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Yared MJ, Marcelot A, Barraud P. Beyond the Anticodon: tRNA Core Modifications and Their Impact on Structure, Translation and Stress Adaptation. Genes (Basel) 2024; 15:374. [PMID: 38540433 PMCID: PMC10969862 DOI: 10.3390/genes15030374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 03/15/2024] [Accepted: 03/18/2024] [Indexed: 06/14/2024] Open
Abstract
Transfer RNAs (tRNAs) are heavily decorated with post-transcriptional chemical modifications. Approximately 100 different modifications have been identified in tRNAs, and each tRNA typically contains 5-15 modifications that are incorporated at specific sites along the tRNA sequence. These modifications may be classified into two groups according to their position in the three-dimensional tRNA structure, i.e., modifications in the tRNA core and modifications in the anticodon-loop (ACL) region. Since many modified nucleotides in the tRNA core are involved in the formation of tertiary interactions implicated in tRNA folding, these modifications are key to tRNA stability and resistance to RNA decay pathways. In comparison to the extensively studied ACL modifications, tRNA core modifications have generally received less attention, although they have been shown to play important roles beyond tRNA stability. Here, we review and place in perspective selected data on tRNA core modifications. We present their impact on tRNA structure and stability and report how these changes manifest themselves at the functional level in translation, fitness and stress adaptation.
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Affiliation(s)
| | | | - Pierre Barraud
- Expression Génétique Microbienne, Université Paris Cité, CNRS, Institut de Biologie Physico-Chimique, F-75005 Paris, France; (M.-J.Y.); (A.M.)
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Wang C, Ye T, Bao J, Dong J, Wang W, Li C, Ding H, Chen H, Wang X, Shi J. 5- methylcytidine effectively improves spermatogenesis recovery in busulfan-induced oligoasthenospermia mice. Eur J Pharmacol 2024; 967:176405. [PMID: 38341078 DOI: 10.1016/j.ejphar.2024.176405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 02/06/2024] [Accepted: 02/07/2024] [Indexed: 02/12/2024]
Abstract
The function and regulatory mechanisms of 5-methylcytidine (m5C) in oligoasthenospermia remain unclear. In this study, we made a mouse model of oligoasthenospermia through the administration of busulfan (BUS). For the first time, we demonstrated that m5C levels decreased in oligoasthenospermia. The m5C levels were upregulated through the treatments of 5-methylcytidine. The testicular morphology and sperm concentrations were improved via upregulating m5C. The cytoskeletal regenerations of testis and sperm were accompanying with m5C treatments. m5C treatments improved T levels and reduced FSH and LH levels. The levels of ROS and MDA were significantly reduced through m5C treatments. RNA sequencing analysis showed m5C treatments increased the expression of genes involved in spermatid differentiation/development and cilium movement. Immunofluorescent staining demonstrated the regeneration of cilium and quantitative PCR (qPCR) confirmed the high expression of genes involved in spermatogenesis. Collectively, our findings suggest that the upregulation of m5C in oligoasthenospermia facilitates testicular morphology recovery and male infertility via multiple pathways, including cytoskeletal regeneration, hormonal levels, attenuating oxidative stress, spermatid differentiation/development and cilium movement. m5C may be a potential therapeutic agent for oligoasthenospermia.
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Affiliation(s)
- Chengniu Wang
- Institute of Reproductive Medicine, Medical School, Nantong University, Nantong, Jiangsu, 226001, China
| | - Taowen Ye
- Institute of Reproductive Medicine, Medical School, Nantong University, Nantong, Jiangsu, 226001, China
| | - Junze Bao
- Institute of Reproductive Medicine, Medical School, Nantong University, Nantong, Jiangsu, 226001, China
| | - Jin Dong
- Institute of Reproductive Medicine, Medical School, Nantong University, Nantong, Jiangsu, 226001, China
| | - Wenran Wang
- Blood Purification Centre, Third People's Hospital of Rugao, Nantong, Jiangsu, 226531, China
| | - Chunhong Li
- Blood Purification Centre, Third People's Hospital of Rugao, Nantong, Jiangsu, 226531, China
| | - Hongping Ding
- Blood Purification Centre, Third People's Hospital of Rugao, Nantong, Jiangsu, 226531, China
| | - Hanqing Chen
- Institute of Reproductive Medicine, Medical School, Nantong University, Nantong, Jiangsu, 226001, China
| | - Xiaorong Wang
- Center for Reproductive Medicine, Affiliated Maternity and Child Health Care Hospital of Nantong University, Nantong, Jiangsu, 226018, China; Nantong Institute of Genetics and Reproductive Medicine, Affiliated Maternity and Child Health Care Hospital of Nantong University, Nantong, Jiangsu, 226018, China; Nantong Key Laboratory of Genetics and Reproductive Medicine, Nantong, Jiangsu, 226018, China.
| | - Jianwu Shi
- Basic Medical Research Centre, Medical School, Nantong University, Nantong, Jiangsu, 226001, China.
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3
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De Zoysa T, Hauke AC, Iyer NR, Marcus E, Ostrowski SM, Stegemann F, Ermolenko DN, Fay JC, Phizicky EM. A connection between the ribosome and two S. pombe tRNA modification mutants subject to rapid tRNA decay. PLoS Genet 2024; 20:e1011146. [PMID: 38295128 PMCID: PMC10861057 DOI: 10.1371/journal.pgen.1011146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 02/12/2024] [Accepted: 01/22/2024] [Indexed: 02/02/2024] Open
Abstract
tRNA modifications are crucial in all organisms to ensure tRNA folding and stability, and accurate translation. In both the yeast Saccharomyces cerevisiae and the evolutionarily distant yeast Schizosaccharomyces pombe, mutants lacking certain tRNA body modifications (outside the anticodon loop) are temperature sensitive due to rapid tRNA decay (RTD) of a subset of hypomodified tRNAs. Here we show that for each of two S. pombe mutants subject to RTD, mutations in ribosomal protein genes suppress the temperature sensitivity without altering tRNA levels. Prior work showed that S. pombe trm8Δ mutants, lacking 7-methylguanosine, were temperature sensitive due to RTD, and that one class of suppressors had mutations in the general amino acid control (GAAC) pathway, which was activated concomitant with RTD, resulting in further tRNA loss. We now find that another class of S. pombe trm8Δ suppressors have mutations in rpl genes, encoding 60S subunit proteins, and that suppression occurs with minimal restoration of tRNA levels and reduced GAAC activation. Furthermore, trm8Δ suppression extends to other mutations in the large or small ribosomal subunit. We also find that S. pombe tan1Δ mutants, lacking 4-acetylcytidine, are temperature sensitive due to RTD, that one class of suppressors have rpl mutations, associated with minimal restoration of tRNA levels, and that suppression extends to other rpl and rps mutations. However, although S. pombe tan1Δ temperature sensitivity is associated with some GAAC activation, suppression by an rpl mutation only modestly inhibits GAAC activation. We propose a model in which ribosomal protein mutations result in reduced ribosome concentrations, leading to both reduced ribosome collisions and a reduced requirement for tRNA, with these effects having different relative importance in trm8Δ and tan1Δ mutants. This model is consistent with our results in S. cerevisiae trm8Δ trm4Δ mutants, known to undergo RTD, fueling speculation that this model applies across eukaryotes.
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Affiliation(s)
- Thareendra De Zoysa
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine, Rochester, New York, United States of America
| | - Alayna C. Hauke
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine, Rochester, New York, United States of America
| | - Nivedita R. Iyer
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine, Rochester, New York, United States of America
| | - Erin Marcus
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine, Rochester, New York, United States of America
| | - Sarah M. Ostrowski
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine, Rochester, New York, United States of America
| | - Franziska Stegemann
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine, Rochester, New York, United States of America
| | - Dmitri N. Ermolenko
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine, Rochester, New York, United States of America
| | - Justin C. Fay
- Department of Biology, University of Rochester, Rochester, New York, United States of America
| | - Eric M. Phizicky
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine, Rochester, New York, United States of America
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Wang Z, Xu X, Li X, Fang J, Huang Z, Zhang M, Liu J, Qiu X. Investigations of Single-Subunit tRNA Methyltransferases from Yeast. J Fungi (Basel) 2023; 9:1030. [PMID: 37888286 PMCID: PMC10608323 DOI: 10.3390/jof9101030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 10/13/2023] [Accepted: 10/13/2023] [Indexed: 10/28/2023] Open
Abstract
tRNA methylations, including base modification and 2'-O-methylation of ribose moiety, play critical roles in the structural stabilization of tRNAs and the fidelity and efficiency of protein translation. These modifications are catalyzed by tRNA methyltransferases (TRMs). Some of the TRMs from yeast can fully function only by a single subunit. In this study, after performing the primary bioinformatic analyses, the progress of the studies of yeast single-subunit TRMs, as well as the studies of their homologues from yeast and other types of eukaryotes and the corresponding TRMs from other types of organisms was systematically reviewed, which will facilitate the understanding of the evolutionary origin of functional diversity of eukaryotic single-subunit TRM.
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Affiliation(s)
- Zhongyuan Wang
- Ministry of Education Key Laboratory of Applied Marine Biotechnology, Ningbo University, Ningbo 315800, China; (Z.W.); (X.L.); (J.F.); (Z.H.); (M.Z.); (J.L.)
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315800, China;
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Centre, Ningbo University, Ningbo 315800, China
| | - Xiangbin Xu
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315800, China;
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Centre, Ningbo University, Ningbo 315800, China
| | - Xinhai Li
- Ministry of Education Key Laboratory of Applied Marine Biotechnology, Ningbo University, Ningbo 315800, China; (Z.W.); (X.L.); (J.F.); (Z.H.); (M.Z.); (J.L.)
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315800, China;
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Centre, Ningbo University, Ningbo 315800, China
| | - Jiaqi Fang
- Ministry of Education Key Laboratory of Applied Marine Biotechnology, Ningbo University, Ningbo 315800, China; (Z.W.); (X.L.); (J.F.); (Z.H.); (M.Z.); (J.L.)
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315800, China;
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Centre, Ningbo University, Ningbo 315800, China
| | - Zhenkuai Huang
- Ministry of Education Key Laboratory of Applied Marine Biotechnology, Ningbo University, Ningbo 315800, China; (Z.W.); (X.L.); (J.F.); (Z.H.); (M.Z.); (J.L.)
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315800, China;
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Centre, Ningbo University, Ningbo 315800, China
| | - Mengli Zhang
- Ministry of Education Key Laboratory of Applied Marine Biotechnology, Ningbo University, Ningbo 315800, China; (Z.W.); (X.L.); (J.F.); (Z.H.); (M.Z.); (J.L.)
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315800, China;
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Centre, Ningbo University, Ningbo 315800, China
| | - Jiameng Liu
- Ministry of Education Key Laboratory of Applied Marine Biotechnology, Ningbo University, Ningbo 315800, China; (Z.W.); (X.L.); (J.F.); (Z.H.); (M.Z.); (J.L.)
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315800, China;
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Centre, Ningbo University, Ningbo 315800, China
| | - Xiaoting Qiu
- Ministry of Education Key Laboratory of Applied Marine Biotechnology, Ningbo University, Ningbo 315800, China; (Z.W.); (X.L.); (J.F.); (Z.H.); (M.Z.); (J.L.)
- College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315800, China;
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Centre, Ningbo University, Ningbo 315800, China
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De Zoysa T, Hauke AC, Iyer NR, Marcus E, Ostrowski SM, Fay JC, Phizicky EM. A connection between the ribosome and two S. pombe tRNA modification mutants subject to rapid tRNA decay. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.18.558340. [PMID: 37790432 PMCID: PMC10542129 DOI: 10.1101/2023.09.18.558340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
tRNA modifications are crucial in all organisms to ensure tRNA folding and stability, and accurate translation in the ribosome. In both the yeast Saccharomyces cerevisiae and the evolutionarily distant yeast Schizosaccharomyces pombe, mutants lacking certain tRNA body modifications (outside the anticodon loop) are temperature sensitive due to rapid tRNA decay (RTD) of a subset of hypomodified tRNAs. Here we show that for each of two S. pombe mutants subject to RTD, mutations in ribosomal protein genes suppress the temperature sensitivity without altering tRNA levels. Prior work showed that S. pombe trm8Δ mutants, lacking 7-methylguanosine, were temperature sensitive due to RTD and that one class of suppressors had mutations in the general amino acid control (GAAC) pathway, which was activated concomitant with RTD, resulting in further tRNA loss. We now find that another class of S. pombe trm8Δ suppressors have mutations in rpl genes, encoding 60S subunit proteins, and that suppression occurs with minimal restoration of tRNA levels and reduced GAAC activation. Furthermore, trm8Δ suppression extends to other mutations in the large or small ribosomal subunit. We also find that S. pombe tan1Δ mutants, lacking 4-acetylcytidine, are temperature sensitive due to RTD, that one class of suppressors have rpl mutations, associated with minimal restoration of tRNA levels, and that suppression extends to other rpl and rps mutations. However, although S. pombe tan1Δ temperature sensitivity is associated with some GAAC activation, suppression by an rpl mutation does not significantly inhibit GAAC activation. These results suggest that ribosomal protein mutations suppress the temperature sensitivity of S. pombe trm8Δ and tan1Δ mutants due to reduced ribosome concentrations, leading to both a reduced requirement for tRNA, and reduced ribosome collisions and GAAC activation. Results with S. cerevisiae trm8Δ trm4Δ mutants are consistent with this model, and fuel speculation that similar results will apply across eukaryotes.
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Affiliation(s)
- Thareendra De Zoysa
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine, Rochester, NY, USA 14642
| | - Alayna C. Hauke
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine, Rochester, NY, USA 14642
| | - Nivedita R. Iyer
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine, Rochester, NY, USA 14642
| | - Erin Marcus
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine, Rochester, NY, USA 14642
| | - Sarah M. Ostrowski
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine, Rochester, NY, USA 14642
| | - Justin C. Fay
- Department of Biology, University of Rochester, Rochester, NY, USA 14627
| | - Eric M. Phizicky
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine, Rochester, NY, USA 14642
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Abstract
The study of eukaryotic tRNA processing has given rise to an explosion of new information and insights in the last several years. We now have unprecedented knowledge of each step in the tRNA processing pathway, revealing unexpected twists in biochemical pathways, multiple new connections with regulatory pathways, and numerous biological effects of defects in processing steps that have profound consequences throughout eukaryotes, leading to growth phenotypes in the yeast Saccharomyces cerevisiae and to neurological and other disorders in humans. This review highlights seminal new results within the pathways that comprise the life of a tRNA, from its birth after transcription until its death by decay. We focus on new findings and revelations in each step of the pathway including the end-processing and splicing steps, many of the numerous modifications throughout the main body and anticodon loop of tRNA that are so crucial for tRNA function, the intricate tRNA trafficking pathways, and the quality control decay pathways, as well as the biogenesis and biology of tRNA-derived fragments. We also describe the many interactions of these pathways with signaling and other pathways in the cell.
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Affiliation(s)
- Eric M Phizicky
- Department of Biochemistry and Biophysics and Center for RNA Biology, University of Rochester School of Medicine, Rochester, New York 14642, USA
| | - Anita K Hopper
- Department of Molecular Genetics and Center for RNA Biology, Ohio State University, Columbus, Ohio 43235, USA
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Mao XL, Li ZH, Huang MH, Wang JT, Zhou JB, Li QR, Xu H, Wang XJ, Zhou XL. Mutually exclusive substrate selection strategy by human m3C RNA transferases METTL2A and METTL6. Nucleic Acids Res 2021; 49:8309-8323. [PMID: 34268557 PMCID: PMC8373065 DOI: 10.1093/nar/gkab603] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 06/27/2021] [Accepted: 07/01/2021] [Indexed: 12/28/2022] Open
Abstract
tRNAs harbor the most diverse posttranscriptional modifications. The 3-methylcytidine (m3C) is widely distributed at position C32 (m3C32) of eukaryotic tRNAThr and tRNASer species. m3C32 is decorated by the single methyltransferase Trm140 in budding yeasts; however, two (Trm140 and Trm141 in fission yeasts) or three enzymes (METTL2A, METTL2B and METTL6 in mammals) are involved in its biogenesis. The rationale for the existence of multiple m3C32 methyltransferases and their substrate discrimination mechanism is hitherto unknown. Here, we revealed that both METTL2A and METTL2B are expressed in vivo. We purified human METTL2A, METTL2B, and METTL6 to high homogeneity. We successfully reconstituted m3C32 modification activity for tRNAThr by METT2A and for tRNASer(GCU) by METTL6, assisted by seryl-tRNA synthetase (SerRS) in vitro. Compared with METTL2A, METTL2B exhibited dramatically lower activity in vitro. Both G35 and t6A at position 37 (t6A37) are necessary but insufficient prerequisites for tRNAThr m3C32 formation, while the anticodon loop and the long variable arm, but not t6A37, are key determinants for tRNASer(GCU) m3C32 biogenesis, likely being recognized synergistically by METTL6 and SerRS, respectively. Finally, we proposed a mutually exclusive substrate selection model to ensure correct discrimination among multiple tRNAs by multiple m3C32 methyltransferases.
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Affiliation(s)
- Xue-Ling Mao
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Zi-Han Li
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Meng-Han Huang
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Jin-Tao Wang
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Jing-Bo Zhou
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Qing-Run Li
- CAS Key Laboratory of Systems Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Hong Xu
- Shanghai Key Laboratory of Embryo Original Diseases, the International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, 910 Heng Shan Road, Shanghai 200030, China
| | - Xi-Jin Wang
- Department of Neurology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, 1665 Kong Jiang Road, Shanghai 200092, China
| | - Xiao-Long Zhou
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
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Galvanin A, Vogt LM, Grober A, Freund I, Ayadi L, Bourguignon-Igel V, Bessler L, Jacob D, Eigenbrod T, Marchand V, Dalpke A, Helm M, Motorin Y. Bacterial tRNA 2'-O-methylation is dynamically regulated under stress conditions and modulates innate immune response. Nucleic Acids Res 2020; 48:12833-12844. [PMID: 33275131 PMCID: PMC7736821 DOI: 10.1093/nar/gkaa1123] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 11/03/2020] [Indexed: 12/23/2022] Open
Abstract
RNA modifications are a well-recognized way of gene expression regulation at the post-transcriptional level. Despite the importance of this level of regulation, current knowledge on modulation of tRNA modification status in response to stress conditions is far from being complete. While it is widely accepted that tRNA modifications are rather dynamic, such variations are mostly assessed in terms of total tRNA, with only a few instances where changes could be traced to single isoacceptor species. Using Escherichia coli as a model system, we explored stress-induced modulation of 2'-O-methylations in tRNAs by RiboMethSeq. This analysis and orthogonal analytical measurements by LC-MS show substantial, but not uniform, increase of the Gm18 level in selected tRNAs under mild bacteriostatic antibiotic stress, while other Nm modifications remain relatively constant. The absence of Gm18 modification in tRNAs leads to moderate alterations in E. coli mRNA transcriptome, but does not affect polysomal association of mRNAs. Interestingly, the subset of motility/chemiotaxis genes is significantly overexpressed in ΔTrmH mutant, this corroborates with increased swarming motility of the mutant strain. The stress-induced increase of tRNA Gm18 level, in turn, reduced immunostimulation properties of bacterial tRNAs, which is concordant with the previous observation that Gm18 is a suppressor of Toll-like receptor 7 (TLR7)-mediated interferon release. This documents an effect of stress induced modulation of tRNA modification that acts outside protein translation.
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Affiliation(s)
- Adeline Galvanin
- Université de Lorraine, CNRS, IMoPA (UMR7365), F54000 Nancy, France
| | - Lea-Marie Vogt
- Institute of Pharmaceutical and Biomedical Science, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
| | - Antonia Grober
- Institute of Medical Microbiology and Hygiene, Technische Universität Dresden, 01307 Dresden, Germany
| | - Isabel Freund
- Department of Infectious Diseases, Medical Microbiology and Hygiene, Ruprecht-Karls University Heidelberg, 69117 Heidelberg, Germany
| | - Lilia Ayadi
- Université de Lorraine, CNRS, IMoPA (UMR7365), F54000 Nancy, France
- Université de Lorraine, CNRS, INSERM, IBSLor (UMS2008/US40), Epitranscriptomics and RNA Sequencing Core Facility, F54000 Nancy, France
| | - Valerie Bourguignon-Igel
- Université de Lorraine, CNRS, IMoPA (UMR7365), F54000 Nancy, France
- Université de Lorraine, CNRS, INSERM, IBSLor (UMS2008/US40), Epitranscriptomics and RNA Sequencing Core Facility, F54000 Nancy, France
| | - Larissa Bessler
- Institute of Pharmaceutical and Biomedical Science, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
| | - Dominik Jacob
- Institute of Pharmaceutical and Biomedical Science, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
| | - Tatjana Eigenbrod
- Department of Infectious Diseases, Medical Microbiology and Hygiene, Ruprecht-Karls University Heidelberg, 69117 Heidelberg, Germany
| | - Virginie Marchand
- Université de Lorraine, CNRS, INSERM, IBSLor (UMS2008/US40), Epitranscriptomics and RNA Sequencing Core Facility, F54000 Nancy, France
| | - Alexander Dalpke
- Institute of Medical Microbiology and Hygiene, Technische Universität Dresden, 01307 Dresden, Germany
| | - Mark Helm
- Institute of Pharmaceutical and Biomedical Science, Johannes Gutenberg-University Mainz, 55128 Mainz, Germany
| | - Yuri Motorin
- Université de Lorraine, CNRS, IMoPA (UMR7365), F54000 Nancy, France
- Université de Lorraine, CNRS, INSERM, IBSLor (UMS2008/US40), Epitranscriptomics and RNA Sequencing Core Facility, F54000 Nancy, France
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De Zoysa T, Phizicky EM. Hypomodified tRNA in evolutionarily distant yeasts can trigger rapid tRNA decay to activate the general amino acid control response, but with different consequences. PLoS Genet 2020; 16:e1008893. [PMID: 32841241 PMCID: PMC7473580 DOI: 10.1371/journal.pgen.1008893] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 09/04/2020] [Accepted: 07/22/2020] [Indexed: 12/14/2022] Open
Abstract
All tRNAs are extensively modified, and modification deficiency often results in growth defects in the budding yeast Saccharomyces cerevisiae and neurological or other disorders in humans. In S. cerevisiae, lack of any of several tRNA body modifications results in rapid tRNA decay (RTD) of certain mature tRNAs by the 5'-3' exonucleases Rat1 and Xrn1. As tRNA quality control decay mechanisms are not extensively studied in other eukaryotes, we studied trm8Δ mutants in the evolutionarily distant fission yeast Schizosaccharomyces pombe, which lack 7-methylguanosine at G46 (m7G46) of their tRNAs. We report here that S. pombe trm8Δ mutants are temperature sensitive primarily due to decay of tRNATyr(GUA) and that spontaneous mutations in the RAT1 ortholog dhp1+ restored temperature resistance and prevented tRNA decay, demonstrating conservation of the RTD pathway. We also report for the first time evidence linking the RTD and the general amino acid control (GAAC) pathways, which we show in both S. pombe and S. cerevisiae. In S. pombe trm8Δ mutants, spontaneous GAAC mutations restored temperature resistance and tRNA levels, and the trm8Δ temperature sensitivity was precisely linked to GAAC activation due to tRNATyr(GUA) decay. Similarly, in the well-studied S. cerevisiae trm8Δ trm4Δ RTD mutant, temperature sensitivity was closely linked to GAAC activation due to tRNAVal(AAC) decay; however, in S. cerevisiae, GAAC mutations increased tRNA loss and exacerbated temperature sensitivity. A similar exacerbated growth defect occurred upon GAAC mutation in S. cerevisiae trm8Δ and other single modification mutants that triggered RTD. Thus, these results demonstrate a conserved GAAC activation coincident with RTD in S. pombe and S. cerevisiae, but an opposite impact of the GAAC response in the two organisms. We speculate that the RTD pathway and its regulation of the GAAC pathway is widely conserved in eukaryotes, extending to other mutants affecting tRNA body modifications.
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Affiliation(s)
- Thareendra De Zoysa
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine, Rochester, NY, United States of America
| | - Eric M. Phizicky
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine, Rochester, NY, United States of America
- * E-mail:
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10
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Wang X, Ren X, Ning L, Wang P, Xu K. Stability and absorption mechanism of typical plant miRNAs in an in vitro gastrointestinal environment: basis for their cross-kingdom nutritional effects. J Nutr Biochem 2020; 81:108376. [PMID: 32330841 DOI: 10.1016/j.jnutbio.2020.108376] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 02/29/2020] [Accepted: 03/09/2020] [Indexed: 12/15/2022]
Abstract
Plant miRNAs, a group of 19-24 nt noncoding RNAs from plant foods, were recently found to have immunomodulatory and nutritional effects on mammalian and human bodies. However, how the miRNAs survive gastrointestinal (GI) environment and how the stable miRNAs are absorbed, which serve the basis for their biological functions, were not unraveled. Here, we investigated the stabilities of six typical plant miRNAs in simulated gastric and intestinal environments, and the absorption mechanisms by Caco-2 cells. The results showed that the miRNAs can survive the environment with certain concentrations. The mixture of food ingredients enhanced the stabilities of the plant miRNAs in the gastric conditions, while 2'-O-methyl modification protects the miRNAs in intestinal juice. The stabilities of the miRNAs vary significantly in the environment and are related to their secondary structures. The stable plant miRNAs can be absorbed by Caco-2 cells via clathrin- and caveolin-mediated endocytosis. Uptake of the miRNAs was sequence dependent, facilitated by NACh and TLR9, two typical receptors on cell membrane. The results suggest that some of plant miRNAs are stable in the mimic GI environment and can be absorbed by Caco-2 cells, underlying the potential of their cross-kingdom regulation effects.
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Affiliation(s)
- Xingyu Wang
- College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xi'an 710062, Shaanxi, China.
| | - Xiaoyu Ren
- Department of Joint Surgery, Hong Hui Hospital, Xi'an Jiaotong University, Xi'an 710054, Shaanxi, China
| | - Lufang Ning
- College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xi'an 710062, Shaanxi, China
| | - Pengfei Wang
- College of Food science and Engineering, Ocean University of China, Qingdao, 266003, Shandong, China
| | - Ke Xu
- Department of Joint Surgery, Hong Hui Hospital, Xi'an Jiaotong University, Xi'an 710054, Shaanxi, China.
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11
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Barraud P, Tisné C. To be or not to be modified: Miscellaneous aspects influencing nucleotide modifications in tRNAs. IUBMB Life 2019; 71:1126-1140. [PMID: 30932315 PMCID: PMC6850298 DOI: 10.1002/iub.2041] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 03/10/2019] [Indexed: 12/12/2022]
Abstract
Transfer RNAs (tRNAs) are essential components of the cellular protein synthesis machineries, but are also implicated in many roles outside translation. To become functional, tRNAs, initially transcribed as longer precursor tRNAs, undergo a tightly controlled biogenesis process comprising the maturation of their extremities, removal of intronic sequences if present, addition of the 3'-CCA amino-acid accepting sequence, and aminoacylation. In addition, the most impressive feature of tRNA biogenesis consists in the incorporation of a large number of posttranscriptional chemical modifications along its sequence. The chemical nature of these modifications is highly diverse, with more than hundred different modifications identified in tRNAs to date. All functions of tRNAs in cells are controlled and modulated by modifications, making the understanding of the mechanisms that determine and influence nucleotide modifications in tRNAs an essential point in tRNA biology. This review describes the different aspects that determine whether a certain position in a tRNA molecule is modified or not. We describe how sequence and structural determinants, as well as the presence of prior modifications control modification processes. We also describe how environmental factors and cellular stresses influence the level and/or the nature of certain modifications introduced in tRNAs, and report situations where these dynamic modulations of tRNA modification levels are regulated by active demodification processes. © 2019 IUBMB Life, 71(8):1126-1140, 2019.
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Affiliation(s)
- Pierre Barraud
- Expression génétique microbienneInstitut de biologie physico‐chimique (IBPC), UMR 8261, CNRS, Université Paris DiderotParisFrance
| | - Carine Tisné
- Expression génétique microbienneInstitut de biologie physico‐chimique (IBPC), UMR 8261, CNRS, Université Paris DiderotParisFrance
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12
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Levi O, Arava Y. mRNA association by aminoacyl tRNA synthetase occurs at a putative anticodon mimic and autoregulates translation in response to tRNA levels. PLoS Biol 2019; 17:e3000274. [PMID: 31100060 PMCID: PMC6542539 DOI: 10.1371/journal.pbio.3000274] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 05/30/2019] [Accepted: 05/02/2019] [Indexed: 12/25/2022] Open
Abstract
Aminoacyl-tRNA synthetases (aaRSs) are well studied for their role in binding and charging tRNAs with cognate amino acids. Recent RNA interactome studies had suggested that these enzymes can also bind polyadenylated RNAs. Here, we explored the mRNA repertoire bound by several yeast aaRSs. RNA immunoprecipitation (RIP) followed by deep sequencing revealed unique sets of mRNAs bound by each aaRS. Interestingly, for every tested aaRSs, a preferential association with its own mRNA was observed, suggesting an autoregulatory process. Self-association of histidyl-tRNA synthetase (HisRS) was found to be mediated primarily through binding to a region predicted to fold into a tRNAHis anticodon-like structure. Introducing point mutations that are expected to disassemble this putative anticodon mimic alleviated self-association, concomitant with increased synthesis of the protein. Finally, we found that increased cellular levels of uncharged tRNAHis lead to reduced self-association and increased HisRS translation, in a manner that depends on the anticodon-like element. Together, these results reveal a novel post-transcriptional autoregulatory mechanism that exploits binding mimicry to control mRNA translation according to tRNA demands. Better known for their enzymatic role in charging tRNAs with their cognate amino acids, this study shows that tRNA synthetases also bind mRNAs, regulating translation in order to balance the production of a tRNA synthetase with the level of its cognate tRNA.
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Affiliation(s)
- Ofri Levi
- Faculty of Biology, Technion, Israel Institute of Technology, Haifa, Israel
| | - Yoav Arava
- Faculty of Biology, Technion, Israel Institute of Technology, Haifa, Israel
- * E-mail:
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13
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Preston MA, Porter DF, Chen F, Buter N, Lapointe CP, Keles S, Kimble J, Wickens M. Unbiased screen of RNA tailing activities reveals a poly(UG) polymerase. Nat Methods 2019; 16:437-445. [PMID: 30988468 PMCID: PMC6613791 DOI: 10.1038/s41592-019-0370-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 02/24/2019] [Accepted: 03/05/2019] [Indexed: 12/22/2022]
Abstract
Ribonucleotidyl transferases (rNTases) add untemplated ribonucleotides to diverse RNAs. We have developed TRAID-seq, a screening strategy in Saccharomyces cerevisiae to identify sequences added to a reporter RNA at single-nucleotide resolution by overexpressed candidate enzymes from different organisms. The rNTase activities of 22 previously unexplored enzymes were determined. In addition to poly(A)- and poly(U)-adding enzymes, we identified a cytidine-adding enzyme that is likely to be part of a two-enzyme system that adds CCA to tRNAs in a eukaryote; a nucleotidyl transferase that adds nucleotides to RNA without apparent nucleotide preference; and a poly(UG) polymerase, Caenorhabditis elegans MUT-2, that adds alternating uridine and guanosine nucleotides to form poly(UG) tails. MUT-2 is known to be required for certain forms of RNA silencing, and mutants of the enzyme that result in defective silencing did not add poly(UG) tails in our assay. We propose that MUT-2 poly(UG) polymerase activity is required to promote genome integrity and RNA silencing.
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Affiliation(s)
- Melanie A Preston
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
- Promega Corporation, Madison, WI, USA
| | - Douglas F Porter
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
- Program in Epithelial Biology, Stanford University Medical School, Stanford, CA, USA
| | - Fan Chen
- Department of Statistics, University of Wisconsin-Madison, Madison, WI, USA
| | - Natascha Buter
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
- Promega Corporation, Madison, WI, USA
| | - Christopher P Lapointe
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
- Department of Structural Biology, Stanford University, Stanford, CA, USA
| | - Sunduz Keles
- Department of Statistics, University of Wisconsin-Madison, Madison, WI, USA
- Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison, Madison, WI, USA
| | - Judith Kimble
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
- Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, WI, USA
| | - Marvin Wickens
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA.
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14
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The Role of 3' to 5' Reverse RNA Polymerization in tRNA Fidelity and Repair. Genes (Basel) 2019; 10:genes10030250. [PMID: 30917604 PMCID: PMC6471195 DOI: 10.3390/genes10030250] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 03/20/2019] [Accepted: 03/21/2019] [Indexed: 12/16/2022] Open
Abstract
The tRNAHis guanylyltransferase (Thg1) superfamily includes enzymes that are found in all three domains of life that all share the common ability to catalyze the 3′ to 5′ synthesis of nucleic acids. This catalytic activity, which is the reverse of all other known DNA and RNA polymerases, makes this enzyme family a subject of biological and mechanistic interest. Previous biochemical, structural, and genetic investigations of multiple members of this family have revealed that Thg1 enzymes use the 3′ to 5′ chemistry for multiple reactions in biology. Here, we describe the current state of knowledge regarding the catalytic features and biological functions that have been so far associated with Thg1 and its homologs. Progress toward the exciting possibility of utilizing this unusual protein activity for applications in biotechnology is also discussed.
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15
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Hori H. Regulatory Factors for tRNA Modifications in Extreme- Thermophilic Bacterium Thermus thermophilus. Front Genet 2019; 10:204. [PMID: 30906314 PMCID: PMC6418473 DOI: 10.3389/fgene.2019.00204] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Accepted: 02/26/2019] [Indexed: 01/02/2023] Open
Abstract
Thermus thermophilus is an extreme-thermophilic bacterium that can grow at a wide range of temperatures (50-83°C). To enable T. thermophilus to grow at high temperatures, several biomolecules including tRNA and tRNA modification enzymes show extreme heat-resistance. Therefore, the modified nucleosides in tRNA from T. thermophilus have been studied mainly from the view point of tRNA stabilization at high temperatures. Such studies have shown that several modifications stabilize the structure of tRNA and are essential for survival of the organism at high temperatures. Together with tRNA modification enzymes, the modified nucleosides form a network that regulates the extent of different tRNA modifications at various temperatures. In this review, I describe this network, as well as the tRNA recognition mechanism of individual tRNA modification enzymes. Furthermore, I summarize the roles of other tRNA stabilization factors such as polyamines and metal ions.
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Affiliation(s)
- Hiroyuki Hori
- Department of Materials Sciences and Biotechnology, Graduate School of Science and Engineering, Ehime University, Matsuyama, Japan
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16
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Lant JT, Berg MD, Heinemann IU, Brandl CJ, O'Donoghue P. Pathways to disease from natural variations in human cytoplasmic tRNAs. J Biol Chem 2019; 294:5294-5308. [PMID: 30643023 DOI: 10.1074/jbc.rev118.002982] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Perfectly accurate translation of mRNA into protein is not a prerequisite for life. Resulting from errors in protein synthesis, mistranslation occurs in all cells, including human cells. The human genome encodes >600 tRNA genes, providing both the raw material for genetic variation and a buffer to ensure that resulting translation errors occur at tolerable levels. On the basis of data from the 1000 Genomes Project, we highlight the unanticipated prevalence of mistranslating tRNA variants in the human population and review studies on synthetic and natural tRNA mutations that cause mistranslation or de-regulate protein synthesis. Although mitochondrial tRNA variants are well known to drive human diseases, including developmental disorders, few studies have revealed a role for human cytoplasmic tRNA mutants in disease. In the context of the unexpectedly large number of tRNA variants in the human population, the emerging literature suggests that human diseases may be affected by natural tRNA variants that cause mistranslation or de-regulate tRNA expression and nucleotide modification. This review highlights examples relevant to genetic disorders, cancer, and neurodegeneration in which cytoplasmic tRNA variants directly cause or exacerbate disease and disease-linked phenotypes in cells, animal models, and humans. In the near future, tRNAs may be recognized as useful genetic markers to predict the onset or severity of human disease.
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Affiliation(s)
| | | | | | | | - Patrick O'Donoghue
- From the Departments of Biochemistry and .,Chemistry, The University of Western Ontario, London, Ontario N6A 5C1, Canada
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17
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The emerging impact of tRNA modifications in the brain and nervous system. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2018; 1862:412-428. [PMID: 30529455 DOI: 10.1016/j.bbagrm.2018.11.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 11/21/2018] [Accepted: 11/23/2018] [Indexed: 01/19/2023]
Abstract
A remarkable number of neurodevelopmental disorders have been linked to defects in tRNA modifications. These discoveries place tRNA modifications in the spotlight as critical modulators of gene expression pathways that are required for proper organismal growth and development. Here, we discuss the emerging molecular and cellular functions of the diverse tRNA modifications linked to cognitive and neurological disorders. In particular, we describe how the structure and location of a tRNA modification influences tRNA folding, stability, and function. We then highlight how modifications in tRNA can impact multiple aspects of protein translation that are instrumental for maintaining proper cellular proteostasis. Importantly, we describe how perturbations in tRNA modification lead to a spectrum of deleterious biological outcomes that can disturb neurodevelopment and neurological function. Finally, we summarize the biological themes shared by the different tRNA modifications linked to cognitive disorders and offer insight into the future questions that remain to decipher the role of tRNA modifications. This article is part of a Special Issue entitled: mRNA modifications in gene expression control edited by Dr. Soller Matthias and Dr. Fray Rupert.
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18
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Hori H, Kawamura T, Awai T, Ochi A, Yamagami R, Tomikawa C, Hirata A. Transfer RNA Modification Enzymes from Thermophiles and Their Modified Nucleosides in tRNA. Microorganisms 2018; 6:E110. [PMID: 30347855 PMCID: PMC6313347 DOI: 10.3390/microorganisms6040110] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 10/17/2018] [Accepted: 10/17/2018] [Indexed: 12/11/2022] Open
Abstract
To date, numerous modified nucleosides in tRNA as well as tRNA modification enzymes have been identified not only in thermophiles but also in mesophiles. Because most modified nucleosides in tRNA from thermophiles are common to those in tRNA from mesophiles, they are considered to work essentially in steps of protein synthesis at high temperatures. At high temperatures, the structure of unmodified tRNA will be disrupted. Therefore, thermophiles must possess strategies to stabilize tRNA structures. To this end, several thermophile-specific modified nucleosides in tRNA have been identified. Other factors such as RNA-binding proteins and polyamines contribute to the stability of tRNA at high temperatures. Thermus thermophilus, which is an extreme-thermophilic eubacterium, can adapt its protein synthesis system in response to temperature changes via the network of modified nucleosides in tRNA and tRNA modification enzymes. Notably, tRNA modification enzymes from thermophiles are very stable. Therefore, they have been utilized for biochemical and structural studies. In the future, thermostable tRNA modification enzymes may be useful as biotechnology tools and may be utilized for medical science.
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Affiliation(s)
- Hiroyuki Hori
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Bunkyo 3, Matsuyama, Ehime 790-8577, Japan.
| | - Takuya Kawamura
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Bunkyo 3, Matsuyama, Ehime 790-8577, Japan.
| | - Takako Awai
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Bunkyo 3, Matsuyama, Ehime 790-8577, Japan.
| | - Anna Ochi
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Bunkyo 3, Matsuyama, Ehime 790-8577, Japan.
| | - Ryota Yamagami
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Bunkyo 3, Matsuyama, Ehime 790-8577, Japan.
| | - Chie Tomikawa
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Bunkyo 3, Matsuyama, Ehime 790-8577, Japan.
| | - Akira Hirata
- Department of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Bunkyo 3, Matsuyama, Ehime 790-8577, Japan.
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19
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Han L, Guy MP, Kon Y, Phizicky EM. Lack of 2'-O-methylation in the tRNA anticodon loop of two phylogenetically distant yeast species activates the general amino acid control pathway. PLoS Genet 2018; 14:e1007288. [PMID: 29596413 PMCID: PMC5892943 DOI: 10.1371/journal.pgen.1007288] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 04/10/2018] [Accepted: 03/05/2018] [Indexed: 01/03/2023] Open
Abstract
Modification defects in the tRNA anticodon loop often impair yeast growth and cause human disease. In the budding yeast Saccharomyces cerevisiae and the phylogenetically distant fission yeast Schizosaccharomyces pombe, trm7Δ mutants grow poorly due to lack of 2'-O-methylation of C32 and G34 in the tRNAPhe anticodon loop, and lesions in the human TRM7 homolog FTSJ1 cause non-syndromic X-linked intellectual disability (NSXLID). However, it is unclear why trm7Δ mutants grow poorly. We show here that despite the fact that S. cerevisiae trm7Δ mutants had no detectable tRNAPhe charging defect in rich media, the cells constitutively activated a robust general amino acid control (GAAC) response, acting through Gcn2, which senses uncharged tRNA. Consistent with reduced available charged tRNAPhe, the trm7Δ growth defect was suppressed by spontaneous mutations in phenylalanyl-tRNA synthetase (PheRS) or in the pol III negative regulator MAF1, and by overexpression of tRNAPhe, PheRS, or EF-1A; all of these also reduced GAAC activation. Genetic analysis also demonstrated that the trm7Δ growth defect was due to the constitutive robust GAAC activation as well as to the reduced available charged tRNAPhe. Robust GAAC activation was not observed with several other anticodon loop modification mutants. Analysis of S. pombe trm7 mutants led to similar observations. S. pombe Trm7 depletion also resulted in no observable tRNAPhe charging defect and a robust GAAC response, and suppressors mapped to PheRS and reduced GAAC activation. We speculate that GAAC activation is widely conserved in trm7 mutants in eukaryotes, including metazoans, and might play a role in FTSJ1-mediated NSXLID. The ubiquitous tRNA anticodon loop modifications have important but poorly understood functions in decoding mRNAs in the ribosome to ensure accurate and efficient protein synthesis, and their lack often impairs yeast growth and causes human disease. Here we investigate why ribose methylation of residues 32 and 34 in the anticodon loop is important. Mutations in the corresponding methyltransferase Trm7/FTSJ1 cause poor growth in the budding yeast Saccharomyces cerevisiae and near lethality in the evolutionarily distant fission yeast Schizosaccharomyces pombe, each due to reduced functional tRNAPhe. We previously showed that tRNAPhe anticodon loop modification in yeast and humans required two evolutionarily conserved Trm7 interacting proteins for Cm32 and Gm34 modification, which then stimulated G37 modification. We show here that both S. cerevisiae and S. pombe trm7Δ mutants have apparently normal tRNAPhe charging, but constitutively activate a robust general amino acid control (GAAC) response, acting through Gcn2, which senses uncharged tRNA. We also show that S. cerevisiae trm7Δ mutants grow poorly due in part to constitutive GAAC activation as well as to the uncharged tRNAPhe. We propose that TRM7 is important to prevent constitutive GAAC activation throughout eukaryotes, including metazoans, which may explain non-syndromic X-linked intellectual disability associated with human FTSJ1 mutations.
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Affiliation(s)
- Lu Han
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine, Rochester, NY, United States of America
| | - Michael P. Guy
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine, Rochester, NY, United States of America
- Department of Chemistry and Biochemistry, Northern Kentucky University, Highland Heights, KY, United States of America
| | - Yoshiko Kon
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine, Rochester, NY, United States of America
| | - Eric M. Phizicky
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine, Rochester, NY, United States of America
- * E-mail:
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20
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Schaefer M, Kapoor U, Jantsch MF. Understanding RNA modifications: the promises and technological bottlenecks of the 'epitranscriptome'. Open Biol 2018; 7:rsob.170077. [PMID: 28566301 PMCID: PMC5451548 DOI: 10.1098/rsob.170077] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 05/02/2017] [Indexed: 01/08/2023] Open
Abstract
The discovery of mechanisms that alter genetic information via RNA editing or introducing covalent RNA modifications points towards a complexity in gene expression that challenges long-standing concepts. Understanding the biology of RNA modifications represents one of the next frontiers in molecular biology. To this date, over 130 different RNA modifications have been identified, and improved mass spectrometry approaches are still adding to this list. However, only recently has it been possible to map selected RNA modifications at single-nucleotide resolution, which has created a number of exciting hypotheses about the biological function of RNA modifications, culminating in the proposition of the ‘epitranscriptome’. Here, we review some of the technological advances in this rapidly developing field, identify the conceptual challenges and discuss approaches that are needed to rigorously test the biological function of specific RNA modifications.
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Affiliation(s)
- Matthias Schaefer
- Center for Anatomy and Cell Biology, Medical University Vienna, Schwarzspanierstrasse 17-I, 1090 Vienna, Austria
| | - Utkarsh Kapoor
- Center for Anatomy and Cell Biology, Medical University Vienna, Schwarzspanierstrasse 17-I, 1090 Vienna, Austria
| | - Michael F Jantsch
- Center for Anatomy and Cell Biology, Medical University Vienna, Schwarzspanierstrasse 17-I, 1090 Vienna, Austria
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21
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22
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Lorenz C, Lünse CE, Mörl M. tRNA Modifications: Impact on Structure and Thermal Adaptation. Biomolecules 2017; 7:E35. [PMID: 28375166 PMCID: PMC5485724 DOI: 10.3390/biom7020035] [Citation(s) in RCA: 216] [Impact Index Per Article: 30.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Revised: 03/27/2017] [Accepted: 03/28/2017] [Indexed: 12/27/2022] Open
Abstract
Transfer RNAs (tRNAs) are central players in translation, functioning as adapter molecules between the informational level of nucleic acids and the functional level of proteins. They show a highly conserved secondary and tertiary structure and the highest density of post-transcriptional modifications among all RNAs. These modifications concentrate in two hotspots-the anticodon loop and the tRNA core region, where the D- and T-loop interact with each other, stabilizing the overall structure of the molecule. These modifications can cause large rearrangements as well as local fine-tuning in the 3D structure of a tRNA. The highly conserved tRNA shape is crucial for the interaction with a variety of proteins and other RNA molecules, but also needs a certain flexibility for a correct interplay. In this context, it was shown that tRNA modifications are important for temperature adaptation in thermophilic as well as psychrophilic organisms, as they modulate rigidity and flexibility of the transcripts, respectively. Here, we give an overview on the impact of modifications on tRNA structure and their importance in thermal adaptation.
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Affiliation(s)
- Christian Lorenz
- Institute of Biochemistry, Leipzig University, Brüderstraße 34, 04103 Leipzig, Germany.
| | - Christina E Lünse
- Institute of Biochemistry, Leipzig University, Brüderstraße 34, 04103 Leipzig, Germany.
| | - Mario Mörl
- Institute of Biochemistry, Leipzig University, Brüderstraße 34, 04103 Leipzig, Germany.
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23
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Abstract
Protein translation is one of the most energetically demanding processes for a cell to undertake. Changes in the nutrient environment may result in conditions that cannot support the rates of translation required for cell proliferation. As such, a cell must monitor its metabolic state to determine which mRNAs to translate into protein. How the various RNA species that participate in translation might relay information about metabolic state to regulate this process is not well understood. In this review, we discuss emerging examples of the influence of metabolism on aspects of RNA biology. We discuss how metabolic state impacts the localization and fate of different RNA species, as well as how nutrient cues can impact post-transcriptional modifications of RNA to regulate their functions in the control of translation.
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Affiliation(s)
- Chien-Der Lee
- a Department of Biochemistry , University of Texas Southwestern Medical Center , Dallas , TX , USA
| | - Benjamin P Tu
- a Department of Biochemistry , University of Texas Southwestern Medical Center , Dallas , TX , USA
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24
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Shigematsu M, Kirino Y. 5'-Terminal nucleotide variations in human cytoplasmic tRNAHisGUG and its 5'-halves. RNA (NEW YORK, N.Y.) 2017; 23:161-168. [PMID: 27879434 PMCID: PMC5238791 DOI: 10.1261/rna.058024.116] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 11/18/2016] [Indexed: 06/06/2023]
Abstract
Transfer RNAs (tRNAs) are fundamental adapter components of translational machinery. tRNAs can further serve as a source of tRNA-derived noncoding RNAs that play important roles in various biological processes beyond translation. Among all species of tRNAs, tRNAHisGUG has been known to uniquely contain an additional guanosine residue at the -1 position (G-1) of its 5'-end. To analyze this -1 nucleotide in detail, we developed a TaqMan qRT-PCR method that can distinctively quantify human mature cytoplasmic tRNAHisGUG containing G-1, U-1, A-1, or C-1 or lacking the -1 nucleotide (starting from G1). Application of this method to the mature tRNA fraction of BT-474 breast cancer cells revealed the presence of tRNAHisGUG containing U-1 as well as the one containing G-1 Moreover, tRNA lacking the -1 nucleotide was also detected, thus indicating the heterogeneous expression of 5'-tRNAHisGUG variants. A sequence library of sex hormone-induced 5'-tRNA halves (5'-SHOT-RNAs), identified via cP-RNA-seq of a BT-474 small RNA fraction, also demonstrated the expression of 5'-tRNAHisGUG halves containing G-1, U-1, or G1 as 5'-terminal nucleotides. Although the detected 5'-nucleotide species were identical, the relative abundances differed widely between mature tRNA and 5'-half from the same BT-474 cells. The majority of mature tRNAs contained the -1 nucleotide, whereas the majority of 5'-halves lacked this nucleotide, which was biochemically confirmed using a primer extension assay. These results reveal the novel identities of tRNAHisGUG molecules and provide insights into tRNAHisGUG maturation and the regulation of tRNA half production.
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Affiliation(s)
- Megumi Shigematsu
- Computational Medicine Center, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
| | - Yohei Kirino
- Computational Medicine Center, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
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25
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Burgess A, David R, Searle IR. Deciphering the epitranscriptome: A green perspective. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2016; 58:822-835. [PMID: 27172004 PMCID: PMC5094531 DOI: 10.1111/jipb.12483] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 05/10/2016] [Indexed: 05/13/2023]
Abstract
The advent of high-throughput sequencing technologies coupled with new detection methods of RNA modifications has enabled investigation of a new layer of gene regulation - the epitranscriptome. With over 100 known RNA modifications, understanding the repertoire of RNA modifications is a huge undertaking. This review summarizes what is known about RNA modifications with an emphasis on discoveries in plants. RNA ribose modifications, base methylations and pseudouridylation are required for normal development in Arabidopsis, as mutations in the enzymes modifying them have diverse effects on plant development and stress responses. These modifications can regulate RNA structure, turnover and translation. Transfer RNA and ribosomal RNA modifications have been mapped extensively and their functions investigated in many organisms, including plants. Recent work exploring the locations, functions and targeting of N6 -methyladenosine (m6 A), 5-methylcytosine (m5 C), pseudouridine (Ψ), and additional modifications in mRNAs and ncRNAs are highlighted, as well as those previously known on tRNAs and rRNAs. Many questions remain as to the exact mechanisms of targeting and functions of specific modified sites and whether these modifications have distinct functions in the different classes of RNAs.
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Affiliation(s)
- Alice Burgess
- School of Biological Sciences, The University of Adelaide, South Australia,, 5005, Australia
- School of Agriculture, Food and Wine, The Waite Research Institute, The University of Adelaide, South Australia,, 5005, Australia
| | - Rakesh David
- School of Biological Sciences, The University of Adelaide, South Australia,, 5005, Australia
- School of Agriculture, Food and Wine, The Waite Research Institute, The University of Adelaide, South Australia,, 5005, Australia
| | - Iain Robert Searle
- School of Biological Sciences, The University of Adelaide, South Australia,, 5005, Australia.
- School of Agriculture, Food and Wine, The Waite Research Institute, The University of Adelaide, South Australia,, 5005, Australia.
- The University of Adelaide and Shanghai Jiao Tong University Joint International Centre for Agriculture and Health, Joint International Research Laboratory of Metabolic & Developmental Sciences, Adelaide, Australia.
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26
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Duechler M, Leszczyńska G, Sochacka E, Nawrot B. Nucleoside modifications in the regulation of gene expression: focus on tRNA. Cell Mol Life Sci 2016; 73:3075-95. [PMID: 27094388 PMCID: PMC4951516 DOI: 10.1007/s00018-016-2217-y] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 03/25/2016] [Accepted: 04/04/2016] [Indexed: 01/10/2023]
Abstract
Both, DNA and RNA nucleoside modifications contribute to the complex multi-level regulation of gene expression. Modified bases in tRNAs modulate protein translation rates in a highly dynamic manner. Synonymous codons, which differ by the third nucleoside in the triplet but code for the same amino acid, may be utilized at different rates according to codon-anticodon affinity. Nucleoside modifications in the tRNA anticodon loop can favor the interaction with selected codons by stabilizing specific base pairs. Similarly, weakening of base pairing can discriminate against binding to near-cognate codons. mRNAs enriched in favored codons are translated in higher rates constituting a fine-tuning mechanism for protein synthesis. This so-called codon bias establishes a basic protein level, but sometimes it is necessary to further adjust the production rate of a particular protein to actual requirements, brought by, e.g., stages in circadian rhythms, cell cycle progression or exposure to stress. Such an adjustment is realized by the dynamic change of tRNA modifications resulting in the preferential translation of mRNAs coding for example for stress proteins to facilitate cell survival. Furthermore, tRNAs contribute in an entirely different way to another, less specific stress response consisting in modification-dependent tRNA cleavage that contributes to the general down-regulation of protein synthesis. In this review, we summarize control functions of nucleoside modifications in gene regulation with a focus on recent findings on protein synthesis control by tRNA base modifications.
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Affiliation(s)
- Markus Duechler
- Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-363, Lodz, Poland.
| | - Grażyna Leszczyńska
- Institute of Organic Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924, Lodz, Poland
| | - Elzbieta Sochacka
- Institute of Organic Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924, Lodz, Poland
| | - Barbara Nawrot
- Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-363, Lodz, Poland
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27
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Huang HY, Hopper AK. Multiple Layers of Stress-Induced Regulation in tRNA Biology. Life (Basel) 2016; 6:life6020016. [PMID: 27023616 PMCID: PMC4931453 DOI: 10.3390/life6020016] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 03/14/2016] [Accepted: 03/17/2016] [Indexed: 01/28/2023] Open
Abstract
tRNAs are the fundamental components of the translation machinery as they deliver amino acids to the ribosomes during protein synthesis. Beyond their essential function in translation, tRNAs also function in regulating gene expression, modulating apoptosis and several other biological processes. There are multiple layers of regulatory mechanisms in each step of tRNA biogenesis. For example, tRNA 3′ trailer processing is altered upon nutrient stress; tRNA modification is reprogrammed under various stresses; nuclear accumulation of tRNAs occurs upon nutrient deprivation; tRNA halves accumulate upon oxidative stress. Here we address how environmental stresses can affect nearly every step of tRNA biology and we describe the possible regulatory mechanisms that influence the function or expression of tRNAs under stress conditions.
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Affiliation(s)
- Hsiao-Yun Huang
- Department of Biology, Indiana University, 915 E third St., Myers 300, Bloomington, IN 47405, USA.
| | - Anita K Hopper
- Department of Molecular Genetics and Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA.
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28
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Foretek D, Wu J, Hopper AK, Boguta M. Control of Saccharomyces cerevisiae pre-tRNA processing by environmental conditions. RNA (NEW YORK, N.Y.) 2016; 22:339-49. [PMID: 26729922 PMCID: PMC4748812 DOI: 10.1261/rna.054973.115] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 11/17/2015] [Indexed: 05/21/2023]
Abstract
tRNA is essential for translation and decoding of the proteome. The yeast proteome responds to stress and tRNA biosynthesis contributes in this response by repression of tRNA transcription and alterations of tRNA modification. Here we report that the stress response also involves processing of pre-tRNA 3' termini. By a combination of Northern analyses and RNA sequencing, we show that upon shift to elevated temperatures and/or to glycerol-containing medium, aberrant pre-tRNAs accumulate in yeast cells. For pre-tRNAUAU(Ile) and pre-tRNAUUU Lys) these aberrant forms are unprocessed at the 5' ends, but they possess extended 3' termini. Sequencing analyses showed that partial 3' processing precedes 5' processing for pre-tRNAUAU(Ile). An aberrant pre-tRNA(Tyr) that accumulates also possesses extended 3' termini, but it is processed at the 5' terminus. Similar forms of these aberrant pre-tRNAs are detected in the rex1Δ strain that is defective in 3' exonucleolytic trimming of pre-tRNAs but are absent in the lhp1Δ mutant lacking 3' end protection. We further show direct correlation between the inhibition of 3' end processing rate and the stringency of growth conditions. Moreover, under stress conditions Rex1 nuclease seems to be limiting for 3' end processing, by decreased availability linked to increased protection by Lhp1. Thus, our data document complex 3' processing that is inhibited by stress in a tRNA-type and condition-specific manner. This stress-responsive tRNA 3' end maturation process presumably contributes to fine-tune the levels of functional tRNA in budding yeast in response to environmental conditions.
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Affiliation(s)
- Dominika Foretek
- Department of Genetics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland
| | - Jingyan Wu
- Department of Molecular Genetics, Center for RNA Biology, Ohio State University, Columbus, Ohio 43210, USA
| | - Anita K Hopper
- Department of Molecular Genetics, Center for RNA Biology, Ohio State University, Columbus, Ohio 43210, USA
| | - Magdalena Boguta
- Department of Genetics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland
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29
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Abstract
tRNA molecules undergo extensive post-transcriptional processing to generate the mature functional tRNA species that are essential for translation in all organisms. These processing steps include the introduction of numerous specific chemical modifications to nucleotide bases and sugars; among these modifications, methylation reactions are by far the most abundant. The tRNA methyltransferases comprise a diverse enzyme superfamily, including members of multiple structural classes that appear to have arisen independently during evolution. Even among closely related family members, examples of unusual substrate specificity and chemistry have been observed. Here we review recent advances in tRNA methyltransferase mechanism and function with a particular emphasis on discoveries of alternative substrate specificities and chemistry associated with some methyltransferases. Although the molecular function for a specific tRNA methylation may not always be clear, mutations in tRNA methyltransferases have been increasingly associated with human disease. The impact of tRNA methylation on human biology is also discussed.
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Affiliation(s)
- William E Swinehart
- a Center for RNA Biology and Department of Chemistry and Biochemistry ; Ohio State University ; Columbus , OH USA
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30
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Thiaville PC, Legendre R, Rojas-Benítez D, Baudin-Baillieu A, Hatin I, Chalancon G, Glavic A, Namy O, de Crécy-Lagard V. Global translational impacts of the loss of the tRNA modification t 6A in yeast. MICROBIAL CELL 2016; 3:29-45. [PMID: 26798630 PMCID: PMC4717488 DOI: 10.15698/mic2016.01.473] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The universal tRNA modification t6A is found at position 37 of nearly
all tRNAs decoding ANN codons. The absence of t6A37 leads
to severe growth defects in baker’s yeast, phenotypes similar to those caused by
defects in mcm5s2U34 synthesis. Mutants in
mcm5s2U34 can be suppressed by
overexpression of tRNALysUUU, but we show t6A
phenotypes could not be suppressed by expressing any individual ANN decoding
tRNA, and t6A and mcm5s2U are not determinants
for each other’s formation. Our results suggest that t6A deficiency,
like mcm5s2U deficiency, leads to protein folding defects,
and show that the absence of t6A led to stress sensitivities (heat,
ethanol, salt) and sensitivity to TOR pathway inhibitors. Additionally,
L-homoserine suppressed the slow growth phenotype seen in
t6A-deficient strains, and proteins aggregates and Advanced Glycation
End-products (AGEs) were increased in the mutants. The global consequences on
translation caused by t6A absence were examined by ribosome
profiling. Interestingly, the absence of t6A did not lead to global
translation defects, but did increase translation initiation at upstream non-AUG
codons and increased frame-shifting in specific genes. Analysis of codon
occupancy rates suggests that one of the major roles of t6A is to
homogenize the process of elongation by slowing the elongation rate at codons
decoded by high abundance tRNAs and I34:C3 pairs while
increasing the elongation rate of rare tRNAs and G34:U3
pairs. This work reveals that the consequences of t6A absence are
complex and multilayered and has set the stage to elucidate the molecular basis
of the observed phenotypes.
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Affiliation(s)
- Patrick C Thiaville
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA; Genetics and Genomics Graduate Program, University of Florida, Gainesville, FL 32610, USA; University of Florida Genetics Institute, University of Florida, Gainesville, FL 32610, USA; Institut de Biologie Intégrative de la Cellule (I2BC), CEA, CNRS, Université Paris-Sud, Bâtiment 400, 91400 Orsay, France
| | - Rachel Legendre
- Institut de Biologie Intégrative de la Cellule (I2BC), CEA, CNRS, Université Paris-Sud, Bâtiment 400, 91400 Orsay, France
| | - Diego Rojas-Benítez
- Centro de Regulación del Genoma. Facultad de Ciencias - Universidad de Chile, Santiago, Chile
| | - Agnès Baudin-Baillieu
- Institut de Biologie Intégrative de la Cellule (I2BC), CEA, CNRS, Université Paris-Sud, Bâtiment 400, 91400 Orsay, France
| | - Isabelle Hatin
- Institut de Biologie Intégrative de la Cellule (I2BC), CEA, CNRS, Université Paris-Sud, Bâtiment 400, 91400 Orsay, France
| | - Guilhem Chalancon
- Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Alvaro Glavic
- Centro de Regulación del Genoma. Facultad de Ciencias - Universidad de Chile, Santiago, Chile
| | - Olivier Namy
- Institut de Biologie Intégrative de la Cellule (I2BC), CEA, CNRS, Université Paris-Sud, Bâtiment 400, 91400 Orsay, France
| | - Valérie de Crécy-Lagard
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA; University of Florida Genetics Institute, University of Florida, Gainesville, FL 32610, USA
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31
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Müller M, Hartmann M, Schuster I, Bender S, Thüring KL, Helm M, Katze JR, Nellen W, Lyko F, Ehrenhofer-Murray AE. Dynamic modulation of Dnmt2-dependent tRNA methylation by the micronutrient queuine. Nucleic Acids Res 2015; 43:10952-62. [PMID: 26424849 PMCID: PMC4678861 DOI: 10.1093/nar/gkv980] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 09/17/2015] [Indexed: 01/13/2023] Open
Abstract
Dnmt2 enzymes are cytosine-5 methyltransferases that methylate C38 of several tRNAs. We report here that the activities of two Dnmt2 homologs, Pmt1 from Schizosaccharomyces pombe and DnmA from Dictyostelium discoideum, are strongly stimulated by prior queuosine (Q) modification of the substrate tRNA. In vivo tRNA methylation levels were stimulated by growth of cells in queuine-containing medium; in vitro Pmt1 activity was enhanced on Q-containing RNA; and queuine-stimulated in vivo methylation was abrogated by the absence of the enzyme that inserts queuine into tRNA, eukaryotic tRNA-guanine transglycosylase. Global analysis of tRNA methylation in S. pombe showed a striking selectivity of Pmt1 for tRNA(Asp) methylation, which distinguishes Pmt1 from other Dnmt2 homologs. The present analysis also revealed a novel Pmt1- and Q-independent tRNA methylation site in S. pombe, C34 of tRNA(Pro). Notably, queuine is a micronutrient that is scavenged by higher eukaryotes from the diet and gut microflora. This work therefore reveals an unanticipated route by which the environment can modulate tRNA modification in an organism.
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Affiliation(s)
- Martin Müller
- Institut für Biologie, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
| | - Mark Hartmann
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, 69120 Heidelberg, Germany
| | | | - Sebastian Bender
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, 69120 Heidelberg, Germany
| | - Kathrin L Thüring
- Institut für Pharmakologie und Biochemie, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - Mark Helm
- Institut für Pharmakologie und Biochemie, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - Jon R Katze
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Wolfgang Nellen
- Abteilung für Genetik, Universität Kassel, 34132 Kassel, Germany
| | - Frank Lyko
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, 69120 Heidelberg, Germany
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32
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Shaheen R, Abdel-Salam GMH, Guy MP, Alomar R, Abdel-Hamid MS, Afifi HH, Ismail SI, Emam BA, Phizicky EM, Alkuraya FS. Mutation in WDR4 impairs tRNA m(7)G46 methylation and causes a distinct form of microcephalic primordial dwarfism. Genome Biol 2015; 16:210. [PMID: 26416026 PMCID: PMC4587777 DOI: 10.1186/s13059-015-0779-x] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 09/14/2015] [Indexed: 04/13/2023] Open
Abstract
Background Primordial dwarfism is a state of extreme prenatal and postnatal growth deficiency, and is characterized by marked clinical and genetic heterogeneity. Results Two presumably unrelated consanguineous families presented with an apparently novel form of primordial dwarfism in which severe growth deficiency is accompanied by distinct facial dysmorphism, brain malformation (microcephaly, agenesis of corpus callosum, and simplified gyration), and severe encephalopathy with seizures. Combined autozygome/exome analysis revealed a novel missense mutation in WDR4 as the likely causal variant. WDR4 is the human ortholog of the yeast Trm82, an essential component of the Trm8/Trm82 holoenzyme that effects a highly conserved and specific (m7G46) methylation of tRNA. The human mutation and the corresponding yeast mutation result in a significant reduction of m7G46 methylation of specific tRNA species, which provides a potential mechanism for primordial dwarfism associated with this lesion, since reduced m7G46 modification causes a growth deficiency phenotype in yeast. Conclusion Our study expands the number of biological pathways underlying primordial dwarfism and adds to a growing list of human diseases linked to abnormal tRNA modification. Electronic supplementary material The online version of this article (doi:10.1186/s13059-015-0779-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ranad Shaheen
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Ghada M H Abdel-Salam
- Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Michael P Guy
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.,Current address: Department of Chemistry, Northern Kentucky University, Highland Heights, KY, USA
| | - Rana Alomar
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Mohamed S Abdel-Hamid
- Medical Molecular Genetics Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Hanan H Afifi
- Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Samira I Ismail
- Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Bayoumi A Emam
- Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Eric M Phizicky
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia. .,Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia.
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33
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Wilusz JE. Controlling translation via modulation of tRNA levels. WILEY INTERDISCIPLINARY REVIEWS-RNA 2015; 6:453-70. [PMID: 25919480 DOI: 10.1002/wrna.1287] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 03/13/2015] [Accepted: 04/06/2015] [Indexed: 12/22/2022]
Abstract
Transfer RNAs (tRNAs) are critical adaptor molecules that carry amino acids to a messenger RNA (mRNA) template during protein synthesis. Although tRNAs have commonly been viewed as abundant 'house-keeping' RNAs, it is becoming increasingly clear that tRNA expression is tightly regulated. Depending on a cell's proliferative status, the pool of active tRNAs is rapidly changed, enabling distinct translational programs to be expressed in differentiated versus proliferating cells. Here, I highlight several post-transcriptional regulatory mechanisms that allow the expression or functions of tRNAs to be altered. Modulating the modification status or structural stability of individual tRNAs can cause those specific tRNA transcripts to selectively accumulate or be degraded. Decay generally occurs via the rapid tRNA decay pathway or by the nuclear RNA surveillance machinery. In addition, the CCA-adding enzyme plays a critical role in determining the fate of a tRNA. The post-transcriptional addition of CCA to the 3' ends of stable tRNAs generates the amino acid attachment site, whereas addition of CCACCA to unstable tRNAs prevents aminoacylation and marks the tRNA for degradation. In response to various stresses, tRNAs can accumulate in the nucleus or be further cleaved into small RNAs, some of which inhibit translation. By implementing these various post-transcriptional control mechanisms, cells are able to fine-tune tRNA levels to regulate subsets of mRNAs as well as overall translation rates.
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Affiliation(s)
- Jeremy E Wilusz
- Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
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34
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Han L, Kon Y, Phizicky EM. Functional importance of Ψ38 and Ψ39 in distinct tRNAs, amplified for tRNAGln(UUG) by unexpected temperature sensitivity of the s2U modification in yeast. RNA (NEW YORK, N.Y.) 2015; 21:188-201. [PMID: 25505024 PMCID: PMC4338347 DOI: 10.1261/rna.048173.114] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The numerous modifications of tRNA play central roles in controlling tRNA structure and translation. Modifications in and around the anticodon loop often have critical roles in decoding mRNA and in maintaining its reading frame. Residues U38 and U39 in the anticodon stem-loop are frequently modified to pseudouridine (Ψ) by members of the widely conserved TruA/Pus3 family of pseudouridylases. We investigate here the cause of the temperature sensitivity of pus3Δ mutants of the yeast Saccharomyces cerevisiae and find that, although Ψ38 or Ψ39 is found on at least 19 characterized cytoplasmic tRNA species, the temperature sensitivity is primarily due to poor function of tRNA(Gln(UUG)), which normally has Ψ38. Further investigation reveals that at elevated temperatures there are substantially reduced levels of the s(2)U moiety of mcm(5)s(2)U34 of tRNA(Gln(UUG)) and the other two cytoplasmic species with mcm(5)s(2)U34, that the reduced s(2)U levels occur in the parent strain BY4741 and in the widely used strain W303, and that reduced levels of the s(2)U moiety are detectable in BY4741 at temperatures as low as 33°C. Additional examination of the role of Ψ38,39 provides evidence that Ψ38 is important for function of tRNA(Gln(UUG)) at permissive temperature, and indicates that Ψ39 is important for the function of tRNA(Trp(CCA)) in trm10Δ pus3Δ mutants and of tRNA(Leu(CAA)) as a UAG nonsense suppressor. These results provide evidence for important roles of both Ψ38 and Ψ39 in specific tRNAs, and establish that modification of the wobble position is subject to change under relatively mild growth conditions.
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Affiliation(s)
- Lu Han
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine, Rochester, New York 14642, USA
| | - Yoshiko Kon
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine, Rochester, New York 14642, USA
| | - Eric M Phizicky
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine, Rochester, New York 14642, USA
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35
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Guy MP, Phizicky EM. Conservation of an intricate circuit for crucial modifications of the tRNAPhe anticodon loop in eukaryotes. RNA (NEW YORK, N.Y.) 2015; 21:61-74. [PMID: 25404562 PMCID: PMC4274638 DOI: 10.1261/rna.047639.114] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Post-transcriptional tRNA modifications are critical for efficient and accurate translation, and have multiple different roles. Lack of modifications often leads to different biological consequences in different organisms, and in humans is frequently associated with neurological disorders. We investigate here the conservation of a unique circuitry for anticodon loop modification required for healthy growth in the yeast Saccharomyces cerevisiae. S. cerevisiae Trm7 interacts separately with Trm732 and Trm734 to 2'-O-methylate three substrate tRNAs at anticodon loop residues C₃₂ and N₃₄, and these modifications are required for efficient wybutosine formation at m(1)G₃₇ of tRNA(Phe). Moreover, trm7Δ and trm732Δ trm734Δ mutants grow poorly due to lack of functional tRNA(Phe). It is unknown if this circuitry is conserved and important for tRNA(Phe) modification in other eukaryotes, but a likely human TRM7 ortholog is implicated in nonsyndromic X-linked intellectual disability. We find that the distantly related yeast Schizosaccharomyces pombe has retained this circuitry for anticodon loop modification, that S. pombe trm7Δ and trm734Δ mutants have more severe phenotypes than the S. cerevisiae mutants, and that tRNA(Phe) is the major biological target. Furthermore, we provide evidence that Trm7 and Trm732 function is widely conserved throughout eukaryotes, since human FTSJ1 and THADA, respectively, complement growth defects of S. cerevisiae trm7Δ and trm732Δ trm734Δ mutants by modifying C₃₂ of tRNA(Phe), each working with the corresponding S. cerevisiae partner protein. These results suggest widespread importance of 2'-O-methylation of the tRNA anticodon loop, implicate tRNA(Phe) as the crucial substrate, and suggest that this modification circuitry is important for human neuronal development.
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Affiliation(s)
- Michael P Guy
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine, Rochester, New York 14642, USA
| | - Eric M Phizicky
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine, Rochester, New York 14642, USA
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36
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Abstract
Cellular RNAs can be chemically modified over a hundred different ways. These modifications were once thought to be static, discrete, and utilized to fine-tune RNA structure and function. However, recent studies have revealed that some modifications, like mRNA methylation, can be reversed, and these reversible modifications may play active roles in regulating diverse biological processes. In this perspective, we summarize examples of dynamic RNA modifications that affect biological functions. We further propose that reversible modifications might occur on tRNA, rRNA, and other noncoding RNAs to regulate gene expression analogous to the reversible mRNA methylation.
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37
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Damon JR, Pincus D, Ploegh HL. tRNA thiolation links translation to stress responses in Saccharomyces cerevisiae. Mol Biol Cell 2014; 26:270-82. [PMID: 25392298 PMCID: PMC4294674 DOI: 10.1091/mbc.e14-06-1145] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The URM1 pathway functions in a tRNA thiolation reaction that is required for synthesis of the mcm5s2U34 nucleoside found in tRNAs. Growth of Saccharomyces cerevisiae cells at an elevated temperature results in altered levels of modification enzymes, and this leads to decreased levels of tRNA thiolation. tRNA thiolation is tied to cellular stress responses. Although tRNA modifications have been well catalogued, the precise functions of many modifications and their roles in mediating gene expression are still being elucidated. Whereas tRNA modifications were long assumed to be constitutive, it is now apparent that the modification status of tRNAs changes in response to different environmental conditions. The URM1 pathway is required for thiolation of the cytoplasmic tRNAs tGluUUC, tGlnUUG, and tLysUUU in Saccharomyces cerevisiae. We demonstrate that URM1 pathway mutants have impaired translation, which results in increased basal activation of the Hsf1-mediated heat shock response; we also find that tRNA thiolation levels in wild-type cells decrease when cells are grown at elevated temperature. We show that defects in tRNA thiolation can be conditionally advantageous, conferring resistance to endoplasmic reticulum stress. URM1 pathway proteins are unstable and hence are more sensitive to changes in the translational capacity of cells, which is decreased in cells experiencing stresses. We propose a model in which a stress-induced decrease in translation results in decreased levels of URM1 pathway components, which results in decreased tRNA thiolation levels, which further serves to decrease translation. This mechanism ensures that tRNA thiolation and translation are tightly coupled and coregulated according to need.
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Affiliation(s)
- Jadyn R Damon
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142
| | - David Pincus
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142
| | - Hidde L Ploegh
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142
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Hori H. Methylated nucleosides in tRNA and tRNA methyltransferases. Front Genet 2014; 5:144. [PMID: 24904644 PMCID: PMC4033218 DOI: 10.3389/fgene.2014.00144] [Citation(s) in RCA: 141] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 05/04/2014] [Indexed: 12/26/2022] Open
Abstract
To date, more than 90 modified nucleosides have been found in tRNA and the biosynthetic pathways of the majority of tRNA modifications include a methylation step(s). Recent studies of the biosynthetic pathways have demonstrated that the availability of methyl group donors for the methylation in tRNA is important for correct and efficient protein synthesis. In this review, I focus on the methylated nucleosides and tRNA methyltransferases. The primary functions of tRNA methylations are linked to the different steps of protein synthesis, such as the stabilization of tRNA structure, reinforcement of the codon-anticodon interaction, regulation of wobble base pairing, and prevention of frameshift errors. However, beyond these basic functions, recent studies have demonstrated that tRNA methylations are also involved in the RNA quality control system and regulation of tRNA localization in the cell. In a thermophilic eubacterium, tRNA modifications and the modification enzymes form a network that responses to temperature changes. Furthermore, several modifications are involved in genetic diseases, infections, and the immune response. Moreover, structural, biochemical, and bioinformatics studies of tRNA methyltransferases have been clarifying the details of tRNA methyltransferases and have enabled these enzymes to be classified. In the final section, the evolution of modification enzymes is discussed.
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Affiliation(s)
- Hiroyuki Hori
- Department of Materials Science and Biotechnology, Applied Chemistry, Graduate School of Science and Engineering, Ehime University Matsuyama, Japan
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