multifactorial step in translation that undergoes dynamic regulation owing to cellular state and environmental determinants. Recent studies involving genome-wide approaches have uncovered some crucial aspects of translation elongation including the mRNA itself and the nascent polypeptide chain. Additionally, these studies have fuelled quantitative and mathematical modelling of translation elongation. In this review, we provide a comprehensive overview of the key determinants of translation elongation. We discuss consequences of ribosome stalling or collision, and how the cells regulate translation in case of such events. Next, we review theoretical approaches and widely used mathematical models that have become an essential ingredient to interpret complex molecular datasets and study translation dynamics quantitatively. Finally, we review recent advances in live-cell reporter and related analysis techniques, to monitor the translation dynamics of single cells and single-mRNA molecules in real time.
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Affiliation(s)
| | | | | | | | - Felix Naef
- Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
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26
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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: 53] [Impact Index Per Article: 13.3] [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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27
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Heterogeneity in mRNA Translation. Trends Cell Biol 2020; 30:606-618. [DOI: 10.1016/j.tcb.2020.04.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 04/23/2020] [Accepted: 04/30/2020] [Indexed: 11/18/2022]
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28
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Mikl M, Pilpel Y, Segal E. High-throughput interrogation of programmed ribosomal frameshifting in human cells. Nat Commun 2020; 11:3061. [PMID: 32546731 PMCID: PMC7297798 DOI: 10.1038/s41467-020-16961-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 05/28/2020] [Indexed: 12/30/2022] Open
Abstract
Programmed ribosomal frameshifting (PRF) is the controlled slippage of the translating ribosome to an alternative frame. This process is widely employed by human viruses such as HIV and SARS coronavirus and is critical for their replication. Here, we developed a high-throughput approach to assess the frameshifting potential of a sequence. We designed and tested >12,000 sequences based on 15 viral and human PRF events, allowing us to systematically dissect the rules governing ribosomal frameshifting and discover novel regulatory inputs based on amino acid properties and tRNA availability. We assessed the natural variation in HIV gag-pol frameshifting rates by testing >500 clinical isolates and identified subtype-specific differences and associations between viral load in patients and the optimality of PRF rates. We devised computational models that accurately predict frameshifting potential and frameshifting rates, including subtle differences between HIV isolates. This approach can contribute to the development of antiviral agents targeting PRF.
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Affiliation(s)
- Martin Mikl
- Department of Computer Science and Applied Mathematics, Rehovot, 7610001, Israel.
- Department of Molecular Cell Biology and Weizmann Institute of Science, Rehovot, 7610001, Israel.
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 7610001, Israel.
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, Mount Carmel, Haifa, 31905, Israel.
| | - Yitzhak Pilpel
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Eran Segal
- Department of Computer Science and Applied Mathematics, Rehovot, 7610001, Israel.
- Department of Molecular Cell Biology and Weizmann Institute of Science, Rehovot, 7610001, Israel.
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29
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Cialek CA, Koch AL, Galindo G, Stasevich TJ. Lighting up single-mRNA translation dynamics in living cells. Curr Opin Genet Dev 2020; 61:75-82. [PMID: 32408104 PMCID: PMC7508770 DOI: 10.1016/j.gde.2020.04.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 03/12/2020] [Accepted: 04/08/2020] [Indexed: 12/11/2022]
Abstract
Over the past five years, technological advances have made it possible to image the translation of single mRNA in the natural context of living cells. With these advances, researchers are beginning to shed light on when, where, and to what degree mRNA are translated with single-molecule precision. These works provide insight into the heterogeneity of translation amongst single transcripts, behavior that is averaged out in complementary bulk assays. In this review, we discuss the rapidly maturing field of live-cell, single-mRNA imaging of translation, beginning with a brief overview of recent technological advances. The remainder of the review focuses on the new biological insights gained from these technologies. We conclude with a discussion of the future of this technology.
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Affiliation(s)
- Charlotte A Cialek
- Department of Biochemistry & Molecular Biology, Colorado State University, Fort Collins, Colorado 80523, USA
| | - Amanda L Koch
- Department of Biochemistry & Molecular Biology, Colorado State University, Fort Collins, Colorado 80523, USA
| | - Gabriel Galindo
- Department of Biochemistry & Molecular Biology, Colorado State University, Fort Collins, Colorado 80523, USA
| | - Timothy J Stasevich
- Department of Biochemistry & Molecular Biology, Colorado State University, Fort Collins, Colorado 80523, USA; World Research Hub Initiative, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 2268503, Japan.
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30
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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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31
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Quantification of mRNA translation in live cells using single-molecule imaging. Nat Protoc 2020; 15:1371-1398. [PMID: 32076351 DOI: 10.1038/s41596-019-0284-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 12/13/2019] [Indexed: 11/09/2022]
Abstract
mRNA translation is a key step in gene expression. Proper regulation of translation efficiency ensures correct protein expression levels in the cell, which is essential to cell function. Different methods used to study translational control in the cell rely on population-based assays that do not provide information about translational heterogeneity between cells or between mRNAs of the same gene within a cell, and generally provide only a snapshot of translation. To study translational heterogeneity and measure translation dynamics, we have developed microscopy-based methods that enable visualization of translation of single mRNAs in live cells. These methods consist of a set of genetic tools, an imaging-based approach and sophisticated computational tools. Using the translation imaging method, one can investigate many new aspects of translation in single living cells, such as translation start-site selection, 3'-UTR (untranslated region) translation and translation-coupled mRNA decay. Here, we describe in detail how to perform such experiments, including reporter design, cell line generation, image acquisition and analysis. This protocol also provides a detailed description of the image analysis pipeline and computational modeling that will enable non-experts to correctly interpret fluorescence measurements. The protocol takes 2-4 d to complete (after cell lines expressing all required transgenes have been generated).
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32
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Schmidt A, Gao G, Little SR, Jalihal AP, Walter NG. Following the messenger: Recent innovations in live cell single molecule fluorescence imaging. WILEY INTERDISCIPLINARY REVIEWS-RNA 2020; 11:e1587. [PMID: 31990126 DOI: 10.1002/wrna.1587] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 12/19/2019] [Accepted: 01/04/2020] [Indexed: 01/16/2023]
Abstract
Messenger RNAs (mRNAs) convey genetic information from the DNA genome to proteins and thus lie at the heart of gene expression and regulation of all cellular activities. Live cell single molecule tracking tools enable the investigation of mRNA trafficking, translation and degradation within the complex environment of the cell and in real time. Over the last 5 years, nearly all tools within the mRNA tracking toolbox have been improved to achieve high-quality multi-color tracking in live cells. For example, the bacteriophage-derived MS2-MCP system has been improved to facilitate cloning and achieve better signal-to-noise ratio, while the newer PP7-PCP system now allows for orthogonal tracking of a second mRNA or mRNA region. The coming of age of epitope-tagging technologies, such as the SunTag, MoonTag and Frankenbody, enables monitoring the translation of single mRNA molecules. Furthermore, the portfolio of fluorogenic RNA aptamers has been expanded to improve cellular stability and achieve a higher fluorescence "turn-on" signal upon fluorogen binding. Finally, microinjection-based tools have been shown to be able to track multiple RNAs with only small fluorescent appendages and to track mRNAs together with their interacting partners. We systematically review and compare the advantages, disadvantages and demonstrated applications in discovering new RNA biology of this refined, expanding toolbox. Finally, we discuss developments expected in the near future based on the limitations of the current methods. This article is categorized under: RNA Export and Localization > RNA Localization RNA Structure and Dynamics > RNA Structure, Dynamics, and Chemistry RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes.
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Affiliation(s)
- Andreas Schmidt
- Single Molecule Analysis Group, Department of Chemistry, University of Michigan, Ann Arbor, Michigan
| | - Guoming Gao
- Single Molecule Analysis Group, Department of Chemistry, University of Michigan, Ann Arbor, Michigan.,Biophysics Graduate Program, University of Michigan, Ann Arbor, Michigan
| | - Saffron R Little
- Single Molecule Analysis Group, Department of Chemistry, University of Michigan, Ann Arbor, Michigan.,Program in Chemical Biology, University of Michigan, Ann Arbor, Michigan
| | - Ameya P Jalihal
- Single Molecule Analysis Group, Department of Chemistry, University of Michigan, Ann Arbor, Michigan.,Cell and Molecular Biology Program, University of Michigan, Ann Arbor, Michigan
| | - Nils G Walter
- Single Molecule Analysis Group, Department of Chemistry, University of Michigan, Ann Arbor, Michigan
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33
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Aguilera LU, Raymond W, Fox ZR, May M, Djokic E, Morisaki T, Stasevich TJ, Munsky B. Computational design and interpretation of single-RNA translation experiments. PLoS Comput Biol 2019; 15:e1007425. [PMID: 31618265 PMCID: PMC6816579 DOI: 10.1371/journal.pcbi.1007425] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 10/28/2019] [Accepted: 09/19/2019] [Indexed: 01/18/2023] Open
Abstract
Advances in fluorescence microscopy have introduced new assays to quantify live-cell translation dynamics at single-RNA resolution. We introduce a detailed, yet efficient sequence-based stochastic model that generates realistic synthetic data for several such assays, including Fluorescence Correlation Spectroscopy (FCS), ribosome Run-Off Assays (ROA) after Harringtonine application, and Fluorescence Recovery After Photobleaching (FRAP). We simulate these experiments under multiple imaging conditions and for thousands of human genes, and we evaluate through simulations which experiments are most likely to provide accurate estimates of elongation kinetics. Finding that FCS analyses are optimal for both short and long length genes, we integrate our model with experimental FCS data to capture the nascent protein statistics and temporal dynamics for three human genes: KDM5B, β-actin, and H2B. Finally, we introduce a new open-source software package, RNA Sequence to NAscent Protein Simulator (rSNAPsim), to easily simulate the single-molecule translation dynamics of any gene sequence for any of these assays and for different assumptions regarding synonymous codon usage, tRNA level modifications, or ribosome pauses. rSNAPsim is implemented in Python and is available at: https://github.com/MunskyGroup/rSNAPsim.git.
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Affiliation(s)
- Luis U. Aguilera
- Department of Chemical and Biological Engineering, Colorado State University Fort Collins, Colorado, United States of America
| | - William Raymond
- Department of Chemical and Biological Engineering, Colorado State University Fort Collins, Colorado, United States of America
- School of Biomedical Engineering, Colorado State University Fort Collins, Colorado, United States of America
| | - Zachary R. Fox
- School of Biomedical Engineering, Colorado State University Fort Collins, Colorado, United States of America
| | - Michael May
- School of Biomedical Engineering, Colorado State University Fort Collins, Colorado, United States of America
| | - Elliot Djokic
- School of Biomedical Engineering, Colorado State University Fort Collins, Colorado, United States of America
| | - Tatsuya Morisaki
- Department of Biochemistry and Molecular Biology and Institute for Genome Architecture and Function, Colorado State University, Fort Collins, Colorado, United States of America
| | - Timothy J. Stasevich
- Department of Biochemistry and Molecular Biology and Institute for Genome Architecture and Function, Colorado State University, Fort Collins, Colorado, United States of America
- Cell Biology Unit, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta-cho 4259, Midori-ku, Yokohama, Kanagawa, Japan
| | - Brian Munsky
- Department of Chemical and Biological Engineering, Colorado State University Fort Collins, Colorado, United States of America
- School of Biomedical Engineering, Colorado State University Fort Collins, Colorado, United States of America
- * E-mail:
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34
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Zhao N, Kamijo K, Fox PD, Oda H, Morisaki T, Sato Y, Kimura H, Stasevich TJ. A genetically encoded probe for imaging nascent and mature HA-tagged proteins in vivo. Nat Commun 2019; 10:2947. [PMID: 31270320 PMCID: PMC6610143 DOI: 10.1038/s41467-019-10846-1] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 05/29/2019] [Indexed: 01/07/2023] Open
Abstract
To expand the toolbox of imaging in living cells, we have engineered a single-chain variable fragment binding the linear HA epitope with high affinity and specificity in vivo. The resulting probe, called the HA frankenbody, can light up in multiple colors HA-tagged nuclear, cytoplasmic, membrane, and mitochondrial proteins in diverse cell types. The HA frankenbody also enables state-of-the-art single-molecule experiments in living cells, which we demonstrate by tracking single HA-tagged histones in U2OS cells and single mRNA translation dynamics in both U2OS cells and neurons. Together with the SunTag, we also track two mRNA species simultaneously to demonstrate comparative single-molecule studies of translation can now be done with genetically encoded tools alone. Finally, we use the HA frankenbody to precisely quantify the expression of HA-tagged proteins in developing zebrafish embryos. The versatility of the HA frankenbody makes it a powerful tool for imaging protein dynamics in vivo.
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Affiliation(s)
- Ning Zhao
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, 80523, USA
| | - Kouta Kamijo
- Graduate School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
| | - Philip D Fox
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, 80523, USA
| | - Haruka Oda
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
| | - Tatsuya Morisaki
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, 80523, USA
| | - Yuko Sato
- Graduate School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
| | - Hiroshi Kimura
- Graduate School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
- World Research Hub Initiative, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
| | - Timothy J Stasevich
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, 80523, USA.
- World Research Hub Initiative, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503, Japan.
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35
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Blake LA, Wu B. One Message, Many Translations: Heterogeneity Revealed with Multicolor Imaging. Mol Cell 2019; 75:3-4. [DOI: 10.1016/j.molcel.2019.06.026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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36
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Boersma S, Khuperkar D, Verhagen BMP, Sonneveld S, Grimm JB, Lavis LD, Tanenbaum ME. Multi-Color Single-Molecule Imaging Uncovers Extensive Heterogeneity in mRNA Decoding. Cell 2019; 178:458-472.e19. [PMID: 31178119 PMCID: PMC6630898 DOI: 10.1016/j.cell.2019.05.001] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 03/05/2019] [Accepted: 04/30/2019] [Indexed: 12/17/2022]
Abstract
mRNA translation is a key step in decoding genetic information. Genetic decoding is surprisingly heterogeneous because multiple distinct polypeptides can be synthesized from a single mRNA sequence. To study translational heterogeneity, we developed the MoonTag, a fluorescence labeling system to visualize translation of single mRNAs. When combined with the orthogonal SunTag system, the MoonTag enables dual readouts of translation, greatly expanding the possibilities to interrogate complex translational heterogeneity. By placing MoonTag and SunTag sequences in different translation reading frames, each driven by distinct translation start sites, start site selection of individual ribosomes can be visualized in real time. We find that start site selection is largely stochastic but that the probability of using a particular start site differs among mRNA molecules and can be dynamically regulated over time. This study provides key insights into translation start site selection heterogeneity and provides a powerful toolbox to visualize complex translation dynamics. Development of MoonTag, a fluorescence labeling system to visualize translation Combining MoonTag and SunTag enables visualization of translational heterogeneity mRNAs from a single gene vary in initiation frequency at different start sites Ribosomes take many different “paths” along the 5′ UTR of a single mRNA molecule
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Affiliation(s)
- Sanne Boersma
- Oncode Institute, Hubrecht Institute - KNAW and University Medical Center Utrecht, Utrecht, the Netherlands
| | - Deepak Khuperkar
- Oncode Institute, Hubrecht Institute - KNAW and University Medical Center Utrecht, Utrecht, the Netherlands
| | - Bram M P Verhagen
- Oncode Institute, Hubrecht Institute - KNAW and University Medical Center Utrecht, Utrecht, the Netherlands
| | - Stijn Sonneveld
- Oncode Institute, Hubrecht Institute - KNAW and University Medical Center Utrecht, Utrecht, the Netherlands
| | - Jonathan B Grimm
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Luke D Lavis
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Marvin E Tanenbaum
- Oncode Institute, Hubrecht Institute - KNAW and University Medical Center Utrecht, Utrecht, the Netherlands.
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37
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Adivarahan S, Zenklusen D. Lessons from (pre-)mRNA Imaging. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1203:247-284. [DOI: 10.1007/978-3-030-31434-7_9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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