1
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Kindongo O, Lieb G, Skaggs B, Dusserre Y, Vincenzetti V, Pelet S. Implication of polymerase recycling for nascent transcript quantification by live cell imaging. Yeast 2024; 41:279-294. [PMID: 38389243 DOI: 10.1002/yea.3929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 12/29/2023] [Accepted: 01/18/2024] [Indexed: 02/24/2024] Open
Abstract
Transcription enables the production of RNA from a DNA template. Due to the highly dynamic nature of transcription, live-cell imaging methods play a crucial role in measuring the kinetics of this process. For instance, transcriptional bursts have been visualized using fluorescent phage-coat proteins that associate tightly with messenger RNA (mRNA) stem loops formed on nascent transcripts. To convert the signal emanating from a transcription site into meaningful estimates of transcription dynamics, the influence of various parameters on the measured signal must be evaluated. Here, the effect of gene length on the intensity of the transcription site focus was analyzed. Intuitively, a longer gene can support a larger number of transcribing polymerases, thus leading to an increase in the measured signal. However, measurements of transcription induced by hyper-osmotic stress responsive promoters display independence from gene length. A mathematical model of the stress-induced transcription process suggests that the formation of gene loops that favor the recycling of polymerase from the terminator to the promoter can explain the observed behavior. One experimentally validated prediction from this model is that the amount of mRNA produced from a short gene should be higher than for a long one as the density of active polymerase on the short gene will be increased by polymerase recycling. Our data suggest that this recycling contributes significantly to the expression output from a gene and that polymerase recycling is modulated by the promoter identity and the cellular state.
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Affiliation(s)
- Olivia Kindongo
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Guillaume Lieb
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Benjamin Skaggs
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Yves Dusserre
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Vincent Vincenzetti
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Serge Pelet
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
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2
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Kukhtevich IV, Rivero-Romano M, Rakesh N, Bheda P, Chadha Y, Rosales-Becerra P, Hamperl S, Bureik D, Dornauer S, Dargemont C, Kirmizis A, Schmoller KM, Schneider R. Quantitative RNA imaging in single live cells reveals age-dependent asymmetric inheritance. Cell Rep 2022; 41:111656. [DOI: 10.1016/j.celrep.2022.111656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 08/31/2022] [Accepted: 10/20/2022] [Indexed: 11/18/2022] Open
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3
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Spinach-based RNA mimicking GFP in plant cells. Funct Integr Genomics 2022; 22:423-428. [PMID: 35267109 PMCID: PMC9197860 DOI: 10.1007/s10142-022-00835-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 02/16/2022] [Accepted: 02/16/2022] [Indexed: 12/23/2022]
Abstract
Spinach RNA-mimicking GFP (S-RMG) has been successfully used to monitor cellular RNAs including microRNAs in bacterium, yeast, and human cells. However, S-RMG has not been established in plants. In this study, we found that like bacterial, yeast, and human cellular tRNAs, plant tRNAs such as tRNALys can protect and/or stabilize the Spinach RNA aptamer interaction with the fluorophore DFHBI enabling detectable levels of green fluorescence to be emitted. The tRNALys-Spinach-tRNALys, once delivered into "chloroplast-free" onion epidermal cells can emit strong green fluorescence in the presence of DFHBI. Our results demonstrate for the first time that Spinach-based RNA visualization has the potential for in vivo monitoring of RNAs in plant cells.
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4
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Christopher JA, Geladaki A, Dawson CS, Vennard OL, Lilley KS. Subcellular Transcriptomics and Proteomics: A Comparative Methods Review. Mol Cell Proteomics 2022; 21:100186. [PMID: 34922010 PMCID: PMC8864473 DOI: 10.1016/j.mcpro.2021.100186] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 11/16/2021] [Accepted: 12/13/2021] [Indexed: 12/23/2022] Open
Abstract
The internal environment of cells is molecularly crowded, which requires spatial organization via subcellular compartmentalization. These compartments harbor specific conditions for molecules to perform their biological functions, such as coordination of the cell cycle, cell survival, and growth. This compartmentalization is also not static, with molecules trafficking between these subcellular neighborhoods to carry out their functions. For example, some biomolecules are multifunctional, requiring an environment with differing conditions or interacting partners, and others traffic to export such molecules. Aberrant localization of proteins or RNA species has been linked to many pathological conditions, such as neurological, cancer, and pulmonary diseases. Differential expression studies in transcriptomics and proteomics are relatively common, but the majority have overlooked the importance of subcellular information. In addition, subcellular transcriptomics and proteomics data do not always colocate because of the biochemical processes that occur during and after translation, highlighting the complementary nature of these fields. In this review, we discuss and directly compare the current methods in spatial proteomics and transcriptomics, which include sequencing- and imaging-based strategies, to give the reader an overview of the current tools available. We also discuss current limitations of these strategies as well as future developments in the field of spatial -omics.
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Affiliation(s)
- Josie A Christopher
- Department of Biochemistry, Cambridge Centre for Proteomics, University of Cambridge, Cambridge, UK; Milner Therapeutics Institute, Jeffrey Cheah Biomedical Centre, Cambridge, UK
| | - Aikaterini Geladaki
- Department of Biochemistry, Cambridge Centre for Proteomics, University of Cambridge, Cambridge, UK; Department of Genetics, University of Cambridge, Cambridge, UK
| | - Charlotte S Dawson
- Department of Biochemistry, Cambridge Centre for Proteomics, University of Cambridge, Cambridge, UK; Milner Therapeutics Institute, Jeffrey Cheah Biomedical Centre, Cambridge, UK
| | - Owen L Vennard
- Department of Biochemistry, Cambridge Centre for Proteomics, University of Cambridge, Cambridge, UK; Milner Therapeutics Institute, Jeffrey Cheah Biomedical Centre, Cambridge, UK
| | - Kathryn S Lilley
- Department of Biochemistry, Cambridge Centre for Proteomics, University of Cambridge, Cambridge, UK; Milner Therapeutics Institute, Jeffrey Cheah Biomedical Centre, Cambridge, UK.
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5
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Basyuk E, Rage F, Bertrand E. RNA transport from transcription to localized translation: a single molecule perspective. RNA Biol 2021; 18:1221-1237. [PMID: 33111627 PMCID: PMC8354613 DOI: 10.1080/15476286.2020.1842631] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 10/21/2020] [Accepted: 10/22/2020] [Indexed: 12/21/2022] Open
Abstract
Transport of mRNAs is an important step of gene expression, which brings the genetic message from the DNA in the nucleus to a precise cytoplasmic location in a regulated fashion. Perturbation of this process can lead to pathologies such as developmental and neurological disorders. In this review, we discuss recent advances in the field of mRNA transport made using single molecule fluorescent imaging approaches. We present an overview of these approaches in fixed and live cells and their input in understanding the key steps of mRNA journey: transport across the nucleoplasm, export through the nuclear pores and delivery to its final cytoplasmic location. This review puts a particular emphasis on the coupling of mRNA transport with translation, such as localization-dependent translational regulation and translation-dependent mRNA localization. We also highlight the recently discovered translation factories, and how cellular and viral RNAs can hijack membrane transport systems to travel in the cytoplasm.
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Affiliation(s)
- Eugenia Basyuk
- Institut de Génétique Humaine, CNRS-UMR9002, Univ Montpellier, Montpellier, France
- Present address: Laboratoire de Microbiologie Fondamentale et Pathogénicité, CNRS-UMR 5234, Université de Bordeaux, Bordeaux, France
| | - Florence Rage
- Institut de Génétique Moléculaire de Montpellier, CNRS-UMR5535, Univ Montpellier, Montpellier, France
| | - Edouard Bertrand
- Institut de Génétique Humaine, CNRS-UMR9002, Univ Montpellier, Montpellier, France
- Institut de Génétique Moléculaire de Montpellier, CNRS-UMR5535, Univ Montpellier, Montpellier, France
- Equipe Labélisée Ligue Nationale Contre Le Cancer, Montpellier, France
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6
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Sumner MC, Torrisi SB, Brickner DG, Brickner JH. Random sub-diffusion and capture of genes by the nuclear pore reduces dynamics and coordinates inter-chromosomal movement. eLife 2021; 10:66238. [PMID: 34002694 PMCID: PMC8195609 DOI: 10.7554/elife.66238] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 05/17/2021] [Indexed: 11/13/2022] Open
Abstract
Hundreds of genes interact with the yeast nuclear pore complex (NPC), localizing at the nuclear periphery and clustering with co-regulated genes. Dynamic tracking of peripheral genes shows that they cycle on and off the NPC and that interaction with the NPC slows their sub-diffusive movement. Furthermore, NPC-dependent inter-chromosomal clustering leads to coordinated movement of pairs of loci separated by hundreds of nanometers. We developed fractional Brownian motion simulations for chromosomal loci in the nucleoplasm and interacting with NPCs. These simulations predict the rate and nature of random sub-diffusion during repositioning from nucleoplasm to periphery and match measurements from two different experimental models, arguing that recruitment to the nuclear periphery is due to random sub-diffusion and transient capture by NPCs. Finally, the simulations do not lead to inter-chromosomal clustering or coordinated movement, suggesting that interaction with the NPC is necessary, but not sufficient, to cause clustering.
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Affiliation(s)
- Michael Chas Sumner
- Department of Molecular Biosciences, Northwestern University, Evanston, United States
| | - Steven B Torrisi
- Department of Physics, Harvard University, Cambridge, United States
| | - Donna G Brickner
- Department of Molecular Biosciences, Northwestern University, Evanston, United States
| | - Jason H Brickner
- Department of Molecular Biosciences, Northwestern University, Evanston, United States
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7
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A malachite green light-up aptasensor for the detection of theophylline. Talanta 2021; 232:122417. [PMID: 34074405 DOI: 10.1016/j.talanta.2021.122417] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 04/01/2021] [Accepted: 04/08/2021] [Indexed: 11/24/2022]
Abstract
Biosensors are of interest for the quantitative detection of small molecules (metabolites, drugs and contaminants for instance). To this end, fluorescence is a widely used technique that is easily associated to aptamers. Light-up aptamers constitute a particular class of oligonucleotides that, specifically induce fluorescence emission when binding to cognate fluorogenic ligands such as malachite green (MG). We engineered a dual aptasensor for theophylline (Th) based on the combination of switching hairpin aptamers specific for MG on the one hand and for Th on the other hand, hence their names: malaswitch (Msw) and theoswitch (Thsw). The two aptaswitches form a loop-loop or kissing Msw-Thsw complex only in the presence of theophylline, allowing binding of MG, subsequently generating a fluorescent signal. The combination of the best Msw and Thsw variants, MswG12 and Thsw19.1, results in a 20-fold fluorescence enhancement of MG at saturating theophylline concentration. This aptasensor discriminates between theophylline and its analogues caffeine and theobromine. Kissing aptaswitches derived from light-up aptamers constitute a novel sensing device.
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8
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Ryckelynck M. Development and Applications of Fluorogen/Light-Up RNA Aptamer Pairs for RNA Detection and More. Methods Mol Biol 2021; 2166:73-102. [PMID: 32710404 DOI: 10.1007/978-1-0716-0712-1_5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The central role of RNA in living systems made it highly desirable to have noninvasive and sensitive technologies allowing for imaging the synthesis and the location of these molecules in living cells. This need motivated the development of small pro-fluorescent molecules called "fluorogens" that become fluorescent upon binding to genetically encodable RNAs called "light-up aptamers." Yet, the development of these fluorogen/light-up RNA pairs is a long and thorough process starting with the careful design of the fluorogen and pursued by the selection of a specific and efficient synthetic aptamer. This chapter summarizes the main design and the selection strategies used up to now prior to introducing the main pairs. Then, the vast application potential of these molecules for live-cell RNA imaging and other applications is presented and discussed.
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Affiliation(s)
- Michael Ryckelynck
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, Strasbourg, France.
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9
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Nishio M, Tsukakoshi K, Ikebukuro K. G-quadruplex: Flexible conformational changes by cations, pH, crowding and its applications to biosensing. Biosens Bioelectron 2021; 178:113030. [PMID: 33524709 DOI: 10.1016/j.bios.2021.113030] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 01/07/2021] [Accepted: 01/20/2021] [Indexed: 12/20/2022]
Abstract
G-quadruplex (G4) is a non-canonical structure that is formed in G-rich sequences of nucleic acids. G4s play important roles in vivo, such as telomere maintenance, transcription, and DNA replication. There are three typical topologies of G4: parallel, anti-parallel, and hybrid. In general, metal cations, such as potassium and sodium, stabilize G4s through coordination in the G-quartet. While G4s have some functions in vivo, there are many reports of developed applications that use G4s. As various conformations of G4s could form from one sequence depending on varying conditions, many researchers have developed G4-based sensors. Furthermore, G4 is a great scaffold of aptamers since many aptamers folded into G4s have also been reported. However, there are some challenges about its practical use due to the difference between practical sample conditions and experimental ones. G4 conformations are dramatically altered by the surrounding conditions, such as metal cations, pH, and crowding. Many studies have been conducted to characterize G4 conformations under various conditions, not only to use G4s in practical applications but also to reveal its function in vivo. In this review, we summarize recent studies that have investigated the effects of surrounding conditions (e.g., metal cations, pH, and crowding) on G4 conformations and the application of G4s mainly in biosensor fields, and in others.
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Affiliation(s)
- Maui Nishio
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Kaori Tsukakoshi
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Kazunori Ikebukuro
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan.
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10
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Al Mazid MF, Shkel O, Kharkivska Y, Lee JS. Application of fluorescent turn-on aptamers in RNA studies. Mol Omics 2021; 17:483-491. [PMID: 34137415 DOI: 10.1039/d1mo00085c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
RNA is an intermediate player between DNA transcription and protein translation. RNAs also interact with other macromolecules and metabolites and regulate their fate. The emerging number of RNA identifications expanded new areas of study to determine their applicability and functional analysis. Recently, extensive research has been focused on visualizing RNA in living biological samples and a method has been developed by the evolution of specific fluorophore-binding aptamers through the Systematic Evolution of Ligands by Exponential Enrichment (SELEX) method. Several promising fluorescent turn-on aptamers are currently available, and they can detect RNA-RNA, RNA-protein, ligand binding, small molecule, and metabolite interactions in vitro and under live-cell conditions. Here we review the currently available fluorescent turn-on aptamers and discuss their applicability for analyzing the fate of targeted RNAs in in vitro and in vivo systems.
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Affiliation(s)
| | - Olha Shkel
- Bio-Med Program KIST-School UST, Seoul, 02792, Republic of Korea
| | | | - Jun-Seok Lee
- Department of Pharmacology, Korea University College of Medicine, Seoul, 02841, Republic of Korea.
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11
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Zhang W, Wu Q. Applications of phage-derived RNA-based technologies in synthetic biology. Synth Syst Biotechnol 2020; 5:343-360. [PMID: 33083579 PMCID: PMC7564126 DOI: 10.1016/j.synbio.2020.09.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 09/22/2020] [Accepted: 09/27/2020] [Indexed: 12/20/2022] Open
Abstract
As the most abundant biological entities with incredible diversity, bacteriophages (also known as phages) have been recognized as an important source of molecular machines for the development of genetic-engineering tools. At the same time, phages are crucial for establishing and improving basic theories of molecular biology. Studies on phages provide rich sources of essential elements for synthetic circuit design as well as powerful support for the improvement of directed evolution platforms. Therefore, phages play a vital role in the development of new technologies and central scientific concepts. After the RNA world hypothesis was proposed and developed, novel biological functions of RNA continue to be discovered. RNA and its related elements are widely used in many fields such as metabolic engineering and medical diagnosis, and their versatility led to a major role of RNA in synthetic biology. Further development of RNA-based technologies will advance synthetic biological tools as well as provide verification of the RNA world hypothesis. Most synthetic biology efforts are based on reconstructing existing biological systems, understanding fundamental biological processes, and developing new technologies. RNA-based technologies derived from phages will offer abundant sources for synthetic biological components. Moreover, phages as well as RNA have high impact on biological evolution, which is pivotal for understanding the origin of life, building artificial life-forms, and precisely reprogramming biological systems. This review discusses phage-derived RNA-based technologies terms of phage components, the phage lifecycle, and interactions between phages and bacteria. The significance of RNA-based technology derived from phages for synthetic biology and for understanding the earliest stages of biological evolution will be highlighted.
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Affiliation(s)
- Wenhui Zhang
- MOE Key Lab. Bioinformatics, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Qiong Wu
- MOE Key Lab. Bioinformatics, School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Center for Synthetic and Systems Biology, Tsinghua University, Beijing, 100084, China
- Corresponding author. MOE Key Lab. Bioinformatics, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
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12
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Ebrahimi SB, Samanta D, Mirkin CA. DNA-Based Nanostructures for Live-Cell Analysis. J Am Chem Soc 2020; 142:11343-11356. [DOI: 10.1021/jacs.0c04978] [Citation(s) in RCA: 94] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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13
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Markey FB, Parashar V, Batish M. Methods for spatial and temporal imaging of the different steps involved in RNA processing at single-molecule resolution. WILEY INTERDISCIPLINARY REVIEWS-RNA 2020; 12:e1608. [PMID: 32543077 DOI: 10.1002/wrna.1608] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 05/06/2020] [Accepted: 05/07/2020] [Indexed: 12/26/2022]
Abstract
RNA plays a quintessential role as a messenger of information from genotype (DNA) to phenotype (proteins), as well as acts as a regulatory molecule (noncoding RNAs). All steps in the journey of RNA from synthesis (transcription), splicing, transport, localization, translation, to its eventual degradation, comprise important steps in gene expression, thereby controlling the fate of the cell. This lifecycle refers to the majority of RNAs (primarily mRNAs), but not other RNAs such as tRNAs. Imaging these processes in fixed cells and in live cells has been an important tool in developing an understanding of the regulatory steps in RNAs journey. Single-cell and single-molecule imaging techniques enable a much deeper understanding of cellular biology, which is not possible with bulk studies involving RNA isolated from a large pool of cells. Classic techniques, such as fluorescence in situ hybridization (FISH), as well as more recent aptamer-based approaches, have provided detailed insights into RNA localization, and have helped to predict the functions carried out by many RNA species. However, there are still certain processing steps that await high-resolution imaging, which is an exciting and upcoming area of research. In this review, we will discuss the methods that have revolutionized single-molecule resolution imaging in general, the steps of RNA processing in which these methods have been used, and new emerging technologies. This article is categorized under: RNA Export and Localization > RNA Localization RNA Methods > RNA Analyses in Cells RNA Interactions with Proteins and Other Molecules > Small Molecule-RNA Interactions.
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Affiliation(s)
- Fatu Badiane Markey
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers University, Newark, New Jersey, USA
| | - Vijay Parashar
- Department of Medical and Molecular Sciences, University of Delaware, Newark, Delaware, USA
| | - Mona Batish
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers University, Newark, New Jersey, USA.,Department of Medical and Molecular Sciences, University of Delaware, Newark, Delaware, USA
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14
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Savage JC, Davare MA, Shinde U. Subtle sequence variations alter tripartite complex kinetics and G-quadruplex dynamics in RNA aptamer Broccoli. Chem Commun (Camb) 2020; 56:2634-2637. [PMID: 32016232 DOI: 10.1039/c9cc09375c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Though extensively utilized, the fluorescent RNA aptamer Broccoli is poorly characterized with an unknown structure. Spectroscopic and kinetic investigations of tripartite complex formation reveal surprising differences between Broccoli and Spinach aptamers despite extreme sequence conservation. Our studies highlight how subtle sequence variations impart functional consequences of G-quadruplex-cation interactions in RNA.
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Affiliation(s)
- Jonathan C Savage
- Department of Chemical Physiology & Biochemistry, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd, Portland, OR 97239, USA.
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15
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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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16
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A dimerization-based fluorogenic dye-aptamer module for RNA imaging in live cells. Nat Chem Biol 2019; 16:69-76. [PMID: 31636432 PMCID: PMC6920041 DOI: 10.1038/s41589-019-0381-8] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Accepted: 08/22/2019] [Indexed: 01/19/2023]
Abstract
Live-cell imaging of RNA has remained a challenge because of the lack of naturally fluorescent RNAs. Recently developed RNA aptamers that can light-up small fluorogenic dyes could overcome this limitation, but they still suffer from poor brightness and photostability. Here, we propose a concept of cell-permeable fluorogenic dimer of sulforhodamine B dyes (Gemini-561) and corresponding dimerized aptamer (o-Coral) that can drastically enhance performance of the current RNA imaging method. The unprecedented brightness and photostability together with high affinity of this complex allowed, for the first time, direct fluorescence imaging in live mammalian cells of RNA polymerase-III transcription products as well as messenger RNAs labelled with a single copy of the aptamer, i.e. without tag multimerization. The developed fluorogenic module enables fast and sensitive detection of RNA inside live cells, while the proposed design concept opens the route to new generation of ultrabright RNA probes.
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17
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Zinskie JA, Roig M, Janetopoulos C, Myers KA, Bruist MF. Live-cell imaging of small nucleolar RNA tagged with the broccoli aptamer in yeast. FEMS Yeast Res 2019; 18:5078348. [PMID: 30137288 DOI: 10.1093/femsyr/foy093] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 08/20/2018] [Indexed: 11/14/2022] Open
Abstract
The development of the RNA 'vegetable' aptamers, Spinach and Broccoli, has simplified RNA imaging, especially in live cells. These RNA aptamers interact with a fluorophore (DFHBI or DFHBI-1T) to produce a green fluorescence signal. Although used in mammalian and Escherichia coli cells, the use of these aptamers in yeast has been limited. Here we describe how the Saccharomyces cerevisiae snoRNA, snR30, was tagged with the Spinach or the Broccoli aptamers and observed in live cells. The ability to observe aptamer fluorescence in polyacrylamide gels stained with a fluorophore or with a microplate reader can ease preliminary screening of the aptamers in different RNA scaffolds. In snR30 a tandem repeat of the Broccoli aptamer produced the best signal in vitro. Multiple factors in cell preparation were vital for obtaining a good fluorescence signal. These factors included the clearance of the native unmodified snR30, the amount and length of dye incubation and the rinsing of cells. In cells, the aptamers did not interfere with the structure or essential function of snR30, as the tagged RNA localized to the nucleolus and directed processing of ribosomal RNA in yeast. High-resolution images of the tagged snoRNA were obtained with live cells immobilized by a microcompressor.
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Affiliation(s)
- Jessica A Zinskie
- University of the Sciences, Department of Chemistry & Biochemistry, 600 S. 43rd St., Philadelphia, PA 19104.,Rowan University, School of Osteopathic Medicine, Department of Cell Biology and Neuroscience, 2 Medical Center Dr., Stratford, NJ 08084
| | - Meghan Roig
- University of the Sciences, Department of Chemistry & Biochemistry, 600 S. 43rd St., Philadelphia, PA 19104.,Florida International University, Department of Biochemistry and Biochemistry, 11200 SW 8th St., Miami, FL 33199
| | | | - Kenneth A Myers
- University of the Sciences, Department of Biological Sciences, Philadelphia, PA 19104
| | - Michael F Bruist
- University of the Sciences, Department of Chemistry & Biochemistry, 600 S. 43rd St., Philadelphia, PA 19104
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18
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Truong L, Ferré-D'Amaré AR. From fluorescent proteins to fluorogenic RNAs: Tools for imaging cellular macromolecules. Protein Sci 2019; 28:1374-1386. [PMID: 31017335 DOI: 10.1002/pro.3632] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 04/23/2019] [Indexed: 01/01/2023]
Abstract
The explosion in genome-wide sequencing has revealed that noncoding RNAs are ubiquitous and highly conserved in biology. New molecular tools are needed for their study in live cells. Fluorescent RNA-small molecule complexes have emerged as powerful counterparts to fluorescent proteins, which are well established, universal tools in the study of proteins in cell biology. No naturally fluorescent RNAs are known; all current fluorescent RNA tags are in vitro evolved or engineered molecules that bind a conditionally fluorescent small molecule and turn on its fluorescence by up to 5000-fold. Structural analyses of several such fluorescence turn-on aptamers show that these compact (30-100 nucleotides) RNAs have diverse molecular architectures that can restrain their photoexcited fluorophores in their maximally fluorescent states, typically by stacking between planar nucleotide arrangements, such as G-quadruplexes, base triples, or base pairs. The diversity of fluorogenic RNAs as well as fluorophores that are cell permeable and bind weakly to endogenous cellular macromolecules has already produced RNA-fluorophore complexes that span the visual spectrum and are useful for tagging and visualizing RNAs in cells. Because the ligand binding sites of fluorogenic RNAs are not constrained by the need to autocatalytically generate fluorophores as are fluorescent proteins, they may offer more flexibility in molecular engineering to generate photophysical properties that are tailored to experimental needs.
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Affiliation(s)
- Lynda Truong
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, Bethesda, Maryland, 20892-8012
| | - Adrian R Ferré-D'Amaré
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, Bethesda, Maryland, 20892-8012
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19
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Wang F, Wang L, Zou X, Duan S, Li Z, Deng Z, Luo J, Lee SY, Chen S. Advances in CRISPR-Cas systems for RNA targeting, tracking and editing. Biotechnol Adv 2019; 37:708-729. [PMID: 30926472 DOI: 10.1016/j.biotechadv.2019.03.016] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Revised: 03/26/2019] [Accepted: 03/26/2019] [Indexed: 12/21/2022]
Abstract
Clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein (Cas) systems, especially type II (Cas9) systems, have been widely used in gene/genome targeting. Modifications of Cas9 enable these systems to become platforms for precise DNA manipulations. However, the utilization of CRISPR-Cas systems in RNA targeting remains preliminary. The discovery of type VI CRISPR-Cas systems (Cas13) shed light on RNA-guided RNA targeting. Cas13d, the smallest Cas13 protein, with a length of only ~930 amino acids, is a promising platform for RNA targeting compatible with viral delivery systems. Much effort has also been made to develop Cas9, Cas13a and Cas13b applications for RNA-guided RNA targeting. The discovery of new RNA-targeting CRISPR-Cas systems as well as the development of RNA-targeting platforms with Cas9 and Cas13 will promote RNA-targeting technology substantially. Here, we review new advances in RNA-targeting CRISPR-Cas systems as well as advances in applications of these systems in RNA targeting, tracking and editing. We also compare these Cas protein-based technologies with traditional technologies for RNA targeting, tracking and editing. Finally, we discuss remaining questions and prospects for the future.
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Affiliation(s)
- Fei Wang
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, Brain Center, School of Pharmaceutical Sciences, Zhongnan Hospital, Wuhan University, Wuhan 430071, Hubei, China; Taihe Hospital, Hubei University of Medicine, Shiyan 442000, Hubei, China
| | - Lianrong Wang
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, Brain Center, School of Pharmaceutical Sciences, Zhongnan Hospital, Wuhan University, Wuhan 430071, Hubei, China; Taihe Hospital, Hubei University of Medicine, Shiyan 442000, Hubei, China
| | - Xuan Zou
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, Brain Center, School of Pharmaceutical Sciences, Zhongnan Hospital, Wuhan University, Wuhan 430071, Hubei, China; Department of Chemical and Biomolecular Engineering (BK21 Plus Program), Korea Advanced Institute of Science and Technology, Yuseong-gu, 34141 Daejeon, Republic of Korea
| | - Suling Duan
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, Brain Center, School of Pharmaceutical Sciences, Zhongnan Hospital, Wuhan University, Wuhan 430071, Hubei, China
| | - Zhiqiang Li
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, Brain Center, School of Pharmaceutical Sciences, Zhongnan Hospital, Wuhan University, Wuhan 430071, Hubei, China
| | - Zixin Deng
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, Brain Center, School of Pharmaceutical Sciences, Zhongnan Hospital, Wuhan University, Wuhan 430071, Hubei, China
| | - Jie Luo
- Taihe Hospital, Hubei University of Medicine, Shiyan 442000, Hubei, China
| | - Sang Yup Lee
- Department of Chemical and Biomolecular Engineering (BK21 Plus Program), Korea Advanced Institute of Science and Technology, Yuseong-gu, 34141 Daejeon, Republic of Korea.
| | - Shi Chen
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, Brain Center, School of Pharmaceutical Sciences, Zhongnan Hospital, Wuhan University, Wuhan 430071, Hubei, China; Taihe Hospital, Hubei University of Medicine, Shiyan 442000, Hubei, China.
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20
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Neubacher S, Hennig S. RNA Structure and Cellular Applications of Fluorescent Light-Up Aptamers. Angew Chem Int Ed Engl 2019; 58:1266-1279. [PMID: 30102012 PMCID: PMC6391945 DOI: 10.1002/anie.201806482] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Indexed: 12/16/2022]
Abstract
The cellular functions of RNA are not limited to their role as blueprints for protein synthesis. In particular, noncoding RNA, such as, snRNAs, lncRNAs, miRNAs, play important roles. With increasing numbers of RNAs being identified, it is well known that the transcriptome outnumbers the proteome by far. This emphasizes the great importance of functional RNA characterization and the need to further develop tools for these investigations, many of which are still in their infancy. Fluorescent light-up aptamers (FLAPs) are RNA sequences that can bind nontoxic, cell-permeable small-molecule fluorogens and enhance their fluorescence over many orders of magnitude upon binding. FLAPs can be encoded on the DNA level using standard molecular biology tools and are subsequently transcribed into RNA by the cellular machinery, so that they can be used as fluorescent RNA tags (FLAP-tags). In this Minireview, we give a brief overview of the fluorogens that have been developed and their binding RNA aptamers, with a special focus on published crystal structures. A summary of current and future cellular FLAP applications with an emphasis on the study of RNA-RNA and RNA-protein interactions using split-FLAP and Förster resonance energy transfer (FRET) systems is given.
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Affiliation(s)
- Saskia Neubacher
- Department of Chemistry & Pharmaceutical SciencesVU University AmsterdamDe Boelelaan 11081081HZAmsterdamThe Netherlands
| | - Sven Hennig
- Department of Chemistry & Pharmaceutical SciencesVU University AmsterdamDe Boelelaan 11081081HZAmsterdamThe Netherlands
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21
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Nab3's localization to a nuclear granule in response to nutrient deprivation is determined by its essential prion-like domain. PLoS One 2018; 13:e0209195. [PMID: 30557374 PMCID: PMC6296506 DOI: 10.1371/journal.pone.0209195] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 11/30/2018] [Indexed: 12/20/2022] Open
Abstract
Ribonucleoprotein (RNP) granules are higher order assemblies of RNA, RNA-binding proteins, and other proteins, that regulate the transcriptome and protect RNAs from environmental challenge. There is a diverse range of RNP granules, many cytoplasmic, which provide various levels of regulation of RNA metabolism. Here we present evidence that the yeast transcription termination factor, Nab3, is targeted to intranuclear granules in response to glucose starvation by Nab3’s proline/glutamine-rich, prion-like domain (PrLD) which can assemble into amyloid in vitro. Localization to the granule is reversible and sensitive to the chemical probe 1,6 hexanediol suggesting condensation is driven by phase separation. Nab3’s RNA recognition motif is also required for localization as seen for other PrLD-containing RNA-binding proteins that phase separate. Although the PrLD is necessary, it is not sufficient to localize to the granule. A heterologous PrLD that functionally replaces Nab3’s essential PrLD, directed localization to the nuclear granule, however a chimeric Nab3 molecule with a heterologous PrLD that cannot restore termination function or viability, does not form granules. The Nab3 nuclear granule shows properties similar to well characterized cytoplasmic compartments formed by phase separation, suggesting that, as seen for other elements of the transcription machinery, termination factor condensation is functionally important.
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22
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Fluorogenic RNA Aptamers: A Nano-platform for Fabrication of Simple and Combinatorial Logic Gates. NANOMATERIALS 2018; 8:nano8120984. [PMID: 30486495 PMCID: PMC6315349 DOI: 10.3390/nano8120984] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 11/16/2018] [Accepted: 11/20/2018] [Indexed: 12/14/2022]
Abstract
RNA aptamers that bind non-fluorescent dyes and activate their fluorescence are highly sensitive, nonperturbing, and convenient probes in the field of synthetic biology. These RNA molecules, referred to as light-up aptamers, operate as molecular nanoswitches that alter folding and fluorescence function in response to ligand binding, which is important in biosensing and molecular computing. Herein, we demonstrate a conceptually new generation of smart RNA nano-devices based on malachite green (MG)-binding RNA aptamer, which fluorescence output controlled by addition of short DNA oligonucleotides inputs. Four types of RNA switches possessing AND, OR, NAND, and NOR Boolean logic functions were created in modular form, allowing MG dye binding affinity to be changed by altering 3D conformation of the RNA aptamer. It is essential to develop higher-level logic circuits for the production of multi-task nanodevices for data processing, typically requiring combinatorial logic gates. Therefore, we further designed and synthetized higher-level half adder logic circuit by “in parallel” integration of two logic gates XOR and AND within a single RNA nanoparticle. The design utilizes fluorescence emissions from two different RNA aptamers: MG-binding RNA aptamer (AND gate) and Broccoli RNA aptamer that binds DFHBI dye (XOR gate). All computationally designed RNA devices were synthesized and experimentally tested in vitro. The ability to design smart nanodevices based on RNA binding aptamers offers a new route to engineer “label-free” ligand-sensing regulatory circuits, nucleic acid detection systems, and gene control elements.
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23
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Neubacher S, Hennig S. RNA Structure and Cellular Applications of Fluorescent Light-Up Aptamers. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201806482] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Saskia Neubacher
- Department of Chemistry & Pharmaceutical Sciences; VU University Amsterdam; De Boelelaan 1108 1081 HZ Amsterdam The Netherlands
| | - Sven Hennig
- Department of Chemistry & Pharmaceutical Sciences; VU University Amsterdam; De Boelelaan 1108 1081 HZ Amsterdam The Netherlands
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24
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Pichon X, Lagha M, Mueller F, Bertrand E. A Growing Toolbox to Image Gene Expression in Single Cells: Sensitive Approaches for Demanding Challenges. Mol Cell 2018; 71:468-480. [DOI: 10.1016/j.molcel.2018.07.022] [Citation(s) in RCA: 112] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 07/19/2018] [Accepted: 07/20/2018] [Indexed: 12/21/2022]
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25
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Modular cell-internalizing aptamer nanostructure enables targeted delivery of large functional RNAs in cancer cell lines. Nat Commun 2018; 9:2283. [PMID: 29891903 PMCID: PMC5995956 DOI: 10.1038/s41467-018-04691-x] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 05/09/2018] [Indexed: 02/07/2023] Open
Abstract
Large RNAs and ribonucleoprotein complexes have powerful therapeutic potential, but effective cell-targeted delivery tools are limited. Aptamers that internalize into target cells can deliver siRNAs (<15 kDa, 19–21 nt/strand). We demonstrate a modular nanostructure for cellular delivery of large, functional RNA payloads (50–80 kDa, 175–250 nt) by aptamers that recognize multiple human B cell cancer lines and transferrin receptor-expressing cells. Fluorogenic RNA reporter payloads enable accelerated testing of platform designs and rapid evaluation of assembly and internalization. Modularity is demonstrated by swapping in different targeting and payload aptamers. Both modules internalize into leukemic B cell lines and remained colocalized within endosomes. Fluorescence from internalized RNA persists for ≥2 h, suggesting a sizable window for aptamer payloads to exert influence upon targeted cells. This demonstration of aptamer-mediated, cell-internalizing delivery of large RNAs with retention of functional structure raises the possibility of manipulating endosomes and cells by delivering large aptamers and regulatory RNAs. Large RNAs and ribonucleoprotein complexes have shown potential as novel therapeutic agents, but their targeted delivery to cells is still challenging. Here the authors present a modular aptamer nanostructure for intracellular delivery of RNAs up to 250 nucleotides to cancer cells.
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26
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Ying ZM, Tu B, Liu L, Tang H, Tang LJ, Jiang JH. Spinach-based fluorescent light-up biosensors for multiplexed and label-free detection of microRNAs. Chem Commun (Camb) 2018; 54:3010-3013. [PMID: 29511749 DOI: 10.1039/c8cc00123e] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A novel Spinach-based fluorescent light-up biosensor utilizing the T7 in vitro transcription process to generate unmodified Spinach sequences for multiplexed microRNA detection has been developed.
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Affiliation(s)
- Zhan-Ming Ying
- Institute of Chemical Biology and Nanomedicine, State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, P. R. China.
| | - Bin Tu
- Institute of Chemical Biology and Nanomedicine, State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, P. R. China.
| | - Lan Liu
- Institute of Chemical Biology and Nanomedicine, State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, P. R. China.
| | - Hao Tang
- Institute of Chemical Biology and Nanomedicine, State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, P. R. China.
| | - Li-Juan Tang
- Institute of Chemical Biology and Nanomedicine, State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, P. R. China.
| | - Jian-Hui Jiang
- Institute of Chemical Biology and Nanomedicine, State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, P. R. China.
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27
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Autour A, C Y Jeng S, D Cawte A, Abdolahzadeh A, Galli A, Panchapakesan SSS, Rueda D, Ryckelynck M, Unrau PJ. Fluorogenic RNA Mango aptamers for imaging small non-coding RNAs in mammalian cells. Nat Commun 2018; 9:656. [PMID: 29440634 PMCID: PMC5811451 DOI: 10.1038/s41467-018-02993-8] [Citation(s) in RCA: 176] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 01/11/2018] [Indexed: 12/26/2022] Open
Abstract
Despite having many key roles in cellular biology, directly imaging biologically important RNAs has been hindered by a lack of fluorescent tools equivalent to the fluorescent proteins available to study cellular proteins. Ideal RNA labelling systems must preserve biological function, have photophysical properties similar to existing fluorescent proteins, and be compatible with established live and fixed cell protein labelling strategies. Here, we report a microfluidics-based selection of three new high-affinity RNA Mango fluorogenic aptamers. Two of these are as bright or brighter than enhanced GFP when bound to TO1-Biotin. Furthermore, we show that the new Mangos can accurately image the subcellular localization of three small non-coding RNAs (5S, U6, and a box C/D scaRNA) in fixed and live mammalian cells. These new aptamers have many potential applications to study RNA function and dynamics both in vitro and in mammalian cells.
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Affiliation(s)
- Alexis Autour
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, 67000, Strasbourg, France
| | - Sunny C Y Jeng
- Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Adam D Cawte
- Single Molecule Imaging Group, MRC London Institute of Medical Sciences, Du Cane Road, London, W12 0NN, UK.,Department of Medicine, Molecular Virology, Imperial College London, Du Cane Road, London, W12 0NN, UK
| | - Amir Abdolahzadeh
- Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Angela Galli
- Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Shanker S S Panchapakesan
- Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - David Rueda
- Single Molecule Imaging Group, MRC London Institute of Medical Sciences, Du Cane Road, London, W12 0NN, UK. .,Department of Medicine, Molecular Virology, Imperial College London, Du Cane Road, London, W12 0NN, UK.
| | - Michael Ryckelynck
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, 67000, Strasbourg, France.
| | - Peter J Unrau
- Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada.
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28
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Filonov GS. Rapid Selection of RNA Aptamers that Activate Fluorescence of Small Molecules. Methods Mol Biol 2018; 1575:273-289. [PMID: 28255887 DOI: 10.1007/978-1-4939-6857-2_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
RNA aptamers can serve as valuable tools for studying and manipulating live cells. Fluorescent aptamers are the ones that bind to and turn on fluorescence of small-molecule dyes (fluorogens). Similarly to fluorescent proteins, fluorescent RNA aptamers can be used to image spatial and temporal RNA dynamics in live cells. Additionally, these aptamers can serve as a basis for engineering genetically encoded fluorescent biosensors. This chapter presents a protocol for rapid and efficient screening of RNA aptamer libraries to isolate fluorescent aptamers. The protocol describes how to design, clone, and express RNA aptamer library in bacterial cells and how to screen the bacteria to find aptamers with the desired fluorescent properties.
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Affiliation(s)
- Grigory S Filonov
- Essen Bioscience, Ann Arbor, MI, USA. .,Department of Pharmacology, Weill Medical College, Cornell University, New York, NY, USA.
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29
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Abstract
The last past decade has witnessed a revolution in our appreciation of transcriptome complexity and regulation. This remarkable expansion in our knowledge largely originates from the advent of high-throughput methodologies, and the consecutive discovery that up to 90% of eukaryotic genomes are transcribed, thus generating an unanticipated large range of noncoding RNAs (Hangauer et al., 15(4):112, 2014). Besides leading to the identification of new noncoding RNA species, transcriptome-wide studies have uncovered novel layers of posttranscriptional regulatory mechanisms controlling RNA processing, maturation or translation, and each contributing to the precise and dynamic regulation of gene expression. Remarkably, the development of systems-level studies has been accompanied by tremendous progress in the visualization of individual RNA molecules in single cells, such that it is now possible to image RNA species with a single-molecule resolution from birth to translation or decay. Monitoring quantitatively, with unprecedented spatiotemporal resolution, the fate of individual molecules has been key to understanding the molecular mechanisms underlying the different steps of RNA regulation. This has also revealed biologically relevant, intracellular and intercellular heterogeneities in RNA distribution or regulation. More recently, the convergence of imaging and high-throughput technologies has led to the emergence of spatially resolved transcriptomic techniques that provide a means to perform large-scale analyses while preserving spatial information. By generating transcriptome-wide data on single-cell RNA content, or even subcellular RNA distribution, these methodologies are opening avenues to a wide range of network-level studies at the cell and organ-level, and promise to strongly improve disease diagnostic and treatment.In this introductory chapter, we highlight how recently developed technologies aiming at detecting and visualizing RNA molecules have contributed to the emergence of entirely new research fields, and to dramatic progress in our understanding of gene expression regulation.
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Affiliation(s)
- Caroline Medioni
- Université Côte d'Azur, CNRS, Inserm, iBV, Parc Valrose, 06100, Nice, France
| | - Florence Besse
- Université Côte d'Azur, CNRS, Inserm, iBV, Parc Valrose, 06100, Nice, France.
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30
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Bouhedda F, Autour A, Ryckelynck M. Light-Up RNA Aptamers and Their Cognate Fluorogens: From Their Development to Their Applications. Int J Mol Sci 2017; 19:ijms19010044. [PMID: 29295531 PMCID: PMC5795994 DOI: 10.3390/ijms19010044] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 12/14/2017] [Accepted: 12/15/2017] [Indexed: 12/31/2022] Open
Abstract
An RNA-based fluorogenic module consists of a light-up RNA aptamer able to specifically interact with a fluorogen to form a fluorescent complex. Over the past decade, significant efforts have been devoted to the development of such modules, which now cover the whole visible spectrum, as well as to their engineering to serve in a wide range of applications. In this review, we summarize the different strategies used to develop each partner (the fluorogen and the light-up RNA aptamer) prior to giving an overview of their applications that range from live-cell RNA imaging to the set-up of high-throughput drug screening pipelines. We then conclude with a critical discussion on the current limitations of these modules and how combining in vitro selection with screening approaches may help develop even better molecules.
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Affiliation(s)
- Farah Bouhedda
- Architecture et Réactivité de l'ARN, CNRS, Université de Strasbourg, UPR 9002, F-67000 Strasbourg, France.
| | - Alexis Autour
- Architecture et Réactivité de l'ARN, CNRS, Université de Strasbourg, UPR 9002, F-67000 Strasbourg, France.
| | - Michael Ryckelynck
- Architecture et Réactivité de l'ARN, CNRS, Université de Strasbourg, UPR 9002, F-67000 Strasbourg, France.
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31
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Synthetic biological approaches for RNA labelling and imaging: design principles and future opportunities. Curr Opin Biotechnol 2017; 48:153-158. [DOI: 10.1016/j.copbio.2017.04.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 04/07/2017] [Accepted: 04/17/2017] [Indexed: 12/15/2022]
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32
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Fernandez-Millan P, Autour A, Ennifar E, Westhof E, Ryckelynck M. Crystal structure and fluorescence properties of the iSpinach aptamer in complex with DFHBI. RNA (NEW YORK, N.Y.) 2017; 23:1788-1795. [PMID: 28939697 PMCID: PMC5689000 DOI: 10.1261/rna.063008.117] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2017] [Accepted: 09/05/2017] [Indexed: 05/05/2023]
Abstract
Fluorogenic RNA aptamers are short nucleic acids able to specifically interact with small molecules and strongly enhance their fluorescence upon complex formation. Among the different systems recently introduced, Spinach, an aptamer forming a fluorescent complex with the 3,5-difluoro-4-hydroxybenzylidene imidazolinone (DFHBI), is one of the most promising. Using random mutagenesis and ultrahigh-throughput screening, we recently developed iSpinach, an improved version of the aptamer, endowed with an increased folding efficiency and thermal stability. iSpinach is a shorter version of Spinach, comprising five mutations for which the exact role has not yet been deciphered. In this work, we cocrystallized a reengineered version of iSpinach in complex with the DFHBI and solved the X-ray structure of the complex at 2 Å resolution. Only a few mutations were required to optimize iSpinach production and crystallization, underlying the good folding capacity of the molecule. The measured fluorescence half-lives in the crystal were 60% higher than in solution. Comparisons with structures previously reported for Spinach sheds some light on the possible function of the different beneficial mutations carried by iSpinach.
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Affiliation(s)
- Pablo Fernandez-Millan
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, F-67000 Strasbourg, France
| | - Alexis Autour
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, F-67000 Strasbourg, France
| | - Eric Ennifar
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, F-67000 Strasbourg, France
| | - Eric Westhof
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, F-67000 Strasbourg, France
| | - Michael Ryckelynck
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, F-67000 Strasbourg, France
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33
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An improved MS2 system for accurate reporting of the mRNA life cycle. Nat Methods 2017; 15:81-89. [PMID: 29131164 PMCID: PMC5843578 DOI: 10.1038/nmeth.4502] [Citation(s) in RCA: 206] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 10/04/2017] [Indexed: 12/19/2022]
Abstract
The MS2-MCP system enables researchers to image multiple steps of the mRNA life cycle with high temporal and spatial resolution. However, for short-lived mRNAs, the tight binding of the MS2 coat protein (MCP) to the MS2 binding sites (MBS) protects the RNA from being efficiently degraded, and this confounds the study of mRNA regulation. Here, we describe a reporter system (MBSV6) with reduced affinity for the MCP, which allows mRNA degradation while preserving single-molecule detection determined by single-molecule FISH (smFISH) or live imaging. Constitutive mRNAs (MDN1 and DOA1) and highly-regulated mRNAs (GAL1 and ASH1) endogenously tagged with MBSV6 in Saccharomyces cerevisiae degrade normally. As a result, short-lived mRNAs were imaged throughout their complete life cycle. The MBSV6 reporter revealed that, in contrast to previous findings, coordinated recruitment of mRNAs at specialized structures such as P-bodies during stress did not occur, and mRNA degradation was heterogeneously distributed in the cytoplasm.
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34
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Huang K, Doyle F, Wurz ZE, Tenenbaum SA, Hammond RK, Caplan JL, Meyers BC. FASTmiR: an RNA-based sensor for in vitro quantification and live-cell localization of small RNAs. Nucleic Acids Res 2017; 45:e130. [PMID: 28586459 PMCID: PMC5737440 DOI: 10.1093/nar/gkx504] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 05/27/2017] [Indexed: 01/19/2023] Open
Abstract
Small RNAs, including microRNAs (miRNAs) and small interfering RNAs (siRNAs), play a variety of important regulatory roles in many eukaryotes. Their small size has made it challenging to study them directly in live cells. Here we describe an RNA-based fluorescent sensor for small RNA detection both in vitro and in vivo, adaptable for any small RNA. It utilizes an sxRNA switch for detection of miRNA–mRNA interactions combined with a fluorophore-binding sequence ‘Spinach’, a GFP-like RNA aptamer for which the RNA–fluorophore complex exhibits strong and consistent fluorescence under an excitation wavelength. Two example sensors, FASTmiR171 and FASTmiR122, can rapidly detect and quantify the levels of miR171 and miR122 in vitro. The sensors can determine relative levels of miRNAs in total RNA extracts with sensitivity similar to small RNA sequencing and northern blots. FASTmiR sensors were also used to estimate the copy number range of miRNAs in total RNA extracts. To localize and analyze the spatial distribution of small RNAs in live, single cells, tandem copies of FASTmiR122 were expressed in different cell lines. FASTmiR122 was able to quantitatively detect the differences in miR122 levels in Huh7 and HEK293T cells demonstrating its potential for tracking miRNA expression and localization in vivo.
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Affiliation(s)
- Kun Huang
- Bio-Imaging Center, Delaware Biotechnology Institute, University of Delaware, Newark, DE 19711, USA.,Department of Plant and Soil Sciences, University of Delaware, Newark, DE 19716, USA
| | - Francis Doyle
- Nanobioscience Constellation, State University of New York- Polytechnic Institute, College of Nanoscale Science and Engineering, Albany, NY 12203, USA
| | - Zachary E Wurz
- Nanobioscience Constellation, State University of New York- Polytechnic Institute, College of Nanoscale Science and Engineering, Albany, NY 12203, USA
| | - Scott A Tenenbaum
- Nanobioscience Constellation, State University of New York- Polytechnic Institute, College of Nanoscale Science and Engineering, Albany, NY 12203, USA
| | - Reza K Hammond
- Bio-Imaging Center, Delaware Biotechnology Institute, University of Delaware, Newark, DE 19711, USA.,Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE 19711, USA
| | - Jeffrey L Caplan
- Bio-Imaging Center, Delaware Biotechnology Institute, University of Delaware, Newark, DE 19711, USA.,Department of Plant and Soil Sciences, University of Delaware, Newark, DE 19716, USA
| | - Blake C Meyers
- Department of Plant and Soil Sciences, University of Delaware, Newark, DE 19716, USA.,Donald Danforth Plant Science Center, 975 North Warson Road, St Louis, MO 63132, USA.,University of Missouri-Columbia, Division of Plant Sciences, 52 Agriculture Lab, Columbia, MO 65211, USA
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35
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Enabling tools for high-throughput detection of metabolites: Metabolic engineering and directed evolution applications. Biotechnol Adv 2017; 35:950-970. [PMID: 28723577 DOI: 10.1016/j.biotechadv.2017.07.005] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 06/07/2017] [Accepted: 07/11/2017] [Indexed: 12/21/2022]
Abstract
Within the Design-Build-Test Cycle for strain engineering, rapid product detection and selection strategies remain challenging and limit overall throughput. Here we summarize a wide variety of modalities that transduce chemical concentrations into easily measured absorbance, luminescence, and fluorescence signals. Specifically, we cover protein-based biosensors (including transcription factors), nucleic acid-based biosensors, coupled enzyme reactions, bioorthogonal chemistry, and fluorescent and chromogenic dyes and substrates as modalities for detection. We focus on the use of these methods for strain engineering and enzyme discovery and conclude with remarks on the current and future state of biosensor development for application in the metabolic engineering field.
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36
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Guzmán-Zapata D, Domínguez-Anaya Y, Macedo-Osorio KS, Tovar-Aguilar A, Castrejón-Flores JL, Durán-Figueroa NV, Badillo-Corona JA. mRNA imaging in the chloroplast of Chlamydomonas reinhardtii using the light-up aptamer Spinach. J Biotechnol 2017; 251:186-188. [PMID: 28359866 DOI: 10.1016/j.jbiotec.2017.03.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 02/22/2017] [Accepted: 03/23/2017] [Indexed: 01/08/2023]
Abstract
Light-up aptamers are practical tools to image RNA localization in vivo. A now classical light-up aptamer system is the combination of the 3,5-difluoro-4-hydroxybenzylidene (DFHBI) fluorogen and the RNA aptamer Spinach, which has been successfully used in bacterial and mammalian cells. However, light-up aptamers have not been used in algae. Here, we show that a simple vector, carrying Spinach, transcriptionally fused to the aphA-6 gene, can be effectively used to generate a functional light-up aptamer in the chloroplast of Chlamydomonas reinhardtii. After incubation with DFHBI, lines expressing the aphA-6/Spinach mRNA were observed with laser confocal microscopy to evaluate the functionality of the light-up aptamer in the chloroplast of C. reinhardtii. Clear and strong fluorescence was localized to the chloroplast, in the form of discrete spots. There was no background fluorescence in the strain lacking Spinach. Light-up aptamers could be further engineered to image RNA or to develop genetically encoded biosensors in algae.
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Affiliation(s)
- Daniel Guzmán-Zapata
- Instituto Politécnico Nacional, Unidad Profesional Interdisciplinaria de Biotecnología, Av. Acueducto S/N., Col. Barrio La Laguna Ticomán, 07340 México City, Mexico
| | - Yael Domínguez-Anaya
- Instituto Politécnico Nacional, Unidad Profesional Interdisciplinaria de Biotecnología, Av. Acueducto S/N., Col. Barrio La Laguna Ticomán, 07340 México City, Mexico
| | - Karla S Macedo-Osorio
- Instituto Politécnico Nacional, Unidad Profesional Interdisciplinaria de Biotecnología, Av. Acueducto S/N., Col. Barrio La Laguna Ticomán, 07340 México City, Mexico
| | - Andrea Tovar-Aguilar
- Instituto Politécnico Nacional, Unidad Profesional Interdisciplinaria de Biotecnología, Av. Acueducto S/N., Col. Barrio La Laguna Ticomán, 07340 México City, Mexico
| | - José L Castrejón-Flores
- Instituto Politécnico Nacional, Unidad Profesional Interdisciplinaria de Biotecnología, Av. Acueducto S/N., Col. Barrio La Laguna Ticomán, 07340 México City, Mexico
| | - Noé V Durán-Figueroa
- Instituto Politécnico Nacional, Unidad Profesional Interdisciplinaria de Biotecnología, Av. Acueducto S/N., Col. Barrio La Laguna Ticomán, 07340 México City, Mexico.
| | - Jesús A Badillo-Corona
- Instituto Politécnico Nacional, Unidad Profesional Interdisciplinaria de Biotecnología, Av. Acueducto S/N., Col. Barrio La Laguna Ticomán, 07340 México City, Mexico.
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37
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Skúpa K, Urban J. Modifications of the chromophore of Spinach aptamer based on QM:MM calculations. J Mol Model 2017; 23:46. [PMID: 28154983 DOI: 10.1007/s00894-017-3232-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 01/13/2017] [Indexed: 10/20/2022]
Abstract
Spinach aptamer was developed as an RNA analog of the green fluorescent protein. The aptamer interacts with its ligand and modifies its electronic spectrum so that it fluoresces brightly at the wavelength of 501 nm. Song et al. investigated modifications of the ligand in their experimental study and found a molecule emitting at 523 nm upon creating a complex with the Spinach aptamer. The crystal structure of the aptamer in complex with its original ligand has been published, which enabled us to study the system computationally. In this article, we suggest several new modifications of the ligand that shift the emission maximum of the complex to even longer wavelengths. Our results are based on combined quantum mechanical/molecular mechanical calculations with DFT method used for geometry optimization and TD-DFT for calculations of absorption and emission energies.
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Affiliation(s)
- Katarína Skúpa
- Faculty of Mathematics, Physics and Informatics, Comenius University in Bratislava, Bratislava, Slovakia.
| | - Ján Urban
- Faculty of Mathematics, Physics and Informatics, Comenius University in Bratislava, Bratislava, Slovakia
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38
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Raices M, D'Angelo MA. Nuclear pore complexes and regulation of gene expression. Curr Opin Cell Biol 2017; 46:26-32. [PMID: 28088069 DOI: 10.1016/j.ceb.2016.12.006] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 12/09/2016] [Accepted: 12/21/2016] [Indexed: 12/31/2022]
Abstract
Nuclear pore complexes (NPCs), are large multiprotein channels that penetrate the nuclear envelope connecting the nucleus to the cytoplasm. Accumulating evidence shows that besides their main role in regulating the exchange of molecules between these two compartments, NPCs and their components also play important transport-independent roles, including gene expression regulation, chromatin organization, DNA repair, RNA processing and quality control, and cell cycle control. Here, we will describe the recent findings about the role of these structures in the regulation of gene expression.
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Affiliation(s)
- Marcela Raices
- Sanford Burnham Prebys Medical Discovery Institute, Development, Aging and Regeneration Program, 10901 N. Torrey Pines Road, La Jolla, 92037 CA, United States
| | - Maximiliano A D'Angelo
- Sanford Burnham Prebys Medical Discovery Institute, Development, Aging and Regeneration Program, 10901 N. Torrey Pines Road, La Jolla, 92037 CA, United States.
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39
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Heinrich S, Derrer CP, Lari A, Weis K, Montpetit B. Temporal and spatial regulation of mRNA export: Single particle RNA-imaging provides new tools and insights. Bioessays 2017; 39. [PMID: 28052353 DOI: 10.1002/bies.201600124] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The transport of messenger RNAs (mRNAs) from the nucleus to cytoplasm is an essential step in the gene expression program of all eukaryotes. Recent technological advances in the areas of RNA-labeling, microscopy, and sequencing are leading to novel insights about mRNA biogenesis and export. This includes quantitative single molecule imaging (SMI) of RNA molecules in live cells, which is providing knowledge of the spatial and temporal dynamics of the export process. As this information becomes available, it leads to new questions, the reinterpretation of previous findings, and revised models of mRNA export. In this review, we will briefly highlight some of these recent findings and discuss how live cell SMI approaches may be used to further our current understanding of mRNA export and gene expression.
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Affiliation(s)
| | | | - Azra Lari
- Department of Cell Biology, University of Alberta, Edmonton, Canada
| | - Karsten Weis
- Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
| | - Ben Montpetit
- Department of Cell Biology, University of Alberta, Edmonton, Canada.,Department of Viticulture and Enology, University of California, Davis, CA, USA
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40
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Wang R, Kamgoue A, Normand C, Léger-Silvestre I, Mangeat T, Gadal O. High resolution microscopy reveals the nuclear shape of budding yeast during cell cycle and in various biological states. J Cell Sci 2016; 129:4480-4495. [PMID: 27831493 PMCID: PMC5201014 DOI: 10.1242/jcs.188250] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 11/01/2016] [Indexed: 01/10/2023] Open
Abstract
How spatial organization of the genome depends on nuclear shape is unknown, mostly because accurate nuclear size and shape measurement is technically challenging. In large cell populations of the yeast Saccharomyces cerevisiae, we assessed the geometry (size and shape) of nuclei in three dimensions with a resolution of 30 nm. We improved an automated fluorescence localization method by implementing a post-acquisition correction of the spherical microscopic aberration along the z-axis, to detect the three dimensional (3D) positions of nuclear pore complexes (NPCs) in the nuclear envelope. Here, we used a method called NucQuant to accurately estimate the geometry of nuclei in 3D throughout the cell cycle. To increase the robustness of the statistics, we aggregated thousands of detected NPCs from a cell population in a single representation using the nucleolus or the spindle pole body (SPB) as references to align nuclei along the same axis. We could detect asymmetric changes of the nucleus associated with modification of nucleolar size. Stereotypical modification of the nucleus toward the nucleolus further confirmed the asymmetric properties of the nuclear envelope. Summary: This novel method to explore 3D geometry of the nuclear envelope with enhanced resolution and post-acquisition correction of z-axis aberration revealed increased NPC density near the SPB and the nucleolus.
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Affiliation(s)
- Renjie Wang
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse 31000, France
| | - Alain Kamgoue
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse 31000, France
| | - Christophe Normand
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse 31000, France
| | - Isabelle Léger-Silvestre
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse 31000, France
| | - Thomas Mangeat
- Laboratoire de Biologie Cellulaire et Moléculaire du Contrôle de la Prolifération, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse 31000, France
| | - Olivier Gadal
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse 31000, France
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41
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Saad H, Cobb JA. A decade of understanding spatio-temporal regulation of DNA repair by the nuclear architecture. Biochem Cell Biol 2016; 94:433-440. [DOI: 10.1139/bcb-2016-0085] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The nucleus is a hub for gene expression and is a highly organized entity. The nucleoplasm is heterogeneous, owing to the preferential localization of specific metabolic factors, which lead to the definition of nuclear compartments or bodies. The genome is organized into chromosome territories, as well as heterochromatin and euchromatin domains. Recent observations have indicated that nuclear organization is important for maintaining genomic stability. For example, nuclear organization has been implicated in stabilizing damaged DNA, repair-pathway choice, and in preventing chromosomal rearrangements. Over the past decade, several studies have revealed that dynamic changes in the nuclear architecture are important during double-strand break repair. Stemming from work in yeast, relocation of a damaged site prior to repair appears to be at least partially conserved in multicellular eukaryotes. In this review, we will discuss genome and nucleoplasm architecture, particularly the importance of the nuclear periphery in genome stability. We will also discuss how the site of relocation regulates repair-pathway choice.
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Affiliation(s)
- Hicham Saad
- Southern Alberta Cancer Research Institute, Departments of Biochemistry & Molecular Biology and Oncology, Robson DNA Science Centre, Arnie Charbonneau Cancer Institute, Cumming School of Medicine; University of Calgary; 3330 Hospital Drive N.W., Calgary, AB T2N 4N1, Canada
- Southern Alberta Cancer Research Institute, Departments of Biochemistry & Molecular Biology and Oncology, Robson DNA Science Centre, Arnie Charbonneau Cancer Institute, Cumming School of Medicine; University of Calgary; 3330 Hospital Drive N.W., Calgary, AB T2N 4N1, Canada
| | - Jennifer A. Cobb
- Southern Alberta Cancer Research Institute, Departments of Biochemistry & Molecular Biology and Oncology, Robson DNA Science Centre, Arnie Charbonneau Cancer Institute, Cumming School of Medicine; University of Calgary; 3330 Hospital Drive N.W., Calgary, AB T2N 4N1, Canada
- Southern Alberta Cancer Research Institute, Departments of Biochemistry & Molecular Biology and Oncology, Robson DNA Science Centre, Arnie Charbonneau Cancer Institute, Cumming School of Medicine; University of Calgary; 3330 Hospital Drive N.W., Calgary, AB T2N 4N1, Canada
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42
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Niño CA, Guet D, Gay A, Brutus S, Jourquin F, Mendiratta S, Salamero J, Géli V, Dargemont C. Posttranslational marks control architectural and functional plasticity of the nuclear pore complex basket. J Cell Biol 2016; 212:167-80. [PMID: 26783300 PMCID: PMC4738382 DOI: 10.1083/jcb.201506130] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Ubiquitin modifications of the nuclear pore complex (NPC) control the architectural plasticity of the nuclear basket, contributing to its tethering to the core NPC, with consequences on the cellular response to DNA damage and telomere recombination. The nuclear pore complex (NPC) serves as both the unique gate between the nucleus and the cytoplasm and a major platform that coordinates nucleocytoplasmic exchanges, gene expression, and genome integrity. To understand how the NPC integrates these functional constraints, we dissected here the posttranslational modifications of the nuclear basket protein Nup60 and analyzed how they intervene to control the plasticity of the NPC. Combined approaches highlight the role of monoubiquitylation in regulating the association dynamics of Nup60 and its partner, Nup2, with the NPC through an interaction with Nup84, a component of the Y complex. Although major nuclear transport routes are not regulated by Nup60 modifications, monoubiquitylation of Nup60 is stimulated upon genotoxic stress and regulates the DNA-damage response and telomere repair. Together, these data reveal an original mechanism contributing to the plasticity of the NPC at a molecular-organization and functional level.
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Affiliation(s)
- Carlos A Niño
- University Paris Diderot, Sorbonne Paris Cité, Pathologie et Virologie Moléculaire, Institut National de la Santé et de la Recherche Medicale (INSERM), Centre National de la Recherche Scientifique (CNRS), Equipe labellisée Ligue contre le cancer, Hôpital St. Louis, 75475 Paris, France
| | - David Guet
- University Paris Diderot, Sorbonne Paris Cité, Pathologie et Virologie Moléculaire, Institut National de la Santé et de la Recherche Medicale (INSERM), Centre National de la Recherche Scientifique (CNRS), Equipe labellisée Ligue contre le cancer, Hôpital St. Louis, 75475 Paris, France
| | - Alexandre Gay
- University Paris Diderot, Sorbonne Paris Cité, Pathologie et Virologie Moléculaire, Institut National de la Santé et de la Recherche Medicale (INSERM), Centre National de la Recherche Scientifique (CNRS), Equipe labellisée Ligue contre le cancer, Hôpital St. Louis, 75475 Paris, France
| | - Sergine Brutus
- University Paris Diderot, Sorbonne Paris Cité, Pathologie et Virologie Moléculaire, Institut National de la Santé et de la Recherche Medicale (INSERM), Centre National de la Recherche Scientifique (CNRS), Equipe labellisée Ligue contre le cancer, Hôpital St. Louis, 75475 Paris, France
| | - Frédéric Jourquin
- Aix-Marseille University, CNRS UMR 7258, INSERM UMR1068, Institut Paoli-Calmettes, Cancer Research Center of Marseille, Equipe labellisée Ligue contre le cancer, 13273 Marseille, France
| | - Shweta Mendiratta
- University Paris Diderot, Sorbonne Paris Cité, Pathologie et Virologie Moléculaire, Institut National de la Santé et de la Recherche Medicale (INSERM), Centre National de la Recherche Scientifique (CNRS), Equipe labellisée Ligue contre le cancer, Hôpital St. Louis, 75475 Paris, France
| | - Jean Salamero
- Institut Curie, PSL Research University, CNRS UMR 144, Pierre-and-Marie-Curie Université, Team-Space time imaging of endomembranes and organelles dynamics and PICT-IBiSA Imaging Core Facility, 75005 Paris, France
| | - Vincent Géli
- Aix-Marseille University, CNRS UMR 7258, INSERM UMR1068, Institut Paoli-Calmettes, Cancer Research Center of Marseille, Equipe labellisée Ligue contre le cancer, 13273 Marseille, France
| | - Catherine Dargemont
- University Paris Diderot, Sorbonne Paris Cité, Pathologie et Virologie Moléculaire, Institut National de la Santé et de la Recherche Medicale (INSERM), Centre National de la Recherche Scientifique (CNRS), Equipe labellisée Ligue contre le cancer, Hôpital St. Louis, 75475 Paris, France
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43
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Kikuchi N, Kolpashchikov DM. Split Spinach Aptamer for Highly Selective Recognition of DNA and RNA at Ambient Temperatures. Chembiochem 2016; 17:1589-92. [PMID: 27305425 DOI: 10.1002/cbic.201600323] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Indexed: 12/25/2022]
Abstract
Split spinach aptamer (SSA) probes for fluorescent analysis of nucleic acids were designed and tested. In SSA design, two RNA or RNA/DNA strands hybridized to a specific nucleic acid analyte and formed a binding site for low-fluorescent 3,5-difluoro-4-hydroxybenzylidene imidazolinone (DFHBI) dye, which resulted in up to a 270-fold increase in fluorescence. The major advantage of the SSA over state-of-the art fluorescent probes is high selectivity: it produces only background fluorescence in the presence of a single-base-mismatched analyte, even at room temperature. SSA is therefore a promising tool for label-free analysis of nucleic acids at ambient temperatures.
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Affiliation(s)
- Nanami Kikuchi
- Chemistry Department, University of Central Florida, 4000 Central Florida Boulevard, Orlando, FL, 32816-2366, USA
| | - Dmitry M Kolpashchikov
- Chemistry Department, University of Central Florida, 4000 Central Florida Boulevard, Orlando, FL, 32816-2366, USA.
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44
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Abstract
Seeing is not only believing; it also includes understanding. Cellular imaging with GFP in live cells has been transformative in many research fields. Modulation of cellular regulation is tightly regulated and innovative imaging technologies contribute to further understand cellular signaling and physiology. New types of genetically encoded biosensors have been developed over the last decade. They are RNA aptamers that bind with their cognate fluorogen ligands and activate their fluorescence. The emergence and the evolution of these RNA aptamers as well as their conversion into a wide spectrum of applications are examined in a global way.
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Affiliation(s)
- Jonathan Ouellet
- Department of Chemistry and Physics, Monmouth UniversityWest Long Branch, NJ, USA
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45
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Pfeiffer F, Mayer G. Selection and Biosensor Application of Aptamers for Small Molecules. Front Chem 2016; 4:25. [PMID: 27379229 PMCID: PMC4908669 DOI: 10.3389/fchem.2016.00025] [Citation(s) in RCA: 143] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Accepted: 05/30/2016] [Indexed: 12/12/2022] Open
Abstract
Small molecules play a major role in the human body and as drugs, toxins, and chemicals. Tools to detect and quantify them are therefore in high demand. This review will give an overview about aptamers interacting with small molecules and their selection. We discuss the current state of the field, including advantages as well as problems associated with their use and possible solutions to tackle these. We then discuss different kinds of small molecule aptamer-based sensors described in literature and their applications, ranging from detecting drinking water contaminations to RNA imaging.
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Affiliation(s)
- Franziska Pfeiffer
- Department of Chemical Biology, Life and Medical Sciences Institute, University of Bonn Bonn, Germany
| | - Günter Mayer
- Department of Chemical Biology, Life and Medical Sciences Institute, University of Bonn Bonn, Germany
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46
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Krasnov AN, Mazina MY, Nikolenko JV, Vorobyeva NE. On the way of revealing coactivator complexes cross-talk during transcriptional activation. Cell Biosci 2016; 6:15. [PMID: 26913181 PMCID: PMC4765067 DOI: 10.1186/s13578-016-0081-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 02/09/2016] [Indexed: 08/07/2023] Open
Abstract
Transcriptional activation is a complex, multistage process implemented by hundreds of proteins. Many transcriptional proteins are organized into coactivator complexes, which participate in transcription regulation at numerous genes and are a driver of this process. The molecular action mechanisms of coactivator complexes remain largely understudied. Relevant publications usually deal with the involvement of these complexes in the entire process of transcription, and only a few studies are aimed to elucidate their functions at its particular stages. This review summarizes available information on the participation of key coactivator complexes in transcriptional activation. The timing of coactivator complex binding/removal has been used for restructuring previously described information about the transcriptional process. Several major stages of transcriptional activation have been distinguished based on the presence of covalent histone modifications and general transcriptional factors, and the recruitment and/or removal phases have been determined for each coactivator included in analysis. Recruitment of Mediator, SWItch/Sucrose Non-Fermentable and NUcleosome Remodeling Factor complexes during transcription activation has been investigated thoroughly; CHD and INOsitol auxotrophy 80 families are less well studied. In most cases, the molecular mechanisms responsible for the removal of certain coactivator complexes after the termination of their functions at the promoters are still not understood. On the basis of the summarized information, we propose a scheme that illustrates the involvement of coactivator complexes in different stages of the transcription activation process. This scheme may help to gain a deeper insight into the molecular mechanism of functioning of coactivator complexes, find novel participants of the process, and reveal novel structural or functional connections between different coactivators.
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Affiliation(s)
- Aleksey N Krasnov
- Department of Transcription Regulation and Chromatin Dynamic, Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334 Russia
| | - Marina Yu Mazina
- Department of Transcription Regulation and Chromatin Dynamic, Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334 Russia
| | - Julia V Nikolenko
- Department of Transcription Regulation and Chromatin Dynamic, Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334 Russia
| | - Nadezhda E Vorobyeva
- Department of Transcription Regulation and Chromatin Dynamic, Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334 Russia
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