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Elder JJH, Papadopoulos R, Hayne CK, Stanley RE. The making and breaking of tRNAs by ribonucleases. Trends Genet 2024:S0168-9525(24)00069-6. [PMID: 38641471 DOI: 10.1016/j.tig.2024.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 03/21/2024] [Accepted: 03/21/2024] [Indexed: 04/21/2024]
Abstract
Ribonucleases (RNases) play important roles in supporting canonical and non-canonical roles of tRNAs by catalyzing the cleavage of the tRNA phosphodiester backbone. Here, we highlight how recent advances in cryo-electron microscopy (cryo-EM), protein structure prediction, reconstitution experiments, tRNA sequencing, and other studies have revealed new insight into the nucleases that process tRNA. This represents a very diverse group of nucleases that utilize distinct mechanisms to recognize and cleave tRNA during different stages of a tRNA's life cycle including biogenesis, fragmentation, surveillance, and decay. In this review, we provide a synthesis of the structure, mechanism, regulation, and modes of tRNA recognition by tRNA nucleases, along with open questions for future investigation.
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Affiliation(s)
- Jessica J H Elder
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA
| | - Ry Papadopoulos
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA; Department of Chemistry, University of Chicago, Chicago, IL, USA
| | - Cassandra K Hayne
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA.
| | - Robin E Stanley
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA.
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2
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Wilhelm CA, Mallik L, Kelly AL, Brotzman S, Mendoza J, Anders AG, Leskaj S, Castillo C, Ruotolo BT, Cianfrocco MA, Koutmos M. Bacterial RNA-free RNase P: Structural and functional characterization of multiple oligomeric forms of a minimal protein-only ribonuclease P. J Biol Chem 2023; 299:105327. [PMID: 37806495 PMCID: PMC10652100 DOI: 10.1016/j.jbc.2023.105327] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 09/08/2023] [Accepted: 09/19/2023] [Indexed: 10/10/2023] Open
Abstract
tRNAs are typically transcribed with extended 5' and 3' ends that must be removed before they attain their active form. One of the first steps of tRNA processing in nearly every organism is the removal of the 5' leader sequence by ribonuclease P (RNase P). Here, we investigate a recently discovered class of RNase P enzymes, Homologs of Aquifex RNase P (HARPs). In contrast to other RNase Ps, HARPs consist only of a metallonuclease domain and lack the canonical substrate recognition domain essential in other classes of proteinaceous RNase P. We determined the cryo-EM structure of Aquifex aeolicus HARP (Aq880) and two crystal structures of Hydrogenobacter thermophilus HARP (Hth1307) to reveal that both enzymes form large ring-like assemblies: a dodecamer in Aq880 and a tetradecamer in Hth1307. In both oligomers, the enzyme active site is 42 Å away from a positively charged helical region, as seen in other protein-only RNase P enzymes, which likely serves to recognize and bind the elbow region of the pre-tRNA substrate. In addition, we use native mass spectrometry to confirm and characterize the previously unreported tetradecamer state. Notably, we find that multiple oligomeric states of Hth1307 are able to cleave pre-tRNAs. Furthermore, our single-turnover kinetic studies indicate that Hth1307 cleaves pre-tRNAs from multiple species with a preference for native substrates. These data provide a closer look at the nuanced similarities and differences in tRNA processing across disparate classes of RNase P.
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Affiliation(s)
| | - Leena Mallik
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA; Center for Computational and Genomic Medicine and Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Abigail L Kelly
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Shayna Brotzman
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Johnny Mendoza
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Anna G Anders
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Suada Leskaj
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Carmen Castillo
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Brandon T Ruotolo
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Michael A Cianfrocco
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, USA; Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, USA
| | - Markos Koutmos
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA; Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, USA; Program in Biophysics, University of Michigan, Ann Arbor, Michigan, USA.
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3
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Trinquier A, Condon C, Braun F. Effect of tRNA Maturase Depletion on Levels and Stabilities of Ribosome Assembly Cofactor and Other mRNAs in Bacillus subtilis. Microbiol Spectr 2023; 11:e0513422. [PMID: 36840557 PMCID: PMC10100781 DOI: 10.1128/spectrum.05134-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 01/30/2023] [Indexed: 02/24/2023] Open
Abstract
The impact of translation on mRNA stability can be varied, ranging from a protective effect of ribosomes that shield mRNA from RNases to preferentially exposing sites of RNase cleavage. These effects can change depending on whether ribosomes are actively moving along the mRNA or stalled at particular sequences or structures or awaiting charged tRNAs. We recently observed that depleting Bacillus subtilis cells of their tRNA maturation enzymes RNase P and RNase Z led to altered mRNA levels of a number of assembly factors involved in the biogenesis of the 30S ribosomal subunit. Here, we extended this study to other assembly factor and non-assembly factor mRNAs in B. subtilis. We additionally identified multiple transcriptional and translational layers of regulation of the rimM operon mRNA that occur in response to the depletion of functional tRNAs. IMPORTANCE The passage of ribosomes across individual mRNAs during translation can have different effects on their degradation, ranging from a protective effect by shielding from ribonucleases to, in some cases, making the mRNA more vulnerable to RNase action. We recently showed that some mRNAs coding for proteins involved in ribosome assembly were highly sensitive to the availability of functional tRNA. Using strains depleted of the major tRNA processing enzymes RNase P and RNase Z, we expanded this observation to a wider set of mRNAs, including some unrelated to ribosome biogenesis. We characterized the impact of tRNA maturase depletion on the rimM operon mRNA and show that it is highly complex, with multiple levels of transcriptional and posttranscriptional effects coming into play.
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Affiliation(s)
- Aude Trinquier
- CNRS, Université Paris Cité, Expression Génétique Microbienne, Institut de Biologie Physico-Chimique, Paris, France
| | - Ciarán Condon
- CNRS, Université Paris Cité, Expression Génétique Microbienne, Institut de Biologie Physico-Chimique, Paris, France
| | - Frédérique Braun
- CNRS, Université Paris Cité, Expression Génétique Microbienne, Institut de Biologie Physico-Chimique, Paris, France
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4
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Wang L, Lin S. Emerging functions of tRNA modifications in mRNA translation and diseases. J Genet Genomics 2022; 50:223-232. [PMID: 36309201 DOI: 10.1016/j.jgg.2022.10.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Revised: 10/17/2022] [Accepted: 10/17/2022] [Indexed: 11/06/2022]
Abstract
tRNAs are essential modulators that recognize mRNA codons and bridge amino acids for mRNA translation. The tRNAs are heavily modified, which is essential for forming a complex secondary structure that facilitates codon recognition and mRNA translation. In recent years, studies have identified the regulatory roles of tRNA modifications in mRNA translation networks. Misregulation of tRNA modifications is closely related to the progression of developmental diseases and cancers. In this review, we summarize the tRNA biogenesis process and then discuss the effects and mechanisms of tRNA modifications on tRNA processing and mRNA translation. Finally, we provide a comprehensive overview of tRNA modifications' physiological and pathological functions, focusing on diseases including cancers.
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Affiliation(s)
- Lu Wang
- Department of Medical Laboratory, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, Guangdong 510515, China; Center for Translational Medicine, Precision Medicine Institute, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510080, China
| | - Shuibin Lin
- Center for Translational Medicine, Precision Medicine Institute, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510080, China; State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong 510080, China.
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5
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Cortazar MA, Erickson B, Fong N, Pradhan SJ, Ntini E, Bentley DL. Xrn2 substrate mapping identifies torpedo loading sites and extensive premature termination of RNA pol II transcription. Genes Dev 2022; 36:1062-1078. [PMID: 36396340 PMCID: PMC9744234 DOI: 10.1101/gad.350004.122] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 10/31/2022] [Indexed: 11/19/2022]
Abstract
The exonuclease torpedo Xrn2 loads onto nascent RNA 5'-PO4 ends and chases down pol II to promote termination downstream from polyA sites. We report that Xrn2 is recruited to preinitiation complexes and "travels" to 3' ends of genes. Mapping of 5'-PO4 ends in nascent RNA identified Xrn2 loading sites stabilized by an active site mutant, Xrn2(D235A). Xrn2 loading sites are approximately two to 20 bases downstream from where CPSF73 cleaves at polyA sites and histone 3' ends. We propose that processing of all mRNA 3' ends comprises cleavage and limited 5'-3' trimming by CPSF73, followed by handoff to Xrn2. A similar handoff occurs at tRNA 3' ends, where cotranscriptional RNase Z cleavage generates novel Xrn2 substrates. Exonuclease-dead Xrn2 increased transcription in 3' flanking regions by inhibiting polyA site-dependent termination. Surprisingly, the mutant Xrn2 also rescued transcription in promoter-proximal regions to the same extent as in 3' flanking regions. eNET-seq revealed Xrn2-mediated degradation of sense and antisense nascent RNA within a few bases of the TSS, where 5'-PO4 ends may be generated by decapping or endonucleolytic cleavage. These results suggest that a major fraction of pol II complexes terminates prematurely close to the start site under normal conditions by an Xrn2-mediated torpedo mechanism.
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Affiliation(s)
- Michael A. Cortazar
- Department of Biochemistry and Molecular Genetics, RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Benjamin Erickson
- Department of Biochemistry and Molecular Genetics, RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Nova Fong
- Department of Biochemistry and Molecular Genetics, RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Sarala J. Pradhan
- Department of Biochemistry and Molecular Genetics, RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Evgenia Ntini
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology–Hellas (FORTH), Heraklion GR-70013, Greece
| | - David L. Bentley
- Department of Biochemistry and Molecular Genetics, RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
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6
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Hayne CK, Lewis TA, Stanley RE. Recent insights into the structure, function, and regulation of the eukaryotic transfer RNA splicing endonuclease complex. Wiley Interdiscip Rev RNA 2022; 13:e1717. [PMID: 35156311 PMCID: PMC9465713 DOI: 10.1002/wrna.1717] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 01/12/2022] [Accepted: 01/13/2022] [Indexed: 04/30/2023]
Abstract
The splicing of transfer RNA (tRNA) introns is a critical step of tRNA maturation, for intron-containing tRNAs. In eukaryotes, tRNA splicing is a multi-step process that relies on several RNA processing enzymes to facilitate intron removal and exon ligation. Splicing is initiated by the tRNA splicing endonuclease (TSEN) complex which catalyzes the excision of the intron through its two nuclease subunits. Mutations in all four subunits of the TSEN complex are linked to a family of neurodegenerative and neurodevelopmental diseases known as pontocerebellar hypoplasia (PCH). Recent studies provide molecular insights into the structure, function, and regulation of the eukaryotic TSEN complex and are beginning to illuminate how mutations in the TSEN complex lead to neurodegenerative disease. Using new advancements in the prediction of protein structure, we created a three-dimensional model of the human TSEN complex. We review functions of the TSEN complex beyond tRNA splicing by highlighting recently identified substrates of the eukaryotic TSEN complex and discuss mechanisms for the regulation of tRNA splicing, by enzymes that modify cleaved tRNA exons and introns. Finally, we review recent biochemical and animal models that have worked to address the mechanisms that drive PCH and synthesize these studies with previous studies to try to better understand PCH pathogenesis. This article is categorized under: RNA Processing > tRNA Processing RNA in Disease and Development > RNA in Disease RNA Interactions with Proteins and Other Molecules > Protein-RNA Recognition.
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Affiliation(s)
- Cassandra K Hayne
- Department of Health and Human Services, Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Tanae A Lewis
- Department of Chemistry, North Carolina Agricultural and Technical State University, Greensboro, North Carolina, USA
| | - Robin E Stanley
- Department of Health and Human Services, Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
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7
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Lai LB, Lai SM, Szymanski ES, Kapur M, Choi EK, Al-Hashimi HM, Ackerman SL, Gopalan V. Structural basis for impaired 5' processing of a mutant tRNA associated with defects in neuronal homeostasis. Proc Natl Acad Sci U S A 2022; 119:e2119529119. [PMID: 35238631 DOI: 10.1073/pnas.2119529119] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Understanding and treating neurological disorders are global priorities. Some of these diseases are engendered by mutations that cause defects in the cellular synthesis of transfer RNAs (tRNAs), which function as adapter molecules that translate messenger RNAs into proteins. During tRNA biogenesis, ribonuclease P catalyzes removal of the transcribed sequence upstream of the mature tRNA. Here, we focus on a cytoplasmic tRNAArgUCU that is expressed specifically in neurons and, when harboring a particular point mutation, contributes to neurodegeneration in mice. Our results suggest that this mutation favors stable alternative structures that are not cleaved by mouse ribonuclease P and motivate a paradigm that may help to understand the molecular basis for disease-associated mutations in other tRNAs. n-Tr20 is a neuron-specific, cytoplasmic transfer RNAArgUCU (tRNAArgUCU) isodecoder that affects seizure susceptibility, neuronal excitability, and translation signaling in mice. In addition, the C50U substitution in n-Tr20 (n-Tr20C50U), which is found in the widely used C57BL/6J (B6J) inbred mouse line, contributes to neurodegeneration by epistatic interactions with mutations in Gtpbp1 or Gtpbp2, two factors that rescue ribosomal stalling. The brains of B6J mice have high levels of immature and low levels of mature n-Tr20C50U, implicating defective tRNA biogenesis as the basis for neuronal dysfunction, a hypothesis tested in this study. We demonstrate that partially purified mouse brain ribonuclease P, the endonuclease responsible for 5′ maturation of tRNAs, exhibits at 1 mM magnesium a 20-fold lower apparent cleavage rate for processing the n-Tr20C50U precursor than the wild-type precursor. Thermal denaturation studies unexpectedly revealed that substituting the native C50-G64 base pair with the U50-G64 wobble pair in n-Tr20C50U increased the Tm by as much as 8 °C, with the magnitude of the change dependent on [Mg2+]. Moreover, results from thermal denaturation, native gel electrophoresis, 1H nuclear magnetic resonance spectroscopy, and kinetic studies collectively support the presence of stable alternative folds for n-Tr20C50U that may also be sampled transiently and in low abundance by the wild-type tRNA. These findings suggest that mutation-driven restructuring could foster nonnative folds and that conformational toggling of tRNAs poses an intrinsic risk for dysfunction when point mutations selectively stabilize nonnative states. This model may be applicable for understanding the molecular basis of other diseases that are associated with tRNA mutations.
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8
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Seki M, Komuro A, Ishikawa T, Takahashi M, Nashimoto M. Genes for tRNA recycling are upregulated in response to infection with Theiler's mouse encephalitis virus. Biochem Biophys Res Commun 2022; 587:63-68. [PMID: 34864548 DOI: 10.1016/j.bbrc.2021.11.091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 11/25/2021] [Accepted: 11/25/2021] [Indexed: 11/17/2022]
Abstract
The concept of tRNA recycling has recently emerged from the studies of ribosome-associated quality control. Therein tRNase ZS removes the 2', 3'>p from the ANKZF1-cleaved tRNA and the subsequent TRNT1 action re-generates the intact tRNA. To know the roles of the tRNA recycling in vivo, we investigated how viral infection affects the tRNA recycling system by analyzing the mRNA levels of tRNase ZS and TRNT1. We found that both genes in HeLa cells are upregulated in response to infection of Theiler's mouse encephalitis virus but not to that of an influenza A virus. Upregulation was also observed in cells infected with encephalomyocarditis virus with reduced efficiency. The levels of the IFN-β mRNA appeared to positively correlate with those of the tRNase ZS and TRNT1 mRNAs. The tRNase ZS gene may be regulated post-transcriptionally in the cells infected with Theiler's mouse encephalitis virus.
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Affiliation(s)
- Mineaki Seki
- Research Institute for Healthy Living, Niigata University of Pharmacy and Applied Life Sciences, Niigata, Niigata, 956-8603, Japan.
| | - Akihiko Komuro
- Research Institute for Healthy Living, Niigata University of Pharmacy and Applied Life Sciences, Niigata, Niigata, 956-8603, Japan; Faculty of Pharmaceutical Sciences, Department of Biochemistry, Niigata University of Pharmacy and Applied Life Sciences, Niigata, Niigata, 956-8603, Japan
| | - Tatsuya Ishikawa
- Research Institute for Healthy Living, Niigata University of Pharmacy and Applied Life Sciences, Niigata, Niigata, 956-8603, Japan
| | - Masayuki Takahashi
- Research Institute for Healthy Living, Niigata University of Pharmacy and Applied Life Sciences, Niigata, Niigata, 956-8603, Japan
| | - Masayuki Nashimoto
- Research Institute for Healthy Living, Niigata University of Pharmacy and Applied Life Sciences, Niigata, Niigata, 956-8603, Japan
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9
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Pandey KK, Madhry D, Ravi Kumar YS, Malvankar S, Sapra L, Srivastava RK, Bhattacharyya S, Verma B. Regulatory roles of tRNA-derived RNA fragments in human pathophysiology. Mol Ther Nucleic Acids 2021; 26:161-173. [PMID: 34513302 PMCID: PMC8413677 DOI: 10.1016/j.omtn.2021.06.023] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Hundreds of tRNA genes and pseudogenes are encoded by the human genome. tRNAs are the second most abundant type of RNA in the cell. Advancement in deep-sequencing technologies have revealed the presence of abundant expression of functional tRNA-derived RNA fragments (tRFs). They are either generated from precursor (pre-)tRNA or mature tRNA. They have been found to play crucial regulatory roles during different pathological conditions. Herein, we briefly summarize the discovery and recent advances in deciphering the regulatory role played by tRFs in the pathophysiology of different human diseases.
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Affiliation(s)
- Kush Kumar Pandey
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | - Deeksha Madhry
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | - Y S Ravi Kumar
- Department of Biotechnology, M.S. Ramaiah, Institute of Technology, MSR Nagar, Bengaluru, India
| | - Shivani Malvankar
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | - Leena Sapra
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | - Rupesh K Srivastava
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | - Sankar Bhattacharyya
- Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, India
| | - Bhupendra Verma
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
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10
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Tosar JP, Ivanov P, Ribas de Pouplana L, Torres AG. Editorial: Understanding the Importance of Non-Canonical tRNA Function. Front Mol Biosci 2021; 8:769784. [PMID: 34692774 PMCID: PMC8529061 DOI: 10.3389/fmolb.2021.769784] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 09/21/2021] [Indexed: 11/13/2022] Open
Affiliation(s)
- Juan Pablo Tosar
- Functional Genomics Unit, Institute Pasteur de Montevideo, Montevideo, Uruguay.,Faculty of Science, Universidad de la República, Montevideo, Uruguay
| | - Pavel Ivanov
- Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Boston, MA, United States.,Department of Medicine, Harvard Medical School, Boston, MA, United States.,The Broad Institute of Harvard and M.I.T., Cambridge, MA, United States
| | - Lluís Ribas de Pouplana
- Catalan Institution for Research and Advanced Studies, Barcelona, Spain.,Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Adrian Gabriel Torres
- Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, Barcelona, Spain
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11
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Zeng D, Abzhanova A, Brown BP, Reiter NJ. Dissecting Monomer-Dimer Equilibrium of an RNase P Protein Provides Insight Into the Synergistic Flexibility of 5' Leader Pre-tRNA Recognition. Front Mol Biosci 2021; 8:730274. [PMID: 34540901 PMCID: PMC8447495 DOI: 10.3389/fmolb.2021.730274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 08/18/2021] [Indexed: 11/13/2022] Open
Abstract
Ribonuclease P (RNase P) is a universal RNA-protein endonuclease that catalyzes 5' precursor-tRNA (ptRNA) processing. The RNase P RNA plays the catalytic role in ptRNA processing; however, the RNase P protein is required for catalysis in vivo and interacts with the 5' leader sequence. A single P RNA and a P protein form the functional RNase P holoenzyme yet dimeric forms of bacterial RNase P can interact with non-tRNA substrates and influence bacterial cell growth. Oligomeric forms of the P protein can also occur in vitro and occlude the 5' leader ptRNA binding interface, presenting a challenge in accurately defining the substrate recognition properties. To overcome this, concentration and temperature dependent NMR studies were performed on a thermostable RNase P protein from Thermatoga maritima. NMR relaxation (R1, R2), heteronuclear NOE, and diffusion ordered spectroscopy (DOSY) experiments were analyzed, identifying a monomeric species through the determination of the diffusion coefficients (D) and rotational correlation times (τc). Experimental diffusion coefficients and τc values for the predominant monomer (2.17 ± 0.36 * 10-10 m2/s, τ c = 5.3 ns) or dimer (1.87 ± 0.40* 10-10 m2/s, τ c = 9.7 ns) protein assemblies at 45°C correlate well with calculated diffusion coefficients derived from the crystallographic P protein structure (PDB 1NZ0). The identification of a monomeric P protein conformer from relaxation data and chemical shift information enabled us to gain novel insight into the structure of the P protein, highlighting a lack of structural convergence of the N-terminus (residues 1-14) in solution. We propose that the N-terminus of the bacterial P protein is partially disordered and adopts a stable conformation in the presence of RNA. In addition, we have determined the location of the 5' leader RNA in solution and measured the affinity of the 5' leader RNA-P protein interaction. We show that the monomer P protein interacts with RNA at the 5' leader binding cleft that was previously identified using X-ray crystallography. Data support a model where N-terminal protein flexibility is stabilized by holoenzyme formation and helps to accommodate the 5' leader region of ptRNA. Taken together, local structural changes of the P protein and the 5' leader RNA provide a means to obtain optimal substrate alignment and activation of the RNase P holoenzyme.
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Affiliation(s)
- Danyun Zeng
- Department of Chemistry, Marquette University, Milwaukee, WI, United States
| | - Ainur Abzhanova
- Department of Chemistry, Marquette University, Milwaukee, WI, United States
| | - Benjamin P Brown
- Chemical and Physical Biology Program, Medical Scientist Training Program, Vanderbilt University, Nashville, TN, United States.,Center for Structural Biology, Vanderbilt University School of Medicine, Nashville, TN, United States
| | - Nicholas J Reiter
- Department of Chemistry, Marquette University, Milwaukee, WI, United States
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12
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Phan HD, Lai LB, Zahurancik WJ, Gopalan V. The many faces of RNA-based RNase P, an RNA-world relic. Trends Biochem Sci 2021; 46:976-991. [PMID: 34511335 DOI: 10.1016/j.tibs.2021.07.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 07/11/2021] [Accepted: 07/28/2021] [Indexed: 12/24/2022]
Abstract
RNase P is an essential enzyme that catalyzes removal of the 5' leader from precursor transfer RNAs. The ribonucleoprotein (RNP) form of RNase P is present in all domains of life and comprises a single catalytic RNA (ribozyme) and a variable number of protein cofactors. Recent cryo-electron microscopy structures of representative archaeal and eukaryotic (nuclear) RNase P holoenzymes bound to tRNA substrate/product provide high-resolution detail on subunit organization, topology, and substrate recognition in these large, multisubunit catalytic RNPs. These structures point to the challenges in understanding how proteins modulate the RNA functional repertoire and how the structure of an ancient RNA-based catalyst was reshaped during evolution by new macromolecular associations that were likely necessitated by functional/regulatory coupling.
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Affiliation(s)
- Hong-Duc Phan
- Department of Chemistry & Biochemistry, The Ohio State University, Columbus, OH 43210, USA; Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA; Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
| | - Lien B Lai
- Department of Chemistry & Biochemistry, The Ohio State University, Columbus, OH 43210, USA; Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA.
| | - Walter J Zahurancik
- Department of Chemistry & Biochemistry, The Ohio State University, Columbus, OH 43210, USA; Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Venkat Gopalan
- Department of Chemistry & Biochemistry, The Ohio State University, Columbus, OH 43210, USA; Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA; Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA.
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13
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Karasik A, Wilhelm CA, Fierke CA, Koutmos M. Disease-associated mutations in mitochondrial precursor tRNAs affect binding, m1R9 methylation, and tRNA processing by mtRNase P. RNA 2021; 27:420-432. [PMID: 33380464 PMCID: PMC7962481 DOI: 10.1261/rna.077198.120] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 12/16/2020] [Indexed: 06/12/2023]
Abstract
Mitochondrial diseases linked to mutations in mitochondrial (mt) tRNA sequences are common. However, the contributions of these tRNA mutations to the development of diseases is mostly unknown. Mutations may affect interactions with (mt)tRNA maturation enzymes or protein synthesis machinery leading to mitochondrial dysfunction. In human mitochondria, in most cases the first step of tRNA processing is the removal of the 5' leader of precursor tRNAs (pre-tRNA) catalyzed by the three-component enzyme, mtRNase P. Additionally, one component of mtRNase P, mitochondrial RNase P protein 1 (MRPP1), catalyzes methylation of the R9 base in pre-tRNAs. Despite the central role of 5' end processing in mitochondrial tRNA maturation, the link between mtRNase P and diseases is mostly unexplored. Here, we investigate how 11 different human disease-linked mutations in (mt)pre-tRNAIle, (mt)pre-tRNALeu(UUR), and (mt)pre-tRNAMet affect the activities of mtRNase P. We find that several mutations weaken the pre-tRNA binding affinity (KD s are approximately two- to sixfold higher than that of wild-type), while the majority of mutations decrease 5' end processing and methylation activity catalyzed by mtRNase P (up to ∼55% and 90% reduction, respectively). Furthermore, all of the investigated mutations in (mt)pre-tRNALeu(UUR) alter the tRNA fold which contributes to the partial loss of function of mtRNase P. Overall, these results reveal an etiological link between early steps of (mt)tRNA-substrate processing and mitochondrial disease.
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Affiliation(s)
- Agnes Karasik
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814, USA
| | - Catherine A Wilhelm
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Carol A Fierke
- Department of Chemistry, Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
- Department of Chemistry, Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, USA
| | - Markos Koutmos
- Department of Chemistry, Program in Biophysics, University of Michigan, Ann Arbor, Michigan 48109, USA
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14
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Yip MCJ, Savickas S, Gygi SP, Shao S. ELAC1 Repairs tRNAs Cleaved during Ribosome-Associated Quality Control. Cell Rep 2021; 30:2106-2114.e5. [PMID: 32075755 DOI: 10.1016/j.celrep.2020.01.082] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 12/30/2019] [Accepted: 01/22/2020] [Indexed: 12/31/2022] Open
Abstract
Ribosome-associated quality control (RQC) disassembles aberrantly stalled translation complexes to recycle or degrade the constituent parts. A key step of RQC is the cleavage of P-site tRNA by the endonuclease ANKZF1 (Vms1 in yeast) to release incompletely synthesized polypeptides from ribosomes for degradation. Re-use of the cleaved tRNA for translation requires re-addition of the universal 3'CCA nucleotides removed by ANKZF1. Here, we show that ELAC1 is both necessary and sufficient to remove the 2',3'-cyclic phosphate on ANKZF1-cleaved tRNAs to permit CCA re-addition by TRNT1. ELAC1 activity is optimized for tRNA recycling, whereas ELAC2, the essential RNase Z isoform in eukaryotes, is required to remove 3' trailers during tRNA biogenesis. Cells lacking ELAC1 specifically accumulate unrepaired tRNA intermediates upon the induction of ribosome stalling. Thus, optimal recycling of ANKZF1-cleaved tRNAs in vertebrates is achieved through the duplication and specialization of a conserved tRNA biosynthesis enzyme.
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Affiliation(s)
- Matthew C J Yip
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Simonas Savickas
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA; Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Steven P Gygi
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Sichen Shao
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA.
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15
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Porat J, Kothe U, Bayfield MA. Revisiting tRNA chaperones: New players in an ancient game. RNA 2021; 27:rna.078428.120. [PMID: 33593999 PMCID: PMC8051267 DOI: 10.1261/rna.078428.120] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 02/10/2021] [Indexed: 05/03/2023]
Abstract
tRNAs undergo an extensive maturation process including post-transcriptional modifications that influence secondary and tertiary interactions. Precursor and mature tRNAs lacking key modifications are often recognized as aberrant and subsequently targeted for decay, illustrating the importance of modifications in promoting structural integrity. tRNAs also rely on tRNA chaperones to promote the folding of misfolded substrates into functional conformations. The best characterized tRNA chaperone is the La protein, which interacts with nascent RNA polymerase III transcripts to promote folding and offers protection from exonucleases. More recently, certain tRNA modification enzymes have also been demonstrated to possess tRNA folding activity distinct from their catalytic activity, suggesting that they may act as tRNA chaperones. In this review, we will discuss pioneering studies relating post-transcriptional modification to tRNA stability and decay pathways, present recent advances into the mechanism by which the RNA chaperone La assists pre-tRNA maturation, and summarize emerging research directions aimed at characterizing modification enzymes as tRNA chaperones. Together, these findings shed light on the importance of tRNA folding and how tRNA chaperones, in particular, increase the fraction of nascent pre-tRNAs that adopt a folded, functional conformation.
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16
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Schwarz TS, Berkemer SJ, Bernhart SH, Weiß M, Ferreira-Cerca S, Stadler PF, Marchfelder A. Splicing Endonuclease Is an Important Player in rRNA and tRNA Maturation in Archaea. Front Microbiol 2020; 11:594838. [PMID: 33329479 PMCID: PMC7714728 DOI: 10.3389/fmicb.2020.594838] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 10/21/2020] [Indexed: 12/20/2022] Open
Abstract
In all three domains of life, tRNA genes contain introns that must be removed to yield functional tRNA. In archaea and eukarya, the first step of this process is catalyzed by a splicing endonuclease. The consensus structure recognized by the splicing endonuclease is a bulge-helix-bulge (BHB) motif which is also found in rRNA precursors. So far, a systematic analysis to identify all biological substrates of the splicing endonuclease has not been carried out. In this study, we employed CRISPRi to repress expression of the splicing endonuclease in the archaeon Haloferax volcanii to identify all substrates of this enzyme. Expression of the splicing endonuclease was reduced to 1% of its normal level, resulting in a significant extension of lag phase in H. volcanii growth. In the repression strain, 41 genes were down-regulated and 102 were up-regulated. As an additional approach in identifying new substrates of the splicing endonuclease, we isolated and sequenced circular RNAs, which identified excised introns removed from tRNA and rRNA precursors as well as from the 5' UTR of the gene HVO_1309. In vitro processing assays showed that the BHB sites in the 5' UTR of HVO_1309 and in a 16S rRNA-like precursor are processed by the recombinant splicing endonuclease. The splicing endonuclease is therefore an important player in RNA maturation in archaea.
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Affiliation(s)
| | - Sarah J Berkemer
- Bioinformatics, Department of Computer Science, Leipzig University, Leipzig, Germany.,Max Planck Institute for Mathematics in the Sciences, Leipzig, Germany.,Competence Center for Scalable Data Services and Solutions, Leipzig University, Leipzig, Germany
| | - Stephan H Bernhart
- Bioinformatics, Department of Computer Science, Leipzig University, Leipzig, Germany.,Interdisciplinary Center for Bioinformatics, Leipzig University, Leipzig, Germany
| | - Matthias Weiß
- Regensburg Center for Biochemistry, Biochemistry III - Institute of Biochemistry, Genetics and Microbiology, University of Regensburg, Regensburg, Germany
| | - Sébastien Ferreira-Cerca
- Regensburg Center for Biochemistry, Biochemistry III - Institute of Biochemistry, Genetics and Microbiology, University of Regensburg, Regensburg, Germany
| | - Peter F Stadler
- Bioinformatics, Department of Computer Science, Leipzig University, Leipzig, Germany.,Max Planck Institute for Mathematics in the Sciences, Leipzig, Germany.,Interdisciplinary Center for Bioinformatics, Leipzig University, Leipzig, Germany.,German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany.,Research Center for Civilization Diseases, Leipzig University, Leipzig, Germany.,Facultad de Ciencias, Universidad Nacional de Colombia, Bogotá, Colombia.,Institute for Theoretical Chemistry, University of Vienna, Vienna, Austria.,Center for RNA in Technology and Health, University of Copenhagen, Frederiksberg, Denmark.,Santa Fe Institute, Santa Fe, NM, United States
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17
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Abstract
La proteins have well-established roles in the maturation of RNA polymerase III transcripts, including pre-tRNAs. In addition to protecting the 3' end of pre-tRNAs from exonuclease digestion, La proteins also promote the native fold of the pre-tRNA using RNA chaperone activity. tRNA-mediated suppression in the fission yeast S. pombe has been an invaluable tool in determining the mechanistic basis by which La proteins promote the maturation of defective pre-tRNAs that benefit from RNA chaperone activity. More recently, tRNA-mediated suppression has been adapted to test for RNA chaperone function in the La-related proteins and in the promoting of tRNA function by tRNA modification enzymes. Thus tRNA-mediated suppression can be a useful assay for the investigation of various proteins hypothesized to promote tRNA folding through RNA chaperone related activities.
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18
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Leamy KA, Yamagami R, Yennawar NH, Bevilacqua PC. Single-nucleotide control of tRNA folding cooperativity under near-cellular conditions. Proc Natl Acad Sci U S A 2019; 116:23075-82. [PMID: 31666318 DOI: 10.1073/pnas.1913418116] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
RNA folding is often studied by renaturing full-length RNA in vitro and tracking folding transitions. However, the intracellular transcript folds as it emerges from the RNA polymerase. Here, we investigate the folding pathways and stability of numerous late-transcriptional intermediates of yeast and Escherichia coli transfer RNAs (tRNAs). Transfer RNA is a highly regulated functional RNA that undergoes multiple steps of posttranscriptional processing and is found in very different lengths during its lifetime in the cell. The precursor transcript is extended on both the 5' and 3' ends of the cloverleaf core, and these extensions get trimmed before addition of the 3'-CCA and aminoacylation. We studied the thermodynamics and structures of the precursor tRNA and of late-transcriptional intermediates of the cloverleaf structure. We examined RNA folding at both the secondary and tertiary structural levels using multiple biochemical and biophysical approaches. Our findings suggest that perhaps nature has selected for a single-base addition to control folding to the functional 3D structure. In near-cellular conditions, yeast tRNAPhe and E. coli tRNAAla transcripts fold in a single, cooperative transition only when nearly all of the nucleotides in the cloverleaf are transcribed by indirectly enhancing folding cooperativity. Furthermore, native extensions on the 5' and 3' ends do not interfere with cooperative core folding. This highly controlled cooperative folding has implications for recognition of tRNA by processing and modification enzymes and quality control of tRNA in cells.
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19
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Nozawa Y, Hagihara M, Rahman MS, Matsumura S, Ikawa Y. Rational Design of an Orthogonal Pair of Bimolecular RNase P Ribozymes through Heterologous Assembly of Their Modular Domains. Biology (Basel) 2019; 8:biology8030065. [PMID: 31480450 PMCID: PMC6783828 DOI: 10.3390/biology8030065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 08/28/2019] [Accepted: 08/28/2019] [Indexed: 12/14/2022]
Abstract
The modular structural domains of multidomain RNA enzymes can often be dissected into separate domain RNAs and their noncovalent assembly can often reconstitute active enzymes. These properties are important to understand their basic characteristics and are useful for their application to RNA-based nanostructures. Bimolecular forms of bacterial RNase P ribozymes consisting of S-domain and C-domain RNAs are attractive as platforms for catalytic RNA nanostructures, but their S-domain/C-domain assembly was not optimized for this purpose. Through analysis and engineering of bimolecular forms of the two bacterial RNase P ribozymes, we constructed a chimeric ribozyme with improved catalytic ability and S-domain/C-domain assembly and developed a pair of bimolecular RNase P ribozymes the assembly of which was considerably orthogonal to each other.
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Affiliation(s)
- Yuri Nozawa
- Department of Chemistry, Graduate School of Science and Engineering, University of Toyama, Gofuku 3190, Toyama 930-8555, Japan
| | - Megumi Hagihara
- Department of Chemistry, Graduate School of Science and Engineering, University of Toyama, Gofuku 3190, Toyama 930-8555, Japan
| | - Md Sohanur Rahman
- Graduate School of Innovative Life Science, University of Toyama, Gofuku 3190, Toyama 930-8555, Japan
| | - Shigeyoshi Matsumura
- Department of Chemistry, Graduate School of Science and Engineering, University of Toyama, Gofuku 3190, Toyama 930-8555, Japan
- Graduate School of Innovative Life Science, University of Toyama, Gofuku 3190, Toyama 930-8555, Japan
| | - Yoshiya Ikawa
- Department of Chemistry, Graduate School of Science and Engineering, University of Toyama, Gofuku 3190, Toyama 930-8555, Japan.
- Graduate School of Innovative Life Science, University of Toyama, Gofuku 3190, Toyama 930-8555, Japan.
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20
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Schwarz TS, Wäber NB, Feyh R, Weidenbach K, Schmitz RA, Marchfelder A, Hartmann RK. Homologs of aquifex aeolicus protein-only RNase P are not the major RNase P activities in the archaea haloferax volcanii and methanosarcina mazei. IUBMB Life 2019; 71:1109-1116. [PMID: 31283101 DOI: 10.1002/iub.2122] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 06/07/2019] [Accepted: 06/09/2019] [Indexed: 01/20/2023]
Abstract
The mature 5'-ends of tRNAs are generated by RNase P in all domains of life. The ancient form of the enzyme is a ribonucleoprotein consisting of a catalytic RNA and one or more protein subunits. However, in the hyperthermophilic bacterium Aquifex aeolicus and close relatives, RNase P is a protein-only enzyme consisting of a single type of polypeptide (Aq_880, ~23 kDa). In many archaea, homologs of Aq_880 were identified (termed HARPs for Homologs of Aquifex RNase P) in addition to the RNA-based RNase P, raising the question about the functions of HARP and the classical RNase P in these archaea. Here we investigated HARPs from two euryarchaeotes, Haloferax volcanii and Methanosarcina mazei. Archaeal strains with HARP gene knockouts showed no growth phenotypes under standard conditions, temperature and salt stress (H. volcanii) or nitrogen deficiency (M. mazei). Recombinant H. volcanii and M. mazei HARPs were basically able to catalyse specific tRNA 5'-end maturation in vitro. Furthermore, M. mazei HARP was able to rescue growth of an Escherichia coli RNase P depletion strain with comparable efficiency as Aq_880, while H. volcanii HARP was unable to do so. In conclusion, both archaeal HARPs showed the capacity (in at least one functional assay) to act as RNases P. However, the ease to obtain knockouts of the singular HARP genes and the lack of growth phenotypes upon HARP gene deletion contrasts with the findings that the canonical RNase P RNA gene cannot be deleted in H. volcanii, and a knockdown of RNase P RNA in H. volcanii results in severe tRNA processing defects. We conclude that archaeal HARPs do not make a major contribution to global tRNA 5'-end maturation in archaea, but may well exert a specialised, yet unknown function in (t)RNA metabolism. © 2019 IUBMB Life, 2019 © 2019 IUBMB Life, 71(8):1109-1116, 2019.
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Affiliation(s)
| | - Nadine B Wäber
- Institute of Pharmaceutical Chemistry, Philipps University, Marburg, Germany
| | - Rebecca Feyh
- Institute of Pharmaceutical Chemistry, Philipps University, Marburg, Germany
| | - Katrin Weidenbach
- Institute of General Microbiology, Christian-Albrechts-Universität, Kiel, Germany
| | - Ruth A Schmitz
- Institute of General Microbiology, Christian-Albrechts-Universität, Kiel, Germany
| | | | - Roland K Hartmann
- Institute of Pharmaceutical Chemistry, Philipps University, Marburg, Germany
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21
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He X, Wang Y, Yang F, Wang B, Xie H, Gu L, Zhao T, Liu X, Zhang D, Ren Q, Liu X, Liu Y, Gao C, Gu F. Boosting activity of high-fidelity CRISPR/Cas9 variants using a tRNA Gln-processing system in human cells. J Biol Chem 2019; 294:9308-9315. [PMID: 31010827 PMCID: PMC6556588 DOI: 10.1074/jbc.ra119.007791] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 04/11/2019] [Indexed: 01/08/2023] Open
Abstract
CRISPR/Cas9 nucleases are widely used for genome editing but can induce unwanted off-target mutations. High-fidelity Cas9 variants have been identified; however, they often have reduced activity, constraining their utility, which presents a major challenge for their use in research applications and therapeutics. Here we developed a tRNAGln-processing system to restore the activity of multiple high-fidelity Cas9 variants in human cells, including SpCas9-HF1, eSpCas9, and xCas9. Specifically, acting on previous observations that small guide RNAs (sgRNAs) harboring an extra A or G (A/G) in the first 5' nucleotide greatly affect the activity of high-fidelity Cas9 variants and that tRNA-sgRNA fusions improve Cas9 activity, we investigated whether a GN20 sgRNA fused to different tRNAs (G-tRNA-N20) could restore the activity of SpCas9 variants in human cells. Using flow cytometry, a T7E1 assay, deep sequencing-based DNA cleavage activity assays, and HEK-293 cells, we observed that a tRNAGln-sgRNA fusion system enhanced the activity of Cas9 variants, which could be harnessed for efficient correction of a pathogenic mutation in the retinoschisin 1 (RS1) gene, resulting in 6- to 8-fold improved Cas9 activity. We propose that the tRNA-processing system developed here specifically for human cells could facilitate high-fidelity Cas9-mediated human genome-editing applications.
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Affiliation(s)
- Xiubin He
- From the School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
- the State Key Laboratory and Key Laboratory of Vision Science, Ministry of Health, Wenzhou, Zhejiang 325027, China
- the Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027, China
| | - Yufei Wang
- From the School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
- the State Key Laboratory and Key Laboratory of Vision Science, Ministry of Health, Wenzhou, Zhejiang 325027, China
- the Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027, China
| | - Fayu Yang
- From the School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
- the State Key Laboratory and Key Laboratory of Vision Science, Ministry of Health, Wenzhou, Zhejiang 325027, China
- the Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027, China
| | - Bang Wang
- From the School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
- the State Key Laboratory and Key Laboratory of Vision Science, Ministry of Health, Wenzhou, Zhejiang 325027, China
- the Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027, China
| | - Haihua Xie
- From the School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
- the State Key Laboratory and Key Laboratory of Vision Science, Ministry of Health, Wenzhou, Zhejiang 325027, China
- the Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027, China
| | - Lingkai Gu
- From the School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
- the State Key Laboratory and Key Laboratory of Vision Science, Ministry of Health, Wenzhou, Zhejiang 325027, China
- the Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027, China
| | - Tianyuan Zhao
- From the School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
- the State Key Laboratory and Key Laboratory of Vision Science, Ministry of Health, Wenzhou, Zhejiang 325027, China
- the Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027, China
| | - Xiexie Liu
- From the School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
- the State Key Laboratory and Key Laboratory of Vision Science, Ministry of Health, Wenzhou, Zhejiang 325027, China
- the Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027, China
| | - Dingbo Zhang
- the State Key Laboratory of Plant Cell and Chromosome Engineering and Center for Genome Editing, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China, and
- the University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qianwen Ren
- From the School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
- the State Key Laboratory and Key Laboratory of Vision Science, Ministry of Health, Wenzhou, Zhejiang 325027, China
- the Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027, China
| | - Xiaoyu Liu
- From the School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
- the State Key Laboratory and Key Laboratory of Vision Science, Ministry of Health, Wenzhou, Zhejiang 325027, China
- the Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027, China
| | - Yong Liu
- From the School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
- the State Key Laboratory and Key Laboratory of Vision Science, Ministry of Health, Wenzhou, Zhejiang 325027, China
- the Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027, China
| | - Caixia Gao
- the State Key Laboratory of Plant Cell and Chromosome Engineering and Center for Genome Editing, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China, and
| | - Feng Gu
- From the School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China,
- the State Key Laboratory and Key Laboratory of Vision Science, Ministry of Health, Wenzhou, Zhejiang 325027, China
- the Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang 325027, China
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22
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Colquhoun JM, Ha L, Beckley A, Meyers B, Flaherty DP, Dunman PM. Identification of Small Molecule Inhibitors of Staphylococcus aureus RnpA. Antibiotics (Basel) 2019; 8:antibiotics8020048. [PMID: 31035380 PMCID: PMC6627331 DOI: 10.3390/antibiotics8020048] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 04/23/2019] [Accepted: 04/25/2019] [Indexed: 12/17/2022] Open
Abstract
Staphylococcus aureus RnpA is thought to be a unique dual functional antimicrobial target that is required for two essential cellular processes, precursor tRNA processing and messenger RNA degradation. Herein, we used a previously described whole cell-based mupirocin synergy assay to screen members of a 53,000 compound small molecule diversity library and simultaneously enrich for agents with cellular RnpA inhibitory activity. A medicinal chemistry-based campaign was launched to generate a preliminary structure activity relationship and guide early optimization of two novel chemical classes of RnpA inhibitors identified, phenylcarbamoyl cyclic thiophene and piperidinecarboxamide. Representatives of each chemical class displayed potent anti-staphylococcal activity, limited the protein’s in vitro ptRNA processing and mRNA degradation activities, and exhibited favorable therapeutic indexes. The most potent piperidinecarboxamide RnpA inhibitor, JC2, displayed inhibition of cellular RnpA mRNA turnover, RnpA-depletion strain hypersusceptibility, and exhibited antimicrobial efficacy in a wax worm model of S. aureus infection. Taken together, these results establish that the whole cell screening assay used is amenable to identifying small molecule RnpA inhibitors within large chemical libraries and that the chemical classes identified here may represent progenitors of new classes of antimicrobials that target RnpA.
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Affiliation(s)
- Jennifer M Colquhoun
- Department of Microbiology and Immunology, University of Rochester School of Medicine, Rochester, NY 14642, USA.
| | - Lisha Ha
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN 47906, USA.
| | - Andrew Beckley
- Department of Microbiology and Immunology, University of Rochester School of Medicine, Rochester, NY 14642, USA.
| | - Brinkley Meyers
- Department of Microbiology and Immunology, University of Rochester School of Medicine, Rochester, NY 14642, USA.
| | - Daniel P Flaherty
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN 47906, USA.
- Purdue Institute of Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN 47906, USA.
- Purdue Institute for Drug Discovery, Purdue University, West Lafayette, IN 47906, USA.
| | - Paul M Dunman
- Department of Microbiology and Immunology, University of Rochester School of Medicine, Rochester, NY 14642, USA.
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23
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Daniels CJ, Lai LB, Chen TH, Gopalan V. Both kinds of RNase P in all domains of life: surprises galore. RNA 2019; 25:286-291. [PMID: 30578286 PMCID: PMC6380272 DOI: 10.1261/rna.068379.118] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 12/18/2018] [Indexed: 05/03/2023]
Abstract
RNase P, an essential housekeeping endonuclease needed for 5'-processing of tRNAs, exists in two distinct forms: one with an RNA- and the other with a protein-based active site. The notion that the protein form of RNase P exists only in eukaryotes has been upended by the recent discovery of a protein-only variant in Bacteria and Archaea. The use of these two divergent scaffolds, shaped by convergent evolution, in all three domains of life inspires questions relating to the ancestral form of RNase P, as well as their origins and function(s) in vivo. Results from our analysis of publicly available bacterial and archaeal genomes suggest that the widespread RNA-based ribonucleoprotein variant is likely the ancient form. We also discuss the possible genetic origins and function of RNase P, including how the simultaneous presence of its variants may contribute to the fitness of their host organisms.
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Affiliation(s)
- Charles J Daniels
- Department of Microbiology, The Ohio State University, Columbus, Ohio 43210, USA
- Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA
| | - Lien B Lai
- Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
| | - Tien-Hao Chen
- Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
| | - Venkat Gopalan
- Department of Microbiology, The Ohio State University, Columbus, Ohio 43210, USA
- Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
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Mohanty BK, Kushner SR. Analysis of post-transcriptional RNA metabolism in prokaryotes. Methods 2018; 155:124-130. [PMID: 30448478 DOI: 10.1016/j.ymeth.2018.11.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 11/08/2018] [Accepted: 11/13/2018] [Indexed: 02/08/2023] Open
Abstract
Post-transcriptional RNA metabolic pathways play important roles in permitting prokaryotes to operate under a variety of environmental conditions. Although significant progress has been made during the last decade in deciphering RNA processing pathways in a number of bacteria, a complete understanding of post-transcriptional RNA metabolism in any single microorganism is far from reality. Here we describe multiple experimental approaches that can be used to study mRNA stability, tRNA and rRNA processing, sRNA metabolism, and polyadenylation in prokaryotes. The methods described here can be readily utilized in both Gram-negative and Gram-positive bacteria with simple modifications.
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Affiliation(s)
- Bijoy K Mohanty
- Department of Genetics, University of Georgia, Athens, GA 30602, United States
| | - Sidney R Kushner
- Department of Genetics, University of Georgia, Athens, GA 30602, United States.
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25
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Nickel AI, Wäber NB, Gößringer M, Lechner M, Linne U, Toth U, Rossmanith W, Hartmann RK. Minimal and RNA-free RNase P in Aquifex aeolicus. Proc Natl Acad Sci U S A 2017; 114:11121-6. [PMID: 29073018 DOI: 10.1073/pnas.1707862114] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
RNase P is an essential tRNA-processing enzyme in all domains of life. We identified an unknown type of protein-only RNase P in the hyperthermophilic bacterium Aquifex aeolicus: Without an RNA subunit and the smallest of its kind, the 23-kDa polypeptide comprises a metallonuclease domain only. The protein has RNase P activity in vitro and rescued the growth of Escherichia coli and Saccharomyces cerevisiae strains with inactivations of their more complex and larger endogenous ribonucleoprotein RNase P. Homologs of Aquifex RNase P (HARP) were identified in many Archaea and some Bacteria, of which all Archaea and most Bacteria also encode an RNA-based RNase P; activity of both RNase P forms from the same bacterium or archaeon could be verified in two selected cases. Bioinformatic analyses suggest that A. aeolicus and related Aquificaceae likely acquired HARP by horizontal gene transfer from an archaeon.
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26
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Oerum S, Roovers M, Leichsenring M, Acquaviva-Bourdain C, Beermann F, Gemperle-Britschgi C, Fouilhoux A, Korwitz-Reichelt A, Bailey HJ, Droogmans L, Oppermann U, Sass JO, Yue WW. Novel patient missense mutations in the HSD17B10 gene affect dehydrogenase and mitochondrial tRNA modification functions of the encoded protein. Biochim Biophys Acta Mol Basis Dis 2017; 1863:3294-3302. [PMID: 28888424 DOI: 10.1016/j.bbadis.2017.09.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 08/16/2017] [Accepted: 09/05/2017] [Indexed: 10/18/2022]
Abstract
MRPP2 (also known as HSD10/SDR5C1) is a multifunctional protein that harbours both catalytic and non-catalytic functions. The protein belongs to the short-chain dehydrogenase/reductases (SDR) family and is involved in the catabolism of isoleucine in vivo and steroid metabolism in vitro. MRPP2 also moonlights in a complex with the MRPP1 (also known as TRMT10C) protein for N1-methylation of purines at position 9 of mitochondrial tRNA, and in a complex with MRPP1 and MRPP3 (also known as PRORP) proteins for 5'-end processing of mitochondrial precursor tRNA. Inherited mutations in the HSD17B10 gene encoding MRPP2 protein lead to a childhood disorder characterised by progressive neurodegeneration, cardiomyopathy or both. Here we report two patients with novel missense mutations in the HSD17B10 gene (c.34G>C and c.526G>A), resulting in the p.V12L and p.V176M substitutions. Val12 and Val176 are highly conserved residues located at different regions of the MRPP2 structure. Recombinant mutant proteins were expressed and characterised biochemically to investigate their effects towards the functions of MRPP2 and associated complexes in vitro. Both mutant proteins showed significant reduction in the dehydrogenase, methyltransferase and tRNA processing activities compared to wildtype, associated with reduced stability for protein with p.V12L, whereas the protein carrying p.V176M showed impaired kinetics and complex formation. This study therefore identified two distinctive molecular mechanisms to explain the biochemical defects for the novel missense patient mutations.
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Affiliation(s)
- Stephanie Oerum
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, Old Road Campus, Roosevelt Drive, OX3 7DQ Oxford, UK
| | - Martine Roovers
- Institut de Recherches Microbiologiques Jean-Marie Wiame, Bruxelles, Belgium
| | - Michael Leichsenring
- Department for Children and Adolescent Medicine, Ulm University Medical School, Ulm, Germany
| | - Cécile Acquaviva-Bourdain
- Groupement Hospitalier Est, Centre de Biologie Est, Service Maladies Héréditaires du Métabolisme, Bron, France
| | - Frauke Beermann
- University of Freiburg Children's Hospital, Laboratory of Clinical Biochemistry and Metabolism, Freiburg, Germany
| | - Corinne Gemperle-Britschgi
- University Children's Hospital and Children's Research Center, Clinical Chemistry & Biochemistry, Zürich, Switzerland
| | - Alain Fouilhoux
- Centre de Référence des Maladies Héréditaires du Métabolisme, HCL, Bron, France
| | - Anne Korwitz-Reichelt
- Bonn-Rhein-Sieg University of Applied Sciences, Department of Natural Sciences, von-Liebig-Str. 20, 53359 Rheinbach, Germany
| | - Henry J Bailey
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, Old Road Campus, Roosevelt Drive, OX3 7DQ Oxford, UK
| | - Louis Droogmans
- Laboratoire de Microbiologie, Universite libre de Bruxelles, Belgium
| | - Udo Oppermann
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, Old Road Campus, Roosevelt Drive, OX3 7DQ Oxford, UK; Botnar Research Centre, NIHR Oxford Biomedical Research Unit, Oxford, UK
| | - Jörn Oliver Sass
- University of Freiburg Children's Hospital, Laboratory of Clinical Biochemistry and Metabolism, Freiburg, Germany; University Children's Hospital and Children's Research Center, Clinical Chemistry & Biochemistry, Zürich, Switzerland; Bonn-Rhein-Sieg University of Applied Sciences, Department of Natural Sciences, von-Liebig-Str. 20, 53359 Rheinbach, Germany.
| | - Wyatt W Yue
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, Old Road Campus, Roosevelt Drive, OX3 7DQ Oxford, UK.
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27
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Numamoto M, Maekawa H, Kaneko Y. Efficient genome editing by CRISPR/Cas9 with a tRNA-sgRNA fusion in the methylotrophic yeast Ogataea polymorpha. J Biosci Bioeng 2017; 124:487-92. [PMID: 28666889 DOI: 10.1016/j.jbiosc.2017.06.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 06/02/2017] [Accepted: 06/02/2017] [Indexed: 11/30/2022]
Abstract
The methylotrophic yeast Ogataea polymorpha (syn. Hansenula polymorpha) is an attractive industrial non-conventional yeast showing high thermo-tolerance (up to 50°C) and xylose assimilation. However, genetic manipulation of O. polymorpha is often laborious and time-consuming because it has lower homologous recombination efficiency relative to Saccharomyces cerevisiae. To overcome this disadvantage, we applied the CRISPR/Cas9 system as a powerful genome editing tool in O. polymorpha. In this system, both single guide RNA (sgRNA) and endonuclease Cas9 were expressed by a single autonomously-replicable plasmid and the sgRNA portion could be easily changed by using PCR and In-Fusion cloning techniques. Because the mutation efficiency of the CRISPR/Cas9 system was relatively low when the sgRNA was expressed under the control of the OpSNR6 promoter, the tRNACUG gene was used for sgRNA expression. The editing efficiency of this system ranged from 17% to 71% of transformants in several target genes tested (ADE12, PHO1, PHO11, and PHO84). These findings indicate that genetic manipulation of O. polymorpha will be more convenient and accelerated by using this CRISPR/Cas9 system.
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Abstract
Circular (circ)RNAs have recently become a subject of great biologic interest. It is now clear that they represent a diverse and abundant class of RNAs with regulated expression and evolutionarily conserved functions. There are several mechanisms by which RNA circularization can occur in vivo. Here, we focus on the biogenesis of tRNA intronic circular RNAs (tricRNAs) in archaea and animals, and we detail their use as research tools for orthogonal, directed circRNA expression in vivo.
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Affiliation(s)
- John J Noto
- a Curriculum in Genetics and Molecular Biology , The University of North Carolina at Chapel Hill , Chapel Hill , NC , USA.,b Integrative Program for Biological and Genome Sciences , The University of North Carolina at Chapel Hill , Chapel Hill , NC , USA
| | - Casey A Schmidt
- a Curriculum in Genetics and Molecular Biology , The University of North Carolina at Chapel Hill , Chapel Hill , NC , USA.,b Integrative Program for Biological and Genome Sciences , The University of North Carolina at Chapel Hill , Chapel Hill , NC , USA
| | - A Gregory Matera
- a Curriculum in Genetics and Molecular Biology , The University of North Carolina at Chapel Hill , Chapel Hill , NC , USA.,b Integrative Program for Biological and Genome Sciences , The University of North Carolina at Chapel Hill , Chapel Hill , NC , USA.,c Lineberger Comprehensive Cancer Center , The University of North Carolina at Chapel Hill , Chapel Hill , NC , USA.,d Department of Biology , The University of North Carolina at Chapel Hill , Chapel Hill , NC , USA.,e Department of Genetics , The University of North Carolina at Chapel Hill , Chapel Hill , NC , USA
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29
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Foretek D, Nuc P, Żywicki M, Karlowski WM, Kudla G, Boguta M. Maf1-mediated regulation of yeast RNA polymerase III is correlated with CCA addition at the 3' end of tRNA precursors. Gene 2016; 612:12-18. [PMID: 27575455 PMCID: PMC5390780 DOI: 10.1016/j.gene.2016.08.033] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 08/18/2016] [Accepted: 08/20/2016] [Indexed: 11/30/2022]
Abstract
In eukaryotic cells tRNA synthesis is negatively regulated by the protein Maf1, conserved from yeast to humans. Maf1 from yeast Saccharomyces cerevisiae mediates repression of trna transcription when cells are transferred from medium with glucose to medium with glycerol, a non-fermentable carbon source. The strain with deleted gene encoding Maf1 (maf1Δ) is viable but accumulates tRNA precursors. In this study tRNA precursors were analysed by RNA-Seq and Northern hybridization in wild type strain and maf1Δ mutant grown in glucose medium or upon shift to repressive conditions. A negative effect of maf1Δ mutant on the addition of the auxiliary CCA nucleotides to the 3′ end of pre-tRNAs was observed in cells shifted to unfavourable growth conditions. This effect was reduced by overexpression of the yeast CCA1 gene encoding ATP(CTP):tRNA nucleotidyltransferase. The CCA sequence at the 3′ end is important for export of tRNA precursors from the nucleus and essential for tRNA charging with amino acids. Data presented here indicate that CCA-addition to intron-containing end-processed tRNA precursors is a limiting step in tRNA maturation when there is no Maf1 mediated RNA polymerase III (Pol III) repression. The correlation between CCA synthesis and Pol III regulation by Maf1 could be important in coordination of tRNA transcription, processing and regulation of translation. Effect of Maf1 on maturation of tRNA precursors was analysed in yeast cells. CCA addition to the 3′ end of pre-tRNA was down-regulated in maf1Δ mutant under stress. Effect of inactivation and overproduction of Cca1 enzyme in maf1Δ cells was examined. Link between CCA synthesis and RNA polymerase III regulation is discussed.
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Affiliation(s)
- Dominika Foretek
- Department of Genetics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland
| | - Przemysław Nuc
- Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, 61-614 Poznan, Poland
| | - Marek Żywicki
- Department of Computational Biology, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, 61-614 Poznan, Poland
| | - Wojciech M Karlowski
- Department of Computational Biology, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, 61-614 Poznan, Poland
| | - Grzegorz Kudla
- MRC Human Genetics Unit, IGMM, University of Edinburgh, Edinburgh, Scotland, UK
| | - Magdalena Boguta
- Department of Genetics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland.
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30
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Ogawa A, Tabuchi J, Doi Y, Takamatsu M. Biofunction-assisted DNA detection through RNase H-enhanced 3' processing of a premature tRNA probe in a wheat germ extract. Bioorg Med Chem Lett 2016; 26:3658-61. [PMID: 27289318 DOI: 10.1016/j.bmcl.2016.05.091] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 05/27/2016] [Accepted: 05/31/2016] [Indexed: 12/22/2022]
Abstract
We have developed a novel type of biofunction-assisted, signal-turn-on sensor for simply and homogenously detecting DNA. This sensor system is composed of two types of in vitro-transcribed label-free RNAs (a 3' premature amber suppressor tRNA probe and an amber-mutated mRNA encoding a reporter protein), RNase H, and a wheat germ extract (WGE). A target DNA induces the 3' end maturation of the tRNA probe, which is enhanced by RNase H and leads to the expression of a full-length reporter protein through amber suppression in WGE, while there is almost no expression without the target due to the inactivity of the premature probe. Therefore, the target can be readily detected with the activity of the translated reporter. The catalytic reuse of the target with the help of RNase H in addition to various bioprocesses in WGE enables this sensor system to exhibit relatively high selectivity and sensitivity.
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Affiliation(s)
- Atsushi Ogawa
- Proteo-Science Center, Ehime University, 3 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan.
| | - Junichiro Tabuchi
- Proteo-Science Center, Ehime University, 3 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan
| | - Yasunori Doi
- Proteo-Science Center, Ehime University, 3 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan
| | - Masashi Takamatsu
- Proteo-Science Center, Ehime University, 3 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan
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31
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Samanta MP, Lai SM, Daniels CJ, Gopalan V. Sequence Analysis and Comparative Study of the Protein Subunits of Archaeal RNase P. Biomolecules 2016; 6:biom6020022. [PMID: 27104580 PMCID: PMC4919917 DOI: 10.3390/biom6020022] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 04/05/2016] [Accepted: 04/08/2016] [Indexed: 12/21/2022] Open
Abstract
RNase P, a ribozyme-based ribonucleoprotein (RNP) complex that catalyzes tRNA 5′-maturation, is ubiquitous in all domains of life, but the evolution of its protein components (RNase P proteins, RPPs) is not well understood. Archaeal RPPs may provide clues on how the complex evolved from an ancient ribozyme to an RNP with multiple archaeal and eukaryotic (homologous) RPPs, which are unrelated to the single bacterial RPP. Here, we analyzed the sequence and structure of archaeal RPPs from over 600 available genomes. All five RPPs are found in eight archaeal phyla, suggesting that these RPPs arose early in archaeal evolutionary history. The putative ancestral genomic loci of archaeal RPPs include genes encoding several members of ribosome, exosome, and proteasome complexes, which may indicate coevolution/coordinate regulation of RNase P with other core cellular machineries. Despite being ancient, RPPs generally lack sequence conservation compared to other universal proteins. By analyzing the relative frequency of residues at every position in the context of the high-resolution structures of each of the RPPs (either alone or as functional binary complexes), we suggest residues for mutational analysis that may help uncover structure-function relationships in RPPs.
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Affiliation(s)
| | - Stella M Lai
- Department of Chemistry & Biochemistry, The Ohio State University, Columbus, OH 43210, USA.
- Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA.
| | - Charles J Daniels
- Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA.
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA.
| | - Venkat Gopalan
- Department of Chemistry & Biochemistry, The Ohio State University, Columbus, OH 43210, USA.
- Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA.
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32
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Abstract
In this resource, Wu et al. present the first comprehensive unbiased analysis of the role of nearly an entire proteome in tRNA biology and describe 162 novel and 12 previously known Saccharomyces cerevisiae gene products that function in tRNA processing, turnover, and subcellular movement. The findings from this genome-wide screen describe putative novel pathways for tRNA nuclear export and extensive links between tRNA biology and other aspects of cell physiology. Transfer ribonucleic acids (tRNAs) are essential for protein synthesis. However, key gene products involved in tRNA biogenesis and subcellular movement remain to be discovered. We conducted the first comprehensive unbiased analysis of the role of nearly an entire proteome in tRNA biology and describe 162 novel and 12 previously known Saccharomyces cerevisiae gene products that function in tRNA processing, turnover, and subcellular movement. tRNA nuclear export is of particular interest because it is essential, but the known tRNA exporters (Los1 [exportin-t] and Msn5 [exportin-5]) are unessential. We report that mutations of CRM1 (Exportin-1), MEX67/MTR2 (TAP/p15), and five nucleoporins cause accumulation of unspliced tRNA, a hallmark of defective tRNA nuclear export. CRM1 mutation genetically interacts with los1Δ and causes altered tRNA nuclear–cytoplasmic distribution. The data implicate roles for the protein and mRNA nuclear export machineries in tRNA nuclear export. Mutations of genes encoding actin cytoskeleton components and mitochondrial outer membrane proteins also cause accumulation of unspliced tRNA, likely due to defective splicing on mitochondria. Additional gene products, such as chromatin modification enzymes, have unanticipated effects on pre-tRNA end processing. Thus, this genome-wide screen uncovered putative novel pathways for tRNA nuclear export and extensive links between tRNA biology and other aspects of cell physiology.
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Affiliation(s)
- Jingyan Wu
- Department of Molecular Genetics, Center for RNA biology, The Ohio State University, Columbus, Ohio 43210, USA
| | | | - Kunal Chatterjee
- Department of Molecular Genetics, Center for RNA biology, The Ohio State University, Columbus, Ohio 43210, USA
| | - Yao Wan
- Department of Molecular Genetics, Center for RNA biology, The Ohio State University, Columbus, Ohio 43210, USA
| | - Anita K Hopper
- Department of Molecular Genetics, Center for RNA biology, The Ohio State University, Columbus, Ohio 43210, USA
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Huang HY, Hopper AK. Multiple Layers of Stress-Induced Regulation in tRNA Biology. Life (Basel) 2016; 6:life6020016. [PMID: 27023616 PMCID: PMC4931453 DOI: 10.3390/life6020016] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 03/14/2016] [Accepted: 03/17/2016] [Indexed: 01/28/2023] Open
Abstract
tRNAs are the fundamental components of the translation machinery as they deliver amino acids to the ribosomes during protein synthesis. Beyond their essential function in translation, tRNAs also function in regulating gene expression, modulating apoptosis and several other biological processes. There are multiple layers of regulatory mechanisms in each step of tRNA biogenesis. For example, tRNA 3′ trailer processing is altered upon nutrient stress; tRNA modification is reprogrammed under various stresses; nuclear accumulation of tRNAs occurs upon nutrient deprivation; tRNA halves accumulate upon oxidative stress. Here we address how environmental stresses can affect nearly every step of tRNA biology and we describe the possible regulatory mechanisms that influence the function or expression of tRNAs under stress conditions.
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Affiliation(s)
- Hsiao-Yun Huang
- Department of Biology, Indiana University, 915 E third St., Myers 300, Bloomington, IN 47405, USA.
| | - Anita K Hopper
- Department of Molecular Genetics and Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA.
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Lu Z, Filonov GS, Noto JJ, Schmidt CA, Hatkevich TL, Wen Y, Jaffrey SR, Matera AG. Metazoan tRNA introns generate stable circular RNAs in vivo. RNA 2015; 21:1554-65. [PMID: 26194134 PMCID: PMC4536317 DOI: 10.1261/rna.052944.115] [Citation(s) in RCA: 137] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 07/06/2015] [Indexed: 05/23/2023]
Abstract
We report the discovery of a class of abundant circular noncoding RNAs that are produced during metazoan tRNA splicing. These transcripts, termed tRNA intronic circular (tric)RNAs, are conserved features of animal transcriptomes. Biogenesis of tricRNAs requires anciently conserved tRNA sequence motifs and processing enzymes, and their expression is regulated in an age-dependent and tissue-specific manner. Furthermore, we exploited this biogenesis pathway to develop an in vivo expression system for generating "designer" circular RNAs in human cells. Reporter constructs expressing RNA aptamers such as Spinach and Broccoli can be used to follow the transcription and subcellular localization of tricRNAs in living cells. Owing to the superior stability of circular vs. linear RNA isoforms, this expression system has a wide range of potential applications, from basic research to pharmaceutical science.
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Affiliation(s)
- Zhipeng Lu
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599, USA
| | - Grigory S Filonov
- Department of Pharmacology, Weill Cornell Medical College, New York, New York 10065, USA
| | - John J Noto
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, North Carolina 27599, USA
| | - Casey A Schmidt
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, North Carolina 27599, USA
| | - Talia L Hatkevich
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, North Carolina 27599, USA
| | - Ying Wen
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, North Carolina 27599, USA
| | - Samie R Jaffrey
- Department of Pharmacology, Weill Cornell Medical College, New York, New York 10065, USA
| | - A Gregory Matera
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599, USA Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, North Carolina 27599, USA Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, North Carolina 27599, USA Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599, USA Department of Genetics, University of North Carolina, Chapel Hill, North Carolina 27599, USA
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35
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Mefferd AL, Kornepati AVR, Bogerd HP, Kennedy EM, Cullen BR. Expression of CRISPR/Cas single guide RNAs using small tRNA promoters. RNA 2015; 21:1683-9. [PMID: 26187160 PMCID: PMC4536327 DOI: 10.1261/rna.051631.115] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 06/12/2015] [Indexed: 05/08/2023]
Abstract
The in vivo application of CRISPR/Cas-based DNA editing technology will require the development of efficient delivery methods that likely will be dependent on adeno-associated virus (AAV)-based viral vectors. However, AAV vectors have only a modest, ∼4.7-kb packaging capacity, which will necessitate the identification and characterization of highly active Cas9 proteins that are substantially smaller than the prototypic Streptococcus pyogenes Cas9 protein, which covers ∼4.2 kb of coding sequence, as well as the development of single guide RNA (sgRNA) expression cassettes substantially smaller than the current ∼360 bp size. Here, we report that small, ∼70-bp tRNA promoters can be used to express high levels of tRNA:sgRNA fusion transcripts that are efficiently and precisely cleaved by endogenous tRNase Z to release fully functional sgRNAs. Importantly, cells stably expressing functional tRNA:sgRNA precursors did not show a detectable change in the level of endogenous tRNA expression. This novel sgRNA expression strategy should greatly facilitate the construction of effective AAV-based Cas9/sgRNA vectors for future in vivo use.
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Affiliation(s)
- Adam L Mefferd
- Department of Molecular Genetics & Microbiology and Center for Virology, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Anand V R Kornepati
- Department of Molecular Genetics & Microbiology and Center for Virology, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Hal P Bogerd
- Department of Molecular Genetics & Microbiology and Center for Virology, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Edward M Kennedy
- Department of Molecular Genetics & Microbiology and Center for Virology, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Bryan R Cullen
- Department of Molecular Genetics & Microbiology and Center for Virology, Duke University Medical Center, Durham, North Carolina 27710, USA
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36
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Abstract
The clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 nuclease (Cas9) system is being harnessed as a powerful tool for genome engineering in basic research, molecular therapy, and crop improvement. This system uses a small guide RNA (gRNA) to direct Cas9 endonuclease to a specific DNA site; thus, its targeting capability is largely constrained by the gRNA-expressing device. In this study, we developed a general strategy to produce numerous gRNAs from a single polycistronic gene. The endogenous tRNA-processing system, which precisely cleaves both ends of the tRNA precursor, was engineered as a simple and robust platform to boost the targeting and multiplex editing capability of the CRISPR/Cas9 system. We demonstrated that synthetic genes with tandemly arrayed tRNA-gRNA architecture were efficiently and precisely processed into gRNAs with desired 5' targeting sequences in vivo, which directed Cas9 to edit multiple chromosomal targets. Using this strategy, multiplex genome editing and chromosomal-fragment deletion were readily achieved in stable transgenic rice plants with a high efficiency (up to 100%). Because tRNA and its processing system are virtually conserved in all living organisms, this method could be broadly used to boost the targeting capability and editing efficiency of CRISPR/Cas9 toolkits.
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Affiliation(s)
- Kabin Xie
- Department of Plant Pathology and Environmental Microbiology and the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802
| | - Bastian Minkenberg
- Department of Plant Pathology and Environmental Microbiology and the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802
| | - Yinong Yang
- Department of Plant Pathology and Environmental Microbiology and the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802
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37
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Katibah GE, Qin Y, Sidote DJ, Yao J, Lambowitz AM, Collins K. Broad and adaptable RNA structure recognition by the human interferon-induced tetratricopeptide repeat protein IFIT5. Proc Natl Acad Sci U S A 2014; 111:12025-30. [PMID: 25092312 DOI: 10.1073/pnas.1412842111] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Interferon (IFN) responses play key roles in cellular defense against pathogens. Highly expressed IFN-induced proteins with tetratricopeptide repeats (IFITs) are proposed to function as RNA binding proteins, but the RNA binding and discrimination specificities of IFIT proteins remain unclear. Here we show that human IFIT5 has comparable affinity for RNAs with diverse phosphate-containing 5'-ends, excluding the higher eukaryotic mRNA cap. Systematic mutagenesis revealed that sequence substitutions in IFIT5 can alternatively expand or introduce bias in protein binding to RNAs with 5' monophosphate, triphosphate, cap0 (triphosphate-bridged N7-methylguanosine), or cap1 (cap0 with RNA 2'-O-methylation). We defined the breadth of cellular ligands for IFIT5 by using a thermostable group II intron reverse transcriptase for RNA sequencing. We show that IFIT5 binds precursor and processed tRNAs, as well as other RNA polymerase III transcripts. Our findings establish the RNA recognition specificity of the human innate immune response protein IFIT5.
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Long T, Guo D, He D, Shen W, Li X. The tRNA 3'-end processing enzyme tRNase Z2 contributes to chloroplast biogenesis in rice. J Integr Plant Biol 2013; 55:1104-18. [PMID: 24034348 DOI: 10.1111/jipb.12102] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 08/19/2013] [Indexed: 05/08/2023]
Abstract
tRNase Z (TRZ) is a ubiquitous endonuclease that removes the 3'-trailer from precursor tRNAs during maturation. In yeast and animals, TRZ regulates the cell cycle via its (t)RNA processing activity; however, its physiological function in higher plants has not been well characterized. This study describes the identification of a rice (Oryza sativa) TRZ2 mutant; plants homozygous for the osatrz2 mutation were albinos with deficient chlorophyll content. A microscopic analysis of the mutant plants revealed that the transition of proplastids to chloroplasts was arrested at an early stage, and the number and size of the plastids in callus cells was substantially decreased. A genetic complementation test and an RNA interference analysis confirmed that disruption of OsaTRZ2 was responsible for the mutant phenotype. OsaTRZ2 is expressed in all rice tissues, but is preferentially expressed in leaves, sheathes, and calli. OsaTRZ2 was subcellularly localized in chloroplasts, and displayed tRNA 3'-end processing activity in both in vitro and in vivo assays. In the osatrz2 mutants, transcription of plastid-encoded and nucleus-encoded RNA polymerases was severely reduced and moderately increased, respectively. These results suggest that the tRNA 3' processing activity of OsaTRZ2 contributes to chloroplast biogenesis.
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Affiliation(s)
- Tuan Long
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China
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Xie X, Dubrovskaya V, Yacoub N, Walska J, Gleason T, Reid K, Dubrovsky EB. Developmental roles of Drosophila tRNA processing endonuclease RNase ZL as revealed with a conditional rescue system. Dev Biol 2013; 381:324-40. [PMID: 23867108 DOI: 10.1016/j.ydbio.2013.07.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 06/15/2013] [Accepted: 07/03/2013] [Indexed: 01/08/2023]
Abstract
Drosophila RNase Z(L) (dRNaseZ) belongs to a family of endoribonucleases with a major role in tRNA 3'-end processing. The biochemical function of RNase Z(L) is conserved from yeast to human. Here we present a study of its biological function during Drosophila development. In flies, dRNaseZ provides a non-redundant function, as the RNZ(ED24) knockout (KO) mutation causes early larval lethality. Mosaic and conditional rescue techniques were employed to determine dRNaseZ requirements at later stages. We found that dRNaseZ activity is essential for all phases of fly development that involve cell division, including growth of adult tissue progenitors during larval and metamorphic stages, and gametogenesis in adults. At the cellular level, two major phenotypes were identified-cell growth deficiency in endoreplicating tissues and cell cycle arrest in mitotic tissues. While cell growth and proliferation are both dependant on protein synthesis, the two phenotypes displayed reliance on different dRNaseZ functions. We found that dRNaseZ KO completely blocks tRNA maturation without diminishing the abundance of mature tRNA molecules. Our data indicate that growth arrest of endoreplicating cells is primarily attributed to the relocation of the pool of mature tRNAs into the nuclei causing a decrease in translation efficiency. Mitotically dividing cells appear to be less dependent on translation machinery as they maintain their normal size when deprived of dRNaseZ activity, but rather display a cell cycle arrest at the G2-M transition.
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Affiliation(s)
- Xie Xie
- Department of Biology, Fordham University, Bronx, NY 10458, USA
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Howard MJ, Liu X, Lim WH, Klemm BP, Fierke CA, Koutmos M, Engelke DR. RNase P enzymes: divergent scaffolds for a conserved biological reaction. RNA Biol 2013; 10:909-14. [PMID: 23595059 DOI: 10.4161/rna.24513] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Ribonuclease P (RNase P) catalyzes the maturation of the 5' end of precursor-tRNAs (pre-tRNA) and is conserved in all domains of life. However, the composition of RNase P varies from bacteria to archaea and eukarya, making RNase P one of the most diverse enzymes characterized. Most known RNase P enzymes contain a large catalytic RNA subunit that associates with one to 10 proteins. Recently, a protein-only form of RNase P was discovered in mitochondria and chloroplasts of many higher eukaryotes. This proteinaceous RNase P (PRORP) represents a new class of metallonucleases. Here we discuss our recent crystal structure of PRORP1 from Arabidopsis thaliana and speculate on the reasons for the replacement of catalytic RNA by a protein catalyst. We conclude, based on an analysis of the catalytic efficiencies of ribonucleoprotein (RNP) and PRORP enzymes, that the need for greater catalytic efficiency is most likely not the driving force behind the replacement of the RNA with a protein catalyst. The emergence of a protein-based RNase P more likely reflects the increasing complexity of the biological system, including difficulties in importation into organelles and vulnerability of organellar RNAs to cleavage.
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Affiliation(s)
- Michael J Howard
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, USA
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