1
|
Görlitz K, Bessler L, Helm M, Schaffrath R, Klassen R. Fluoropyrimidines trigger decay of hypomodified tRNA in yeast. Nucleic Acids Res 2024; 52:5841-5851. [PMID: 38716877 PMCID: PMC11162795 DOI: 10.1093/nar/gkae341] [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: 01/09/2024] [Revised: 04/10/2024] [Accepted: 04/22/2024] [Indexed: 06/11/2024] Open
Abstract
Therapeutic fluoropyrimidines 5-fluorouracil (5-FU) and 5-fluorocytosine (5-FC) are in long use for treatment of human cancers and severe invasive fungal infections, respectively. 5-Fluorouridine triphosphate represents a bioactive metabolite of both drugs and is incorporated into target cells' RNA. Here we use the model fungus Saccharomyces cerevisiae to define fluorinated tRNA as a key mediator of 5-FU and 5-FC cytotoxicity when specific tRNA methylations are absent. tRNA methylation deficiency caused by loss of Trm4 and Trm8 was previously shown to trigger an RNA quality control mechanism resulting in partial destabilization of hypomodified tRNAValAAC. We demonstrate that, following incorporation into tRNA, fluoropyrimidines strongly enhance degradation of yeast tRNAValAAC lacking Trm4 and Trm8 dependent methylations. At elevated temperature, such effect occurs already in absence of Trm8 alone. Genetic approaches and quantification of tRNA modification levels reveal that enhanced fluoropyrimidine cytotoxicity results from additional, drug induced uridine modification loss and activation of tRNAValAAC decay involving the exonuclease Xrn1. These results suggest that inhibition of tRNA methylation may be exploited to boost therapeutic efficiency of 5-FU and 5-FC.
Collapse
Affiliation(s)
- Katharina Görlitz
- Institute of Biology, Department of Microbiology, Universität Kassel, Kassel 34132, Germany
| | - Larissa Bessler
- Institute of Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-Universität Mainz, Mainz 55128, Germany
| | - Mark Helm
- Institute of Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-Universität Mainz, Mainz 55128, Germany
| | - Raffael Schaffrath
- Institute of Biology, Department of Microbiology, Universität Kassel, Kassel 34132, Germany
| | - Roland Klassen
- Institute of Biology, Department of Microbiology, Universität Kassel, Kassel 34132, Germany
| |
Collapse
|
2
|
Smith TJ, Giles RN, Koutmou KS. Anticodon stem-loop tRNA modifications influence codon decoding and frame maintenance during translation. Semin Cell Dev Biol 2024; 154:105-113. [PMID: 37385829 DOI: 10.1016/j.semcdb.2023.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 06/06/2023] [Accepted: 06/07/2023] [Indexed: 07/01/2023]
Abstract
RNAs are central to protein synthesis, with ribosomal RNA, transfer RNAs and messenger RNAs comprising the core components of the translation machinery. In addition to the four canonical bases (uracil, cytosine, adenine, and guanine) these RNAs contain an array of enzymatically incorporated chemical modifications. Transfer RNAs (tRNAs) are responsible for ferrying amino acids to the ribosome, and are among the most abundant and highly modified RNAs in the cell across all domains of life. On average, tRNA molecules contain 13 post-transcriptionally modified nucleosides that stabilize their structure and enhance function. There is an extensive chemical diversity of tRNA modifications, with over 90 distinct varieties of modifications reported within tRNA sequences. Some modifications are crucial for tRNAs to adopt their L-shaped tertiary structure, while others promote tRNA interactions with components of the protein synthesis machinery. In particular, modifications in the anticodon stem-loop (ASL), located near the site of tRNA:mRNA interaction, can play key roles in ensuring protein homeostasis and accurate translation. There is an abundance of evidence indicating the importance of ASL modifications for cellular health, and in vitro biochemical and biophysical studies suggest that individual ASL modifications can differentially influence discrete steps in the translation pathway. This review examines the molecular level consequences of tRNA ASL modifications in mRNA codon recognition and reading frame maintenance to ensure the rapid and accurate translation of proteins.
Collapse
Affiliation(s)
- Tyler J Smith
- University of Michigan, Department of Chemistry, 930 N University, Ann Arbor, MI 48109, USA
| | - Rachel N Giles
- University of Michigan, Department of Chemistry, 930 N University, Ann Arbor, MI 48109, USA
| | - Kristin S Koutmou
- University of Michigan, Department of Chemistry, 930 N University, Ann Arbor, MI 48109, USA.
| |
Collapse
|
3
|
Pereira M, Ribeiro DR, Berg M, Tsai AP, Dong C, Nho K, Kaiser S, Moutinho M, Soares AR. Amyloid pathology reduces ELP3 expression and tRNA modifications leading to impaired proteostasis. Biochim Biophys Acta Mol Basis Dis 2024; 1870:166857. [PMID: 37640114 DOI: 10.1016/j.bbadis.2023.166857] [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: 05/15/2023] [Revised: 08/09/2023] [Accepted: 08/22/2023] [Indexed: 08/31/2023]
Abstract
Alzheimer's Disease (AD) is a neurodegenerative disorder characterized by accumulation of β-amyloid aggregates and loss of proteostasis. Transfer RNA (tRNA) modifications play a crucial role in maintaining proteostasis, but their impact in AD remains unclear. Here, we report that expression of the tRNA modifying enzyme ELP3 is reduced in the brain of AD patients and amyloid mouse models and negatively correlates with amyloid plaque mean density. We further show that SH-SY5Y neuronal cells carrying the amyloidogenic Swedish familial AD mutation (SH-SWE) display reduced ELP3 levels, tRNA hypomodifications and proteostasis impairments when compared to cells not carrying the mutation (SH-WT). Additionally, exposing SH-WT cells to the secretome of SH-SWE cells led to reduced ELP3 expression, wobble uridine tRNA hypomodification, and increased protein aggregation. Importantly, correcting tRNA deficits due to ELP3 reduction reverted proteostasis impairments. These findings suggest that amyloid pathology dysregulates proteostasis by reducing ELP3 expression and tRNA modification levels, and that targeting tRNA modifications may be a potential therapeutic avenue to restore neuronal proteostasis in AD and preserve neuronal function.
Collapse
Affiliation(s)
- Marisa Pereira
- Institute of Biomedicine (iBiMED), Department of Medical Sciences, University of Aveiro, Aveiro, Portugal
| | - Diana R Ribeiro
- Institute of Biomedicine (iBiMED), Department of Medical Sciences, University of Aveiro, Aveiro, Portugal
| | - Maximilian Berg
- Institute of Pharmaceutical Chemistry, Goethe-University, Frankfurt, 60438, Germany
| | - Andy P Tsai
- Wu Tsai Neurosciences Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Chuanpeng Dong
- Department of Medical and Molecular Genetics, Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Kwangsik Nho
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Stefanie Kaiser
- Institute of Pharmaceutical Chemistry, Goethe-University, Frankfurt, 60438, Germany
| | - Miguel Moutinho
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Ana R Soares
- Institute of Biomedicine (iBiMED), Department of Medical Sciences, University of Aveiro, Aveiro, Portugal.
| |
Collapse
|
4
|
The Human Mercaptopyruvate Sulfurtransferase TUM1 Is Involved in Moco Biosynthesis, Cytosolic tRNA Thiolation and Cellular Bioenergetics in Human Embryonic Kidney Cells. Biomolecules 2023; 13:biom13010144. [PMID: 36671528 PMCID: PMC9856076 DOI: 10.3390/biom13010144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 12/25/2022] [Accepted: 12/28/2022] [Indexed: 01/12/2023] Open
Abstract
Sulfur is an important element that is incorporated into many biomolecules in humans. The incorporation and transfer of sulfur into biomolecules is, however, facilitated by a series of different sulfurtransferases. Among these sulfurtransferases is the human mercaptopyruvate sulfurtransferase (MPST) also designated as tRNA thiouridine modification protein (TUM1). The role of the human TUM1 protein has been suggested in a wide range of physiological processes in the cell among which are but not limited to involvement in Molybdenum cofactor (Moco) biosynthesis, cytosolic tRNA thiolation and generation of H2S as signaling molecule both in mitochondria and the cytosol. Previous interaction studies showed that TUM1 interacts with the L-cysteine desulfurase NFS1 and the Molybdenum cofactor biosynthesis protein 3 (MOCS3). Here, we show the roles of TUM1 in human cells using CRISPR/Cas9 genetically modified Human Embryonic Kidney cells. Here, we show that TUM1 is involved in the sulfur transfer for Molybdenum cofactor synthesis and tRNA thiomodification by spectrophotometric measurement of the activity of sulfite oxidase and liquid chromatography quantification of the level of sulfur-modified tRNA. Further, we show that TUM1 has a role in hydrogen sulfide production and cellular bioenergetics.
Collapse
|
5
|
Liu C, Shi K, Lyu K, Liu D, Wang X. The toxicity of neodymium and genome-scale genetic screen of neodymium-sensitive gene deletion mutations in the yeast Saccharomyces cerevisiae. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:41439-41454. [PMID: 35088271 DOI: 10.1007/s11356-021-18100-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 12/09/2021] [Indexed: 06/14/2023]
Abstract
The wide usage of neodymium (Nd) in industry, agriculture, and medicine has made it become an emerging pollutant in the environment. Increasing Nd pollution has potential hazards to plants, animals, and microorganisms. Thus, it is necessary to study the toxicity of Nd and the mechanism of Nd transportation and detoxification in microorganisms. Through genome-scale screening, we identified 70 yeast monogene deletion mutations sensitive to Nd ions. These genes are mainly involved in metabolism, transcription, protein synthesis, cell cycle, DNA processing, protein folding, modification, and cell transport processes. Furthermore, the regulatory networks of Nd toxicity were identified by using the protein interaction group analysis. These networks are associated with various signal pathways, including calcium ion transport, phosphate pathways, vesicular transport, and cell autophagy. In addition, the content of Nd ions in yeast was detected by an inductively coupled plasma mass spectrometry, and most of these Nd-sensitive mutants showed an increased intracellular Nd content. In all, our results provide the basis for understanding the molecular mechanisms of detoxifying Nd ions in yeast cells, which will be useful for future studies on Nd-related issues in the environment, agriculture, and human health.
Collapse
Affiliation(s)
- Chengkun Liu
- School of Life Sciences, Shandong University of Technology, Zibo, 255049, Shandong, China
| | - Kailun Shi
- School of Life Sciences, Shandong University of Technology, Zibo, 255049, Shandong, China
| | - Keliang Lyu
- School of Life Sciences, Shandong University of Technology, Zibo, 255049, Shandong, China
| | - Dongwu Liu
- School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, 255049, China
| | - Xue Wang
- School of Life Sciences, Shandong University of Technology, Zibo, 255049, Shandong, China
| |
Collapse
|
6
|
Kelley M, Paulines MJ, Yoshida G, Myers R, Jora M, Levoy JP, Addepalli B, Benoit JB, Limbach PA. Ionizing radiation and chemical oxidant exposure impacts on Cryptococcus neoformans transfer RNAs. PLoS One 2022; 17:e0266239. [PMID: 35349591 PMCID: PMC8963569 DOI: 10.1371/journal.pone.0266239] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 03/16/2022] [Indexed: 12/11/2022] Open
Abstract
Cryptococcus neoformans is a fungus that is able to survive abnormally high levels of ionizing radiation (IR). The radiolysis of water by IR generates reactive oxygen species (ROS) such as H2O2 and OH-. C. neoformans withstands the damage caused by IR and ROS through antioxidant production and enzyme-catalyzed breakdown of ROS. Given these particular cellular protein needs, questions arise whether transfer ribonucleic acids molecules (tRNAs) undergo unique chemical modifications to maintain their structure, stability, and/or function under such environmental conditions. Here, we investigated the effects of IR and H2O2 exposure on tRNAs in C. neoformans. We experimentally identified the modified nucleosides present in C. neoformans tRNAs and quantified changes in those modifications upon exposure to oxidative conditions. To better understand these modified nucleoside results, we also evaluated tRNA pool composition in response to the oxidative conditions. We found that regardless of environmental conditions, tRNA modifications and transcripts were minimally affected. A rationale for the stability of the tRNA pool and its concomitant profile of modified nucleosides is proposed based on the lack of codon bias throughout the C. neoformans genome and in particular for oxidative response transcripts. Our findings suggest that C. neoformans can rapidly adapt to oxidative environments as mRNA translation/protein synthesis are minimally impacted by codon bias.
Collapse
Affiliation(s)
- Melissa Kelley
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Mellie June Paulines
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - George Yoshida
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Ryan Myers
- Department of Biological Sciences, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Manasses Jora
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Joel P. Levoy
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio, United States of America
| | | | - Joshua B. Benoit
- Department of Biological Sciences, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Patrick A. Limbach
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio, United States of America
- * E-mail:
| |
Collapse
|
7
|
Li J, Zhu WY, Yang WQ, Li CT, Liu RJ. The occurrence order and cross-talk of different tRNA modifications. SCIENCE CHINA. LIFE SCIENCES 2021; 64:1423-1436. [PMID: 33881742 DOI: 10.1007/s11427-020-1906-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 03/02/2021] [Indexed: 06/12/2023]
Abstract
Chemical modifications expand the composition of RNA molecules from four standard nucleosides to over 160 modified nucleosides, which greatly increase the complexity and utility of RNAs. Transfer RNAs (tRNAs) are the most heavily modified cellular RNA molecules and contain the largest variety of modifications. Modification of tRNAs is pivotal for protein synthesis and also precisely regulates the noncanonical functions of tRNAs. Defects in tRNA modifications lead to numerous human diseases. Up to now, more than 100 types of modifications have been found in tRNAs. Intriguingly, some modifications occur widely on all tRNAs, while others only occur on a subgroup of tRNAs or even only a specific tRNA. The modification frequency of each tRNA is approximately 7% to 25%, with 5-20 modification sites present on each tRNA. The occurrence and modulation of tRNA modifications are specifically noticeable as plenty of interplays among different sites and modifications have been discovered. In particular, tRNA modifications are responsive to environmental changes, indicating their dynamic and highly organized nature. In this review, we summarized the known occurrence order, cross-talk, and cooperativity of tRNA modifications.
Collapse
Affiliation(s)
- Jing Li
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Wen-Yu Zhu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Wen-Qing Yang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Cai-Tao Li
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Ru-Juan Liu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
| |
Collapse
|
8
|
Khonsari B, Klassen R, Schaffrath R. Role of SSD1 in Phenotypic Variation of Saccharomyces cerevisiae Strains Lacking DEG1-Dependent Pseudouridylation. Int J Mol Sci 2021; 22:ijms22168753. [PMID: 34445460 PMCID: PMC8396022 DOI: 10.3390/ijms22168753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 08/09/2021] [Accepted: 08/12/2021] [Indexed: 11/16/2022] Open
Abstract
Yeast phenotypes associated with the lack of wobble uridine (U34) modifications in tRNA were shown to be modulated by an allelic variation of SSD1, a gene encoding an mRNA-binding protein. We demonstrate that phenotypes caused by the loss of Deg1-dependent tRNA pseudouridylation are similarly affected by SSD1 allelic status. Temperature sensitivity and protein aggregation are elevated in deg1 mutants and further increased in the presence of the ssd1-d allele, which encodes a truncated form of Ssd1. In addition, chronological lifespan is reduced in a deg1 ssd1-d mutant, and the negative genetic interactions of the U34 modifier genes ELP3 and URM1 with DEG1 are aggravated by ssd1-d. A loss of function mutation in SSD1, ELP3, and DEG1 induces pleiotropic and overlapping phenotypes, including sensitivity against target of rapamycin (TOR) inhibitor drug and cell wall stress by calcofluor white. Additivity in ssd1 deg1 double mutant phenotypes suggests independent roles of Ssd1 and tRNA modifications in TOR signaling and cell wall integrity. However, other tRNA modification defects cause growth and drug sensitivity phenotypes, which are not further intensified in tandem with ssd1-d. Thus, we observed a modification-specific rather than general effect of SSD1 status on phenotypic variation in tRNA modification mutants. Our results highlight how the cellular consequences of tRNA modification loss can be influenced by protein targeting specific mRNAs.
Collapse
|
9
|
Tavares JF, Davis NK, Poim A, Reis A, Kellner S, Sousa I, Soares AR, Moura GMR, Dedon PC, Santos M. tRNA-modifying enzyme mutations induce codon-specific mistranslation and protein aggregation in yeast. RNA Biol 2021; 18:563-575. [PMID: 32893724 PMCID: PMC7971265 DOI: 10.1080/15476286.2020.1819671] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/31/2020] [Accepted: 09/01/2020] [Indexed: 01/28/2023] Open
Abstract
Protein synthesis rate and accuracy are tightly controlled by the cell and are essential for proteome homoeostasis (proteostasis); however, the full picture of how mRNA translational factors maintain protein synthesis accuracy and co-translational protein folding are far from being fully understood. To address this question, we evaluated the role of 70 yeast tRNA-modifying enzyme genes on protein aggregation and used mass spectrometry to identify the aggregated proteins. We show that modification of uridine at anticodon position 34 (U34) by the tRNA-modifying enzymes Elp1, Elp3, Sml3 and Trm9 is critical for proteostasis, the mitochondrial tRNA-modifying enzyme Slm3 plays a fundamental role in general proteostasis and that stress response proteins whose genes are enriched in codons decoded by tRNAs lacking mcm5U34, mcm5s2U34, ncm5U34, ncm5Um34, modifications are overrepresented in protein aggregates of the ELP1, SLM3 and TRM9 KO strains. Increased rates of amino acid misincorporation were also detected in these strains at protein sites that specifically mapped to the codons sites that are decoded by the hypomodified tRNAs, demonstrating that U34 tRNA modifications safeguard the proteome from translational errors, protein misfolding and proteotoxic stress.
Collapse
Affiliation(s)
- Joana F Tavares
- Department of Medical Sciences, Institute of Biomedicine – iBiMED, University of Aveiro, Aveiro, Portugal
| | - Nick K. Davis
- Department of Biological Engineering, Massachusetts Institute of Technology – MIT, Cambridge, US
| | - Ana Poim
- Department of Medical Sciences, Institute of Biomedicine – iBiMED, University of Aveiro, Aveiro, Portugal
| | - Andreia Reis
- Department of Medical Sciences, Institute of Biomedicine – iBiMED, University of Aveiro, Aveiro, Portugal
| | - Stefanie Kellner
- Department of Biological Engineering, Massachusetts Institute of Technology – MIT, Cambridge, US
| | - Inês Sousa
- Department of Medical Sciences, Institute of Biomedicine – iBiMED, University of Aveiro, Aveiro, Portugal
| | - Ana R. Soares
- Department of Medical Sciences, Institute of Biomedicine – iBiMED, University of Aveiro, Aveiro, Portugal
| | - Gabriela M R Moura
- Department of Medical Sciences, Institute of Biomedicine – iBiMED, University of Aveiro, Aveiro, Portugal
| | - Peter C Dedon
- Department of Biological Engineering, Massachusetts Institute of Technology – MIT, Cambridge, US
- Singapore-MIT Alliance for Research and Technology, Campus for Research Excellence and Technical Enterprise – CREATE, Singapore
| | - Manuel Santos
- Department of Medical Sciences, Institute of Biomedicine – iBiMED, University of Aveiro, Aveiro, Portugal
| |
Collapse
|
10
|
Klassen R, Bruch A, Schaffrath R. Induction of protein aggregation and starvation response by tRNA modification defects. Curr Genet 2020; 66:1053-1057. [PMID: 32860511 PMCID: PMC7599136 DOI: 10.1007/s00294-020-01103-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 08/17/2020] [Accepted: 08/18/2020] [Indexed: 02/06/2023]
Abstract
Posttranscriptional modifications of anticodon loops contribute to the decoding efficiency of tRNAs by supporting codon recognition and loop stability. Consistently, strong synthetic growth defects are observed in yeast strains simultaneously lacking distinct anticodon loop modifications. These phenotypes are accompanied by translational inefficiency of certain mRNAs and disturbed protein homeostasis resulting in accumulation of protein aggregates. Different combinations of anticodon loop modification defects were shown to affect distinct tRNAs but provoke common transcriptional changes that are reminiscent of the cellular response to nutrient starvation. Multiple mechanisms may be involved in mediating inadequate starvation response upon loss of critical tRNA modifications. Recent evidence suggests protein aggregate induction to represent one such trigger.
Collapse
Affiliation(s)
- Roland Klassen
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Heinrich-Plett-Str. 40, 34132, Kassel, Germany.
| | - Alexander Bruch
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Heinrich-Plett-Str. 40, 34132, Kassel, Germany
| | - Raffael Schaffrath
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Heinrich-Plett-Str. 40, 34132, Kassel, Germany
| |
Collapse
|
11
|
Bruch A, Laguna T, Butter F, Schaffrath R, Klassen R. Misactivation of multiple starvation responses in yeast by loss of tRNA modifications. Nucleic Acids Res 2020; 48:7307-7320. [PMID: 32484543 PMCID: PMC7367188 DOI: 10.1093/nar/gkaa455] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 05/14/2020] [Accepted: 05/19/2020] [Indexed: 12/16/2022] Open
Abstract
Previously, combined loss of different anticodon loop modifications was shown to impair the function of distinct tRNAs in Saccharomyces cerevisiae. Surprisingly, each scenario resulted in shared cellular phenotypes, the basis of which is unclear. Since loss of tRNA modification may evoke transcriptional responses, we characterized global transcription patterns of modification mutants with defects in either tRNAGlnUUG or tRNALysUUU function. We observe that the mutants share inappropriate induction of multiple starvation responses in exponential growth phase, including derepression of glucose and nitrogen catabolite-repressed genes. In addition, autophagy is prematurely and inadequately activated in the mutants. We further demonstrate that improper induction of individual starvation genes as well as the propensity of the tRNA modification mutants to form protein aggregates are diminished upon overexpression of tRNAGlnUUG or tRNALysUUU, the tRNA species that lack the modifications of interest. Hence, our data suggest that global alterations in mRNA translation and proteostasis account for the transcriptional stress signatures that are commonly triggered by loss of anticodon modifications in different tRNAs.
Collapse
Affiliation(s)
- Alexander Bruch
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany
| | - Teresa Laguna
- Department of Quantitative Proteomics, IMB Mainz, Ackermannweg 4, 55128 Mainz, Germany
| | - Falk Butter
- Department of Quantitative Proteomics, IMB Mainz, Ackermannweg 4, 55128 Mainz, Germany
| | - Raffael Schaffrath
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany
| | - Roland Klassen
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany
| |
Collapse
|
12
|
Impact of Pus1 Pseudouridine Synthase on Specific Decoding Events in Saccharomyces cerevisiae. Biomolecules 2020; 10:biom10050729. [PMID: 32392804 PMCID: PMC7277083 DOI: 10.3390/biom10050729] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 04/30/2020] [Accepted: 05/05/2020] [Indexed: 12/19/2022] Open
Abstract
Pus1-dependent pseudouridylation occurs in many tRNAs and at multiple positions, yet the functional impact of this modification is incompletely understood. We analyzed the consequences of PUS1 deletion on the essential decoding of CAG (Gln) codons by tRNAGlnCUG in yeast. Synthetic lethality was observed upon combining the modification defect with destabilized variants of tRNAGlnCUG, pointing to a severe CAG-decoding defect of the hypomodified tRNA. In addition, we demonstrated that misreading of UAG stop codons by a tRNAGlnCUG variant is positively affected by Pus1. Genetic approaches further indicated that mildly elevated temperature decreases the decoding efficiency of CAG and UAG via destabilized tRNAGlnCAG variants. We also determined the misreading of CGC (Arg) codons by tRNAHisGUG, where the CGC decoder tRNAArgICG contains Pus1-dependent pseudouridine, but not the mistranslating tRNAHis. We found that the absence of Pus1 increased CGC misreading by tRNAHis, demonstrating a positive role of the modification in the competition against non-synonymous near-cognate tRNA. Part of the in vivo decoding defects and phenotypes in pus1 mutants and strains carrying destabilized tRNAGlnCAG were suppressible by additional deletion of the rapid tRNA decay (RTD)-relevant MET22, suggesting the involvement of RTD-mediated tRNA destabilization.
Collapse
|
13
|
Pollo-Oliveira L, Klassen R, Davis N, Ciftci A, Bacusmo JM, Martinelli M, DeMott MS, Begley TJ, Dedon PC, Schaffrath R, de Crécy-Lagard V. Loss of Elongator- and KEOPS-Dependent tRNA Modifications Leads to Severe Growth Phenotypes and Protein Aggregation in Yeast. Biomolecules 2020; 10:E322. [PMID: 32085421 PMCID: PMC7072221 DOI: 10.3390/biom10020322] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 02/10/2020] [Accepted: 02/11/2020] [Indexed: 12/20/2022] Open
Abstract
Modifications found in the Anticodon Stem Loop (ASL) of tRNAs play important roles in regulating translational speed and accuracy. Threonylcarbamoyl adenosine (t6A37) and 5-methoxycarbonyl methyl-2-thiouridine (mcm5s2U34) are critical ASL modifications that have been linked to several human diseases. The model yeast Saccharomyces cerevisiae is viable despite the absence of both modifications, growth is however greatly impaired. The major observed consequence is a subsequent increase in protein aggregates and aberrant morphology. Proteomic analysis of the t6A-deficient strain (sua5 mutant) revealed a global mistranslation leading to protein aggregation without regard to physicochemical properties or t6A-dependent or biased codon usage in parent genes. However, loss of sua5 led to increased expression of soluble proteins for mitochondrial function, protein quality processing/trafficking, oxidative stress response, and energy homeostasis. These results point to a global function for t6A in protein homeostasis very similar to mcm5/s2U modifications.
Collapse
Affiliation(s)
- Leticia Pollo-Oliveira
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32603, USA; (L.P.-O.); (J.M.B.); (M.M.)
| | - Roland Klassen
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, 34132 Kassel, Germany; (R.K.); (A.C.); (R.S.)
| | - Nick Davis
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; (N.D.); (M.S.D.); (P.C.D.)
| | - Akif Ciftci
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, 34132 Kassel, Germany; (R.K.); (A.C.); (R.S.)
| | - Jo Marie Bacusmo
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32603, USA; (L.P.-O.); (J.M.B.); (M.M.)
| | - Maria Martinelli
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32603, USA; (L.P.-O.); (J.M.B.); (M.M.)
| | - Michael S. DeMott
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; (N.D.); (M.S.D.); (P.C.D.)
| | - Thomas J. Begley
- The RNA Institute, College of Arts and Science, University at Albany, SUNY, Albany, NY 12222, USA;
| | - Peter C. Dedon
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; (N.D.); (M.S.D.); (P.C.D.)
| | - Raffael Schaffrath
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, 34132 Kassel, Germany; (R.K.); (A.C.); (R.S.)
| | - Valérie de Crécy-Lagard
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32603, USA; (L.P.-O.); (J.M.B.); (M.M.)
- University of Florida Genetics Institute, Gainesville, FL 32608, USA
| |
Collapse
|
14
|
SSD1 modifies phenotypes of Elongator mutants. Curr Genet 2019; 66:481-485. [PMID: 31776648 PMCID: PMC7198479 DOI: 10.1007/s00294-019-01048-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2019] [Revised: 11/19/2019] [Accepted: 11/20/2019] [Indexed: 11/15/2022]
Abstract
The translational decoding properties of tRNAs are influenced by post-transcriptional modification of nucleosides in their anticodon region. The Elongator complex promotes the first step in the formation of 5-methoxycarbonylmethyl (mcm5), 5-methoxycarbonylhydroxymethyl (mchm5), and 5-carbamoylmethyl (ncm5) groups on wobble uridine residues in eukaryotic cytosolic tRNAs. Elongator mutants in yeast, worms, plants, mice, and humans not only show a tRNA modification defect, but also a diverse range of additional phenotypes. Even though the phenotypes are almost certainly caused by the reduced functionality of the hypomodified tRNAs in translation, the basis for specific phenotypes is not well understood. Here, we discuss the recent finding that the phenotypes of Saccharomyces cerevisiae Elongator mutants are modulated by the genetic background. This background-effect is largely due to the allelic variation at the SSD1 locus, which encodes an mRNA-binding protein involved in post-transcriptional regulation of gene expression. A nonsense ssd1 allele is found in several wild-type laboratory strains and the presence of this allele aggravates the stress-induced phenotypes of Elongator mutants. Moreover, other phenotypes, such as the histone acetylation and telomeric gene silencing defects, are dependent on the mutant ssd1 allele. Thus, SSD1 is a genetic modifier of the phenotypes of Elongator-deficient yeast cells.
Collapse
|
15
|
Krutyhołowa R, Hammermeister A, Zabel R, Abdel-Fattah W, Reinhardt-Tews A, Helm M, Stark MJR, Breunig KD, Schaffrath R, Glatt S. Kti12, a PSTK-like tRNA dependent ATPase essential for tRNA modification by Elongator. Nucleic Acids Res 2019; 47:4814-4830. [PMID: 30916349 PMCID: PMC6511879 DOI: 10.1093/nar/gkz190] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 02/14/2019] [Accepted: 03/11/2019] [Indexed: 01/08/2023] Open
Abstract
Posttranscriptional RNA modifications occur in all domains of life. Modifications of anticodon bases are of particular importance for ribosomal decoding and proteome homeostasis. The Elongator complex modifies uridines in the wobble position and is highly conserved in eukaryotes. Despite recent insights into Elongator's architecture, the structure and function of its regulatory factor Kti12 have remained elusive. Here, we present the crystal structure of Kti12′s nucleotide hydrolase domain trapped in a transition state of ATP hydrolysis. The structure reveals striking similarities to an O-phosphoseryl-tRNA kinase involved in the selenocysteine pathway. Both proteins employ similar mechanisms of tRNA binding and show tRNASec-dependent ATPase activity. In addition, we demonstrate that Kti12 binds directly to Elongator and that ATP hydrolysis is crucial for Elongator to maintain proper tRNA anticodon modification levels in vivo. In summary, our data reveal a hitherto uncharacterized link between two translational control pathways that regulate selenocysteine incorporation and affect ribosomal tRNA selection via specific tRNA modifications.
Collapse
Affiliation(s)
- Rościsław Krutyhołowa
- Max Planck Research Group at the Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland.,Department of Cell Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | | | - Rene Zabel
- Institut für Biologie, Martin-Luther-Universität Halle-Wittenberg, Halle (Saale), Germany
| | - Wael Abdel-Fattah
- Institut für Biologie, FG Mikrobiologie, Universität Kassel, Kassel, Germany
| | | | - Mark Helm
- Institut für Pharmazie und Biochemie, Universität Mainz, Mainz, Germany
| | - Michael J R Stark
- Centre for Gene Regulation & Expression, University of Dundee, Dundee, UK
| | - Karin D Breunig
- Institut für Biologie, Martin-Luther-Universität Halle-Wittenberg, Halle (Saale), Germany
| | - Raffael Schaffrath
- Institut für Biologie, FG Mikrobiologie, Universität Kassel, Kassel, Germany
| | - Sebastian Glatt
- Max Planck Research Group at the Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
| |
Collapse
|
16
|
Nakai Y, Horiguchi G, Iwabuchi K, Harada A, Nakai M, Hara-Nishimura I, Yano T. tRNA Wobble Modification Affects Leaf Cell Development in Arabidopsis thaliana. PLANT & CELL PHYSIOLOGY 2019; 60:2026-2039. [PMID: 31076779 DOI: 10.1093/pcp/pcz064] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 04/04/2019] [Indexed: 05/14/2023]
Abstract
The tRNA modification at the wobble position of Lys, Glu and Gln (wobbleU* modification) is responsible for the fine-tuning of protein translation efficiency and translation rate. This modification influences organism function in accordance with growth and environmental changes. However, the effects of wobbleU* modification at the cellular, tissue, or individual level have not yet been elucidated. In this study, we show that sulfur modification of wobbleU* of the tRNAs affects leaf development in Arabidopsis thaliana. The sulfur modification was impaired in the two wobbleU*-modification mutants: the URM1-like protein-defective mutant and the Elongator complex-defective mutants. Analyses of the mutant phenotypes revealed that the deficiency in the wobbleU* modification increased the airspaces in the leaves and the leaf size without affecting the number and the area of palisade mesophyll cells. On the other hand, both mutants exhibited increased number of leaf epidermal pavement cells but with reduced cell size. The deficiency in the wobbleU* modification also delayed the initiation of the endoreduplication processes of mesophyll cells. The phenotype of ASYMMETRIC LEAVES2-defective mutant was enhanced in the Elongator-defective mutants, while it was unchanged in the URM1-like protein-defective mutant. Collectively, the findings of this study suggest that the tRNA wobbleU* modification plays an important role in leaf morphogenesis by balancing the development between epidermal and mesophyll tissues.
Collapse
Affiliation(s)
- Yumi Nakai
- Department of Biochemistry, Osaka Medical College, 2-7 Daigakumachi, Takatsuki, Japan
| | - Gorou Horiguchi
- Department of Life Science, College of Science, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo, Japan
| | - Kosei Iwabuchi
- Faculty of Science and Engineering, Konan University, Kobe, Japan
| | - Akiko Harada
- Department of Biology, Osaka Medical College, 2-7 Daigakumachi, Takatsuki, Japan
| | - Masato Nakai
- Institute for Protein Research, Osaka University, 3-2 Yamada-oka, Suita, Japan
| | | | - Takato Yano
- Department of Biochemistry, Osaka Medical College, 2-7 Daigakumachi, Takatsuki, Japan
| |
Collapse
|
17
|
ELP3 Acetyltransferase is phosphorylated and regulated by the oncogenic anaplastic lymphoma kinase (ALK). Biochem J 2019; 476:2239-2254. [DOI: 10.1042/bcj20190106] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 07/20/2019] [Accepted: 07/23/2019] [Indexed: 12/11/2022]
Abstract
AbstractProtein lysine acetylation is one of the major posttranslational modifications (PTMs) with several thousands of proteins identified to be acetylated in mammalian tissues. Mechanistic studies have revealed important functions of acetylation in the regulation of protein function. Much less is known on how the acetyltransferases themselves are regulated. In the current study, we discover that the Elongator protein 3 (ELP3) acetyltransferase is modified by tyrosine phosphorylation. We demonstrate that the anaplastic lymphoma kinase (ALK) is the major tyrosine kinase responsible for ELP3 tyrosine phosphorylation. ELP3 is phosphorylated in tumor cells expressing oncogenic NPM–ALK fusion protein. We further identify Tyr202 as the major ALK phosphorylation site in ELP3. Importantly, the introduction of Y202 phosphorylation mutant ELP3 into ALK-positive tumor cells reduced cell growth and impaired gene expression. Collectively, our study reveals a novel regulatory mechanism for ELP3, provides an example that acetyltransferase itself can be regulated by PTM, and suggests a potential target for ALK-positive cancer therapies.
Collapse
|
18
|
Xu F, Byström AS, Johansson MJO. SSD1 suppresses phenotypes induced by the lack of Elongator-dependent tRNA modifications. PLoS Genet 2019; 15:e1008117. [PMID: 31465447 PMCID: PMC6738719 DOI: 10.1371/journal.pgen.1008117] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 09/11/2019] [Accepted: 08/16/2019] [Indexed: 11/19/2022] Open
Abstract
The Elongator complex promotes formation of 5-methoxycarbonylmethyl (mcm5) and 5-carbamoylmethyl (ncm5) side-chains on uridines at the wobble position of cytosolic eukaryotic tRNAs. In all eukaryotic organisms tested to date, the inactivation of Elongator not only leads to the lack of mcm5/ncm5 groups in tRNAs, but also a wide variety of additional phenotypes. Although the phenotypes are most likely caused by a translational defect induced by reduced functionality of the hypomodified tRNAs, the mechanism(s) underlying individual phenotypes are poorly understood. In this study, we show that the genetic background modulates the phenotypes induced by the lack of mcm5/ncm5 groups in Saccharomyces cerevisiae. We show that the stress-induced growth defects of Elongator mutants are stronger in the W303 than in the closely related S288C genetic background and that the phenotypic differences are caused by the known polymorphism at the locus for the mRNA binding protein Ssd1. Moreover, the mutant ssd1 allele found in W303 cells is required for the reported histone H3 acetylation and telomeric gene silencing defects of Elongator mutants. The difference at the SSD1 locus also partially explains why the simultaneous lack of mcm5 and 2-thio groups at wobble uridines is lethal in the W303 but not in the S288C background. Collectively, our results demonstrate that the SSD1 locus modulates phenotypes induced by the lack of Elongator-dependent tRNA modifications.
Collapse
Affiliation(s)
- Fu Xu
- Department of Molecular Biology, Umeå University, Umeå, Sweden
| | | | | |
Collapse
|
19
|
Ranjan N, Leidel SA. The epitranscriptome in translation regulation: mRNA and tRNA modifications as the two sides of the same coin? FEBS Lett 2019; 593:1483-1493. [PMID: 31206634 DOI: 10.1002/1873-3468.13491] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 06/07/2019] [Accepted: 06/11/2019] [Indexed: 12/17/2022]
Abstract
Translation of mRNA is a highly regulated process that is tightly coordinated with cotranslational protein maturation. Recently, mRNA modifications and tRNA modifications - the so called epitranscriptome - have added a new layer of regulation that is still poorly understood. Both types of modifications can affect codon-anticodon interactions, thereby affecting mRNA translation and protein synthesis in similar ways. Here, we describe an updated view on how the different types of modifications can be mapped, how they affect translation, how they trigger phenotypes and discuss how the combined action of mRNA and tRNA modifications coordinate translation in health and disease.
Collapse
Affiliation(s)
- Namit Ranjan
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Goettingen, Germany
| | - Sebastian A Leidel
- Max Planck Research Group for RNA Biology, Max Planck Institute for Molecular Biomedicine, Münster, Germany.,Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland
| |
Collapse
|
20
|
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.
Collapse
|
21
|
Impact of tRNA Modifications and tRNA-Modifying Enzymes on Proteostasis and Human Disease. Int J Mol Sci 2018; 19:ijms19123738. [PMID: 30477220 PMCID: PMC6321623 DOI: 10.3390/ijms19123738] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 11/17/2018] [Accepted: 11/20/2018] [Indexed: 12/14/2022] Open
Abstract
Transfer RNAs (tRNAs) are key players of protein synthesis, as they decode the genetic information organized in mRNA codons, translating them into the code of 20 amino acids. To be fully active, tRNAs undergo extensive post-transcriptional modifications, catalyzed by different tRNA-modifying enzymes. Lack of these modifications increases the level of missense errors and affects codon decoding rate, contributing to protein aggregation with deleterious consequences to the cell. Recent works show that tRNA hypomodification and tRNA-modifying-enzyme deregulation occur in several diseases where proteostasis is affected, namely, neurodegenerative and metabolic diseases. In this review, we discuss the recent findings that correlate aberrant tRNA modification with proteostasis imbalances, in particular in neurological and metabolic disorders, and highlight the association between tRNAs, their modifying enzymes, translational decoding, and disease onset.
Collapse
|
22
|
Joshi K, Bhatt MJ, Farabaugh PJ. Codon-specific effects of tRNA anticodon loop modifications on translational misreading errors in the yeast Saccharomyces cerevisiae. Nucleic Acids Res 2018; 46:10331-10339. [PMID: 30060218 PMCID: PMC6212777 DOI: 10.1093/nar/gky664] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 07/03/2018] [Accepted: 07/12/2018] [Indexed: 01/10/2023] Open
Abstract
Protein synthesis requires both high speed and accuracy to ensure a healthy cellular environment. Estimates of errors during protein synthesis in Saccharomyces cerevisiae have varied from 10-3 to 10-4 errors per codon. Here, we show that errors made by ${\rm{tRNA}}^{\rm Glu}_{\rm UUC}$ in yeast can vary 100-fold, from 10-6 to 10-4 errors per codon. The most frequent errors require a G•U mismatch at the second position for the near cognate codon GGA (Gly). We also show, contrary to our previous results, that yeast tRNAs can make errors involving mismatches at the wobble position but with low efficiency. We have also assessed the effect on misreading frequency of post-transcriptional modifications of tRNAs, which are known to regulate cognate codon decoding in yeast. We tested the roles of mcm5s2U34 and t6A37 and show that their effects depend on details of the codon anticodon interaction including the position of the modification with respect to the base mismatch and the nature of that mismatch. Both mcm5 and s2 modification of wobble uridine strongly stabilizes G2•U35 mismatches when ${\rm{tRNA}}^{\rm Glu}_{\rm UUC}$ misreads the GGA Gly codon but has weaker effects on other mismatches. By contrast, t6A37 destabilizes U1•U36 mismatches when ${\rm{tRNA}}^{\rm Lys}_{\rm UUU}$ misreads UAA or UAG but stabilizes mismatches at the second and wobble positions.
Collapse
Affiliation(s)
- Kartikeya Joshi
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, MD 21250, USA
| | - Monika J Bhatt
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, MD 21250, USA
| | - Philip J Farabaugh
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, MD 21250, USA
| |
Collapse
|
23
|
Bruch A, Klassen R, Schaffrath R. Unfolded Protein Response Suppression in Yeast by Loss of tRNA Modifications. Genes (Basel) 2018; 9:genes9110516. [PMID: 30360492 PMCID: PMC6275073 DOI: 10.3390/genes9110516] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 10/18/2018] [Accepted: 10/18/2018] [Indexed: 12/28/2022] Open
Abstract
Modifications in the anticodon loop of transfer RNAs (tRNAs) have been shown to ensure optimal codon translation rates and prevent protein homeostasis defects that arise in response to translational pausing. Consequently, several yeast mutants lacking important anticodon loop modifications were shown to accumulate protein aggregates. Here we analyze whether this includes the activation of the unfolded protein response (UPR), which is commonly triggered by protein aggregation within the endoplasmic reticulum (ER). We demonstrate that two different aggregation prone tRNA modification mutants (elp6 ncs2; elp3 deg1) lacking combinations of 5-methoxycarbonylmethyl-2-thiouridine (mcm⁵s²U: elp3; elp6; ncs2) and pseudouridine (Ψ: deg1) reduce, rather than increase, splicing of HAC1 mRNA, an event normally occurring as a precondition of UPR induction. In addition, tunicamycin (TM) induced HAC1 splicing is strongly impaired in the elp3 deg1 mutant. Strikingly, this mutant displays UPR independent resistance against TM, a phenotype we found to be rescued by overexpression of tRNAGln(UUG), the tRNA species usually carrying the mcm⁵s²U34 and Ψ38 modifications. Our data indicate that proper tRNA anticodon loop modifications promote rather than impair UPR activation and reveal that protein synthesis and homeostasis defects in their absence do not routinely result in UPR induction but may relieve endogenous ER stress.
Collapse
Affiliation(s)
- Alexander Bruch
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Heinrich-Plett-Str. 40, D-34132 Kassel, Germany.
| | - Roland Klassen
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Heinrich-Plett-Str. 40, D-34132 Kassel, Germany.
| | - Raffael Schaffrath
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Heinrich-Plett-Str. 40, D-34132 Kassel, Germany.
| |
Collapse
|
24
|
Hawer H, Ütkür K, Arend M, Mayer K, Adrian L, Brinkmann U, Schaffrath R. Importance of diphthamide modified EF2 for translational accuracy and competitive cell growth in yeast. PLoS One 2018; 13:e0205870. [PMID: 30335802 PMCID: PMC6193676 DOI: 10.1371/journal.pone.0205870] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 10/02/2018] [Indexed: 01/23/2023] Open
Abstract
In eukaryotes, the modification of an invariant histidine (His-699 in yeast) residue in translation elongation factor 2 (EF2) with diphthamide involves a conserved pathway encoded by the DPH1-DPH7 gene network. Diphthamide is the target for diphtheria toxin and related lethal ADP ribosylases, which collectively kill cells by inactivating the essential translocase function of EF2 during mRNA translation and protein biosynthesis. Although this notion emphasizes the pathological importance of diphthamide, precisely why cells including our own require EF2 to carry it, is unclear. Mining the synthetic genetic array (SGA) landscape from the budding yeast Saccharomyces cerevisiae has revealed negative interactions between EF2 (EFT1-EFT2) and diphthamide (DPH1-DPH7) gene deletions. In line with these correlations, we confirm in here that loss of diphthamide modification (dphΔ) on EF2 combined with EF2 undersupply (eft2Δ) causes synthetic growth phenotypes in the composite mutant (dphΔ eft2Δ). These reflect negative interference with cell performance under standard as well as thermal and/or chemical stress conditions, cell growth rates and doubling times, competitive fitness, cell viability in the presence of TOR inhibitors (rapamycin, caffeine) and translation indicator drugs (hygromycin, anisomycin). Together with significantly suppressed tolerance towards EF2 inhibition by cytotoxic DPH5 overexpression and increased ribosomal -1 frame-shift errors in mutants lacking modifiable pools of EF2 (dphΔ, dphΔ eft2Δ), our data indicate that diphthamide is important for the fidelity of the EF2 translocation function during mRNA translation.
Collapse
Affiliation(s)
- Harmen Hawer
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Kassel, Germany
| | - Koray Ütkür
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Kassel, Germany
| | - Meike Arend
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Kassel, Germany
| | - Klaus Mayer
- Roche Pharma Research & Early Development, Large Molecule Research, Roche Innovation Center München, Penzberg, Germany
| | - Lorenz Adrian
- AG Geobiochemie, Department Isotopenbiogeochemie, Helmholtz-Zentrum für Umweltforschung GmbH–UFZ, Leipzig, Germany
- Fachgebiet Geobiotechnologie, Technische Universität Berlin, Berlin, Germany
| | - Ulrich Brinkmann
- Roche Pharma Research & Early Development, Large Molecule Research, Roche Innovation Center München, Penzberg, Germany
| | - Raffael Schaffrath
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Kassel, Germany
- * E-mail:
| |
Collapse
|
25
|
Ng CS, Sinha A, Aniweh Y, Nah Q, Babu IR, Gu C, Chionh YH, Dedon PC, Preiser PR. tRNA epitranscriptomics and biased codon are linked to proteome expression in Plasmodium falciparum. Mol Syst Biol 2018; 14:e8009. [PMID: 30287681 PMCID: PMC6171970 DOI: 10.15252/msb.20178009] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 08/09/2018] [Accepted: 09/07/2018] [Indexed: 12/24/2022] Open
Abstract
Among components of the translational machinery, ribonucleoside modifications on tRNAs are emerging as critical regulators of cell physiology and stress response. Here, we demonstrate highly coordinated behavior of the repertoire of tRNA modifications of Plasmodium falciparum throughout the intra-erythrocytic developmental cycle (IDC). We observed both a synchronized increase in 22 of 28 modifications from ring to trophozoite stage, consistent with tRNA maturation during translational up-regulation, and asynchronous changes in six modifications. Quantitative analysis of ~2,100 proteins across the IDC revealed that up- and down-regulated proteins in late but not early stages have a marked codon bias that directly correlates with parallel changes in tRNA modifications and enhanced translational efficiency. We thus propose a model in which tRNA modifications modulate the abundance of stage-specific proteins by enhancing translation efficiency of codon-biased transcripts for critical genes. These findings reveal novel epitranscriptomic and translational control mechanisms in the development and pathogenesis of Plasmodium parasites.
Collapse
Affiliation(s)
- Chee Sheng Ng
- Antimicrobial Resistance Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, Singapore City, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore City, Singapore
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Ameya Sinha
- Antimicrobial Resistance Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, Singapore City, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore City, Singapore
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Yaw Aniweh
- School of Biological Sciences, Nanyang Technological University, Singapore City, Singapore
| | - Qianhui Nah
- Antimicrobial Resistance Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, Singapore City, Singapore
| | - Indrakanti Ramesh Babu
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Chen Gu
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Yok Hian Chionh
- Antimicrobial Resistance Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, Singapore City, Singapore
- Department of Microbiology and Immunology Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore City, Singapore
| | - Peter C Dedon
- Antimicrobial Resistance Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, Singapore City, Singapore
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Peter R Preiser
- Antimicrobial Resistance Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, Singapore City, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore City, Singapore
| |
Collapse
|
26
|
Collaboration of tRNA modifications and elongation factor eEF1A in decoding and nonsense suppression. Sci Rep 2018; 8:12749. [PMID: 30143741 PMCID: PMC6109124 DOI: 10.1038/s41598-018-31158-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 08/13/2018] [Indexed: 01/27/2023] Open
Abstract
Transfer RNA (tRNA) from all domains of life contains multiple modified nucleosides, the functions of which remain incompletely understood. Genetic interactions between tRNA modification genes in Saccharomyces cerevisiae suggest that different tRNA modifications collaborate to maintain translational efficiency. Here we characterize such collaborative functions in the ochre suppressor tRNA SUP4. We quantified ochre read-through efficiency in mutants lacking either of the 7 known modifications in the extended anticodon stem loop (G26-C48). Absence of U34, U35, A37, U47 and C48 modifications partially impaired SUP4 function. We systematically combined modification defects and scored additive or synergistic negative effects on SUP4 performance. Our data reveal different degrees of functional redundancy between specific modifications, the strongest of which was demonstrated for those occurring at positions U34 and A37. SUP4 activity in the absence of critical modifications, however, can be rescued in a gene dosage dependent fashion by TEF1 which encodes elongation factor eEF1A required for tRNA delivery to the ribosome. Strikingly, the rescue ability of higher-than-normal eEF1A levels extends to tRNA modification defects in natural non-suppressor tRNAs suggesting that elevated eEF1A abundance can partially compensate for functional defects induced by loss of tRNA modifications.
Collapse
|
27
|
Lyons SM, Fay MM, Ivanov P. The role of RNA modifications in the regulation of tRNA cleavage. FEBS Lett 2018; 592:2828-2844. [PMID: 30058219 DOI: 10.1002/1873-3468.13205] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 06/28/2018] [Accepted: 07/18/2018] [Indexed: 12/21/2022]
Abstract
Transfer RNA (tRNA) have been harbingers of many paradigms in RNA biology. They are among the first recognized noncoding RNA (ncRNA) playing fundamental roles in RNA metabolism. Although mainly recognized for their role in decoding mRNA and delivering amino acids to the growing polypeptide chain, tRNA also serve as an abundant source of small ncRNA named tRNA fragments. The functional significance of these fragments is only beginning to be uncovered. Early on, tRNA were recognized as heavily post-transcriptionally modified, which aids in proper folding and modulates the tRNA:mRNA anticodon-codon interactions. Emerging data suggest that these modifications play critical roles in the generation and activity of tRNA fragments. Modifications can both protect tRNA from cleavage or promote their cleavage. Modifications to individual fragments may be required for their activity. Recent work has shown that some modifications are critical for stem cell development and that failure to deposit certain modifications has profound effects on disease. This review will discuss how tRNA modifications regulate the generation and activity of tRNA fragments.
Collapse
Affiliation(s)
- Shawn M Lyons
- Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Boston, MA, USA.,Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Marta M Fay
- Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Boston, MA, USA.,Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Pavel Ivanov
- Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Boston, MA, USA.,Department of Medicine, Harvard Medical School, Boston, MA, USA.,The Broad Institute of Harvard and M.I.T., Cambridge, MA, USA
| |
Collapse
|
28
|
Protein Phosphatase Sit4 Affects Lipid Droplet Synthesis and Soraphen A Resistance Independent of Its Role in Regulating Elongator Dependent tRNA Modification. Biomolecules 2018; 8:biom8030049. [PMID: 29997346 PMCID: PMC6165401 DOI: 10.3390/biom8030049] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 07/05/2018] [Accepted: 07/09/2018] [Indexed: 12/15/2022] Open
Abstract
The protein phosphatase Sit4 has been shown to be required for lipogenesis and resistance against the acetyl-CoA carboxylase inhibitor soraphen A. Since Sit4 is also required for biosynthesis of Elongator dependent tRNA modifications such as 5-methoxycarbonylmethyluridine (mcm5U), we investigated the relevance of tRNA modifications in lipogenesis and soraphen A response. While sit4 and Elongator (elp3) mutants copy defects in mcm5U formation and stress sensitivity, they do not share soraphen A sensitivity and low lipid droplet (LD) phenotypes. In contrast to sit4, we found elp3 mutants to display partial soraphen A resistance and a high LD phenotype. Screening a collection of tRNA modification mutants additionally identified the tRNA pseudo-uridine synthase gene DEG1 to be required for soraphen A sensitivity. Since deg1 and elp3 share high LD and soraphen A resistance phenotypes, these are likely caused by translational defects. In support of this notion, we observe overexpression of tRNAGlnUUG suppresses lipolysis defects of deg1 mutants. Hence, the sit4 mutation results in a composite defect including tRNA modification deficiency and loss of Snf1 kinase dephosphorylation, which induce opposite effects on LD regulation. Importantly, however, the Snf1 kinase regulatory defects of the phosphatase mutant dominate over effects on LD regulation imposed by loss of the tRNA modification alone.
Collapse
|
29
|
Lentini JM, Ramos J, Fu D. Monitoring the 5-methoxycarbonylmethyl-2-thiouridine (mcm5s2U) modification in eukaryotic tRNAs via the γ-toxin endonuclease. RNA (NEW YORK, N.Y.) 2018; 24:749-758. [PMID: 29440318 PMCID: PMC5900570 DOI: 10.1261/rna.065581.118] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 02/06/2018] [Indexed: 06/08/2023]
Abstract
The post-transcriptional modification of tRNA at the wobble position is a universal process occurring in all domains of life. In eukaryotes, the wobble uridine of particular tRNAs is transformed to the 5-methoxycarbonylmethyl-2-thiouridine (mcm5s2U) modification which is critical for proper mRNA decoding and protein translation. However, current methods to detect mcm5s2U are technically challenging and/or require specialized instrumental expertise. Here, we show that γ-toxin endonuclease from the yeast Kluyveromyces lactis can be used as a probe for assaying mcm5s2U status in the tRNA of diverse eukaryotic organisms ranging from protozoans to mammalian cells. The assay couples the mcm5s2U-dependent cleavage of tRNA by γ-toxin with standard molecular biology techniques such as northern blot analysis or quantitative PCR to monitor mcm5s2U levels in multiple tRNA isoacceptors. The results gained from the γ-toxin assay reveals the evolutionary conservation of the mcm5s2U modification across eukaryotic species. Moreover, we have used the γ-toxin assay to verify uncharacterized eukaryotic Trm9 and Trm112 homologs that catalyze the formation of mcm5s2U. These findings demonstrate the use of γ-toxin as a detection method to monitor mcm5s2U status in diverse eukaryotic cell types for cellular, genetic, and biochemical studies.
Collapse
Affiliation(s)
- Jenna M Lentini
- Department of Biology, Center for RNA Biology, University of Rochester, Rochester, New York 14627, USA
| | - Jillian Ramos
- Department of Biology, Center for RNA Biology, University of Rochester, Rochester, New York 14627, USA
| | - Dragony Fu
- Department of Biology, Center for RNA Biology, University of Rochester, Rochester, New York 14627, USA
| |
Collapse
|
30
|
Koh CS, Sarin LP. Transfer RNA modification and infection – Implications for pathogenicity and host responses. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2018; 1861:419-432. [DOI: 10.1016/j.bbagrm.2018.01.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 01/04/2018] [Accepted: 01/19/2018] [Indexed: 12/19/2022]
|
31
|
Padgett LR, Lentini JM, Holmes MJ, Stilger KL, Fu D, Sullivan WJ. Elp3 and RlmN: A tale of two mitochondrial tail-anchored radical SAM enzymes in Toxoplasma gondii. PLoS One 2018; 13:e0189688. [PMID: 29293520 PMCID: PMC5749711 DOI: 10.1371/journal.pone.0189688] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 11/30/2017] [Indexed: 11/19/2022] Open
Abstract
Radical S-adenosylmethionine (rSAM) enzymes use a 5'-deoxyadensyl 5'-radical to methylate a wide array of diverse substrates including proteins, lipids and nucleic acids. One such enzyme, Elongator protein-3 (TgElp3), is an essential protein in Toxoplasma gondii, a protozoan parasite that can cause life-threatening opportunistic disease. Unlike Elp3 homologues which are present in all domains of life, TgElp3 localizes to the outer mitochondrial membrane (OMM) via a tail-anchored trafficking mechanism in Toxoplasma. Intriguingly, we identified a second tail-anchored rSAM domain containing protein (TgRlmN) that also localizes to the OMM. The transmembrane domain (TMD) on Toxoplasma Elp3 and RlmN homologues is required for OMM localization and has not been seen beyond the chromalveolates. Both TgElp3 and TgRlmN contain the canonical rSAM amino acid sequence motif (CxxxCxxC) necessary to form the 4Fe-4S cluster required for tRNA modifications. In E. coli, RlmN is responsible for the 2-methlyadenosine (m2A) synthesis at purine 37 in tRNA while in S. cerevisiae, Elp3 is necessary for the formation of 5-methoxycarbonylmethyl-2-thiouridine (mcm5s2U) at the wobble tRNA position. To investigate why these two rSAM enzymes localize to the mitochondrion in Toxoplasma, and whether or not TgRlmN and TgElp3 possess tRNA methyltransferase activity, a series of mutational and biochemical studies were performed. Overexpression of either TgElp3 or TgRlmN resulted in a significant parasite replication defect, but overexpression was tolerated if either the TMD or rSAM domain was mutated. Furthermore, we show the first evidence that Toxoplasma tRNAGlu contains the mcm5s2U modification, which is the putative downstream product generated by TgElp3 activity.
Collapse
Affiliation(s)
- Leah R. Padgett
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Jenna M. Lentini
- Department of Biology, University of Rochester, Rochester, New York, United States of America
| | - Michael J. Holmes
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Krista L. Stilger
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Dragony Fu
- Department of Biology, University of Rochester, Rochester, New York, United States of America
| | - William J. Sullivan
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- * E-mail:
| |
Collapse
|
32
|
Soprano AS, Smetana JHC, Benedetti CE. Regulation of tRNA biogenesis in plants and its link to plant growth and response to pathogens. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2017; 1861:344-353. [PMID: 29222070 DOI: 10.1016/j.bbagrm.2017.12.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 11/29/2017] [Accepted: 12/03/2017] [Indexed: 12/23/2022]
Abstract
The field of tRNA biology, encompassing the functional and structural complexity of tRNAs, has fascinated scientists over the years and is continuously growing. Besides their fundamental role in protein translation, new evidence indicates that tRNA-derived molecules also regulate gene expression and protein synthesis in all domains of life. This review highlights some of the recent findings linking tRNA transcription and modification with plant cell growth and response to pathogens. In fact, mutations in proteins directly involved in tRNA synthesis and modification most often lead to pleiotropic effects on plant growth and immunity. As plants need to optimize and balance their energy and nutrient resources towards growth and defense, regulatory pathways that play a central role in integrating tRNA transcription and protein translation with cell growth control and organ development, such as the auxin-TOR signaling pathway, also influence the plant immune response against pathogens. As a consequence, distinct pathogens employ an array of effector molecules including tRNA fragments to target such regulatory pathways to exploit the plant's translational capacity, gain access to nutrients and evade defenses. An example includes the RNA polymerase III repressor MAF1, a conserved component of the TOR signaling pathway that controls ribosome biogenesis and tRNA synthesis required for plant growth and which is targeted by a pathogen effector molecule to promote disease. This article is part of a Special Issue entitled: SI: Regulation of tRNA synthesis and modification in physiological conditions and disease edited by Dr. Boguta Magdalena.
Collapse
Affiliation(s)
- Adriana Santos Soprano
- Brazilian Nacional Biosciences Laboratory (LNBio), Brazilian Center for Research in Energy and Materials (CNPEM), 13083-100 Campinas, SP, Brazil
| | - Juliana Helena Costa Smetana
- Brazilian Nacional Biosciences Laboratory (LNBio), Brazilian Center for Research in Energy and Materials (CNPEM), 13083-100 Campinas, SP, Brazil
| | - Celso Eduardo Benedetti
- Brazilian Nacional Biosciences Laboratory (LNBio), Brazilian Center for Research in Energy and Materials (CNPEM), 13083-100 Campinas, SP, Brazil.
| |
Collapse
|
33
|
Sokołowski M, Klassen R, Bruch A, Schaffrath R, Glatt S. Cooperativity between different tRNA modifications and their modification pathways. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2017; 1861:409-418. [PMID: 29222069 DOI: 10.1016/j.bbagrm.2017.12.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 11/30/2017] [Accepted: 12/03/2017] [Indexed: 12/11/2022]
Abstract
Ribonucleotide modifications perform a wide variety of roles in synthesis, turnover and functionality of tRNA molecules. The presence of particular chemical moieties can refine the internal interaction network within a tRNA molecule, influence its thermodynamic stability, contribute novel chemical properties and affect its decoding behavior during mRNA translation. As the lack of specific modifications in the anticodon stem and loop causes disrupted proteome homeostasis, diminished response to stress conditions, and the onset of human diseases, the underlying modification cascades have recently gained particular scientific and clinical interest. Nowadays, a complicated but conclusive image of the interconnectivity between different enzymatic modification cascades and their resulting tRNA modifications emerges. Here we summarize the current knowledge in the field, focusing on the known instances of cross talk among the enzymatic tRNA modification pathways and the consequences on the dynamic regulation of the tRNA modificome by various factors. This article is part of a Special Issue entitled: SI: Regulation of tRNA synthesis and modification in physiological conditions and disease edited by Dr. Boguta Magdalena.
Collapse
Affiliation(s)
- Mikołaj Sokołowski
- Max Planck Research Group at the Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland; Postgraduate School of Molecular Medicine, Warsaw, Poland
| | - Roland Klassen
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Kassel, Germany
| | - Alexander Bruch
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Kassel, Germany
| | - Raffael Schaffrath
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Kassel, Germany.
| | - Sebastian Glatt
- Max Planck Research Group at the Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland.
| |
Collapse
|
34
|
Johansson MJO, Xu F, Byström AS. Elongator-a tRNA modifying complex that promotes efficient translational decoding. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2017; 1861:401-408. [PMID: 29170010 DOI: 10.1016/j.bbagrm.2017.11.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 11/19/2017] [Indexed: 12/22/2022]
Abstract
Naturally occurring modifications of the nucleosides in the anticodon region of tRNAs influence their translational decoding properties. Uridines present at the wobble position in eukaryotic cytoplasmic tRNAs often contain a 5-carbamoylmethyl (ncm(5)) or 5-methoxycarbonylmethyl (mcm(5)) side-chain and sometimes also a 2-thio or 2'-O-methyl group. The first step in the formation of the ncm(5) and mcm(5) side-chains requires the conserved six-subunit Elongator complex. Although Elongator has been implicated in several different cellular processes, accumulating evidence suggests that its primary, and possibly only, cellular function is to promote modification of tRNAs. In this review, we discuss the biosynthesis and function of modified wobble uridines in eukaryotic cytoplasmic tRNAs, focusing on the in vivo role of Elongator-dependent modifications in Saccharomyces cerevisiae. This article is part of a Special Issue entitled: SI: Regulation of tRNA synthesis and modification in physiological conditions and disease edited by Dr. Boguta Magdalena.
Collapse
Affiliation(s)
| | - Fu Xu
- Department of Molecular Biology, Umeå University, 901 87 Umeå, Sweden
| | - Anders S Byström
- Department of Molecular Biology, Umeå University, 901 87 Umeå, Sweden.
| |
Collapse
|
35
|
Schaffrath R, Klassen R. Combined tRNA modification defects impair protein homeostasis and synthesis of the yeast prion protein Rnq1. Prion 2017; 11:48-53. [PMID: 28281930 DOI: 10.1080/19336896.2017.1284734] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Modified nucleosides in tRNA anticodon loops such as 5-methoxy-carbonyl-methyl-2-thiouridine (mcm5s2U) and pseuduridine (Ψ) are thought to be required for an efficient decoding process. In Saccharomyces cerevisiae, the simultaneous presence of mcm5s2U and Ψ38 in tRNAGlnUUG was shown to mediate efficient synthesis of the Q/N rich [PIN+] prion forming protein Rnq1. 1 In the absence of these two tRNA modifications, higher than normal levels of hypomodified tRNAGlnUUG, but not its isoacceptor tRNAGlnCUG can restore Rnq1 synthesis. Moroever, tRNA overexpression rescues pleiotropic phenotypes that associate with loss of mcm5s2U and Ψ38 formation. Notably, combined absence of different tRNA modifications are shown to induce the formation of protein aggregates which likely mediate severe cytological abnormalities, including cytokinesis and nuclear segregation defects. In support of this, overexpression of the aggregating polyQ protein Htt103Q, but not its non-aggregating variant Htt25Q phenocopies these cytological abnormalities, most pronouncedly in deg1 single mutants lacking Ψ38 alone. It is concluded that slow decoding of particular codons induces defects in protein homeostasis that interfere with key steps in cytokinesis and nuclear segregation.
Collapse
Affiliation(s)
- Raffael Schaffrath
- a Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel , Kassel , Germany
| | - Roland Klassen
- a Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel , Kassel , Germany
| |
Collapse
|
36
|
Mehlgarten C, Prochaska H, Hammermeister A, Abdel-Fattah W, Wagner M, Krutyhołowa R, Jun SE, Kim GT, Glatt S, Breunig KD, Stark MJR, Schaffrath R. Use of a Yeast tRNase Killer Toxin to Diagnose Kti12 Motifs Required for tRNA Modification by Elongator. Toxins (Basel) 2017; 9:E272. [PMID: 28872616 PMCID: PMC5618205 DOI: 10.3390/toxins9090272] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 08/29/2017] [Accepted: 09/03/2017] [Indexed: 01/23/2023] Open
Abstract
Saccharomyces cerevisiae cells are killed by zymocin, a tRNase ribotoxin complex from Kluyveromyces lactis, which cleaves anticodons and inhibits protein synthesis. Zymocin's action requires specific chemical modification of uridine bases in the anticodon wobble position (U34) by the Elongator complex (Elp1-Elp6). Hence, loss of anticodon modification in mutants lacking Elongator or related KTI (K. lactis Toxin Insensitive) genes protects against tRNA cleavage and confers resistance to the toxin. Here, we show that zymocin can be used as a tool to genetically analyse KTI12, a gene previously shown to code for an Elongator partner protein. From a kti12 mutant pool of zymocin survivors, we identify motifs in Kti12 that are functionally directly coupled to Elongator activity. In addition, shared requirement of U34 modifications for nonsense and missense tRNA suppression (SUP4; SOE1) strongly suggests that Kti12 and Elongator cooperate to assure proper tRNA functioning. We show that the Kti12 motifs are conserved in plant ortholog DRL1/ELO4 from Arabidopsis thaliana and seem to be involved in binding of cofactors (e.g., nucleotides, calmodulin). Elongator interaction defects triggered by mutations in these motifs correlate with phenotypes typical for loss of U34 modification. Thus, tRNA modification by Elongator appears to require physical contact with Kti12, and our preliminary data suggest that metabolic signals may affect proper communication between them.
Collapse
Affiliation(s)
- Constance Mehlgarten
- Institut für Biologie, Martin Luther Universität Halle-Wittenberg, Weinbergweg 10, 06120 Halle/Saale, Germany.
| | - Heike Prochaska
- Institut für Biologie, Martin Luther Universität Halle-Wittenberg, Weinbergweg 10, 06120 Halle/Saale, Germany.
| | - Alexander Hammermeister
- Institut für Biologie, FG Mikrobiologie, Universität Kassel, Heirich-Plett-Str. 40, 34132 Kassel, Germany.
| | - Wael Abdel-Fattah
- Institut für Biologie, FG Mikrobiologie, Universität Kassel, Heirich-Plett-Str. 40, 34132 Kassel, Germany.
| | - Melanie Wagner
- Institut für Biologie, Martin Luther Universität Halle-Wittenberg, Weinbergweg 10, 06120 Halle/Saale, Germany.
| | - Rościsław Krutyhołowa
- Max Planck Research Group at the Malopolska Centre of Biotechnology, Jagiellonian University, 31-007 Krakow, Poland.
- Department of Cell Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 31-007 Krakow, Poland.
| | - Sang Eun Jun
- Department of Molecular Biotechnology, Dong-A University, Busan 604-714, Korea.
| | - Gyung-Tae Kim
- Department of Molecular Biotechnology, Dong-A University, Busan 604-714, Korea.
| | - Sebastian Glatt
- Max Planck Research Group at the Malopolska Centre of Biotechnology, Jagiellonian University, 31-007 Krakow, Poland.
| | - Karin D Breunig
- Institut für Biologie, Martin Luther Universität Halle-Wittenberg, Weinbergweg 10, 06120 Halle/Saale, Germany.
| | - Michael J R Stark
- Centre for Gene Regulation & Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK.
| | - Raffael Schaffrath
- Institut für Biologie, Martin Luther Universität Halle-Wittenberg, Weinbergweg 10, 06120 Halle/Saale, Germany.
- Institut für Biologie, FG Mikrobiologie, Universität Kassel, Heirich-Plett-Str. 40, 34132 Kassel, Germany.
| |
Collapse
|
37
|
Elp3 and Dph3 of Schizosaccharomyces pombe mediate cellular stress responses through tRNA LysUUU modifications. Sci Rep 2017; 7:7225. [PMID: 28775286 PMCID: PMC5543170 DOI: 10.1038/s41598-017-07647-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 06/30/2017] [Indexed: 01/31/2023] Open
Abstract
Efficient protein synthesis in eukaryotes requires diphthamide modification of translation elongation factor eEF2 and wobble uridine modifications of tRNAs. In higher eukaryotes, these processes are important for preventing neurological and developmental defects and cancer. In this study, we used Schizosaccharomyces pombe as a model to analyse mutants defective in eEF2 modification (dph1Δ), in tRNA modifications (elp3Δ), or both (dph3Δ) for sensitivity to cytotoxic agents and thermal stress. The dph3Δ and elp3Δ mutants were sensitive to a range of drugs and had growth defects at low temperature. dph3Δ was epistatic with dph1Δ for sensitivity to hydroxyurea and methyl methanesulfonate, and with elp3Δ for methyl methanesulfonate and growth at 16 °C. The dph1Δ and dph3Δ deletions rescued growth defects of elp3Δ in response to thiabendazole and at 37 °C. Elevated tRNALysUUU levels suppressed the elp3Δ phenotypes and some of the dph3Δ phenotypes, indicating that lack of tRNALysUUU modifications were responsible. Furthermore, we found positive genetic interactions of elp3Δ and dph3Δ with sty1Δ and atf1Δ, indicating that Elp3/Dph3-dependent tRNA modifications are important for efficient biosynthesis of key factors required for accurate responses to cytotoxic stress conditions.
Collapse
|
38
|
Rojas-Benítez D, Eggers C, Glavic A. Modulation of the Proteostasis Machinery to Overcome Stress Caused by Diminished Levels of t6A-Modified tRNAs in Drosophila. Biomolecules 2017; 7:biom7010025. [PMID: 28272317 PMCID: PMC5372737 DOI: 10.3390/biom7010025] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 02/28/2017] [Indexed: 12/17/2022] Open
Abstract
Transfer RNAs (tRNAs) harbor a subset of post-transcriptional modifications required for structural stability or decoding function. N6-threonylcarbamoyladenosine (t6A) is a universally conserved modification found at position 37 in tRNA that pair A-starting codons (ANN) and is required for proper translation initiation and to prevent frame shift during elongation. In its absence, the synthesis of aberrant proteins is likely, evidenced by the formation of protein aggregates. In this work, our aim was to study the relationship between t6A-modified tRNAs and protein synthesis homeostasis machinery using Drosophila melanogaster. We used the Gal4/UAS system to knockdown genes required for t6A synthesis in a tissue and time specific manner and in vivo reporters of unfolded protein response (UPR) activation. Our results suggest that t6A-modified tRNAs, synthetized by the threonyl-carbamoyl transferase complex (TCTC), are required for organismal growth and imaginal cell survival, and is most likely to support proper protein synthesis.
Collapse
Affiliation(s)
- Diego Rojas-Benítez
- Centro de Regulación del Genoma, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Ñuñoa, Santiago 7800024, Chile..
| | - Cristián Eggers
- Centro de Regulación del Genoma, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Ñuñoa, Santiago 7800024, Chile..
| | - Alvaro Glavic
- Centro de Regulación del Genoma, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Ñuñoa, Santiago 7800024, Chile..
| |
Collapse
|
39
|
Abstract
Wobble uridines (U34) are generally modified in all species. U34 modifications can be essential in metazoans but are not required for viability in fungi. In this review, we provide an overview on the types of modifications and how they affect the physico-chemical properties of wobble uridines. We describe the molecular machinery required to introduce these modifications into tRNA posttranscriptionally and discuss how posttranslational regulation may affect the activity of the modifying enzymes. We highlight the activity of anticodon specific RNases that target U34 containing tRNA. Finally, we discuss how defects in wobble uridine modifications lead to phenotypes in different species. Importantly, this review will mainly focus on the cytoplasmic tRNAs of eukaryotes. A recent review has extensively covered their bacterial and mitochondrial counterparts.1
Collapse
Affiliation(s)
- Raffael Schaffrath
- a Institut für Biologie, FG Mikrobiologie , Universität Kassel , Germany
| | - Sebastian A Leidel
- b Max Planck Institute for Molecular Biomedicine , Germany.,c Cells-in-Motion Cluster of Excellence , University of Münster , Münster , Germany.,d Medical Faculty , University of Münster , Albert-Schweitzer-Campus 1, Münster , Germany
| |
Collapse
|
40
|
Klassen R, Schaffrath R. Role of Pseudouridine Formation by Deg1 for Functionality of Two Glutamine Isoacceptor tRNAs. Biomolecules 2017; 7:biom7010008. [PMID: 28134782 PMCID: PMC5372720 DOI: 10.3390/biom7010008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 01/20/2017] [Accepted: 01/20/2017] [Indexed: 12/22/2022] Open
Abstract
Loss of Deg1/Pus3 and concomitant elimination of pseudouridine in tRNA at positions 38 and 39 (ψ38/39) was shown to specifically impair the function of tRNAGlnUUG under conditions of temperature-induced down-regulation of wobble uridine thiolation in budding yeast and is linked to intellectual disability in humans. To further characterize the differential importance of the frequent ψ38/39 modification for tRNAs in yeast, we analyzed the in vivo function of non-sense suppressor tRNAs SUP4 and sup70-65 in the absence of the modifier. In the tRNATyrGψA variant SUP4, UAA read-through is enabled due to an anticodon mutation (UψA), whereas sup70-65 is a mutant form of tRNAGlnCUG (SUP70) that mediates UAG decoding due to a mutation of the anticodon-loop closing base pair (G31:C39 to A31:C39). While SUP4 function is unaltered in deg1/pus3 mutants, the ability of sup70-65 to mediate non-sense suppression and to complement a genomic deletion of the essential SUP70 gene is severely compromised. These results and the differential suppression of growth defects in deg1 mutants by multi-copy SUP70 or tQ(UUG) are consistent with the interpretation that ψ38 is most important for tRNAGlnUUG function under heat stress but becomes crucial for tRNAGlnCUG as well when the anticodon loop is destabilized by the sup70-65 mutation. Thus, ψ38/39 may protect the anticodon loop configuration from disturbances by loss of other modifications or base changes.
Collapse
Affiliation(s)
- Roland Klassen
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Heinrich-Plett-Str. 40, D-34132 Kassel, Germany.
| | - Raffael Schaffrath
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Heinrich-Plett-Str. 40, D-34132 Kassel, Germany.
| |
Collapse
|
41
|
Klassen R, Bruch A, Schaffrath R. Independent suppression of ribosomal +1 frameshifts by different tRNA anticodon loop modifications. RNA Biol 2016; 14:1252-1259. [PMID: 27937809 PMCID: PMC5699549 DOI: 10.1080/15476286.2016.1267098] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
Recently, a role for the anticodon wobble uridine modification 5-methoxycarbonylmethyl-2-thiouridine (mcm5s2U) has been revealed in the suppression of translational +1 frameshifts in Saccharomyces cerevisiae. Loss of either the mcm5U or s2U parts of the modification elevated +1 frameshift rates and results obtained with reporters involving a tRNALysUUU dependent frameshift site suggested these effects are caused by reduced ribosomal A-site binding of the hypomodified tRNA. Combined loss of mcm5U and s2U leads to increased ribosome pausing at tRNALysUUU dependent codons and synergistic growth defects but effects on +1 frameshift rates remained undefined to this end. We show in here that simultaneous removal of mcm5U and s2U results in synergistically increased +1 frameshift rates that are suppressible by extra copies of tRNALysUUU. Thus, two distinct chemical modifications of the same wobble base independently contribute to reading frame maintenance, loss of which may cause or contribute to observed growth defects. Since the thiolation pathway is sensitive to moderately elevated temperatures in yeast, we observe a heat-induced increase of +1 frameshift rates in wild type cells that depends on the sulfur transfer protein Urm1. Furthermore, we find that temperature-induced frameshifting is kept in check by the dehydration of N6-threonylcarbamoyladenosine (t6A) to its cyclic derivative (ct6A) at the anticodon adjacent position 37. Since loss of ct6A in elp3 or urm1 mutant cells is detrimental for temperature stress resistance we assume that conversion of t6A to ct6A serves to limit deleterious effects on translational fidelity caused by hypomodified states of wobble uridine bases.
Collapse
Affiliation(s)
- Roland Klassen
- a Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel , Kassel , Germany
| | - Alexander Bruch
- a Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel , Kassel , Germany
| | - Raffael Schaffrath
- a Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel , Kassel , Germany
| |
Collapse
|
42
|
Kojic M, Wainwright B. The Many Faces of Elongator in Neurodevelopment and Disease. Front Mol Neurosci 2016; 9:115. [PMID: 27847465 PMCID: PMC5088202 DOI: 10.3389/fnmol.2016.00115] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Accepted: 10/18/2016] [Indexed: 12/02/2022] Open
Abstract
Development of the nervous system requires a variety of cellular activities, such as proliferation, migration, axonal outgrowth and guidance and synapse formation during the differentiation of neural precursors into mature neurons. Malfunction of these highly regulated and coordinated events results in various neurological diseases. The Elongator complex is a multi-subunit complex highly conserved in eukaryotes whose function has been implicated in the majority of cellular activities underlying neurodevelopment. These activities include cell motility, actin cytoskeleton organization, exocytosis, polarized secretion, intracellular trafficking and the maintenance of neural function. Several studies have associated mutations in Elongator subunits with the neurological disorders familial dysautonomia (FD), intellectual disability (ID), amyotrophic lateral sclerosis (ALS) and rolandic epilepsy (RE). Here, we review the various cellular activities assigned to this complex and discuss the implications for neural development and disease. Further research in this area has the potential to generate new diagnostic tools, better prevention strategies and more effective treatment options for a wide variety of neurological disorders.
Collapse
Affiliation(s)
- Marija Kojic
- Genomics of Development and Disease Division, Institute for Molecular Bioscience, The University of Queensland Brisbane, QLD, Australia
| | - Brandon Wainwright
- Genomics of Development and Disease Division, Institute for Molecular Bioscience, The University of Queensland Brisbane, QLD, Australia
| |
Collapse
|
43
|
Jüdes A, Bruch A, Klassen R, Helm M, Schaffrath R. Sulfur transfer and activation by ubiquitin-like modifier system Uba4•Urm1 link protein urmylation and tRNA thiolation in yeast. MICROBIAL CELL (GRAZ, AUSTRIA) 2016; 3:554-564. [PMID: 28357324 PMCID: PMC5349211 DOI: 10.15698/mic2016.11.539] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 09/19/2016] [Indexed: 01/03/2023]
Abstract
Urm1 is a unique dual-function member of the ubiquitin protein family and conserved from yeast to man. It acts both as a protein modifier in ubiquitin-like urmylation and as a sulfur donor for tRNA thiolation, which in concert with the Elongator pathway forms 5-methoxy-carbonyl-methyl-2-thio (mcm5s2) modified wobble uridines (U34) in anticodons. Using Saccharomyces cerevisiae as a model to study a relationship between these two functions, we examined whether cultivation temperature and sulfur supply previously implicated in the tRNA thiolation branch of the URM1 pathway also contribute to proper urmylation. Monitoring Urm1 conjugation, we found urmylation of the peroxiredoxin Ahp1 is suppressed either at elevated cultivation temperatures or under sulfur starvation. In line with this, mutants with sulfur transfer defects that are linked to enzymes (Tum1, Uba4) required for Urm1 activation by thiocarboxylation (Urm1-COSH) were found to maintain drastically reduced levels of Ahp1 urmylation and mcm5s2U34 modification. Moreover, as revealed by site specific mutagenesis, the S-transfer rhodanese domain (RHD) in the E1-like activator (Uba4) crucial for Urm1-COSH formation is critical but not essential for protein urmylation and tRNA thiolation. In sum, sulfur supply, transfer and activation chemically link protein urmylation and tRNA thiolation. These are features that distinguish the ubiquitin-like modifier system Uba4•Urm1 from canonical ubiquitin family members and will help elucidate whether, in addition to their mechanistic links, the protein and tRNA modification branches of the URM1 pathway may also relate in function to one another.
Collapse
Affiliation(s)
- André Jüdes
- Universität Kassel, Institut für Biologie, FG Mikrobiologie,
Heinrich-Plett-Str. 40, 34132 Kassel, Germany
| | - Alexander Bruch
- Universität Kassel, Institut für Biologie, FG Mikrobiologie,
Heinrich-Plett-Str. 40, 34132 Kassel, Germany
| | - Roland Klassen
- Universität Kassel, Institut für Biologie, FG Mikrobiologie,
Heinrich-Plett-Str. 40, 34132 Kassel, Germany
| | - Mark Helm
- Johannes Gutenberg Universität Mainz, Institut für Pharmazie und
Biochemie, Staudinger Weg 5, 55128 Mainz, Germany
| | - Raffael Schaffrath
- Universität Kassel, Institut für Biologie, FG Mikrobiologie,
Heinrich-Plett-Str. 40, 34132 Kassel, Germany
| |
Collapse
|
44
|
Klassen R, Ciftci A, Funk J, Bruch A, Butter F, Schaffrath R. tRNA anticodon loop modifications ensure protein homeostasis and cell morphogenesis in yeast. Nucleic Acids Res 2016; 44:10946-10959. [PMID: 27496282 PMCID: PMC5159529 DOI: 10.1093/nar/gkw705] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 07/29/2016] [Indexed: 11/17/2022] Open
Abstract
Using budding yeast, we investigated a negative interaction network among genes for tRNA modifications previously implicated in anticodon-codon interaction: 5-methoxy-carbonyl-methyl-2-thio-uridine (mcm5s2U34: ELP3, URM1), pseudouridine (Ψ38/39: DEG1) and cyclic N6-threonyl-carbamoyl-adenosine (ct6A37: TCD1). In line with functional cross talk between these modifications, we find that combined removal of either ct6A37 or Ψ38/39 and mcm5U34 or s2U34 results in morphologically altered cells with synthetic growth defects. Phenotypic suppression by tRNA overexpression suggests that these defects are caused by malfunction of tRNALysUUU or tRNAGlnUUG, respectively. Indeed, mRNA translation and synthesis of the Gln-rich prion Rnq1 are severely impaired in the absence of Ψ38/39 and mcm5U34 or s2U34, and this defect can be rescued by overexpression of tRNAGlnUUG. Surprisingly, we find that combined modification defects in the anticodon loops of different tRNAs induce similar cell polarity- and nuclear segregation defects that are accompanied by increased aggregation of cellular proteins. Since conditional expression of an artificial aggregation-prone protein triggered similar cytological aberrancies, protein aggregation is likely responsible for loss of morphogenesis and cytokinesis control in mutants with inappropriate tRNA anticodon loop modifications.
Collapse
Affiliation(s)
- Roland Klassen
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Heinrich-Plett-Str. 40, D-34132 Kassel, Germany
| | - Akif Ciftci
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Heinrich-Plett-Str. 40, D-34132 Kassel, Germany
| | - Johanna Funk
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Heinrich-Plett-Str. 40, D-34132 Kassel, Germany
| | - Alexander Bruch
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Heinrich-Plett-Str. 40, D-34132 Kassel, Germany
| | - Falk Butter
- Institut für Molekulare Biologie, Ackermannweg 4, D-55128 Mainz, Germany
| | - Raffael Schaffrath
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Heinrich-Plett-Str. 40, D-34132 Kassel, Germany
| |
Collapse
|
45
|
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.
Collapse
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
| |
Collapse
|
46
|
Ranjan N, Rodnina MV. tRNA wobble modifications and protein homeostasis. ACTA ACUST UNITED AC 2016; 4:e1143076. [PMID: 27335723 DOI: 10.1080/21690731.2016.1143076] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 12/28/2015] [Accepted: 01/12/2016] [Indexed: 12/20/2022]
Abstract
tRNA is a central component of the protein synthesis machinery in the cell. In living cells, tRNAs undergo numerous post-transcriptional modifications. In particular, modifications at the anticodon loop play an important role in ensuring efficient protein synthesis, maintaining protein homeostasis, and helping cell adaptation and survival. Hypo-modification of the wobble position of the tRNA anticodon loop is of particular relevance for translation regulation and is implicated in various human diseases. In this review we summarize recent evidence of how methyl and thiol modifications in eukaryotic tRNA at position 34 affect cellular fitness and modulate regulatory circuits at normal conditions and under stress.
Collapse
Affiliation(s)
- Namit Ranjan
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry , Göttingen, Germany
| | - Marina V Rodnina
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry , Göttingen, Germany
| |
Collapse
|
47
|
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.
Collapse
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
| |
Collapse
|
48
|
Wemhoff S, Klassen R, Meinhardt F. DNA damage induced by the anticodon nuclease from a Pichia acaciae killer strain is linked to ribonucleotide reductase depletion. Cell Microbiol 2015; 18:211-22. [PMID: 26247322 DOI: 10.1111/cmi.12496] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 07/24/2015] [Accepted: 07/26/2015] [Indexed: 11/30/2022]
Abstract
Virus like element (VLE) encoded killer toxins of Pichia acaciae and Kluyveromyces lactis kill target cells through anticodon nuclease (ACNase) activity directed against tRNA(Gln) and tRNA(Glu) respectively. Not only does tRNA cleavage disable translation, it also affects DNA integrity as well. Consistent with DNA damage, which is involved in toxicity, target cells' mutation frequencies are elevated upon ACNase exposure, suggesting a link between translational integrity and genome surveillance. Here, we analysed whether ACNase action impedes the periodically and highly expressed S-phase specific ribonucleotide reductase (RNR) and proved that RNR expression is severely affected by PaT. Because RNR catalyses the rate-limiting step in dNTP synthesis, mutants affected in dNTP synthesis were scrutinized with respect to ACNase action. Mutations elevating cellular dNTPs antagonized the action of both the above ACNases, whereas mutations lowering dNTPs aggravated toxicity. Consistently, prevention of tRNA cleavage in elp3 or trm9 mutants, which both affect the wobble uridine modification of the target tRNA, suppressed the toxin hypersensitivity of a dNTP synthesis mutant. Moreover, dNTP synthesis defects exacerbated the PaT ACNase sensitivity of cells defective in homologous recombination, proving that dNTP depletion is responsible for subsequent DNA damage.
Collapse
Affiliation(s)
- Sabrina Wemhoff
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, 48149, Münster, Germany
| | - Roland Klassen
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, 48149, Münster, Germany
| | - Friedhelm Meinhardt
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, 48149, Münster, Germany
| |
Collapse
|
49
|
Jüdes A, Ebert F, Bär C, Thüring KL, Harrer A, Klassen R, Helm M, Stark MJ, Schaffrath R. Urmylation and tRNA thiolation functions of ubiquitin-like Uba4·Urm1 systems are conserved from yeast to man. FEBS Lett 2015; 589:904-9. [DOI: 10.1016/j.febslet.2015.02.024] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 02/11/2015] [Accepted: 02/24/2015] [Indexed: 02/07/2023]
|