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N MPA, Jeon H, Wang X, Lim HM. Reporter Gene-Based qRT-PCR Assay for Rho-Dependent Termination In Vivo. Cells 2023; 12:2596. [PMID: 37998331 PMCID: PMC10670590 DOI: 10.3390/cells12222596] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 11/06/2023] [Accepted: 11/07/2023] [Indexed: 11/25/2023] Open
Abstract
In bacteria, the Rho protein mediates Rho-dependent termination (RDT) by identifying a non-specific cytosine-rich Rho utilization site on the newly synthesized RNA. As a result of RDT, downstream RNA transcription is reduced. Due to the bias in reverse transcription and PCR amplification, we could not identify the RDT site by directly measuring the amount of mRNA upstream and downstream of RDT sites. To overcome this difficulty, we employed a 77 bp reporter gene argX, (coding tRNAarg) from Brevibacterium albidum, and we transcriptionally fused it to the sequences to be assayed. We constructed a series of plasmids by combining a segment of the galactose (gal) operon sequences, both with and without the RDT regions at the ends of cistrons (galE, galT, and galM) upstream of argX. The RNA polymerase will transcribe the gal operon sequence and argX unless it encounters the RDT encoded by the inserted sequence. Since the quantitative real-time PCR (qRT-PCR) method detects the steady state following mRNA synthesis and degradation, we observed that tRNAarg is degraded at the same rate in these transcriptional fusion plasmids. Therefore, the amount of tRNAarg can directly reflect the mRNA synthesis. Using this approach, we were able to effectively assay the RDTs and Rho-independent termination (RIT) in the gal operon by quantifying the relative amount of tRNAarg using qRT-PCR analyses. The resultant RDT% for galET, galTK, and at the end of galM were 36, 26, and 63, individually. The resultant RIT% at the end of the gal operon is 33%. Our findings demonstrate that combining tRNAarg with qRT-PCR can directly measure RIT, RDT, or any other signal that attenuates transcription efficiencies in vivo, making it a useful tool for gene expression research.
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Affiliation(s)
- Monford Paul Abishek N
- Department of Biological Sciences, College of Biological Sciences and Biotechnology, Chungnam National University, Daejeon 34134, Republic of Korea;
| | - Heungjin Jeon
- Infection Control Convergence Research Center, Chungnam National University College of Medicine, Daejeon 34134, Republic of Korea;
| | - Xun Wang
- National Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Heon M. Lim
- Department of Biological Sciences, College of Biological Sciences and Biotechnology, Chungnam National University, Daejeon 34134, Republic of Korea;
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2
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Chu X, He C, Sang B, Yang C, Yin C, Ji M, Qian A, Tian Y. Transfer RNAs-derived small RNAs and their application potential in multiple diseases. Front Cell Dev Biol 2022; 10:954431. [PMID: 36072340 PMCID: PMC9441921 DOI: 10.3389/fcell.2022.954431] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 07/11/2022] [Indexed: 11/17/2022] Open
Abstract
The role of tRNAs is best known as adapter components of translational machinery. According to the central dogma of molecular biology, DNA is transcribed to RNA and in turn is translated into proteins, in which tRNA outstands by its role of the cellular courier. Recent studies have led to the revision of the canonical function of transfer RNAs (tRNAs), which indicates that tRNAs also serve as a source for short non-coding RNAs called tRNA-derived small RNAs (tsRNAs). tsRNAs play key roles in cellular processes by modulating complicated regulatory networks beyond translation and are widely involved in multiple diseases. Herein, the biogenesis and classification of tsRNAs were firstly clarified. tsRNAs are generated from pre-tRNAs or mature tRNAs and are classified into tRNA-derived fragments (tRFs) and tRNA halves (tiRNA). The tRFs include five types according to the incision loci: tRF-1, tRF-2, tRF-3, tRF-5 and i-tRF which contain 3′ tiRNA and 5′ tiRNA. The functions of tsRNAs and their regulation mechanisms involved in disease processes are systematically summarized as well. The mechanisms can elaborate on the specific regulation of tsRNAs. In conclusion, the current research suggests that tsRNAs are promising targets for modulating pathological processes, such as breast cancer, ischemic stroke, respiratory syncytial virus, osteoporosis and so on, and maintain vital clinical implications in diagnosis and therapeutics of various diseases.
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Affiliation(s)
- Xiaohua Chu
- Lab for Bone Metabolism, Xi’an Key Laboratory of Special Medicine and Health Engineering, Key Lab for Space Biosciences and Biotechnology, Research Center for Special Medicine and Health Systems Engineering, NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi’an, SN, China
| | - Chenyang He
- Department of Oncology, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
| | - Bo Sang
- Lab for Bone Metabolism, Xi’an Key Laboratory of Special Medicine and Health Engineering, Key Lab for Space Biosciences and Biotechnology, Research Center for Special Medicine and Health Systems Engineering, NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi’an, SN, China
| | - Chaofei Yang
- Lab for Bone Metabolism, Xi’an Key Laboratory of Special Medicine and Health Engineering, Key Lab for Space Biosciences and Biotechnology, Research Center for Special Medicine and Health Systems Engineering, NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi’an, SN, China
| | - Chong Yin
- Department of Clinical Laboratory, Academician (expert) Workstation, Lab of Epigenetics and RNA Therapy, Affiliated Hospital of North Sichuan Medical College, Nanchong, China
| | - Mili Ji
- Lab for Bone Metabolism, Xi’an Key Laboratory of Special Medicine and Health Engineering, Key Lab for Space Biosciences and Biotechnology, Research Center for Special Medicine and Health Systems Engineering, NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi’an, SN, China
| | - Airong Qian
- Lab for Bone Metabolism, Xi’an Key Laboratory of Special Medicine and Health Engineering, Key Lab for Space Biosciences and Biotechnology, Research Center for Special Medicine and Health Systems Engineering, NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi’an, SN, China
- *Correspondence: Airong Qian, ; Ye Tian,
| | - Ye Tian
- Lab for Bone Metabolism, Xi’an Key Laboratory of Special Medicine and Health Engineering, Key Lab for Space Biosciences and Biotechnology, Research Center for Special Medicine and Health Systems Engineering, NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi’an, SN, China
- *Correspondence: Airong Qian, ; Ye Tian,
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3
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Das S, Zuko A, Thompson R, Storkebaum E, Ignatova Z. Immunoprecipation Assay to Quantify the Amount of tRNAs associated with Their Interacting Proteins in Tissue and Cell Culture. Bio Protoc 2022; 12:e4335. [DOI: 10.21769/bioprotoc.4335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 10/26/2021] [Accepted: 01/13/2022] [Indexed: 11/02/2022] Open
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Skeparnias I, Zhang J. Cooperativity and Interdependency between RNA Structure and RNA-RNA Interactions. Noncoding RNA 2021; 7:ncrna7040081. [PMID: 34940761 PMCID: PMC8704770 DOI: 10.3390/ncrna7040081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 12/09/2021] [Accepted: 12/10/2021] [Indexed: 11/16/2022] Open
Abstract
Complex RNA–RNA interactions are increasingly known to play key roles in numerous biological processes from gene expression control to ribonucleoprotein granule formation. By contrast, the nature of these interactions and characteristics of their interfaces, especially those that involve partially or wholly structured RNAs, remain elusive. Herein, we discuss different modalities of RNA–RNA interactions with an emphasis on those that depend on secondary, tertiary, or quaternary structure. We dissect recently structurally elucidated RNA–RNA complexes including RNA triplexes, riboswitches, ribozymes, and reverse transcription complexes. These analyses highlight a reciprocal relationship that intimately links RNA structure formation with RNA–RNA interactions. The interactions not only shape and sculpt RNA structures but also are enabled and modulated by the structures they create. Understanding this two-way relationship between RNA structure and interactions provides mechanistic insights into the expanding repertoire of noncoding RNA functions, and may inform the design of novel therapeutics that target RNA structures or interactions.
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Li J, Zhu WY, Yang WQ, Li CT, Liu RJ. The occurrence order and cross-talk of different tRNA modifications. SCIENCE CHINA. LIFE SCIENCES 2021; 64:1423-1436. [PMID: 33881742 DOI: 10.1007/s11427-020-1906-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 03/02/2021] [Indexed: 06/12/2023]
Abstract
Chemical modifications expand the composition of RNA molecules from four standard nucleosides to over 160 modified nucleosides, which greatly increase the complexity and utility of RNAs. Transfer RNAs (tRNAs) are the most heavily modified cellular RNA molecules and contain the largest variety of modifications. Modification of tRNAs is pivotal for protein synthesis and also precisely regulates the noncanonical functions of tRNAs. Defects in tRNA modifications lead to numerous human diseases. Up to now, more than 100 types of modifications have been found in tRNAs. Intriguingly, some modifications occur widely on all tRNAs, while others only occur on a subgroup of tRNAs or even only a specific tRNA. The modification frequency of each tRNA is approximately 7% to 25%, with 5-20 modification sites present on each tRNA. The occurrence and modulation of tRNA modifications are specifically noticeable as plenty of interplays among different sites and modifications have been discovered. In particular, tRNA modifications are responsive to environmental changes, indicating their dynamic and highly organized nature. In this review, we summarized the known occurrence order, cross-talk, and cooperativity of tRNA modifications.
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Affiliation(s)
- Jing Li
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Wen-Yu Zhu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Wen-Qing Yang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Cai-Tao Li
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Ru-Juan Liu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
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Chan CW, Badong D, Rajan R, Mondragón A. Crystal structures of an unmodified bacterial tRNA reveal intrinsic structural flexibility and plasticity as general properties of unbound tRNAs. RNA (NEW YORK, N.Y.) 2020; 26:278-289. [PMID: 31848215 PMCID: PMC7025506 DOI: 10.1261/rna.073478.119] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 12/12/2019] [Indexed: 06/10/2023]
Abstract
Ubiquitous across all domains of life, tRNAs constitute an essential component of cellular physiology, carry out an indispensable role in protein synthesis, and have been historically the subject of a wide range of biochemical and biophysical studies as prototypical folded RNA molecules. Although conformational flexibility is a well-established characteristic of tRNA structure, it is typically regarded as an adaptive property exhibited in response to an inducing event, such as the binding of a tRNA synthetase or the accommodation of an aminoacyl-tRNA into the ribosome. In this study, we present crystallographic data of a tRNA molecule to expand on this paradigm by showing that structural flexibility and plasticity are intrinsic properties of tRNAs, apparent even in the absence of other factors. Based on two closely related conformations observed within the same crystal, we posit that unbound tRNAs by themselves are flexible and dynamic molecules. Furthermore, we demonstrate that the formation of the T-loop conformation by the tRNA TΨC stem-loop, a well-characterized and classic RNA structural motif, is possible even in the absence of important interactions observed in fully folded tRNAs.
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Affiliation(s)
- Clarence W Chan
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208-3500, USA
| | - Deanna Badong
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208-3500, USA
| | - Rakhi Rajan
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208-3500, USA
| | - Alfonso Mondragón
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208-3500, USA
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Jühling T, Duchardt-Ferner E, Bonin S, Wöhnert J, Pütz J, Florentz C, Betat H, Sauter C, Mörl M. Small but large enough: structural properties of armless mitochondrial tRNAs from the nematode Romanomermis culicivorax. Nucleic Acids Res 2019; 46:9170-9180. [PMID: 29986062 PMCID: PMC6158502 DOI: 10.1093/nar/gky593] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 06/20/2018] [Indexed: 12/19/2022] Open
Abstract
As adapter molecules to convert the nucleic acid information into the amino acid sequence, tRNAs play a central role in protein synthesis. To fulfill this function in a reliable way, tRNAs exhibit highly conserved structural features common in all organisms and in all cellular compartments active in translation. However, in mitochondria of metazoans, certain dramatic deviations from the consensus tRNA structure are described, where some tRNAs lack the D- or T-arm without losing their function. In Enoplea, this miniaturization comes to an extreme, and functional mitochondrial tRNAs can lack both arms, leading to a considerable size reduction. Here, we investigate the secondary and tertiary structure of two such armless tRNAs from Romanomermis culicivorax. Despite their high AU content, the transcripts fold into a single and surprisingly stable hairpin structure, deviating from standard tRNAs. The three-dimensional form is boomerang-like and diverges from the standard L-shape. These results indicate that such unconventional miniaturized tRNAs can still fold into a tRNA-like shape, although their length and secondary structure are very unusual. They highlight the remarkable flexibility of the protein synthesis apparatus and suggest that the translational machinery of Enoplea mitochondria may show compensatory adaptations to accommodate these armless tRNAs for efficient translation.
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Affiliation(s)
- Tina Jühling
- Institute for Biochemistry, Leipzig University, Brüderstrasse 34, 04103 Leipzig, Germany.,Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, IBMC, 67084 Strasbourg, France
| | - Elke Duchardt-Ferner
- Institute of Molecular Biosciences, Goethe-University and Center of Biomolecular Magnetic Resonance (BMRZ), Frankfurt/M., Max-von-Laue-Strasse 9, 60438, Frankfurt, Germany
| | - Sonja Bonin
- Institute for Biochemistry, Leipzig University, Brüderstrasse 34, 04103 Leipzig, Germany
| | - Jens Wöhnert
- Institute of Molecular Biosciences, Goethe-University and Center of Biomolecular Magnetic Resonance (BMRZ), Frankfurt/M., Max-von-Laue-Strasse 9, 60438, Frankfurt, Germany
| | - Joern Pütz
- Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, IBMC, 67084 Strasbourg, France
| | - Catherine Florentz
- Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, IBMC, 67084 Strasbourg, France
| | - Heike Betat
- Institute for Biochemistry, Leipzig University, Brüderstrasse 34, 04103 Leipzig, Germany
| | - Claude Sauter
- Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, IBMC, 67084 Strasbourg, France
| | - Mario Mörl
- Institute for Biochemistry, Leipzig University, Brüderstrasse 34, 04103 Leipzig, Germany
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