1
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Yang WQ, Ge JY, Zhang X, Zhu WY, Lin L, Shi Y, Xu B, Liu RJ. THUMPD2 catalyzes the N2-methylation of U6 snRNA of the spliceosome catalytic center and regulates pre-mRNA splicing and retinal degeneration. Nucleic Acids Res 2024; 52:3291-3309. [PMID: 38165050 PMCID: PMC11014329 DOI: 10.1093/nar/gkad1243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Revised: 12/13/2023] [Accepted: 12/21/2023] [Indexed: 01/03/2024] Open
Abstract
The mechanisms by which the relatively conserved spliceosome manages the enormously large number of splicing events that occur in humans (∼200 000 versus ∼300 in yeast) are poorly understood. Here, we show deposition of one RNA modification-N2-methylguanosine (m2G) on the G72 of U6 snRNA (the catalytic center of the spliceosome) promotes efficient pre-mRNA splicing activity in human cells. This modification was identified to be conserved among vertebrates. Further, THUMPD2 was demonstrated as the methyltransferase responsible for U6 m2G72 by explicitly recognizing the U6-specific sequences and structural elements. The knock-out of THUMPD2 eliminated U6 m2G72 and impaired the pre-mRNA splicing activity, resulting in thousands of changed alternative splicing events of endogenous pre-mRNAs in human cells. Notably, the aberrantly spliced pre-mRNA population elicited the nonsense-mediated mRNA decay pathway. We further show that THUMPD2 was associated with age-related macular degeneration and retinal function. Our study thus demonstrates how an RNA epigenetic modification of the major spliceosome regulates global pre-mRNA splicing and impacts physiology and disease.
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Affiliation(s)
- Wen-Qing Yang
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Jian-Yang Ge
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Xiaofeng Zhang
- Division of Reproduction and Genetics, The First Affiliated Hospital of USTC, MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, Hefei National Research Center for Interdisciplinary Sciences at the Microscale, Biomedical Sciences and Health Laboratory of Anhui Province, Division of Life Sciences and Medicine, University of Science and Technology of China, 230027 Hefei, China
| | - Wen-Yu Zhu
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Lin Lin
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Yigong Shi
- Institute of Biology, Westlake Institute for Advanced Study, Westlake University, Hangzhou 310064,Zhejiang Province, China
| | - Beisi Xu
- Center for Applied Bioinformatics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Ru-Juan Liu
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
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2
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Davey-Young J, Hasan F, Tennakoon R, Rozik P, Moore H, Hall P, Cozma E, Genereaux J, Hoffman KS, Chan PP, Lowe TM, Brandl CJ, O’Donoghue P. Mistranslating the genetic code with leucine in yeast and mammalian cells. RNA Biol 2024; 21:1-23. [PMID: 38629491 PMCID: PMC11028032 DOI: 10.1080/15476286.2024.2340297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/03/2024] [Indexed: 04/19/2024] Open
Abstract
Translation fidelity relies on accurate aminoacylation of transfer RNAs (tRNAs) by aminoacyl-tRNA synthetases (AARSs). AARSs specific for alanine (Ala), leucine (Leu), serine, and pyrrolysine do not recognize the anticodon bases. Single nucleotide anticodon variants in their cognate tRNAs can lead to mistranslation. Human genomes include both rare and more common mistranslating tRNA variants. We investigated three rare human tRNALeu variants that mis-incorporate Leu at phenylalanine or tryptophan codons. Expression of each tRNALeu anticodon variant in neuroblastoma cells caused defects in fluorescent protein production without significantly increased cytotoxicity under normal conditions or in the context of proteasome inhibition. Using tRNA sequencing and mass spectrometry we confirmed that each tRNALeu variant was expressed and generated mistranslation with Leu. To probe the flexibility of the entire genetic code towards Leu mis-incorporation, we created 64 yeast strains to express all possible tRNALeu anticodon variants in a doxycycline-inducible system. While some variants showed mild or no growth defects, many anticodon variants, enriched with G/C at positions 35 and 36, including those replacing Leu for proline, arginine, alanine, or glycine, caused dramatic reductions in growth. Differential phenotypic defects were observed for tRNALeu mutants with synonymous anticodons and for different tRNALeu isoacceptors with the same anticodon. A comparison to tRNAAla anticodon variants demonstrates that Ala mis-incorporation is more tolerable than Leu at nearly every codon. The data show that the nature of the amino acid substitution, the tRNA gene, and the anticodon are each important factors that influence the ability of cells to tolerate mistranslating tRNAs.
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Affiliation(s)
- Josephine Davey-Young
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada
| | - Farah Hasan
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada
| | - Rasangi Tennakoon
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada
| | - Peter Rozik
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada
| | - Henry Moore
- Department of Biomolecular Engineering, Baskin School of Engineering & UCSC Genomics Institute, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Peter Hall
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada
| | - Ecaterina Cozma
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada
| | - Julie Genereaux
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada
| | | | - Patricia P. Chan
- Department of Biomolecular Engineering, Baskin School of Engineering & UCSC Genomics Institute, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Todd M. Lowe
- Department of Biomolecular Engineering, Baskin School of Engineering & UCSC Genomics Institute, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Christopher J. Brandl
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada
| | - Patrick O’Donoghue
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada
- Department of Chemistry, The University of Western Ontario, London, Ontario, Canada
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3
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Giegé R, Eriani G. The tRNA identity landscape for aminoacylation and beyond. Nucleic Acids Res 2023; 51:1528-1570. [PMID: 36744444 PMCID: PMC9976931 DOI: 10.1093/nar/gkad007] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 12/21/2022] [Accepted: 01/03/2023] [Indexed: 02/07/2023] Open
Abstract
tRNAs are key partners in ribosome-dependent protein synthesis. This process is highly dependent on the fidelity of tRNA aminoacylation by aminoacyl-tRNA synthetases and relies primarily on sets of identities within tRNA molecules composed of determinants and antideterminants preventing mischarging by non-cognate synthetases. Such identity sets were discovered in the tRNAs of a few model organisms, and their properties were generalized as universal identity rules. Since then, the panel of identity elements governing the accuracy of tRNA aminoacylation has expanded considerably, but the increasing number of reported functional idiosyncrasies has led to some confusion. In parallel, the description of other processes involving tRNAs, often well beyond aminoacylation, has progressed considerably, greatly expanding their interactome and uncovering multiple novel identities on the same tRNA molecule. This review highlights key findings on the mechanistics and evolution of tRNA and tRNA-like identities. In addition, new methods and their results for searching sets of multiple identities on a single tRNA are discussed. Taken together, this knowledge shows that a comprehensive understanding of the functional role of individual and collective nucleotide identity sets in tRNA molecules is needed for medical, biotechnological and other applications.
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Affiliation(s)
- Richard Giegé
- Correspondence may also be addressed to Richard Giegé.
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4
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Huang ZX, Li J, Xiong QP, Li H, Wang ED, Liu RJ. Position 34 of tRNA is a discriminative element for m5C38 modification by human DNMT2. Nucleic Acids Res 2021; 49:13045-13061. [PMID: 34871455 PMCID: PMC8682788 DOI: 10.1093/nar/gkab1148] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 10/05/2021] [Accepted: 11/03/2021] [Indexed: 12/05/2022] Open
Abstract
Dnmt2, a member of the DNA methyltransferase superfamily, catalyzes the formation of 5-methylcytosine at position 38 in the anticodon loop of tRNAs. Dnmt2 regulates many cellular biological processes, especially the production of tRNA-derived fragments and intergenerational transmission of paternal metabolic disorders to offspring. Moreover, Dnmt2 is closely related to human cancers. The tRNA substrates of mammalian Dnmt2s are mainly detected using bisulfite sequencing; however, we lack supporting biochemical data concerning their substrate specificity or recognition mechanism. Here, we deciphered the tRNA substrates of human DNMT2 (hDNMT2) as tRNAAsp(GUC), tRNAGly(GCC) and tRNAVal(AAC). Intriguingly, for tRNAAsp(GUC) and tRNAGly(GCC), G34 is the discriminator element; whereas for tRNAVal(AAC), the inosine modification at position 34 (I34), which is formed by the ADAT2/3 complex, is the prerequisite for hDNMT2 recognition. We showed that the C32U33(G/I)34N35 (C/U)36A37C38 motif in the anticodon loop, U11:A24 in the D stem, and the correct size of the variable loop are required for Dnmt2 recognition of substrate tRNAs. Furthermore, mammalian Dnmt2s possess a conserved tRNA recognition mechanism.
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MESH Headings
- 5-Methylcytosine/metabolism
- Adenosine Deaminase/genetics
- Adenosine Deaminase/metabolism
- Animals
- Anticodon/genetics
- Anticodon/metabolism
- Base Sequence
- DNA (Cytosine-5-)-Methyltransferases/chemistry
- DNA (Cytosine-5-)-Methyltransferases/genetics
- DNA (Cytosine-5-)-Methyltransferases/metabolism
- HEK293 Cells
- HeLa Cells
- Humans
- Inosine/metabolism
- Mice
- Models, Molecular
- NIH 3T3 Cells
- Nucleic Acid Conformation
- Protein Binding
- RNA, Transfer/chemistry
- RNA, Transfer/genetics
- RNA, Transfer/metabolism
- RNA, Transfer, Asp/chemistry
- RNA, Transfer, Asp/genetics
- RNA, Transfer, Asp/metabolism
- RNA, Transfer, Gly/chemistry
- RNA, Transfer, Gly/genetics
- RNA, Transfer, Gly/metabolism
- RNA, Transfer, Val/chemistry
- RNA, Transfer, Val/genetics
- RNA, Transfer, Val/metabolism
- RNA-Binding Proteins/genetics
- RNA-Binding Proteins/metabolism
- Substrate Specificity
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Affiliation(s)
- Zhi-Xuan Huang
- State Key Laboratory of Molecular Biology, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China; University of Chinese Academy of Sciences, Beijing 100039, China
- School of Life Science and Technology, ShanghaiTech University, 393 Middle Hua Xia Road, Shanghai 201210, China
| | - Jing Li
- School of Life Science and Technology, ShanghaiTech University, 393 Middle Hua Xia Road, Shanghai 201210, China
| | - Qing-Ping Xiong
- State Key Laboratory of Molecular Biology, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China; University of Chinese Academy of Sciences, Beijing 100039, China
| | - Hao Li
- School of Life Science and Technology, ShanghaiTech University, 393 Middle Hua Xia Road, Shanghai 201210, China
| | - En-Duo Wang
- State Key Laboratory of Molecular Biology, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China; University of Chinese Academy of Sciences, Beijing 100039, China
- School of Life Science and Technology, ShanghaiTech University, 393 Middle Hua Xia Road, Shanghai 201210, China
| | - Ru-Juan Liu
- School of Life Science and Technology, ShanghaiTech University, 393 Middle Hua Xia Road, Shanghai 201210, China
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5
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Yang WQ, Xiong QP, Ge JY, Li H, Zhu WY, Nie Y, Lin X, Lv D, Li J, Lin H, Liu RJ. THUMPD3-TRMT112 is a m2G methyltransferase working on a broad range of tRNA substrates. Nucleic Acids Res 2021; 49:11900-11919. [PMID: 34669960 PMCID: PMC8599901 DOI: 10.1093/nar/gkab927] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 09/06/2021] [Accepted: 10/08/2021] [Indexed: 12/20/2022] Open
Abstract
Post-transcriptional modifications affect tRNA biology and are closely associated with human diseases. However, progress on the functional analysis of tRNA modifications in metazoans has been slow because of the difficulty in identifying modifying enzymes. For example, the biogenesis and function of the prevalent N2-methylguanosine (m2G) at the sixth position of tRNAs in eukaryotes has long remained enigmatic. Herein, using a reverse genetics approach coupled with RNA-mass spectrometry, we identified that THUMP domain-containing protein 3 (THUMPD3) is responsible for tRNA: m2G6 formation in human cells. However, THUMPD3 alone could not modify tRNAs. Instead, multifunctional methyltransferase subunit TRM112-like protein (TRMT112) interacts with THUMPD3 to activate its methyltransferase activity. In the in vitro enzymatic assay system, THUMPD3-TRMT112 could methylate all the 26 tested G6-containing human cytoplasmic tRNAs by recognizing the characteristic 3'-CCA of mature tRNAs. We also showed that m2G7 of tRNATrp was introduced by THUMPD3-TRMT112. Furthermore, THUMPD3 is widely expressed in mouse tissues, with an extremely high level in the testis. THUMPD3-knockout cells exhibited impaired global protein synthesis and reduced growth. Our data highlight the significance of the tRNA: m2G6/7 modification and pave a way for further studies of the role of m2G in sperm tRNA derived fragments.
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Affiliation(s)
- Wen-Qing Yang
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Qing-Ping Xiong
- CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Jian-Yang Ge
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Hao Li
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Wen-Yu Zhu
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Yan Nie
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai 201210, China
| | - Xiuying Lin
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, China
| | - Daizhu Lv
- Analysis and Testing Center, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China
| | - Jing Li
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Huan Lin
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, China
| | - Ru-Juan Liu
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
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6
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Ehrlich R, Davyt M, López I, Chalar C, Marín M. On the Track of the Missing tRNA Genes: A Source of Non-Canonical Functions? Front Mol Biosci 2021; 8:643701. [PMID: 33796548 PMCID: PMC8007984 DOI: 10.3389/fmolb.2021.643701] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 02/02/2021] [Indexed: 01/31/2023] Open
Abstract
Cellular tRNAs appear today as a diverse population of informative macromolecules with conserved general elements ensuring essential common functions and different and distinctive features securing specific interactions and activities. Their differential expression and the variety of post-transcriptional modifications they are subject to, lead to the existence of complex repertoires of tRNA populations adjusted to defined cellular states. Despite the tRNA-coding genes redundancy in prokaryote and eukaryote genomes, it is surprising to note the absence of genes coding specific translational-active isoacceptors throughout the phylogeny. Through the analysis of different releases of tRNA databases, this review aims to provide a general summary about those “missing tRNA genes.” This absence refers to both tRNAs that are not encoded in the genome, as well as others that show critical sequence variations that would prevent their activity as canonical translation adaptor molecules. Notably, while a group of genes are universally missing, others are absent in particular kingdoms. Functional information available allows to hypothesize that the exclusion of isodecoding molecules would be linked to: 1) reduce ambiguities of signals that define the specificity of the interactions in which the tRNAs are involved; 2) ensure the adaptation of the translational apparatus to the cellular state; 3) divert particular tRNA variants from ribosomal protein synthesis to other cellular functions. This leads to consider the “missing tRNA genes” as a source of putative non-canonical tRNA functions and to broaden the concept of adapter molecules in ribosomal-dependent protein synthesis.
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Affiliation(s)
- Ricardo Ehrlich
- Biochemistry-Molecular Biology, Faculty of Science, Universidad de la República, Montevideo, Uruguay.,Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Marcos Davyt
- Biochemistry-Molecular Biology, Faculty of Science, Universidad de la República, Montevideo, Uruguay
| | - Ignacio López
- Biochemistry-Molecular Biology, Faculty of Science, Universidad de la República, Montevideo, Uruguay
| | - Cora Chalar
- Biochemistry-Molecular Biology, Faculty of Science, Universidad de la República, Montevideo, Uruguay
| | - Mónica Marín
- Biochemistry-Molecular Biology, Faculty of Science, Universidad de la República, Montevideo, Uruguay
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7
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Kim M, van Hoof A. Suppressors of mRNA Decapping Defects Restore Growth Without Major Effects on mRNA Decay Rates or Abundance. Genetics 2020; 216:1051-1069. [PMID: 32998951 PMCID: PMC7768250 DOI: 10.1534/genetics.120.303641] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 09/28/2020] [Indexed: 01/09/2023] Open
Abstract
Faithful degradation of mRNAs is a critical step in gene expression, and eukaryotes share a major conserved mRNA decay pathway. In this major pathway, the two rate-determining steps in mRNA degradation are the initial gradual removal of the poly(A) tail, followed by removal of the cap structure. Removal of the cap structure is carried out by the decapping enzyme, containing the Dcp2 catalytic subunit. Although the mechanism and regulation of mRNA decay is well understood, the consequences of defects in mRNA degradation are less clear. Dcp2 has been reported as either essential or nonessential. Here, we clarify that Dcp2 is not absolutely required for spore germination and extremely slow growth, but in practical terms it is impossible to continuously culture dcp2∆ under laboratory conditions without suppressors arising. We show that null mutations in at least three different genes are each sufficient to restore growth to a dcp2∆, of which kap123∆ and tl(gag)g∆ appear the most specific. We show that kap123∆ and tl(gag)g∆ suppress dcp2 by mechanisms that are different from each other and from previously isolated dcp2 suppressors. The suppression mechanism for tL(GAG)G is determined by the unique GAG anticodon of this tRNA, and thus likely by translation of some CUC or CUU codons. Unlike previously reported suppressors of decapping defects, these suppressors do not detectably restore decapping or mRNA decay to normal rates, but instead allow survival while only modestly affecting RNA homeostasis. These results provide important new insight into the importance of decapping, resolve previously conflicting publications about the essentiality of DCP2, provide the first phenotype for a tl(gag)g mutant, and show that multiple distinct mechanisms can bypass Dcp2 requirement.
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Affiliation(s)
- Minseon Kim
- Microbiology and Molecular Genetics Department, University of Texas Health Science Center at Houston, Houston, Texas 77030
| | - Ambro van Hoof
- Microbiology and Molecular Genetics Department, University of Texas Health Science Center at Houston, Houston, Texas 77030
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8
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Li J, Wang Y, Xu B, Liu Y, Zhou M, Long T, Li H, Dong H, Nie Y, Chen PR, Wang E, Liu R. Intellectual disability-associated gene ftsj1 is responsible for 2'-O-methylation of specific tRNAs. EMBO Rep 2020; 21:e50095. [PMID: 32558197 PMCID: PMC7403668 DOI: 10.15252/embr.202050095] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 05/24/2020] [Accepted: 05/27/2020] [Indexed: 12/31/2022] Open
Abstract
tRNA modifications at the anti-codon loop are critical for accurate decoding. FTSJ1 was hypothesized to be a human tRNA 2'-O-methyltransferase. tRNAPhe (GAA) from intellectual disability patients with mutations in ftsj1 lacks 2'-O-methylation at C32 and G34 (Cm32 and Gm34). However, the catalytic activity, RNA substrates, and pathogenic mechanism of FTSJ1 remain unknown, owing, in part, to the difficulty in reconstituting enzymatic activity in vitro. Here, we identify an interacting protein of FTSJ1, WDR6. For the first time, we reconstitute the 2'-O-methylation activity of the FTSJ1-WDR6 complex in vitro, which occurs at position 34 of specific tRNAs with m1 G37 as a prerequisite. We find that modifications at positions 32, 34, and 37 are interdependent and occur in a hierarchical order in vivo. We also show that the translation efficiency of the UUU codon, but not the UUC codon decoded by tRNAPhe (GAA), is reduced in ftsj1 knockout cells. Bioinformatics analysis reveals that almost 40% of the high TTT-biased genes are related to brain/nervous functions. Our data potentially enhance our understanding of the relationship between FTSJ1 and nervous system development.
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Affiliation(s)
- Jing Li
- State Key Laboratory of Molecular BiologyCAS Center for Excellence in Molecular Cell ScienceShanghai Institute of Biochemistry and Cell BiologyChinese Academy of SciencesUniversity of Chinese Academy of SciencesShanghaiChina
- School of Life Science and TechnologyShanghaiTech UniversityShanghaiChina
| | - Yan‐Nan Wang
- Shanghai Institute for Advanced Immunochemical StudiesShanghaiTech UniversityShanghaiChina
| | - Bei‐Si Xu
- Center for Applied BioinformaticsSt. Jude Children's Research HospitalMemphisTNUSA
| | - Ya‐Ping Liu
- Beijing National Laboratory for Molecular SciencesKey Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of EducationSynthetic and Functional Biomolecules CenterCollege of Chemistry and Molecular EngineeringPeking UniversityBeijingChina
| | - Mi Zhou
- State Key Laboratory of Molecular BiologyCAS Center for Excellence in Molecular Cell ScienceShanghai Institute of Biochemistry and Cell BiologyChinese Academy of SciencesUniversity of Chinese Academy of SciencesShanghaiChina
| | - Tao Long
- State Key Laboratory of Molecular BiologyCAS Center for Excellence in Molecular Cell ScienceShanghai Institute of Biochemistry and Cell BiologyChinese Academy of SciencesUniversity of Chinese Academy of SciencesShanghaiChina
| | - Hao Li
- State Key Laboratory of Molecular BiologyCAS Center for Excellence in Molecular Cell ScienceShanghai Institute of Biochemistry and Cell BiologyChinese Academy of SciencesUniversity of Chinese Academy of SciencesShanghaiChina
| | - Han Dong
- State Key Laboratory of Molecular BiologyCAS Center for Excellence in Molecular Cell ScienceShanghai Institute of Biochemistry and Cell BiologyChinese Academy of SciencesUniversity of Chinese Academy of SciencesShanghaiChina
| | - Yan Nie
- Shanghai Institute for Advanced Immunochemical StudiesShanghaiTech UniversityShanghaiChina
| | - Peng R Chen
- Beijing National Laboratory for Molecular SciencesKey Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of EducationSynthetic and Functional Biomolecules CenterCollege of Chemistry and Molecular EngineeringPeking UniversityBeijingChina
| | - En‐Duo Wang
- State Key Laboratory of Molecular BiologyCAS Center for Excellence in Molecular Cell ScienceShanghai Institute of Biochemistry and Cell BiologyChinese Academy of SciencesUniversity of Chinese Academy of SciencesShanghaiChina
- School of Life Science and TechnologyShanghaiTech UniversityShanghaiChina
| | - Ru‐Juan Liu
- School of Life Science and TechnologyShanghaiTech UniversityShanghaiChina
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9
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Abstract
Aminoacyl-tRNA synthetases (ARSs) are a family of essential "housekeeping" enzymes ubiquitous in the three major domains of life. ARSs uniquely connect the essential minimal units of both major oligomer classes-the 3-nucleotide codons of oligonucleotides and the amino acids of proteins. They catalyze the esterification of amino acids to the 3'-end of cognate transfer RNAs (tRNAs) bearing the correct anticodon triplet to ensure accurate transfer of information from mRNA to protein according to the genetic code. As an essential translation factor responsible for the first biochemical reaction in protein biosynthesis, ARSs control protein production by catalyzing aminoacylation, and by editing of mischarged aminoacyl-tRNAs to maintain translational fidelity. In addition to their primary enzymatic activities, many ARSs have noncanonical functions unrelated to their catalytic activity in protein synthesis. Among the ARSs with "moonlighting" activities, several, including GluProRS (or EPRS), LeuRS, LysRS, SerRS, TyrRS, and TrpRS, exhibit cell signaling-related activities that sense environmental signals, regulate gene expression, and modulate cellular functions. ARS signaling functions generally depend on catalytically-inactive, appended domains not present in ancient enzyme forms, and are activated by stimulus-dependent post-translational modification. Activation often results in cellular re-localization and gain of new interacting partners. The newly formed ARS-bearing complexes conduct a host of signal transduction functions, including immune response, mTORC1 pathway signaling, and fibrogenic and angiogenic signaling, among others. Because noncanonical functions of ARSs in signal transduction are uncoupled from canonical aminoacylation functions, function-specific inhibitors can be developed, thus providing promising opportunities and therapeutic targets for treatment of human disease.
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Affiliation(s)
- Peng Yao
- Aab Cardiovascular Research Institute, Department of Medicine and Department of Biochemistry & Biophysics, The Center for RNA Biology, The Center for Biomedical Informatics, University of Rochester School of Medicine & Dentistry, Rochester, NY, United States.
| | - Paul L Fox
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States.
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10
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Ji QQ, Fang ZP, Ye Q, Chi CW, Wang ED. Self-protective responses to norvaline-induced stress in a leucyl-tRNA synthetase editing-deficient yeast strain. Nucleic Acids Res 2017; 45:7367-7381. [PMID: 28575390 PMCID: PMC5499588 DOI: 10.1093/nar/gkx487] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 05/24/2017] [Indexed: 12/23/2022] Open
Abstract
The editing function of aminoacyl-tRNA synthetases (aaRSs) is indispensible for formation of the correct aminoacyl-tRNAs. Editing deficiency may lead to growth inhibition and the pathogenesis of various diseases. Herein, we confirmed that norvaline (Nva) but not isoleucine or valine is the major threat to the editing function of Saccharomyces cerevisiae leucyl-tRNA synthetase (ScLeuRS), both in vitro and in vivo. Nva could be misincorporated into the proteome of the LeuRS editing-deficient yeast strain (D419A/ScΔleuS), potentially resulting in dysfunctional protein folding and growth delay. Furthermore, the exploration of the Nva-induced intracellular stress response mechanism in D419A/ScΔleuS revealed that Hsp70 chaperones were markedly upregulated in response to the potential protein misfolding. Additionally, proline (Pro), glutamate (Glu) and glutamine (Gln), which may accumulate due to the conversion of Nva, collectively contributed to the reduction of reactive oxygen species (ROS) levels in Nva-treated D419A/ScΔleuS cells. In conclusion, our study highlights the significance of the editing function of LeuRS and provides clues for understanding the intracellular stress protective mechanisms that are triggered in aaRS editing-deficient organisms.
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Affiliation(s)
- Quan-Quan Ji
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, P. R. China
| | - Zhi-Peng Fang
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, P. R. China
| | - Qing Ye
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, P. R. China
| | - Cheng-Wu Chi
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, P. R. China
| | - En-Duo Wang
- State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, P. R. China.,School of Life Science and Technology, Shanghai Tech University, 100 Haike Road, Shanghai 201210, P. R. China
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11
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Yu X, Zhong W. Differentiation of Norvaline and Valine in Peptides by Hot Electron Capture Dissociation. Anal Chem 2016; 88:5914-9. [DOI: 10.1021/acs.analchem.6b00823] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Xiang Yu
- Department of Pharmacokinetics, Pharmacodynamics, & Drug Metabolism (PPDM), Merck Research Laboratories, 770 Sumneytown Pike, West Point, Pennsylvania 19486, United States
| | - Wendy Zhong
- Process/Analytical
Chemistry, Merck Research Laboratories, 126 East Lincoln Avenue, Rahway, New Jersey 07065, United States
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12
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Yan W, Ye Q, Tan M, Chen X, Eriani G, Wang ED. Modulation of Aminoacylation and Editing Properties of Leucyl-tRNA Synthetase by a Conserved Structural Module. J Biol Chem 2015; 290:12256-67. [PMID: 25817995 DOI: 10.1074/jbc.m115.639492] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Indexed: 11/06/2022] Open
Abstract
A conserved structural module following the KMSKS catalytic loop exhibits α-α-β-α topology in class Ia and Ib aminoacyl-tRNA synthetases. However, the function of this domain has received little attention. Here, we describe the effect this module has on the aminoacylation and editing capacities of leucyl-tRNA synthetases (LeuRSs) by characterizing the key residues from various species. Mutation of highly conserved basic residues on the third α-helix of this domain impairs the affinity of LeuRS for the anticodon stem of tRNA(Leu), which decreases both aminoacylation and editing activities. Two glycine residues on this α-helix contribute to flexibility, leucine activation, and editing of LeuRS from Escherichia coli (EcLeuRS). Acidic residues on the β-strand enhance the editing activity of EcLeuRS and sense the size of the tRNA(Leu) D-loop. Incorporation of these residues stimulates the tRNA-dependent editing activity of the chimeric minimalist enzyme Mycoplasma mobile LeuRS fused to the connective polypeptide 1 editing domain and leucine-specific domain from EcLeuRS. Together, these results reveal the stem contact-fold to be a functional as well as a structural linker between the catalytic site and the tRNA binding domain. Sequence comparison of the EcLeuRS stem contact-fold domain with editing-deficient enzymes suggests that key residues of this module have evolved an adaptive strategy to follow the editing functions of LeuRS.
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Affiliation(s)
- Wei Yan
- From the State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Qing Ye
- From the State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Min Tan
- From the State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Xi Chen
- the College of Life Sciences, Wuhan University, 299 Bayi Road, Wuhan 430072, Hubei, China
| | - Gilbert Eriani
- the Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, Institut de Biologie Moléculaire et Cellulaire, 15 Rue René Descartes, Strasbourg 67084, France, and
| | - En-Duo Wang
- From the State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China, the School of Life Science and Technology, Shanghai Tech University, 319 Yue Yang Road, Shanghai 200031,China,
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13
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Klassen R, Grunewald P, Thüring KL, Eichler C, Helm M, Schaffrath R. Loss of anticodon wobble uridine modifications affects tRNA(Lys) function and protein levels in Saccharomyces cerevisiae. PLoS One 2015; 10:e0119261. [PMID: 25747122 PMCID: PMC4352028 DOI: 10.1371/journal.pone.0119261] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Accepted: 01/22/2015] [Indexed: 11/22/2022] Open
Abstract
In eukaryotes, wobble uridines in the anticodons of tRNALysUUU, tRNAGluUUC and tRNAGlnUUG are modified to 5-methoxy-carbonyl-methyl-2-thio-uridine (mcm5s2U). While mutations in subunits of the Elongator complex (Elp1-Elp6), which disable mcm5 side chain formation, or removal of components of the thiolation pathway (Ncs2/Ncs6, Urm1, Uba4) are individually tolerated, the combination of both modification defects has been reported to have lethal effects on Saccharomyces cerevisiae. Contrary to such absolute requirement of mcm5s2U for viability, we demonstrate here that in the S. cerevisiae S288C-derived background, both pathways can be simultaneously inactivated, resulting in combined loss of tRNA anticodon modifications (mcm5U and s2U) without a lethal effect. However, an elp3 disruption strain displays synthetic sick interaction and synergistic temperature sensitivity when combined with either uba4 or urm1 mutations, suggesting major translational defects in the absence of mcm5s2U modifications. Consistent with this notion, we find cellular protein levels drastically decreased in an elp3uba4 double mutant and show that this effect as well as growth phenotypes can be partially rescued by excess of tRNALysUUU. These results may indicate a global translational or protein homeostasis defect in cells simultaneously lacking mcm5 and s2 wobble uridine modification that could account for growth impairment and mainly originates from tRNALysUUU hypomodification and malfunction.
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Affiliation(s)
- Roland Klassen
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Kassel, Germany
- * E-mail: (RK); (RS)
| | - Pia Grunewald
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Kassel, Germany
| | - Kathrin L. Thüring
- Institut für Pharmazie und Biochemie, Johannes Gutenberg Universität Mainz, Mainz, Germany
| | - Christian Eichler
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Kassel, Germany
| | - Mark Helm
- Institut für Pharmazie und Biochemie, Johannes Gutenberg Universität Mainz, Mainz, Germany
| | - Raffael Schaffrath
- Institut für Biologie, Fachgebiet Mikrobiologie, Universität Kassel, Kassel, Germany
- * E-mail: (RK); (RS)
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14
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Novoa EM, Vargas-Rodriguez O, Lange S, Goto Y, Suga H, Musier-Forsyth K, Ribas de Pouplana L. Ancestral AlaX editing enzymes for control of genetic code fidelity are not tRNA-specific. J Biol Chem 2015; 290:10495-503. [PMID: 25724653 DOI: 10.1074/jbc.m115.640060] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Indexed: 01/15/2023] Open
Abstract
Accurate protein synthesis requires the hydrolytic editing of tRNAs incorrectly aminoacylated by aminoacyl-tRNA synthetases (ARSs). Recognition of cognate tRNAs by ARS is less error-prone than amino acid recognition, and, consequently, editing domains are generally believed to act only on the tRNAs cognate to their related ARSs. For example, the AlaX family of editing domains, including the editing domain of alanyl-tRNA synthetase and the related free-standing trans-editing AlaX enzymes, are thought to specifically act on tRNA(Ala), whereas the editing domains of threonyl-tRNA synthetases are specific for tRNA(Thr). Here we show that, contrary to this belief, AlaX-S, the smallest of the extant AlaX enzymes, deacylates Ser-tRNA(Thr) in addition to Ser-tRNA(Ala) and that a single residue is important to determine this behavior. Our data indicate that promiscuous forms of AlaX are ancestral to tRNA-specific AlaXs. We propose that former AlaX domains were used to maintain translational fidelity in earlier stages of genetic code evolution when mis-serylation of several tRNAs was possible.
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Affiliation(s)
- Eva Maria Novoa
- From the Institute for Research in Biomedicine, c/ Baldiri Reixac 10, 08028 Barcelona, Catalonia, Spain
| | - Oscar Vargas-Rodriguez
- the Department of Chemistry and Biochemistry, Center for RNA Biology, Ohio State University, Columbus, Ohio 43210
| | - Stefanie Lange
- From the Institute for Research in Biomedicine, c/ Baldiri Reixac 10, 08028 Barcelona, Catalonia, Spain
| | - Yuki Goto
- the Department of Chemistry, Graduate School of Science, University of Tokyo, Tokyo 113-0033, Japan, and
| | - Hiroaki Suga
- the Department of Chemistry, Graduate School of Science, University of Tokyo, Tokyo 113-0033, Japan, and
| | - Karin Musier-Forsyth
- the Department of Chemistry and Biochemistry, Center for RNA Biology, Ohio State University, Columbus, Ohio 43210
| | - Lluís Ribas de Pouplana
- From the Institute for Research in Biomedicine, c/ Baldiri Reixac 10, 08028 Barcelona, Catalonia, Spain, the Catalan Institution for Research and Advanced Studies, Passeig Lluís Companys 23, 08010 Barcelona, Catalonia, Spain
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15
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Wang G, Zhang J, Wang G, Fan X, Sun X, Qin H, Xu N, Zhong M, Qiao Z, Tang Y, Song R. Proline responding1 Plays a Critical Role in Regulating General Protein Synthesis and the Cell Cycle in Maize. THE PLANT CELL 2014; 26:2582-2600. [PMID: 24951479 PMCID: PMC4114953 DOI: 10.1105/tpc.114.125559] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Revised: 05/19/2014] [Accepted: 05/29/2014] [Indexed: 05/18/2023]
Abstract
Proline, an important amino acid, accumulates in many plant species. Besides its role in plant cell responses to environmental stresses, the potential biological functions of proline in growth and development are unclear. Here, we report cloning and functional characterization of the maize (Zea mays) classic mutant proline responding1 (pro1) gene. This gene encodes a Δ1-pyrroline-5- carboxylate synthetase that catalyzes the biosynthesis of proline from glutamic acid. Loss of function of Pro1 significantly inhibits proline biosynthesis and decreases its accumulation in the pro1 mutant. Proline deficiency results in an increased level of uncharged tRNApro AGG accumulation and triggers the phosphorylation of eukaryotic initiation factor 2α (eIF2α) in the pro1 mutant, leading to a general reduction in protein synthesis in this mutant. Proline deficiency also downregulates major cyclin genes at the transcriptional level, causing cell cycle arrest and suppression of cell proliferation. These processes are reversible when external proline is supplied to the mutant, suggesting that proline plays a regulatory role in the cell cycle transition. Together, the results demonstrate that proline plays an important role in the regulation of general protein synthesis and the cell cycle transition in plants.
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Affiliation(s)
- Gang Wang
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai 200444, P.R. China Coordinated Crop Biology Research Center, Beijing 100193, P.R. China
| | - Jushan Zhang
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai 200444, P.R. China
| | - Guifeng Wang
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai 200444, P.R. China Coordinated Crop Biology Research Center, Beijing 100193, P.R. China
| | - Xiangyu Fan
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai 200444, P.R. China
| | - Xin Sun
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai 200444, P.R. China
| | - Hongli Qin
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai 200444, P.R. China
| | - Nan Xu
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai 200444, P.R. China
| | - Mingyu Zhong
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai 200444, P.R. China
| | - Zhenyi Qiao
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai 200444, P.R. China
| | - Yuanping Tang
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai 200444, P.R. China
| | - Rentao Song
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai 200444, P.R. China Coordinated Crop Biology Research Center, Beijing 100193, P.R. China
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16
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Zhou X, Wang E. Transfer RNA: a dancer between charging and mis-charging for protein biosynthesis. SCIENCE CHINA-LIFE SCIENCES 2013; 56:921-32. [PMID: 23982864 DOI: 10.1007/s11427-013-4542-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 08/13/2013] [Indexed: 01/17/2023]
Abstract
Transfer RNA plays a fundamental role in the protein biosynthesis as an adaptor molecule by functioning as a biological link between the genetic nucleotide sequence in the mRNA and the amino acid sequence in the protein. To perform its role in protein biosynthesis, it has to be accurately recognized by aminoacyl-tRNA synthetases (aaRSs) to generate aminoacyl-tRNAs (aa-tRNAs). The correct pairing between an amino acid with its cognate tRNA is crucial for translational quality control. Production and utilization of mis-charged tRNAs are usually detrimental for all the species, resulting in cellular dysfunctions. Correct aa-tRNAs formation is collectively controlled by aaRSs with distinct mechanisms and/or other trans-factors. However, in very limited instances, mis-charged tRNAs are intermediate for specific pathways or essential components for the translational machinery. Here, from the point of accuracy in tRNA charging, we review our understanding about the mechanism ensuring correct aa-tRNA generation. In addition, some unique mis-charged tRNA species necessary for the organism are also briefly described.
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Affiliation(s)
- Xiaolong Zhou
- Center for RNA Research, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
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17
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Tan M, Wang M, Zhou XL, Yan W, Eriani G, Wang ED. The Yin and Yang of tRNA: proper binding of acceptor end determines the catalytic balance of editing and aminoacylation. Nucleic Acids Res 2013; 41:5513-23. [PMID: 23585282 PMCID: PMC3664829 DOI: 10.1093/nar/gkt252] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Faithful translation of the genetic code depends on accurate coupling of amino acids with cognate transfer RNAs (tRNAs) catalyzed by aminoacyl-tRNA synthetases. The fidelity of leucyl-tRNA synthetase (LeuRS) depends mainly on proofreading at the pre- and post-transfer levels. During the catalytic cycle, the tRNA CCA-tail shuttles between the synthetic and editing domains to accomplish the aminoacylation and editing reactions. Previously, we showed that the Y330D mutation of Escherichia coli LeuRS, which blocks the entry of the tRNA CCA-tail into the connective polypeptide 1domain, abolishes both tRNA-dependent pre- and post-transfer editing. In this study, we identified the counterpart substitutions, which constrain the tRNA acceptor stem binding within the synthetic active site. These mutations negatively impact the tRNA charging activity while retaining the capacity to activate the amino acid. Interestingly, the mutated LeuRSs exhibit increased global editing activity in the presence of a non-cognate amino acid. We used a reaction mimicking post-transfer editing to show that these mutations decrease post-transfer editing owing to reduced tRNA aminoacylation activity. This implied that the increased editing activity originates from tRNA-dependent pre-transfer editing. These results, together with our previous work, provide a comprehensive assessment of how intra-molecular translocation of the tRNA CCA-tail balances the aminoacylation and editing activities of LeuRS.
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Affiliation(s)
- Min Tan
- Center for RNA research, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, The Chinese Academy of Sciences, Shanghai 200031, PR China
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18
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Yan W, Tan M, Eriani G, Wang ED. Leucine-specific domain modulates the aminoacylation and proofreading functional cycle of bacterial leucyl-tRNA synthetase. Nucleic Acids Res 2013; 41:4988-98. [PMID: 23525458 PMCID: PMC3643597 DOI: 10.1093/nar/gkt185] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The leucine-specific domain (LSD) is a compact well-ordered module that participates in positioning of the conserved KMSKS catalytic loop in most leucyl-tRNA synthetases (LeuRSs). However, the LeuRS from Mycoplasma mobile (MmLeuRS) has a tetrapeptide GKDG instead of the LSD. Here, we show that the tetrapeptide GKDG can confer tRNA charging and post-transfer editing activity when transplanted into an inactive Escherichia coli LeuRS (EcLeuRS) that has had its LSD deleted. Reciprocally, the LSD, together with the CP1-editing domain of EcLeuRS, can cooperate when inserted into the scaffold of the minimal MmLeuRS, and this generates an enzyme nearly as active as EcLeuRS. Further, we show that LSD participates in tRNA(Leu) recognition and favours the binding of tRNAs harbouring a large loop in the variable arm. Additional analysis established that the Lys598 in the LSD is the critical residue for tRNA binding. Conversion of Lys598 to Ala simultaneously reduces the tRNA-binding strength and aminoacylation and editing capacities, indicating that these factors are subtly connected and controlled at the level of the LSD. The present work provides a novel framework of co-evolution between LeuRS and its cognate tRNA through LSD.
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Affiliation(s)
- Wei Yan
- State Key Laboratory of Molecular Biology, Center for RNA Research, Institute of Biochemistry and Cell Biology, the Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, PR China
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