1
|
Kuhle B, Chen Q, Schimmel P. tRNA renovatio: Rebirth through fragmentation. Mol Cell 2023; 83:3953-3971. [PMID: 37802077 PMCID: PMC10841463 DOI: 10.1016/j.molcel.2023.09.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 08/15/2023] [Accepted: 09/12/2023] [Indexed: 10/08/2023]
Abstract
tRNA function is based on unique structures that enable mRNA decoding using anticodon trinucleotides. These structures interact with specific aminoacyl-tRNA synthetases and ribosomes using 3D shape and sequence signatures. Beyond translation, tRNAs serve as versatile signaling molecules interacting with other RNAs and proteins. Through evolutionary processes, tRNA fragmentation emerges as not merely random degradation but an act of recreation, generating specific shorter molecules called tRNA-derived small RNAs (tsRNAs). These tsRNAs exploit their linear sequences and newly arranged 3D structures for unexpected biological functions, epitomizing the tRNA "renovatio" (from Latin, meaning renewal, renovation, and rebirth). Emerging methods to uncover full tRNA/tsRNA sequences and modifications, combined with techniques to study RNA structures and to integrate AI-powered predictions, will enable comprehensive investigations of tRNA fragmentation products and new interaction potentials in relation to their biological functions. We anticipate that these directions will herald a new era for understanding biological complexity and advancing pharmaceutical engineering.
Collapse
Affiliation(s)
- Bernhard Kuhle
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA; Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Qi Chen
- Molecular Medicine Program, Department of Human Genetics, and Division of Urology, Department of Surgery, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Paul Schimmel
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA.
| |
Collapse
|
2
|
Akiyama Y, Ivanov P. tRNA-derived RNAs: Biogenesis and roles in translational control. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1805. [PMID: 37406666 PMCID: PMC10766869 DOI: 10.1002/wrna.1805] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 05/17/2023] [Accepted: 06/06/2023] [Indexed: 07/07/2023]
Abstract
Transfer RNA (tRNA)-derived RNAs (tDRs) are a class of small non-coding RNAs that play important roles in different aspects of gene expression. These ubiquitous and heterogenous RNAs, which vary across different species and cell types, are proposed to regulate various biological processes. In this review, we will discuss aspects of their biogenesis, and specifically, their contribution into translational control. We will summarize diverse roles of tDRs and the molecular mechanisms underlying their functions in the regulation of protein synthesis and their impact on related events such as stress-induced translational reprogramming. This article is categorized under: RNA Processing > Processing of Small RNAs Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs Regulatory RNAs/RNAi/Riboswitches > Biogenesis of Effector Small RNAs.
Collapse
Affiliation(s)
- Yasutoshi Akiyama
- Laboratory of Oncology, Pharmacy Practice and Sciences, Tohoku University Graduate School of Pharmaceutical Sciences, Sendai, Japan
| | - Pavel Ivanov
- Division of Rheumatology, Inflammation and Immunity, Brigham and Women's Hospital, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|
3
|
Alings F, Scharmann K, Eggers C, Böttcher B, Sokołowski M, Shvetsova E, Sharma P, Roth J, Rashiti L, Glatt S, Brunke S, Leidel SA. Ncs2* mediates in vivo virulence of pathogenic yeast through sulphur modification of cytoplasmic transfer RNA. Nucleic Acids Res 2023; 51:8133-8149. [PMID: 37462076 PMCID: PMC10450187 DOI: 10.1093/nar/gkad564] [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: 08/25/2022] [Revised: 05/30/2023] [Accepted: 06/21/2023] [Indexed: 08/26/2023] Open
Abstract
Fungal pathogens threaten ecosystems and human health. Understanding the molecular basis of their virulence is key to develop new treatment strategies. Here, we characterize NCS2*, a point mutation identified in a clinical baker's yeast isolate. Ncs2 is essential for 2-thiolation of tRNA and the NCS2* mutation leads to increased thiolation at body temperature. NCS2* yeast exhibits enhanced fitness when grown at elevated temperatures or when exposed to oxidative stress, inhibition of nutrient signalling, and cell-wall stress. Importantly, Ncs2* alters the interaction and stability of the thiolase complex likely mediated by nucleotide binding. The absence of 2-thiolation abrogates the in vivo virulence of pathogenic baker's yeast in infected mice. Finally, hypomodification triggers changes in colony morphology and hyphae formation in the common commensal pathogen Candida albicans resulting in decreased virulence in a human cell culture model. These findings demonstrate that 2-thiolation of tRNA acts as a key mediator of fungal virulence and reveal new mechanistic insights into the function of the highly conserved tRNA-thiolase complex.
Collapse
Affiliation(s)
- Fiona Alings
- Max Planck Research Group for RNA Biology, Max Planck Institute for Molecular Biomedicine, Muenster, Germany
| | - Karin Scharmann
- Max Planck Research Group for RNA Biology, Max Planck Institute for Molecular Biomedicine, Muenster, Germany
| | - Cristian Eggers
- Max Planck Research Group for RNA Biology, Max Planck Institute for Molecular Biomedicine, Muenster, Germany
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Bettina Böttcher
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knoell Institute, Jena, Germany
- Septomics Research Center, Friedrich Schiller University and Leibniz Institute for Natural Product Research and Infection Biology - Hans Knoell Institute, Jena, Germany
| | - Mikołaj Sokołowski
- Max Planck Research Group at the Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
| | - Ekaterina Shvetsova
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Puneet Sharma
- Max Planck Research Group for RNA Biology, Max Planck Institute for Molecular Biomedicine, Muenster, Germany
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
| | - Joël Roth
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
| | - Leon Rashiti
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
| | - Sebastian Glatt
- Max Planck Research Group at the Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
| | - Sascha Brunke
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knoell Institute, Jena, Germany
| | - Sebastian A Leidel
- Max Planck Research Group for RNA Biology, Max Planck Institute for Molecular Biomedicine, Muenster, Germany
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
- Multidisciplinary Center for Infectious Diseases, University of Bern, Bern, Switzerland
| |
Collapse
|
4
|
U A, Viswam P, Kattupalli D, Eppurathu Vasudevan S. Elucidation of transfer RNAs as stress regulating agents and the experimental strategies to conceive the functional role of tRNA-derived fragments in plants. Crit Rev Biotechnol 2023; 43:275-292. [PMID: 35382663 DOI: 10.1080/07388551.2022.2026288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
In plants, the transfer RNAs (tRNAs) exhibit their profound influence in orchestrating diverse physiological activities like cell growth, development, and response to several surrounding stimuli. The tRNAs, which were known to restrict their function solely in deciphering the codons, are now emerging as frontline defenders in stress biology. The plants that are constantly confronted with a huge panoply of stresses rely on tRNA-mediated stress regulation by altering the tRNA abundance, curbing the transport of tRNAs, fragmenting the mature tRNAs during stress. Among them, the studies on the generation of transfer RNA-derived fragments (tRFs) and their biological implication in stress response have attained huge interest. In plants, the tRFs hold stable expression patterns and regulate biological functions under diverse environmental conditions. In this review, we discuss the fate of plant tRNAs upon stress and thereafter how the tRFs are metamorphosed into sharp ammunition to wrestle with stress. We also address the various methods developed to date for uncovering the role of tRFs and their function in plants.
Collapse
Affiliation(s)
- Aswathi U
- Rajiv Gandhi Centre for Biotechnology, Transdisciplinary Biology Laboratory, Thiruvananthapuram, India
| | - Pooja Viswam
- Rajiv Gandhi Centre for Biotechnology, Transdisciplinary Biology Laboratory, Thiruvananthapuram, India
| | - Divya Kattupalli
- Rajiv Gandhi Centre for Biotechnology, Transdisciplinary Biology Laboratory, Thiruvananthapuram, India
| | | |
Collapse
|
5
|
Mathew BA, Katta M, Ludhiadch A, Singh P, Munshi A. Role of tRNA-Derived Fragments in Neurological Disorders: a Review. Mol Neurobiol 2023; 60:655-671. [PMID: 36348262 DOI: 10.1007/s12035-022-03078-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Accepted: 10/05/2022] [Indexed: 11/10/2022]
Abstract
tRFs are small tRNA derived fragments that are emerging as novel therapeutic targets and regulatory molecules in the pathophysiology of various neurological disorders. These are derived from precursor or mature tRNA, forming different subtypes that have been reported to be involved in neurological disorders like stroke, Alzheimer's, epilepsy, Parkinson's, MELAS, autism, and Huntington's disorder. tRFs were earlier believed to be random degradation debris of tRNAs. The significant variation in the expression level of tRFs in disease conditions indicates their salient role as key players in regulation of these disorders. Various animal studies are being carried out to decipher their exact role; however, more inputs are required to transform this research knowledge into clinical application. Future investigations also call for high-throughput technologies that could help to bring out the other hidden aspects of these entities. However, studies on tRFs require further research efforts to overcome the challenges posed in quantifying tRFs, their interactions with other molecules, and the exact mechanism of function. In this review, we are abridging the current understanding of tRFs, including their biogenesis, function, relevance in clinical therapies, and potential as diagnostic and prognostic biomarkers of these neurological disorders.
Collapse
Affiliation(s)
- Blessy Aksa Mathew
- Complex Disease Genomics and Precision Medicine Laboratory, Department of Human Genetics and Molecular Medicine, Central University of Punjab, Bathinda, India, 151401
| | - Madhumitha Katta
- Complex Disease Genomics and Precision Medicine Laboratory, Department of Human Genetics and Molecular Medicine, Central University of Punjab, Bathinda, India, 151401
| | - Abhilash Ludhiadch
- Complex Disease Genomics and Precision Medicine Laboratory, Department of Human Genetics and Molecular Medicine, Central University of Punjab, Bathinda, India, 151401
| | - Paramdeep Singh
- Department of Radiology, All India Institute of Medical Sciences, Bathinda, Punjab, India, 151001
| | - Anjana Munshi
- Complex Disease Genomics and Precision Medicine Laboratory, Department of Human Genetics and Molecular Medicine, Central University of Punjab, Bathinda, India, 151401.
| |
Collapse
|
6
|
Li X, Peng J, Yi C. The epitranscriptome of small non-coding RNAs. Noncoding RNA Res 2021; 6:167-173. [PMID: 34820590 PMCID: PMC8581453 DOI: 10.1016/j.ncrna.2021.10.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 10/14/2021] [Accepted: 10/20/2021] [Indexed: 02/06/2023] Open
Abstract
Small non-coding RNAs are short RNA molecules and involved in many biological processes, including cell proliferation and differentiation, immune response, cell death, epigenetic regulation, metabolic control. A diversity of RNA modifications have been identified in these small non-coding RNAs, including transfer RNAs (tRNAs), microRNAs (miRNAs), PIWI-interacting RNAs (piRNAs), small nuclear RNA (snRNA), small nucleolar RNAs (snoRNAs), and tRNA-derived small RNAs (tsRNAs). These post-transcriptional modifications are involved in the biogenesis and function of these small non-coding RNAs. In this review, we will summarize the existence of RNA modifications in the small non-coding RNAs and the emerging roles of these epitranscriptomic marks.
Collapse
Affiliation(s)
- Xiaoyu Li
- Department of Biochemistry and Department of Gastroenterology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China.,State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, 100871, China
| | - Jinying Peng
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, 100871, China
| | - Chengqi Yi
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, 100871, China.,Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China.,Department of Chemical Biology and Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| |
Collapse
|
7
|
Dannfald A, Favory JJ, Deragon JM. Variations in transfer and ribosomal RNA epitranscriptomic status can adapt eukaryote translation to changing physiological and environmental conditions. RNA Biol 2021; 18:4-18. [PMID: 34159889 PMCID: PMC8677040 DOI: 10.1080/15476286.2021.1931756] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 05/07/2021] [Accepted: 05/13/2021] [Indexed: 01/27/2023] Open
Abstract
The timely reprogramming of gene expression in response to internal and external cues is essential to eukaryote development and acclimation to changing environments. Chemically modifying molecular receptors and transducers of these signals is one way to efficiently induce proper physiological responses. Post-translation modifications, regulating protein biological activities, are central to many well-known signal-responding pathways. Recently, messenger RNA (mRNA) chemical (i.e. epitranscriptomic) modifications were also shown to play a key role in these processes. In contrast, transfer RNA (tRNA) and ribosomal RNA (rRNA) chemical modifications, although critical for optimal function of the translation apparatus, and much more diverse and quantitatively important compared to mRNA modifications, were until recently considered as mainly static chemical decorations. We present here recent observations that are challenging this view and supporting the hypothesis that tRNA and rRNA modifications dynamically respond to various cell and environmental conditions and contribute to adapt translation to these conditions.
Collapse
Affiliation(s)
- Arnaud Dannfald
- CNRS LGDP-UMR5096, Pepignan, France
- Université de Perpignan via Domitia, Perpignan, France
| | - Jean-Jacques Favory
- CNRS LGDP-UMR5096, Pepignan, France
- Université de Perpignan via Domitia, Perpignan, France
| | - Jean-Marc Deragon
- CNRS LGDP-UMR5096, Pepignan, France
- Université de Perpignan via Domitia, Perpignan, France
- Institut Universitaire de France, Paris, France
| |
Collapse
|
8
|
Chen Q, Zhang X, Shi J, Yan M, Zhou T. Origins and evolving functionalities of tRNA-derived small RNAs. Trends Biochem Sci 2021; 46:790-804. [PMID: 34053843 PMCID: PMC8448906 DOI: 10.1016/j.tibs.2021.05.001] [Citation(s) in RCA: 72] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 04/22/2021] [Accepted: 05/03/2021] [Indexed: 12/14/2022]
Abstract
Transfer RNA (tRNA)-derived small RNAs (tsRNAs) are among the most ancient small RNAs in all domains of life and are generated by the cleavage of tRNAs. Emerging studies have begun to reveal the versatile roles of tsRNAs in fundamental biological processes, including gene silencing, ribosome biogenesis, retrotransposition, and epigenetic inheritance, which are rooted in tsRNA sequence conservation, RNA modifications, and protein-binding abilities. We summarize the mechanisms of tsRNA biogenesis and the impact of RNA modifications, and propose how thinking of tsRNA functionality from an evolutionary perspective urges the expansion of tsRNA research into a wider spectrum, including cross-tissue/cross-species regulation and harnessing of the 'tsRNA code' for precision medicine.
Collapse
Affiliation(s)
- Qi Chen
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, USA.
| | - Xudong Zhang
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, USA
| | - Junchao Shi
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA, USA
| | - Menghong Yan
- Institutes of Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai, China; Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA
| | - Tong Zhou
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA.
| |
Collapse
|
9
|
Zhang X, Chen XL. The emerging roles of ubiquitin-like protein Urm1 in eukaryotes. Cell Signal 2021; 81:109946. [PMID: 33548388 DOI: 10.1016/j.cellsig.2021.109946] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/31/2021] [Accepted: 02/01/2021] [Indexed: 10/22/2022]
Abstract
The ubiquitin related modifier Urm1 protein was firstly identified in the yeast Saccharomyces cerevisiae, and was later found to play important roles in different eukaryotes. By the assistance of an E1-like activation enzyme Uba4, Urm1 can function as a modifier to target proteins, called urmylation. The thioredoxin peroxidase Ahp1 was the only identified Urm1 target in the early time. Recently, many other Urm1 targets were identified, which is important for us to fully understand functions of urmylation. Urm1 can also function as a sulfur carrier to play a key role in tRNAs thiolation. Mechanisms of the Urm1 in protein and RNA modifications were finely revealed in the past few years. Biological and physiological functions of Urm1 were also found in different organisms. In this review, we will summarize these emerging progresses.
Collapse
Affiliation(s)
- Xinrong Zhang
- State Key Laboratory of Agricultural Microbiology and Provincial Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Xiao-Lin Chen
- State Key Laboratory of Agricultural Microbiology and Provincial Hubei Key Laboratory of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
| |
Collapse
|
10
|
Lentini JM, Fu D. Monitoring the 5-Methoxycarbonylmethyl-2-Thiouridine (mcm5s2U) Modification Utilizing the Gamma-Toxin Endonuclease. Methods Mol Biol 2021; 2298:197-216. [PMID: 34085247 DOI: 10.1007/978-1-0716-1374-0_13] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The post-transcriptional modification of tRNAs at the wobble position plays a critical role in proper mRNA decoding and efficient protein synthesis. In particular, certain wobble uridines in eukaryotes are converted to 5-methoxycarbonylmethyl-2-thiouridine (mcm5s2U). The mcm5s2U modification modulates decoding during translation by increasing the stringency of the wobble uridine to base pair with its canonical nucleotide partner, thereby restricting decoding to its cognate codon. Here, we outline a technique to monitor wobble uridine status in mcm5s2U-containing tRNAs using the gamma-toxin endonuclease from the yeast Kluyveromyces lactis that naturally cleaves tRNAs containing the mcm5s2U modification. This technique is coupled to Northern blotting or reverse transcription-PCR to enable rapid and sensitive detection of changes in mcm5s2U modification state.
Collapse
Affiliation(s)
- Jenna M Lentini
- Department of Biology, Center for RNA Biology, University of Rochester, Rochester, NY, USA
| | - Dragony Fu
- Department of Biology, Center for RNA Biology, University of Rochester, Rochester, NY, USA.
| |
Collapse
|
11
|
Wang H, Xu C, Zhang Y, Yan X, Jin X, Yao X, Chen P, Zheng B. PtKTI12 genes influence wobble uridine modifications and drought stress tolerance in hybrid poplar. TREE PHYSIOLOGY 2020; 40:1778-1791. [PMID: 32705117 DOI: 10.1093/treephys/tpaa088] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 07/13/2020] [Indexed: 06/11/2023]
Abstract
The multisubunit Elongator complex plays key roles in transcription by interacting with RNA polymerase II and chromatin modeling. Kti proteins have been identified as the auxiliary protein for the Elongator complex. However, our knowledge of Kti proteins in woody plants remains limited. In this study, in total 16 KTI gene homologs were identified in Populus trichocarpa. Among them, the two KTI12 candidates were named PtKTI12A and PtKTI12B. Although PtKTI12A and PtKTI12B were largely different in gene expression level and tissue specificity, both genes were induced by heat and drought stresses. PtKTI12A and PtKTI12B RNAi transgenic poplar plants showed reduced levels of modified nucleosides, in particular 5-carbamoylmethyluridine and 5-methoxycarbonylmethyl-2-thiouridine. Meanwhile, their tolerance to drought was improved when subjected to withdrawal of watering. Also, the protein products of PtKTI12A and PtKTI12B had similar subcellular localization and predicted tertiary structure. The results suggest that Kti12 proteins are involved in tRNA wobble uridine modification, stress response and drought stress tolerance in hybrid poplar.
Collapse
Affiliation(s)
- Hailang Wang
- College of Plant Science and Technology, Huazhong Agricultural University, Xueyuan Rd, Wuhan 430070, China
| | - Chao Xu
- Yuan Longping High-Tech Agriculture Co. Ltd., No. 638, Heping Rd, Changsha 410001, China
| | - Youbing Zhang
- Guangzhou Vipotion Biotechnology Co. Ltd., 5F, Building J5, No.1 Jiantashan Road, Guangzhou Science Park, Guangzhou 510663, China
| | - Xu Yan
- Shacheng Middle School, Longtan W St, Zhangjiakou 075000, China
| | - Xiaohuan Jin
- College of Plant Science and Technology, Huazhong Agricultural University, Xueyuan Rd, Wuhan 430070, China
| | - Xiaoqing Yao
- College of Plant Science and Technology, Huazhong Agricultural University, Xueyuan Rd, Wuhan 430070, China
| | - Peng Chen
- College of Plant Science and Technology, Huazhong Agricultural University, Xueyuan Rd, Wuhan 430070, China
| | - Bo Zheng
- Key Laboratory of Horticultural Plant Biology of Ministry of Education, College of Horticultural and Forestry Sciences, Huazhong Agricultural University, Xueyuan Rd, Wuhan 430070, China
| |
Collapse
|
12
|
Ogawa T, Takahashi K, Ishida W, Aono T, Hidaka M, Terada T, Masaki H. Substrate recognition mechanism of tRNA-targeting ribonuclease, colicin D, and an insight into tRNA cleavage-mediated translation impairment. RNA Biol 2020; 18:1193-1205. [PMID: 33211605 DOI: 10.1080/15476286.2020.1838782] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Colicin D is a plasmid-encoded bacteriocin that specifically cleaves tRNAArg of sensitive Escherichia coli cells. E. coli has four isoaccepting tRNAArgs; the cleavage occurs at the 3' end of anticodon-loop, leading to translation impairment in the sensitive cells. tRNAs form a common L-shaped structure and have many conserved nucleotides that limit tRNA identity elements. How colicin D selects tRNAArgs from the tRNA pool of sensitive E. coli cells is therefore intriguing. Here, we reveal the recognition mechanism of colicin D via biochemical analyses as well as structural modelling. Colicin D recognizes tRNAArgICG, the most abundant species of E. coli tRNAArgs, at its anticodon-loop and D-arm, and selects it as the most preferred substrate by distinguishing its anticodon-loop sequence from that of others. It has been assumed that translation impairment is caused by a decrease in intact tRNA molecules due to cleavage. However, we found that intracellular levels of intact tRNAArgICG do not determine the viability of sensitive cells after such cleavage; rather, an accumulation of cleaved ones does. Cleaved tRNAArgICG dominant-negatively impairs translation in vitro. Moreover, we revealed that EF-Tu, which is required for the delivery of tRNAs, does not compete with colicin D for binding tRNAArgICG, which is consistent with our structural model. Finally, elevation of cleaved tRNAArgICG level decreases the viability of sensitive cells. These results suggest that cleaved tRNAArgICG transiently occupies ribosomal A-site in an EF-Tu-dependent manner, leading to translation impairment. The strategy should also be applicable to other tRNA-targeting RNases, as they, too, recognize anticodon-loops.Abbreviations: mnm5U: 5-methylaminomethyluridine; mcm5s2U: 5-methoxycarbonylmethyl-2-thiouridine.
Collapse
Affiliation(s)
- Tetsuhiro Ogawa
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.,Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo, Japan
| | - Kazutoshi Takahashi
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Wataru Ishida
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Toshihiro Aono
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo, Japan.,Biotechnology Research Center, The University of Tokyo, Tokyo, Japan
| | - Makoto Hidaka
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.,Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo, Japan
| | - Tohru Terada
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.,Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo, Japan
| | - Haruhiko Masaki
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| |
Collapse
|
13
|
Geronikou A, Srimahaeak T, Rantsiou K, Triantafillidis G, Larsen N, Jespersen L. Occurrence of Yeasts in White-Brined Cheeses: Methodologies for Identification, Spoilage Potential and Good Manufacturing Practices. Front Microbiol 2020; 11:582778. [PMID: 33178163 PMCID: PMC7593773 DOI: 10.3389/fmicb.2020.582778] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 09/14/2020] [Indexed: 01/30/2023] Open
Abstract
Yeasts are generally recognized as contaminants in the production of white-brined cheeses, such as Feta and Feta-type cheeses. The most predominant yeasts species are Debaryomyces hansenii, Geotrichum candidum, Kluyveromyces marxianus, Kluyveromyces lactis, Rhodotorula mucilaginosa, and Trichosporon spp. Although their spoilage potential varies at both species and strain levels, yeasts will, in case of excessive growth, present a microbiological hazard, effecting cheese quality. To evaluate the hazard and trace routes of contamination, the exact taxonomic classification of yeasts is required. Today, identification of dairy yeasts is mainly based on DNA sequencing, various genotyping techniques, and, to some extent, advanced phenotypic identification technologies. Even though these technologies are state of the art at the scientific level, they are only hardly implemented at the industrial level. Quality defects, caused by yeasts in white-brined cheese, are mainly linked to enzymatic activities and metabolism of fermentable carbohydrates, leading to production of metabolites (CO2, fatty acids, volatile compounds, amino acids, sulfur compounds, etc.) and resulting in off-flavors, texture softening, discoloration, and swelling of cheese packages. The proliferation of spoilage yeast depends on maturation and storage conditions at each specific dairy, product characteristics, nutrients availability, and interactions with the co-existing microorganisms. To prevent and control yeast contamination, different strategies based on the principles of HACCP and Good Manufacturing Practice (GMP) have been introduced in white-brined cheese production. These strategies include milk pasteurization, refrigeration, hygienic sanitation, air filtration, as well as aseptic and modified atmosphere packaging. Though a lot of research has been dedicated to yeasts in dairy products, the role of yeast contaminants, specifically in white-brined cheeses, is still insufficiently understood. This review aims to summarize the current knowledge on the identification of contaminant yeasts in white-brined cheeses, their occurrence and spoilage potential related to different varieties of white-brined cheeses, their interactions with other microorganisms, as well as guidelines used by dairies to prevent cheese contamination.
Collapse
Affiliation(s)
- Athina Geronikou
- Department of Food Science, Faculty of Science, University of Copenhagen, Frederiksberg, Denmark
| | - Thanyaporn Srimahaeak
- Department of Food Science, Faculty of Science, University of Copenhagen, Frederiksberg, Denmark
| | - Kalliopi Rantsiou
- Department of Agricultural, Forestry and Food Sciences, University of Turin, Turin, Italy
| | | | - Nadja Larsen
- Department of Food Science, Faculty of Science, University of Copenhagen, Frederiksberg, Denmark
| | - Lene Jespersen
- Department of Food Science, Faculty of Science, University of Copenhagen, Frederiksberg, Denmark
| |
Collapse
|
14
|
Rosace D, López J, Blanco S. Emerging roles of novel small non-coding regulatory RNAs in immunity and cancer. RNA Biol 2020; 17:1196-1213. [PMID: 32186461 DOI: 10.1080/15476286.2020.1737442] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The term small non-coding RNAs (ncRNAs) refers to all those RNAs that even without encoding for a protein, can play important functional roles. Transfer RNA and ribosomal RNA-derived fragments (tRFs and rRFs, respectively) are an emerging class of ncRNAs originally considered as simple degradation products, which though play important roles in stress responses, signalling, or gene expression. They control all levels of gene expression regulating transcription and translation and affecting RNA processing and maturation. They have been linked to pivotal cellular processes such as self-renewal, differentiation, and proliferation. For this reason, mis-regulation of this novel class of ncRNAs can lead to various pathological processes such as neurodegenerative and development diseases, metabolism and immune system disorders, and cancer. In this review, we summarise the classification, biogenesis, and functions of tRFs and rRFs with a special focus on their role in immunity and cancer.
Collapse
Affiliation(s)
- Domenico Rosace
- Centro De Investigación Del Cáncer and Instituto De Biología Molecular Y Celular Del Cáncer, Consejo Superior De Investigaciones Científicas (CSIC) - University of Salamanca , Salamanca, Spain
| | - Judith López
- Centro De Investigación Del Cáncer and Instituto De Biología Molecular Y Celular Del Cáncer, Consejo Superior De Investigaciones Científicas (CSIC) - University of Salamanca , Salamanca, Spain
| | - Sandra Blanco
- Centro De Investigación Del Cáncer and Instituto De Biología Molecular Y Celular Del Cáncer, Consejo Superior De Investigaciones Científicas (CSIC) - University of Salamanca , Salamanca, Spain
| |
Collapse
|
15
|
Oberbauer V, Schaefer MR. tRNA-Derived Small RNAs: Biogenesis, Modification, Function and Potential Impact on Human Disease Development. Genes (Basel) 2018; 9:genes9120607. [PMID: 30563140 PMCID: PMC6315542 DOI: 10.3390/genes9120607] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 11/27/2018] [Accepted: 11/29/2018] [Indexed: 12/11/2022] Open
Abstract
Transfer RNAs (tRNAs) are abundant small non-coding RNAs that are crucially important for decoding genetic information. Besides fulfilling canonical roles as adaptor molecules during protein synthesis, tRNAs are also the source of a heterogeneous class of small RNAs, tRNA-derived small RNAs (tsRNAs). Occurrence and the relatively high abundance of tsRNAs has been noted in many high-throughput sequencing data sets, leading to largely correlative assumptions about their potential as biologically active entities. tRNAs are also the most modified RNAs in any cell type. Mutations in tRNA biogenesis factors including tRNA modification enzymes correlate with a variety of human disease syndromes. However, whether it is the lack of tRNAs or the activity of functionally relevant tsRNAs that are causative for human disease development remains to be elucidated. Here, we review the current knowledge in regard to tsRNAs biogenesis, including the impact of RNA modifications on tRNA stability and discuss the existing experimental evidence in support for the seemingly large functional spectrum being proposed for tsRNAs. We also argue that improved methodology allowing exact quantification and specific manipulation of tsRNAs will be necessary before developing these small RNAs into diagnostic biomarkers and when aiming to harness them for therapeutic purposes.
Collapse
Affiliation(s)
- Vera Oberbauer
- Division of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University Vienna, Schwarzspanierstrasse 17, A-1090 Vienna, Austria.
| | - Matthias R Schaefer
- Division of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University Vienna, Schwarzspanierstrasse 17, A-1090 Vienna, Austria.
| |
Collapse
|
16
|
Shigematsu M, Kawamura T, Kirino Y. Generation of 2',3'-Cyclic Phosphate-Containing RNAs as a Hidden Layer of the Transcriptome. Front Genet 2018; 9:562. [PMID: 30538719 PMCID: PMC6277466 DOI: 10.3389/fgene.2018.00562] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 11/06/2018] [Indexed: 01/03/2023] Open
Abstract
Cellular RNA molecules contain phosphate or hydroxyl ends. A 2′,3′-cyclic phosphate (cP) is one of the 3′-terminal forms of RNAs mainly generated from RNA cleavage by ribonucleases. Although transcriptome profiling using RNA-seq has become a ubiquitous tool in biological and medical research, cP-containing RNAs (cP-RNAs) form a hidden transcriptome layer, which is infrequently recognized and characterized, because standard RNA-seq is unable to capture them. Despite cP-RNAs’ invisibility in RNA-seq data, increasing evidence indicates that they are not accumulated simply as non-functional degradation products; rather, they have physiological roles in various biological processes, designating them as noteworthy functional molecules. This review summarizes our current knowledge of cP-RNA biogenesis pathways and their catalytic enzymatic activities, discusses how the cP-RNA generation affects biological processes, and explores future directions to further investigate cP-RNA biology.
Collapse
Affiliation(s)
- Megumi Shigematsu
- Computational Medicine Center, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, United States
| | - Takuya Kawamura
- Computational Medicine Center, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, United States
| | - Yohei Kirino
- Computational Medicine Center, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, United States
| |
Collapse
|
17
|
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: 98] [Impact Index Per Article: 16.3] [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
|
18
|
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
|
19
|
Abstract
Constitutive and regulated turnover of RNAs is necessary to eliminate aberrant RNA molecules and control the level of specific mRNAs to maintain homeostasis or to respond to signals in living cells. Modifications of nucleosides in specific RNAs are important in modulating the functions of these transcripts, but they can also dramatically impact their fate and turnover. This chapter will review how RNA modifications impact the activities of ribonucleases that target these RNAs for degradation or cleavage, focusing more particularly on tRNAs and mRNAs in eukaryotic cells. Many nucleoside modifications are important to promote proper folding of tRNAs, and the absence of specific modifications makes them susceptible to degradation by quality control pathways that eliminate improperly folded species. Modifications in tRNAs can also modulate their cleavage during stress or by fungal toxins that target modified nucleosides. Modifications of the cap structure found at the 5'-end of eukaryotic mRNAs are essential to control the degradation of these mRNAs. In addition, internal modifications of eukaryotic mRNAs can change their secondary structures or provide binding sites for reader proteins, which can dramatically impact their stability. Recent examples show that mRNA modifications play important roles in regulating mRNA stability during development, cellular differentiation and physiological responses. Finally, many modifications can impact microRNA- and siRNA-mediated gene regulation by direct or indirect effects. With the growing number of genomic techniques able to identify modifications genome wide, it is anticipated that novel chemical modifications or new modification sites will be identified, which will play additional regulatory functions for RNA turnover.
Collapse
|
20
|
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
|
21
|
Kolaj-Robin O, Séraphin B. Structures and Activities of the Elongator Complex and Its Cofactors. RNA MODIFICATION 2017; 41:117-149. [DOI: 10.1016/bs.enz.2017.03.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
22
|
Karlsborn T, Tükenmez H, Mahmud AKMF, Xu F, Xu H, Byström AS. Elongator, a conserved complex required for wobble uridine modifications in eukaryotes. RNA Biol 2015; 11:1519-28. [PMID: 25607684 DOI: 10.4161/15476286.2014.992276] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Elongator is a 6 subunit protein complex highly conserved in eukaryotes. The role of this complex has been controversial as the pleiotropic phenotypes of Elongator mutants have implicated the complex in several cellular processes. However, in yeast there is convincing evidence that the primary and probably only role of this complex is in formation of the 5-methoxycarbonylmethyl (mcm(5)) and 5-carbamoylmethyl (ncm(5)) side chains on uridines at wobble position in tRNA. In this review we summarize the cellular processes that have been linked to the Elongator complex and discuss its role in tRNA modification and regulation of translation. We also describe additional gene products essential for formation of ncm(5) and mcm(5) side chains at U34 and their influence on Elongator activity.
Collapse
Affiliation(s)
- Tony Karlsborn
- a Department of Molecular Biology ; Umeå University; Umeå , Sweden
| | | | | | | | | | | |
Collapse
|
23
|
Surveillance and cleavage of eukaryotic tRNAs. Int J Mol Sci 2015; 16:1873-93. [PMID: 25599528 PMCID: PMC4307339 DOI: 10.3390/ijms16011873] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 01/09/2015] [Indexed: 12/27/2022] Open
Abstract
Beyond their central role in protein synthesis, transfer RNAs (tRNAs) have many other crucial functions. This includes various roles in the regulation of gene expression, stress responses, metabolic processes and priming reverse transcription. In the RNA world, tRNAs are, with ribosomal RNAs, among the most stable molecules. Nevertheless, they are not eternal. As key elements of cell function, tRNAs need to be continuously quality-controlled. Two tRNA surveillance pathways have been identified. They act on hypo-modified or mis-processed pre-tRNAs and on mature tRNAs lacking modifications. A short overview of these two pathways will be presented here. Furthermore, while the exoribonucleases acting in these pathways ultimately lead to complete tRNA degradation, numerous tRNA-derived fragments (tRFs) are present within a cell. These cleavage products of tRNAs now potentially emerge as a new class of small non-coding RNAs (sncRNAs) and are suspected to have important regulatory functions. The tRFs are evolutionarily widespread and created by cleavage at different positions by various endonucleases. Here, we review our present knowledge on the biogenesis and function of tRFs in various organisms.
Collapse
|
24
|
Structure, mechanism, and specificity of a eukaryal tRNA restriction enzyme involved in self-nonself discrimination. Cell Rep 2014; 7:339-347. [PMID: 24726365 DOI: 10.1016/j.celrep.2014.03.034] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2014] [Revised: 02/26/2014] [Accepted: 03/11/2014] [Indexed: 11/22/2022] Open
Abstract
tRNA restriction by anticodon nucleases underlies cellular stress responses and self-nonself discrimination in a wide range of taxa. Anticodon breakage inhibits protein synthesis, which, in turn, results in growth arrest or cell death. The eukaryal ribotoxin PaT secreted by Pichia acaciae inhibits growth of Saccharomyces cerevisiae via cleavage of tRNA(Gln(UUG)). We find that recombinant PaT incises a synthetic tRNA(Gln(UUG)) stem-loop RNA by transesterification at a single site 3' of the wobble uridine, yielding 2',3'-cyclic phosphate and 5'-OH ends. Incision is suppressed by replacement of the wobble nucleobase with adenine or guanine. The crystal structure of PaT reveals a distinctive fold and active site, essential components of which are demonstrated by mutagenesis. Pichia acaciae evades self-toxicity via a distinctive intracellular immunity protein, ImmPaT, which binds PaT and blocks nuclease activity. Our results highlight the evolutionary diversity of tRNA restriction and immunity systems.
Collapse
|
25
|
Abstract
Post-transcriptional cleavage of RNA molecules to generate smaller fragments is a widespread mechanism that enlarges the structural and functional complexity of cellular RNomes. Substrates for such RNA fragmentations are coding as well as non-protein-coding RNAs. In particular, fragments derived from both precursor and mature tRNAs represent one of the rapidly growing classes of post-transcriptional RNA pieces. Importantly, these tRNA fragments possess distinct expression patterns, abundance, cellular localizations, or biological roles compared with their parental tRNA molecules. Here we review recent reports on tRNA cleavage and attempt to categorize tRNA pieces according to their origin and cellular function. The biological scope of tRNA-derived fragments ranges from translation control, over RNA silencing, to regulating apoptosis, and thus clearly enlarges the functional repertoire of ncRNA biology.
Collapse
Affiliation(s)
- Jennifer Gebetsberger
- Department of Chemistry and Biochemistry; University of Bern; Bern, Switzerland; Graduate School for Cellular and Biomedical Sciences; University of Bern; Bern, Switzerland
| | - Norbert Polacek
- Department of Chemistry and Biochemistry; University of Bern; Bern, Switzerland; Division of Genomics and RNomics; Medical University Innsbruck; Innsbruck, Austria
| |
Collapse
|
26
|
Sochacka E, Bartos P, Kraszewska K, Nawrot B. Desulfuration of 2-thiouridine with hydrogen peroxide in the physiological pH range 6.6–7.6 is pH-dependent and results in two distinct products. Bioorg Med Chem Lett 2013; 23:5803-5. [DOI: 10.1016/j.bmcl.2013.08.114] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 08/29/2013] [Accepted: 08/30/2013] [Indexed: 10/26/2022]
|
27
|
El Yacoubi B, Bailly M, de Crécy-Lagard V. Biosynthesis and Function of Posttranscriptional Modifications of Transfer RNAs. Annu Rev Genet 2012; 46:69-95. [DOI: 10.1146/annurev-genet-110711-155641] [Citation(s) in RCA: 380] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Basma El Yacoubi
- Department of Microbiology and Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611-0700;
| | - Marc Bailly
- Department of Microbiology and Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611-0700;
| | - Valérie de Crécy-Lagard
- Department of Microbiology and Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611-0700;
| |
Collapse
|
28
|
Meineke B, Shuman S. Determinants of the cytotoxicity of PrrC anticodon nuclease and its amelioration by tRNA repair. RNA (NEW YORK, N.Y.) 2012; 18:145-54. [PMID: 22101242 PMCID: PMC3261736 DOI: 10.1261/rna.030171.111] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Accepted: 10/10/2011] [Indexed: 05/23/2023]
Abstract
Breakage of tRNA(Lys(UUU)) by the Escherichia coli anticodon nuclease PrrC (EcoPrrC) underlies a host antiviral response to phage T4 infection that is ultimately thwarted by a virus-encoded RNA repair system. PrrC homologs are prevalent in other bacteria, but their activities and substrates are not defined. We find that induced expression of EcoPrrC is toxic in Saccharomyces cerevisiae and E. coli, whereas the Neisseria meningitidis PrrC (NmePrrC) is not. PrrCs consist of an N-terminal NTPase module and a C-terminal nuclease module. Domain swaps identified the EcoPrrC nuclease domain as decisive for toxicity when linked to either the Eco or Nme NTPase. Indeed, a single arginine-to-tryptophan change in the NmePrrC nuclease domain (R316W) educed a gain-of-function and rendered NmePrrC toxic to yeast, with genetic evidence for tRNA(Lys(UUU)) being the relevant target. The reciprocal Trp-to-Arg change in EcoPrrC (W335R) abolished its toxicity. Further mutagenesis of the EcoPrrC nuclease domain highlighted an ensemble of 15 essential residues and distinguished between hypomorphic alleles and potential nuclease-nulls. We report that the RNA repair phase of the bacterial virus-host dynamic is also portable to yeast, where coexpression of the T4 enzymes Pnkp and Rnl1 ameliorated the toxicity of NmePrrC-R316W. Plant tRNA ligase AtRNL also countered NmePrrC-R316W toxicity, in a manner that depended on AtRNL's 5'-kinase and ligase functions.
Collapse
Affiliation(s)
- Birthe Meineke
- Molecular Biology Program, Sloan-Kettering Institute, New York, New York 10065, USA
| | - Stewart Shuman
- Molecular Biology Program, Sloan-Kettering Institute, New York, New York 10065, USA
| |
Collapse
|
29
|
The dual role of ubiquitin-like protein Urm1 as a protein modifier and sulfur carrier. Protein Cell 2011; 2:612-9. [PMID: 21904977 DOI: 10.1007/s13238-011-1074-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Accepted: 06/29/2011] [Indexed: 01/20/2023] Open
Abstract
The ubiquitin-related modifier Urm1 can be covalently conjugated to lysine residues of other proteins, such as yeast Ahp1 and human MOCS3, through a mechanism involving the E1-like protein Uba4 (MOCS3 in humans). Similar to ubiquitination, urmylation requires a thioester intermediate and forms isopeptide bonds between Urm1 and its substrates. In addition, the urmylation process can be significantly enhanced by oxidative stress. Recent findings have demonstrated that Urm1 also acts as a sulfur carrier in the thiolation of eukaryotic tRNA via a mechanism that requires the formation of a thiocarboxylated Urm1. This role is very similar to that of prokaryotic sulfur carriers such as MoaD and ThiS. Evidence strongly supports the hypothesis that Urm1 is the molecular fossil in the evolutionary link between prokaryotic sulfur carriers and eukaryotic ubiquitin-like proteins. In the present review, we discuss the dual role of Urm1 in protein and tRNA modification.
Collapse
|
30
|
Zhabokritsky A, Kutky M, Burns LA, Karran RA, Hudak KA. RNA toxins: mediators of stress adaptation and pathogen defense. WILEY INTERDISCIPLINARY REVIEWS-RNA 2011; 2:890-903. [PMID: 21809449 DOI: 10.1002/wrna.99] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
RNA toxins are a group of enzymes primarily synthesized by bacteria, fungi, and plants that either cleave or depurinate RNA molecules. These proteins may be divided according to their RNA substrates: ribotoxins are nucleases that cleave ribosomal RNA (rRNA), ribosome inactivating proteins are glycosidases that remove a base from rRNA, messenger RNA (mRNA) interferases are nucleases that cleave mRNAs, and anticodon nucleases cleave transfer RNAs (tRNAs). These modifications to the RNAs may substantially alter gene expression and translation rates. Given that some of these enzymes cause cell death, it has been suggested that they function mainly in defense, either to kill competing cells or to elicit suicide and thereby limit pathogen spread from infected cells. Although good correlations have been drawn between their enzymatic functions and toxicity, recent work has shown that some RNA toxins cause apoptosis in the absence of damage to RNA and that defense against pathogens can be achieved without host cell death. Moreover, a decrease in cellular translation rate, insufficient to cause cell death, allows some organisms to adapt to stress and environmental change. Although ascribing effects observed in vitro to the roles of these toxins in nature has been challenging, recent results have expanded our understanding of their modes of action, and emphasized the importance of these toxins in development, adaptation to stress and defense against pathogens.
Collapse
|
31
|
Jain R, Poulos MG, Gros J, Chakravarty AK, Shuman S. Substrate specificity and mutational analysis of Kluyveromyces lactis gamma-toxin, a eukaryal tRNA anticodon nuclease. RNA (NEW YORK, N.Y.) 2011; 17:1336-43. [PMID: 21610213 PMCID: PMC3138569 DOI: 10.1261/rna.2722711] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Accepted: 04/11/2011] [Indexed: 05/30/2023]
Abstract
tRNA anticodon damage inflicted by the Kluyveromyces lactis γ-toxin underlies an RNA-based innate immune system that distinguishes self from nonself species. γ-toxin arrests the growth of Saccharomyces cerevisiae by incising a single phosphodiester 3' of the wobble base of tRNA(Glu(UUC)) to generate a break with 2',3'-cyclic phosphate and 5'-OH ends. Recombinant γ-toxin cleaves oligonucleotide substrates in vitro that mimic the anticodon stem-loop of tRNA(Glu). A single 2'-deoxy sugar substitution at the wobble nucleoside abolishes anticodon nuclease activity. To gain further insights to γ-toxin's substrate specificity, we tested deoxynucleoside effects at positions other than the site of transesterification. The results attest to a stringent requirement for a ribonucleoside at the uridine 5' of the wobble base. In contrast, every other nonwobble ribonucleoside in the anticodon loop can be replaced by a deoxy without significantly affecting γ-toxin's cleavage activity. Whereas either the 5' half or the 3' half of the anticodon stem can be replaced en bloc with DNA without a major effect, simultaneously replacing both strands with DNA interfered strongly, signifying that γ-toxin requires an A-form helical conformation of the anticodon stem. We purified γ-toxin mutants identified previously as nontoxic in vivo and gauged their anticodon nuclease activities in vitro. The results highlight Glu9 and Arg151 as candidate catalytic residues, along with His209 implicated previously. By analogy to other endoribonucleases, we speculate that γ-toxin drives transesterification by general acid-base catalysis (via His209 and Glu9) and transition-state stabilization (via Arg151).
Collapse
Affiliation(s)
- Ruchi Jain
- Molecular Biology Program, Sloan-Kettering Institute, New York, New York 10065, USA.
| | | | | | | | | |
Collapse
|
32
|
Tanaka N, Shuman S. RtcB is the RNA ligase component of an Escherichia coli RNA repair operon. J Biol Chem 2011; 286:7727-7731. [PMID: 21224389 DOI: 10.1074/jbc.c111.219022] [Citation(s) in RCA: 124] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
RNA 2',3'-cyclic phosphate ends play important roles in RNA metabolism as substrates for RNA ligases during tRNA restriction-repair and tRNA splicing. Diverse bacteria from multiple phyla encode a two-component RNA repair cassette, comprising Pnkp (polynucleotide kinase-phosphatase-ligase) and Hen1 (RNA 3'-terminal ribose 2'-O-methyltransferase), that heals and then seals broken tRNAs with 2',3'-cyclic phosphate and 5'-OH ends. The Pnkp-Hen1 repair operon is absent in the majority of bacterial species, thereby raising the prospect that other RNA repair systems might be extant. A candidate component is RNA 3'-phosphate cyclase, a widely distributed enzyme that transforms RNA 3'-monophosphate termini into 2',3'-cyclic phosphates but cannot seal the ends it produces. Escherichia coli RNA cyclase (RtcA) is encoded in a σ(54)-regulated operon with RtcB, a protein of unknown function. Taking a cue from Pnkp-Hen1, we purified E. coli RtcB and tested it for RNA ligase activity. We report that RtcB per se seals broken tRNA-like stem-loop structures with 2',3'-cyclic phosphate and 5'-OH ends to form a splice junction with a 2'-OH, 3',5'-phosphodiester. We speculate that: (i) RtcB might afford bacteria a means to recover from stress-induced RNA damage; and (ii) RtcB homologs might catalyze tRNA repair or splicing reactions in archaea and eukarya.
Collapse
Affiliation(s)
- Naoko Tanaka
- From the Molecular Biology Program, Sloan-Kettering Institute, New York, New York 10065
| | - Stewart Shuman
- From the Molecular Biology Program, Sloan-Kettering Institute, New York, New York 10065.
| |
Collapse
|
33
|
Meineke B, Schwer B, Schaffrath R, Shuman S. Determinants of eukaryal cell killing by the bacterial ribotoxin PrrC. Nucleic Acids Res 2010; 39:687-700. [PMID: 20855293 PMCID: PMC3025547 DOI: 10.1093/nar/gkq831] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
tRNA damage inflicted by the Escherichia coli anticodon nuclease PrrC (EcoPrrC) underlies an antiviral response to phage T4 infection. PrrC homologs are present in many bacterial proteomes, though their biological activities are uncharted. PrrCs consist of two domains: an N-terminal NTPase module related to the ABC family and a distinctive C-terminal ribonuclease module. In this article, we report that the expression of EcoPrrC in budding yeast is fungicidal, signifying that PrrC is toxic in a eukaryon in the absence of other bacterial or viral proteins. Whereas Streptococcus PrrC is also toxic in yeast, Neisseria and Xanthomonas PrrCs are not. Via analysis of the effects of 118 mutations on EcoPrrC toxicity in yeast, we identified 22 essential residues in the NTPase domain and 11 in the nuclease domain. Overexpressing PrrCs with mutations in the NTPase active site ameliorated the toxicity of wild-type EcoPrrC. Our findings support a model in which EcoPrrC toxicity is contingent on head-to-tail dimerization of the NTPase domains to form two composite NTP phosphohydrolase sites. Comparisons of EcoPrrC activity in a variety of yeast genetic backgrounds, and the rescuing effects of tRNA overexpression, implicate tRNALys(UUU) as a target of EcoPrrC toxicity in yeast.
Collapse
Affiliation(s)
- Birthe Meineke
- Molecular Biology Program, Sloan-Kettering Institute, Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY 10065 USA and Department of Genetics, University of Leicester, Leicester, LE1 7RH, UK
| | - Beate Schwer
- Molecular Biology Program, Sloan-Kettering Institute, Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY 10065 USA and Department of Genetics, University of Leicester, Leicester, LE1 7RH, UK
| | - Raffael Schaffrath
- Molecular Biology Program, Sloan-Kettering Institute, Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY 10065 USA and Department of Genetics, University of Leicester, Leicester, LE1 7RH, UK
| | - Stewart Shuman
- Molecular Biology Program, Sloan-Kettering Institute, Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY 10065 USA and Department of Genetics, University of Leicester, Leicester, LE1 7RH, UK
- *To whom correspondence should be addressed. Tel: +1 212 639 7145; Fax: +1 212 717 3623;
| |
Collapse
|
34
|
Schaefer M, Pollex T, Hanna K, Tuorto F, Meusburger M, Helm M, Lyko F. RNA methylation by Dnmt2 protects transfer RNAs against stress-induced cleavage. Genes Dev 2010; 24:1590-5. [PMID: 20679393 DOI: 10.1101/gad.586710] [Citation(s) in RCA: 516] [Impact Index Per Article: 36.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Dnmt2 proteins are the most conserved members of the DNA methyltransferase enzyme family, but their substrate specificity and biological functions have been a subject of controversy. We show here that, in addition to tRNA(Asp-GTC), tRNA(Val-AAC) and tRNA(Gly-GCC) are also methylated by Dnmt2. Drosophila Dnmt2 mutants showed reduced viability under stress conditions, and Dnmt2 relocalized to stress granules following heat shock. Strikingly, stress-induced cleavage of tRNAs was Dnmt2-dependent, and Dnmt2-mediated methylation protected tRNAs against ribonuclease cleavage. These results uncover a novel biological function of Dnmt2-mediated tRNA methylation, and suggest a role for Dnmt2 enzymes during the biogenesis of tRNA-derived small RNAs.
Collapse
Affiliation(s)
- Matthias Schaefer
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, Heidelberg 69120, Germany
| | | | | | | | | | | | | |
Collapse
|
35
|
Mehlgarten C, Jablonowski D, Wrackmeyer U, Tschitschmann S, Sondermann D, Jäger G, Gong Z, Byström AS, Schaffrath R, Breunig KD. Elongator function in tRNA wobble uridine modification is conserved between yeast and plants. Mol Microbiol 2010; 76:1082-94. [PMID: 20398216 PMCID: PMC2904499 DOI: 10.1111/j.1365-2958.2010.07163.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/05/2010] [Indexed: 01/17/2023]
Abstract
Based on studies in yeast and mammalian cells the Elongator complex has been implicated in functions as diverse as histone acetylation, polarized protein trafficking and tRNA modification. Here we show that Arabidopsis mutants lacking the Elongator subunit AtELP3/ELO3 have a defect in tRNA wobble uridine modification. Moreover, we demonstrate that yeast elp3 and elp1 mutants expressing the respective Arabidopsis Elongator homologues AtELP3/ELO3 and AtELP1/ELO2 assemble integer Elongator complexes indicating a high degree of structural conservation. Surprisingly, in vivo complementation studies based on Elongator-dependent tRNA nonsense suppression and zymocin tRNase toxin assays indicated that while AtELP1 rescued defects of a yeast elp1 mutant, the most conserved Elongator gene AtELP3, failed to complement an elp3 mutant. This lack of complementation is due to incompatibility with yeast ELP1 as coexpression of both plant genes in an elp1 elp3 yeast mutant restored Elongator's tRNA modification function in vivo. Similarly, AtELP1, not ScELP1 also supported partial complementation by yeast-plant Elp3 hybrids suggesting that AtElp1 has less stringent sequence requirements for Elp3 than ScElp1. We conclude that yeast and plant Elongator share tRNA modification roles and propose that this function might be conserved in Elongator from all eukaryotic kingdoms of life.
Collapse
Affiliation(s)
- Constance Mehlgarten
- Institut für Biologie, Genetik, Martin-Luther-Universität Halle-WittenbergWeinbergweg 10, D-06120 Halle (Saale), Germany
| | - Daniel Jablonowski
- Institut für Biologie, Genetik, Martin-Luther-Universität Halle-WittenbergWeinbergweg 10, D-06120 Halle (Saale), Germany
| | - Uta Wrackmeyer
- Institut für Biologie, Genetik, Martin-Luther-Universität Halle-WittenbergWeinbergweg 10, D-06120 Halle (Saale), Germany
| | - Susan Tschitschmann
- Institut für Biologie, Genetik, Martin-Luther-Universität Halle-WittenbergWeinbergweg 10, D-06120 Halle (Saale), Germany
| | - David Sondermann
- Institut für Biologie, Genetik, Martin-Luther-Universität Halle-WittenbergWeinbergweg 10, D-06120 Halle (Saale), Germany
| | - Gunilla Jäger
- Department of Molecular Biology, Umea University90187 Umea, Sweden
| | - Zhizhong Gong
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural UniversityBeijing 100094, China
| | - Anders S Byström
- Department of Molecular Biology, Umea University90187 Umea, Sweden
| | - Raffael Schaffrath
- Institut für Biologie, Genetik, Martin-Luther-Universität Halle-WittenbergWeinbergweg 10, D-06120 Halle (Saale), Germany
| | - Karin D Breunig
- Institut für Biologie, Genetik, Martin-Luther-Universität Halle-WittenbergWeinbergweg 10, D-06120 Halle (Saale), Germany
| |
Collapse
|
36
|
Mehlgarten C, Jablonowski D, Breunig KD, Stark MJR, Schaffrath R. Elongator function depends on antagonistic regulation by casein kinase Hrr25 and protein phosphatase Sit4. Mol Microbiol 2009; 73:869-81. [PMID: 19656297 DOI: 10.1111/j.1365-2958.2009.06811.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In yeast, the role for the Elongator complex in tRNA anticodon modification is affected by phosphorylation of Elongator subunit Elp1. Thus, hyperphosphorylation of Elp1 due to inactivation of protein phosphatase Sit4 correlates with Elongator-minus phenotypes including resistance towards zymocin, a tRNase cleaving anticodons of Elongator-dependent tRNAs. Here we show that zymocin resistance of casein kinase hrr25 mutants associates with hypophosphorylation of Elp1 and that nonsense suppression by the Elongator-dependent SUP4 tRNA is abolished in hrr25 or sit4 mutants. Thus changes that perturb the evenly balanced ratio between hyper- and hypophosphorylated Elp1 forms present in wild-type cells lead to Elongator inactivation. Antagonistic roles for Hrr25 and Sit4 in Elongator function are further supported by our data that Sit4 inactivation is capable of restoring both zymocin sensitivity and normal ratios between the two Elp1 forms in hrr25 mutants. Hrr25 binds to Elongator in a fashion dependent on Elongator partner Kti12. Like sit4 mutants, overexpression of Kti12 triggers Elp1 hyperphosphorylation. Intriguingly, this effect of Kti12 is blocked by hrr25 mutations, which also show enhanced binding of Kti12 to Elongator. Collectively, our data suggest that rather than directly targeting Elp1, the Hrr25 kinase indirectly affects Elp1 phosphorylation states through control of Sit4-dependent dephosphorylation of Elp1.
Collapse
Affiliation(s)
- Constance Mehlgarten
- Institut für Biologie, Genetik, Martin-Luther-Universität Halle-Wittenberg, Halle (Saale), Germany
| | | | | | | | | |
Collapse
|
37
|
Keppetipola N, Jain R, Meineke B, Diver M, Shuman S. Structure-activity relationships in Kluyveromyces lactis gamma-toxin, a eukaryal tRNA anticodon nuclease. RNA (NEW YORK, N.Y.) 2009; 15:1036-44. [PMID: 19383764 PMCID: PMC2685522 DOI: 10.1261/rna.1637809] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2009] [Accepted: 03/27/2009] [Indexed: 05/23/2023]
Abstract
tRNA anticodon damage inflicted by secreted ribotoxins such as Kluyveromyces lactis gamma-toxin and bacterial colicins underlies a rudimentary innate immune system that distinguishes self from nonself species. The intracellular expression of gamma-toxin (a 232-amino acid polypeptide) arrests the growth of Saccharomyces cerevisiae by incising a single RNA phosphodiester 3' of the modified wobble base of tRNA(Glu). Fungal gamma-toxin bears no primary structure similarity to any known nuclease and has no plausible homologs in the protein database. To gain insight to gamma-toxin's mechanism, we tested the effects of alanine mutations at 62 basic, acidic, and polar amino acids on ribotoxin activity in vivo. We thereby identified 22 essential residues, including 10 lysines, seven arginines, three glutamates, one cysteine, and one histidine (His209, the only histidine present in gamma-toxin). Structure-activity relations were gleaned from the effects of 44 conservative substitutions. Recombinant tag-free gamma-toxin, a monomeric protein, incised an oligonucleotide corresponding to the anticodon stem-loop of tRNA(Glu) at a single phosphodiester 3' of the wobble uridine. The anticodon nuclease was metal independent. RNA cleavage was abolished by ribose 2'-H and 2'-F modifications of the wobble uridine. Mutating His209 to alanine, glutamine, or asparagine abolished nuclease activity. We propose that gamma-toxin catalyzes an RNase A-like transesterification reaction that relies on His209 and a second nonhistidine side chain as general acid-base catalysts.
Collapse
|
38
|
Urm1 at the crossroad of modifications. 'Protein Modifications: Beyond the Usual Suspects' Review Series. EMBO Rep 2009; 9:1196-202. [PMID: 19047990 DOI: 10.1038/embor.2008.209] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2008] [Accepted: 10/20/2008] [Indexed: 11/08/2022] Open
Abstract
The ubiquitin-like protein Urm1 can be covalently conjugated to other proteins, such as the yeast thioredoxin peroxidase protein Ahp1p, through a mechanism involving the ubiquitin E1-like enzyme Uba4. Recent findings have revealed a second function of Urm1 as a sulphur carrier in the thiolation of eukaryotic cytoplasmic transfer RNAs (tRNAs). Interestingly, this new role of Urm1 is similar to the sulphur-carrier activity of its prokaryotic counterparts, strengthening the hypothesis that Urm1 is a molecular fossil of the ubiquitin-like protein family. Here, we discuss the function of Urm1 in light of its dual role in protein and RNA modification.
Collapse
|
39
|
A functional proteomics approach links the ubiquitin-related modifier Urm1 to a tRNA modification pathway. Proc Natl Acad Sci U S A 2008; 105:18255-60. [PMID: 19017811 DOI: 10.1073/pnas.0808756105] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Urm1 is a highly conserved ubiquitin-related modifier of unknown function. A reduction of cellular Urm1 levels causes severe cytokinesis defects in HeLa cells, resulting in the accumulation of enlarged multinucleated cells. To understand the underlying mechanism, we applied a functional proteomics approach and discovered an enzymatic activity that links Urm1 to a tRNA modification pathway. Unlike ubiquitin (Ub) and many Ub-like modifiers, which are commonly conjugated to proteinaceous targets, Urm1 is activated by an unusual mechanism to yield a thiocarboxylate intermediate that serves as sulfur donor in tRNA thiolation reactions. This mechanism is reminiscent of that used by prokaryotic sulfur carriers and thus defines the evolutionary link between ancient Ub progenitors and the eukaryotic Ub/Ub-like modification systems.
Collapse
|
40
|
Huang B, Lu J, Byström AS. A genome-wide screen identifies genes required for formation of the wobble nucleoside 5-methoxycarbonylmethyl-2-thiouridine in Saccharomyces cerevisiae. RNA (NEW YORK, N.Y.) 2008; 14:2183-94. [PMID: 18755837 PMCID: PMC2553728 DOI: 10.1261/rna.1184108] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
We recently showed that the gamma-subunit of Kluyveromyces lactis killer toxin (gamma-toxin) is a tRNA endonuclease that cleaves tRNA(mcm5s2UUC Glu), tRNA(mcm5s2UUU Lys), and tRNA(mcm5s2UUG Gln) 3' of the wobble nucleoside 5-methoxycarbonylmethyl-2-thiouridine (mcm(5)s(2)U). The 5-methoxycarbonylmethyl (mcm(5)) side chain was important for efficient cleavage by gamma-toxin, and defects in mcm(5) side-chain synthesis correlated with resistance to gamma-toxin. Based on this correlation, a genome-wide screen was performed to identify gene products involved in the formation of the mcm(5) side chain. From a collection of 4826 homozygous diploid Saccharomyces cerevisiae strains, each with one nonessential gene deleted, 63 mutants resistant to Kluyveromyces lactis killer toxin were identified. Among these, eight were earlier identified to have a defect in formation of the mcm(5) side chain. Analysis of the remaining mutants and other known gamma-toxin resistant mutants revealed that sit4, kti14, and KTI5 mutants also have a defect in the formation of mcm(5). A mutant lacking two of the Sit4-associated proteins, Sap185 and Sap190, displays the same modification defect as a sit4-null mutant. Interestingly, several mutants were found to be defective in the synthesis of the 2-thio (s(2)) group of the mcm(5)s(2)U nucleoside. In addition to earlier described mutants, formation of the s(2) group was also abolished in urm1, uba4, and ncs2 mutants and decreased in the yor251c mutant. Like the absence of the mcm(5) side chain, the lack of the s(2) group renders tRNA(mcm5s2UUC Glu) less sensitive to gamma-toxin, reinforcing the importance of the wobble nucleoside mcm(5)s(2)U for tRNA cleavage by gamma-toxin.
Collapse
Affiliation(s)
- Bo Huang
- Department of Molecular Biology, Umeå University, 901 87 Umeå, Sweden
| | | | | |
Collapse
|
41
|
Nandakumar J, Schwer B, Schaffrath R, Shuman S. RNA repair: an antidote to cytotoxic eukaryal RNA damage. Mol Cell 2008; 31:278-86. [PMID: 18657509 DOI: 10.1016/j.molcel.2008.05.019] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2008] [Revised: 04/10/2008] [Accepted: 05/02/2008] [Indexed: 02/05/2023]
Abstract
RNA healing and sealing enzymes drive informational and stress response pathways entailing repair of programmed 2',3' cyclic PO(4)/5'-OH breaks. Fungal, plant, and phage tRNA ligases use different strategies to discriminate the purposefully broken ends of the anticodon loop. Whereas phage ligase recognizes the tRNA fold, yeast and plant ligases do not and are instead hardwired to seal only the tRNA 3'-OH, 2'-PO(4) ends formed by healing of a cyclic phosphate. tRNA anticodon damage inflicted by secreted ribotoxins such as fungal gamma-toxin underlies a rudimentary innate immune system. Yeast cells are susceptible to gamma-toxin because the sealing domain of yeast tRNA ligase is unable to rectify a break at the modified wobble base of tRNA(Glu(UUC)). Plant andphage tRNA repair enzymes protect yeast from gamma-toxin because they are able to reverse the damage. Our studies underscore how a ribotoxin exploits an Achilles' heel in the target cell's tRNA repair system.
Collapse
|
42
|
Bär C, Zabel R, Liu S, Stark MJR, Schaffrath R. A versatile partner of eukaryotic protein complexes that is involved in multiple biological processes: Kti11/Dph3. Mol Microbiol 2008; 69:1221-33. [PMID: 18627462 DOI: 10.1111/j.1365-2958.2008.06350.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The Kluyveromyces lactis killer toxin zymocin insensitive 11 (KTI11) gene from Saccharomyces cerevisiae is allelic with the diphthamide synthesis 3 (DPH3) locus. Here, we present evidence that the KTI11 gene product is a versatile partner of proteins and operates in multiple biological processes. Notably, Kti11 immune precipitates contain Elp2 and Elp5, two subunits of the Elongator complex which is involved in transcription, tRNA modification and zymocin toxicity. KTI11 deletion phenocopies Elongator-minus cells and causes antisuppression of nonsense and missense suppressor tRNAs (SUP4, SOE1), zymocin resistance and protection against the tRNase attack of zymocin. In addition and unlike Elongator mutants, kti11 mutants resist diphtheria toxin (DT), protect against ADP-ribosylation of eukaryotic translation elongation factor 2 (eEF2) by DT and induce resistance against sordarin, an eEF2 poisoning antifungal. The latter phenotype applies to all diphthamide mutants (dph1-dph5) tested and Kti11/Dph3 physically interacts with diphthamide synthesis factors Dph1 and Dph2, presumably as part of a trimeric complex. Moreover, we present a separation of function mutation in KTI11, kti11-1, which dissociates zymocin resistance from DT sensitivity. It encodes a C-terminal Kti11 truncation that almost entirely abolishes Elongator interaction without affecting association with Kti13, another Kti11 partner protein.
Collapse
Affiliation(s)
- Christian Bär
- Biologicum, Institut für Genetik, Martin-Luther-Universität Halle-Wittenberg, Weinbergweg 10, D-06120 Halle (Saale), Germany
| | | | | | | | | |
Collapse
|
43
|
Klassen R, Paluszynski JP, Wemhoff S, Pfeiffer A, Fricke J, Meinhardt F. The primary target of the killer toxin from Pichia acaciae is tRNA(Gln). Mol Microbiol 2008; 69:681-97. [PMID: 18532979 DOI: 10.1111/j.1365-2958.2008.06319.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The Pichia acaciae killer toxin (PaT) arrests yeast cells in the S-phase of the cell cycle and induces DNA double-strand breaks (DSBs). Surprisingly, loss of the tRNA-methyltransferase Trm9 - along with the Elongator complex involved in synthesis of 5-methoxy-carbonyl-methyl (mcm(5)) modification in certain tRNAs - conferred resistance against PaT. Overexpression of mcm(5)-modified tRNAs identified tRNA(Gln)((UUG)) as the intracellular target. Consistently, toxin-challenged cells displayed reduced levels of tRNA(Gln) and in vitro the heterologously expressed active toxin subunit disrupts the integrity of tRNA(Gln)((UUG)). Other than Kluyveromyces lactis zymocin, an endonuclease specific for tRNA(Glu)((UUC)), affecting its target in a mcm(5)-dependent manner, PaT exerts activity also on tRNA(Gln) lacking such modification. As sensitivity is restored in trm9 elp3 double mutants, target tRNA cleavage is selectively inhibited by incomplete wobble uridine modification, as seen in trm9, but not in elp3 or trm9 elp3 cells. In addition to tRNA(Gln)((UUG)), tRNA(Gln)((CUG)) is also cleaved in vitro and overexpression of the corresponding gene increased resistance. Consistent with tRNA(Gln)((CUG)) as an additional TRM9-independent target, overexpression of PaT's tRNase subunit abolishes trm9 resistance. Most interestingly, a functional DSB repair pathway confers PaT but also zymocin resistance, suggesting DNA damage to occur generally concomitant with specific tRNA offence.
Collapse
Affiliation(s)
- Roland Klassen
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, Corrensstr. 3, D-48149 Münster, Germany
| | | | | | | | | | | |
Collapse
|