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Gao Z, Jiang W, Zhang Y, Zhang L, Yi M, Wang H, Ma Z, Qu B, Ji X, Long H, Zhang S. Amphioxus adenosine-to-inosine tRNA-editing enzyme that can perform C-to-U and A-to-I deamination of DNA. Commun Biol 2023; 6:744. [PMID: 37464027 PMCID: PMC10354150 DOI: 10.1038/s42003-023-05134-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 07/11/2023] [Indexed: 07/20/2023] Open
Abstract
Adenosine-to-inosine tRNA-editing enzyme has been identified for more than two decades, but the study on its DNA editing activity is rather scarce. We show that amphioxus (Branchiostoma japonicum) ADAT2 (BjADAT2) contains the active site 'HxE-PCxxC' and the key residues for target-base-binding, and amphioxus ADAT3 (BjADAT3) harbors both the N-terminal positively charged region and the C-terminal pseudo-catalytic domain important for recognition of substrates. The sequencing of BjADAT2-transformed Escherichia coli genome suggests that BjADAT2 has the potential to target E. coli DNA and can deaminate at TCG and GAA sites in the E. coli genome. Biochemical analyses further demonstrate that BjADAT2, in complex with BjADAT3, can perform A-to-I editing of tRNA and convert C-to-U and A-to-I deamination of DNA. We also show that BjADAT2 preferentially deaminates adenosines and cytidines in the loop of DNA hairpin structures of substrates, and BjADAT3 also affects the type of DNA substrate targeted by BjADAT2. Finally, we find that C89, N113, C148 and Y156 play critical roles in the DNA editing activity of BjADAT2. Collectively, our study indicates that BjADAT2/3 is the sole naturally occurring deaminase with both tRNA and DNA editing capacity identified so far in Metazoa.
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Affiliation(s)
- Zhan Gao
- Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, 266003, Qingdao, China.
| | - Wanyue Jiang
- Institute of Evolution & Marine Biodiversity, KLMME, Ocean University of China, 266003, Qingdao, China
| | - Yu Zhang
- Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, 266003, Qingdao, China
| | - Liping Zhang
- Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, 266003, Qingdao, China
| | - Mengmeng Yi
- Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, 266003, Qingdao, China
| | - Haitao Wang
- Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, 266003, Qingdao, China
| | - Zengyu Ma
- Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, 266003, Qingdao, China
| | - Baozhen Qu
- Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, 266003, Qingdao, China
| | - Xiaohan Ji
- Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, 266003, Qingdao, China
| | - Hongan Long
- Institute of Evolution & Marine Biodiversity, KLMME, Ocean University of China, 266003, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Laoshan Laboratory, 266237, Qingdao, China
| | - Shicui Zhang
- Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, 266003, Qingdao, China.
- Laboratory for Marine Biology and Biotechnology, Laoshan Laboratory, 266237, Qingdao, China.
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Dolce LG, Zimmer AA, Tengo L, Weis F, Rubio MAT, Alfonzo JD, Kowalinski E. Structural basis for sequence-independent substrate selection by eukaryotic wobble base tRNA deaminase ADAT2/3. Nat Commun 2022; 13:6737. [PMID: 36347890 PMCID: PMC9643335 DOI: 10.1038/s41467-022-34441-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 10/26/2022] [Indexed: 11/09/2022] Open
Abstract
The essential deamination of adenosine A34 to inosine at the wobble base is the individual tRNA modification with the greatest effects on mRNA decoding, empowering a single tRNA to translate three different codons. To date, many aspects of how eukaryotic deaminases specifically select their multiple substrates remain unclear. Here, using cryo-EM, we present the structure of a eukaryotic ADAT2/3 deaminase bound to a full-length tRNA, revealing that the enzyme distorts the anticodon loop, but in contrast to the bacterial enzymes, selects its substrate via sequence-independent contacts of eukaryote-acquired flexible or intrinsically unfolded motifs distal from the conserved catalytic core. A gating mechanism for substrate entry to the active site is identified. Our multi-step tRNA recognition model yields insights into how RNA editing by A34 deamination evolved, shaped the genetic code, and directly impacts the eukaryotic proteome.
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Affiliation(s)
- Luciano G Dolce
- EMBL Grenoble, 71 Avenue des Martyrs, 38042, Grenoble, France
| | - Aubree A Zimmer
- Department of Microbiology and The Center for RNA Biology, The Ohio State University, Columbus, OH, USA
| | - Laura Tengo
- EMBL Grenoble, 71 Avenue des Martyrs, 38042, Grenoble, France
| | - Félix Weis
- EMBL Heidelberg, Structural and Computational Biology Unit, Meyerhofstraße 1, 69117, Heidelberg, Germany
| | - Mary Anne T Rubio
- Department of Microbiology and The Center for RNA Biology, The Ohio State University, Columbus, OH, USA
| | - Juan D Alfonzo
- Department of Microbiology and The Center for RNA Biology, The Ohio State University, Columbus, OH, USA
| | - Eva Kowalinski
- EMBL Grenoble, 71 Avenue des Martyrs, 38042, Grenoble, France.
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3
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Bertotti S, Fleming I, Cámara MDLM, Centeno Cameán C, Carmona SJ, Agüero F, Balouz V, Zahn A, Di Noia JM, Alfonzo JD, Buscaglia CA. Characterization of ADAT2/3 molecules in Trypanosoma cruzi and regulation of mucin gene expression by tRNA editing. Biochem J 2022; 479:561-580. [PMID: 35136964 DOI: 10.1042/bcj20210850] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 01/28/2022] [Accepted: 02/08/2022] [Indexed: 11/17/2022]
Abstract
Adenosine-to-inosine conversion at position 34 (A34-to-I) of certain tRNAs is essential for expanding their decoding capacity. This reaction is catalyzed by the adenosine deaminase acting on tRNA (ADAT) complex, which in Eukarya is formed by two subunits: ADAT2 and ADAT3. We herein identified and thoroughly characterized the ADAT molecules from the protozoan pathogen Trypanosoma cruzi, the causative agent of Chagas Disease. TcADAT2 and TcADAT3 spontaneously form a catalytically active complex, as shown by expression in engineered bacteria and/or by the increased ex vivo tRNA A-to-I deamination activity of T. cruzi epimastigotes overexpressing TcADAT subunits. Importantly, enhanced TcADAT2/3 activity in transgenic parasites caused a shift in their in vivo tRNAThrAGU signature, which correlated with significant changes in the expression of the Thr-rich TcSMUG proteins. To our knowledge, this is the first evidence indicating that T. cruzi tRNA editing can be modulated in vivo, in turn post-transcriptionally changing the expression of specific genes. Our findings suggest tRNA editing/availability as a forcible step in controlling gene expression and driving codon adaptation in T. cruzi. Moreover, we unveil certain differences between parasite and mammalian host tRNA editing and processing, such as cytosine-to-uridine conversion at position 32 of tRNAThrAGU in T. cruzi, that may be exploited for the identification of novel druggable targets of intervention.
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Affiliation(s)
- Santiago Bertotti
- Laboratory of Molecular Biology of Protozoa, Instituto de Investigaciones Biotecnológicas 'Dr Rodolfo Ugalde' (IIBio, Universidad Nacional de San Martín, UNSAM, and Consejo Nacional de Investigaciones Científicas y Técnicas, CONICET), Av. 25 de Mayo y Francia, Campus UNSAM, San Martín (1650), Buenos Aires, Argentina
| | - Ian Fleming
- Department of Microbiology, The Ohio State University, 318 W 12th Ave. (Aronoff Building), Columbus, U.S.A
| | - María de Los Milagros Cámara
- Laboratory of Molecular Biology of Protozoa, Instituto de Investigaciones Biotecnológicas 'Dr Rodolfo Ugalde' (IIBio, Universidad Nacional de San Martín, UNSAM, and Consejo Nacional de Investigaciones Científicas y Técnicas, CONICET), Av. 25 de Mayo y Francia, Campus UNSAM, San Martín (1650), Buenos Aires, Argentina
| | - Camila Centeno Cameán
- Laboratory of Molecular Biology of Protozoa, Instituto de Investigaciones Biotecnológicas 'Dr Rodolfo Ugalde' (IIBio, Universidad Nacional de San Martín, UNSAM, and Consejo Nacional de Investigaciones Científicas y Técnicas, CONICET), Av. 25 de Mayo y Francia, Campus UNSAM, San Martín (1650), Buenos Aires, Argentina
| | - Santiago J Carmona
- Trypanosomatics Laboratory, IIBio (UNSAM and CONICET), Buenos Aires, Argentina
| | - Fernán Agüero
- Trypanosomatics Laboratory, IIBio (UNSAM and CONICET), Buenos Aires, Argentina
| | - Virginia Balouz
- Laboratory of Molecular Biology of Protozoa, Instituto de Investigaciones Biotecnológicas 'Dr Rodolfo Ugalde' (IIBio, Universidad Nacional de San Martín, UNSAM, and Consejo Nacional de Investigaciones Científicas y Técnicas, CONICET), Av. 25 de Mayo y Francia, Campus UNSAM, San Martín (1650), Buenos Aires, Argentina
| | - Astrid Zahn
- Institut de Recherches Cliniques de Montreal (IRCM), Montreal, Quebec, Canada
- Department of Medicine, University of Montreal, Montreal, Quebec, Canada
| | - Javier M Di Noia
- Institut de Recherches Cliniques de Montreal (IRCM), Montreal, Quebec, Canada
- Department of Medicine, University of Montreal, Montreal, Quebec, Canada
| | - Juan D Alfonzo
- Department of Microbiology, The Ohio State University, 318 W 12th Ave. (Aronoff Building), Columbus, U.S.A
| | - Carlos A Buscaglia
- Laboratory of Molecular Biology of Protozoa, Instituto de Investigaciones Biotecnológicas 'Dr Rodolfo Ugalde' (IIBio, Universidad Nacional de San Martín, UNSAM, and Consejo Nacional de Investigaciones Científicas y Técnicas, CONICET), Av. 25 de Mayo y Francia, Campus UNSAM, San Martín (1650), Buenos Aires, Argentina
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4
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Ramos-Morales E, Bayam E, Del-Pozo-Rodríguez J, Salinas-Giegé T, Marek M, Tilly P, Wolff P, Troesch E, Ennifar E, Drouard L, Godin JD, Romier C. The structure of the mouse ADAT2/ADAT3 complex reveals the molecular basis for mammalian tRNA wobble adenosine-to-inosine deamination. Nucleic Acids Res 2021; 49:6529-6548. [PMID: 34057470 PMCID: PMC8216470 DOI: 10.1093/nar/gkab436] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 04/28/2021] [Accepted: 05/05/2021] [Indexed: 01/26/2023] Open
Abstract
Post-transcriptional modification of tRNA wobble adenosine into inosine is crucial for decoding multiple mRNA codons by a single tRNA. The eukaryotic wobble adenosine-to-inosine modification is catalysed by the ADAT (ADAT2/ADAT3) complex that modifies up to eight tRNAs, requiring a full tRNA for activity. Yet, ADAT catalytic mechanism and its implication in neurodevelopmental disorders remain poorly understood. Here, we have characterized mouse ADAT and provide the molecular basis for tRNAs deamination by ADAT2 as well as ADAT3 inactivation by loss of catalytic and tRNA-binding determinants. We show that tRNA binding and deamination can vary depending on the cognate tRNA but absolutely rely on the eukaryote-specific ADAT3 N-terminal domain. This domain can rotate with respect to the ADAT catalytic domain to present and position the tRNA anticodon-stem-loop correctly in ADAT2 active site. A founder mutation in the ADAT3 N-terminal domain, which causes intellectual disability, does not affect tRNA binding despite the structural changes it induces but most likely hinders optimal presentation of the tRNA anticodon-stem-loop to ADAT2.
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Affiliation(s)
- Elizabeth Ramos-Morales
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), UMR 7104, U 1258, 1 rue Laurent Fries, B.P. 10142, 67404, Illkirch Cedex, France
| | - Efil Bayam
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), UMR 7104, U 1258, 1 rue Laurent Fries, B.P. 10142, 67404, Illkirch Cedex, France
| | - Jordi Del-Pozo-Rodríguez
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), UMR 7104, U 1258, 1 rue Laurent Fries, B.P. 10142, 67404, Illkirch Cedex, France
| | - Thalia Salinas-Giegé
- Institut de biologie moléculaire des plantes-CNRS, Université de Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France
| | - Martin Marek
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), UMR 7104, U 1258, 1 rue Laurent Fries, B.P. 10142, 67404, Illkirch Cedex, France
| | - Peggy Tilly
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), UMR 7104, U 1258, 1 rue Laurent Fries, B.P. 10142, 67404, Illkirch Cedex, France
| | - Philippe Wolff
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, 67000 Strasbourg, France
| | - Edouard Troesch
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), UMR 7104, U 1258, 1 rue Laurent Fries, B.P. 10142, 67404, Illkirch Cedex, France
| | - Eric Ennifar
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, 67000 Strasbourg, France
| | - Laurence Drouard
- Institut de biologie moléculaire des plantes-CNRS, Université de Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France
| | - Juliette D Godin
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), UMR 7104, U 1258, 1 rue Laurent Fries, B.P. 10142, 67404, Illkirch Cedex, France
| | - Christophe Romier
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), UMR 7104, U 1258, 1 rue Laurent Fries, B.P. 10142, 67404, Illkirch Cedex, France
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5
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Srinivasan S, Torres AG, Ribas de Pouplana L. Inosine in Biology and Disease. Genes (Basel) 2021; 12:600. [PMID: 33921764 PMCID: PMC8072771 DOI: 10.3390/genes12040600] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 04/13/2021] [Accepted: 04/15/2021] [Indexed: 02/06/2023] Open
Abstract
The nucleoside inosine plays an important role in purine biosynthesis, gene translation, and modulation of the fate of RNAs. The editing of adenosine to inosine is a widespread post-transcriptional modification in transfer RNAs (tRNAs) and messenger RNAs (mRNAs). At the wobble position of tRNA anticodons, inosine profoundly modifies codon recognition, while in mRNA, inosines can modify the sequence of the translated polypeptide or modulate the stability, localization, and splicing of transcripts. Inosine is also found in non-coding and exogenous RNAs, where it plays key structural and functional roles. In addition, molecular inosine is an important secondary metabolite in purine metabolism that also acts as a molecular messenger in cell signaling pathways. Here, we review the functional roles of inosine in biology and their connections to human health.
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Affiliation(s)
- Sundaramoorthy Srinivasan
- Institute for Research in Biomedicine, Barcelona Institute of Science and Technology, 08028 Barcelona, Catalonia, Spain; (S.S.); (A.G.T.)
| | - Adrian Gabriel Torres
- Institute for Research in Biomedicine, Barcelona Institute of Science and Technology, 08028 Barcelona, Catalonia, Spain; (S.S.); (A.G.T.)
| | - Lluís Ribas de Pouplana
- Institute for Research in Biomedicine, Barcelona Institute of Science and Technology, 08028 Barcelona, Catalonia, Spain; (S.S.); (A.G.T.)
- Catalan Institution for Research and Advanced Studies, 08010 Barcelona, Catalonia, Spain
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6
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Liu X, Chen R, Sun Y, Chen R, Zhou J, Tian Q, Tao X, Zhang Z, Luo GZ, Xie W. Crystal structure of the yeast heterodimeric ADAT2/3 deaminase. BMC Biol 2020; 18:189. [PMID: 33272269 PMCID: PMC7713142 DOI: 10.1186/s12915-020-00920-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 11/06/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND The adenosine-to-inosine (A-to-I) editing in anticodons of tRNAs is critical for wobble base-pairing during translation. This modification is produced via deamination on A34 and catalyzed by the adenosine deaminase acting on tRNA (ADAT) enzyme. Eukaryotic ADATs are heterodimers composed of the catalytic subunit ADAT2 and the structural subunit ADAT3, but their molecular assemblies and catalytic mechanisms are largely unclear. RESULTS Here, we report a 2.8-Å crystal structure of Saccharomyces cerevisiae ADAT2/3 (ScADAT2/3), revealing its heterodimeric assembly and substrate recognition mechanism. While each subunit clearly contains a domain resembling their prokaryotic homolog TadA, suggesting an evolutionary gene duplication event, they also display accessory domains for additional structural or functional purposes. The N-lobe of ScADAT3 exhibits a positively charged region with a potential role in the recognition and binding of tRNA, supported by our biochemical analysis. Interestingly, ScADAT3 employs its C-terminus to block tRNA's entry into its pseudo-active site and thus inactivates itself for deamination despite the preservation of a zinc-binding site, a mechanism possibly shared only among yeasts. CONCLUSIONS Combining the structural with biochemical, bioinformatic, and in vivo functional studies, we propose a stepwise model for the pathway of deamination by ADAT2/3. Our work provides insight into the molecular mechanism of the A-to-I editing by the eukaryotic ADAT heterodimer, especially the role of ADAT3 in catalysis.
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Affiliation(s)
- Xiwen Liu
- grid.12981.330000 0001 2360 039XMOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 W. Xingang Rd., Guangzhou, 510275 Guangdong People’s Republic of China ,grid.12981.330000 0001 2360 039XDepartment of Colorectal Surgery, The Sixth Affiliated Hospital, Sun Yat-sen University, 26 Yuancun Erheng Rd., Guangzhou, 510655 Guangdong People’s Republic of China
| | - Ruoyu Chen
- grid.12981.330000 0001 2360 039XMOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 W. Xingang Rd., Guangzhou, 510275 Guangdong People’s Republic of China
| | - Yujie Sun
- grid.12981.330000 0001 2360 039XMOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 W. Xingang Rd., Guangzhou, 510275 Guangdong People’s Republic of China
| | - Ran Chen
- grid.12981.330000 0001 2360 039XMOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 W. Xingang Rd., Guangzhou, 510275 Guangdong People’s Republic of China
| | - Jie Zhou
- grid.12981.330000 0001 2360 039XMOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 W. Xingang Rd., Guangzhou, 510275 Guangdong People’s Republic of China
| | - Qingnan Tian
- grid.207374.50000 0001 2189 3846School of Life Sciences, Zhengzhou University, 100 Kexue Rd., Zhengzhou, 450001 Henan People’s Republic of China
| | - Xuan Tao
- grid.12981.330000 0001 2360 039XMOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-sen University, 135 W. Xingang Rd., Guangzhou, 510275 Guangdong China
| | - Zhang Zhang
- grid.12981.330000 0001 2360 039XMOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 W. Xingang Rd., Guangzhou, 510275 Guangdong People’s Republic of China
| | - Guan-zheng Luo
- grid.12981.330000 0001 2360 039XMOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 W. Xingang Rd., Guangzhou, 510275 Guangdong People’s Republic of China
| | - Wei Xie
- grid.12981.330000 0001 2360 039XMOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 W. Xingang Rd., Guangzhou, 510275 Guangdong People’s Republic of China
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Ramos J, Proven M, Halvardson J, Hagelskamp F, Kuchinskaya E, Phelan B, Bell R, Kellner SM, Feuk L, Thuresson AC, Fu D. Identification and rescue of a tRNA wobble inosine deficiency causing intellectual disability disorder. RNA (NEW YORK, N.Y.) 2020; 26:1654-1666. [PMID: 32763916 PMCID: PMC7566568 DOI: 10.1261/rna.076380.120] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 07/20/2020] [Indexed: 06/11/2023]
Abstract
The deamination of adenosine to inosine at the wobble position of tRNA is an essential post-transcriptional RNA modification required for wobble decoding in bacteria and eukaryotes. In humans, the wobble inosine modification is catalyzed by the heterodimeric ADAT2/3 complex. Here, we describe novel pathogenic ADAT3 variants impairing adenosine deaminase activity through a distinct mechanism that can be corrected through expression of the heterodimeric ADAT2 subunit. The variants were identified in a family in which all three siblings exhibit intellectual disability linked to biallelic variants in the ADAT3 locus. The biallelic ADAT3 variants result in a missense variant converting alanine to valine at a conserved residue or the introduction of a premature stop codon in the deaminase domain. Fibroblast cells derived from two ID-affected individuals exhibit a reduction in tRNA wobble inosine levels and severely diminished adenosine tRNA deaminase activity. Notably, the ADAT3 variants exhibit impaired interaction with the ADAT2 subunit and alterations in ADAT2-dependent nuclear localization. Based upon these findings, we find that tRNA adenosine deaminase activity and wobble inosine modification can be rescued in patient cells by overexpression of the ADAT2 catalytic subunit. These results uncover a key role for the inactive ADAT3 deaminase domain in proper assembly with ADAT2 and demonstrate that ADAT2/3 nuclear import is required for maintaining proper levels of the wobble inosine modification in tRNA.
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Affiliation(s)
- Jillian Ramos
- Department of Biology, Center for RNA Biology, University of Rochester, Rochester, New York 14627, USA
| | - Melissa Proven
- Department of Biology, Center for RNA Biology, University of Rochester, Rochester, New York 14627, USA
| | - Jonatan Halvardson
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, 751 08 Uppsala, Sweden
| | | | - Ekaterina Kuchinskaya
- Department of Clinical Genetics, and Department of Clinical Medicine, Linköping University, 581 83 Linköping, Sweden
| | - Benjamin Phelan
- Department of Biology, Center for RNA Biology, University of Rochester, Rochester, New York 14627, USA
| | - Ryan Bell
- Department of Biology, Center for RNA Biology, University of Rochester, Rochester, New York 14627, USA
| | | | - Lars Feuk
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, 751 08 Uppsala, Sweden
| | - Ann-Charlotte Thuresson
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, 751 08 Uppsala, Sweden
| | - Dragony Fu
- Department of Biology, Center for RNA Biology, University of Rochester, Rochester, New York 14627, USA
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8
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Formation of tRNA Wobble Inosine in Humans Is Disrupted by a Millennia-Old Mutation Causing Intellectual Disability. Mol Cell Biol 2019; 39:MCB.00203-19. [PMID: 31263000 PMCID: PMC6751630 DOI: 10.1128/mcb.00203-19] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 06/27/2019] [Indexed: 12/20/2022] Open
Abstract
The formation of inosine at the wobble position of eukaryotic tRNAs is an essential modification catalyzed by the ADAT2/ADAT3 complex. In humans, a valine-to-methionine mutation (V144M) in ADAT3 that originated ∼1,600 years ago is the most common cause of autosomal recessive intellectual disability (ID) in Arabia. While the mutation is predicted to affect protein structure, the molecular and cellular effects of the V144M mutation are unknown. The formation of inosine at the wobble position of eukaryotic tRNAs is an essential modification catalyzed by the ADAT2/ADAT3 complex. In humans, a valine-to-methionine mutation (V144M) in ADAT3 that originated ∼1,600 years ago is the most common cause of autosomal recessive intellectual disability (ID) in Arabia. While the mutation is predicted to affect protein structure, the molecular and cellular effects of the V144M mutation are unknown. Here, we show that cell lines derived from ID-affected individuals expressing only ADAT3-V144M exhibit decreased wobble inosine in certain tRNAs. Moreover, extracts from the same cell lines of ID-affected individuals display a severe reduction in tRNA deaminase activity. While ADAT3-V144M maintains interactions with ADAT2, the purified ADAT2/3-V144M complexes exhibit defects in activity. Notably, ADAT3-V144M exhibits an increased propensity to form aggregates associated with cytoplasmic chaperonins that can be suppressed by ADAT2 overexpression. These results identify a key role for ADAT2-dependent folding of ADAT3 in wobble inosine modification and indicate that proper formation of an active ADAT2/3 complex is crucial for proper neurodevelopment.
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9
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Roura Frigolé H, Camacho N, Castellví Coma M, Fernández-Lozano C, García-Lema J, Rafels-Ybern À, Canals A, Coll M, Ribas de Pouplana L. tRNA deamination by ADAT requires substrate-specific recognition mechanisms and can be inhibited by tRFs. RNA (NEW YORK, N.Y.) 2019; 25:607-619. [PMID: 30737359 PMCID: PMC6467012 DOI: 10.1261/rna.068189.118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 01/28/2019] [Indexed: 05/30/2023]
Abstract
Adenosine deaminase acting on transfer RNA (ADAT) is an essential eukaryotic enzyme that catalyzes the deamination of adenosine to inosine at the first position of tRNA anticodons. Mammalian ADATs modify eight different tRNAs, having increased their substrate range from a bacterial ancestor that likely deaminated exclusively tRNAArg Here we investigate the recognition mechanisms of tRNAArg and tRNAAla by human ADAT to shed light on the process of substrate expansion that took place during the evolution of the enzyme. We show that tRNA recognition by human ADAT does not depend on conserved identity elements, but on the overall structural features of tRNA. We find that ancestral-like interactions are conserved for tRNAArg, while eukaryote-specific substrates use alternative mechanisms. These recognition studies show that human ADAT can be inhibited by tRNA fragments in vitro, including naturally occurring fragments involved in important regulatory pathways.
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MESH Headings
- Adenosine/metabolism
- Adenosine Deaminase/genetics
- Adenosine Deaminase/metabolism
- Anticodon/chemistry
- Anticodon/genetics
- Anticodon/metabolism
- Base Sequence
- Deamination
- Evolution, Molecular
- Gene Expression
- Humans
- Inosine/metabolism
- Nucleic Acid Conformation
- RNA, Transfer, Ala/chemistry
- RNA, Transfer, Ala/genetics
- RNA, Transfer, Ala/metabolism
- RNA, Transfer, Arg/chemistry
- RNA, Transfer, Arg/genetics
- RNA, Transfer, Arg/metabolism
- Sequence Alignment
- Substrate Specificity
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Affiliation(s)
- Helena Roura Frigolé
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona Institute of Science and Technology, 08028 Barcelona, Catalonia, Spain
| | - Noelia Camacho
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona Institute of Science and Technology, 08028 Barcelona, Catalonia, Spain
| | - Maria Castellví Coma
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona Institute of Science and Technology, 08028 Barcelona, Catalonia, Spain
| | - Carla Fernández-Lozano
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona Institute of Science and Technology, 08028 Barcelona, Catalonia, Spain
| | - Jorge García-Lema
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona Institute of Science and Technology, 08028 Barcelona, Catalonia, Spain
| | - Àlbert Rafels-Ybern
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona Institute of Science and Technology, 08028 Barcelona, Catalonia, Spain
| | - Albert Canals
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona Institute of Science and Technology, 08028 Barcelona, Catalonia, Spain
- Molecular Biology Institute of Barcelona, Consejo Superior de Investigaciones Científicas, 08028 Barcelona, Catalonia, Spain
| | - Miquel Coll
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona Institute of Science and Technology, 08028 Barcelona, Catalonia, Spain
- Molecular Biology Institute of Barcelona, Consejo Superior de Investigaciones Científicas, 08028 Barcelona, Catalonia, Spain
| | - Lluís Ribas de Pouplana
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona Institute of Science and Technology, 08028 Barcelona, Catalonia, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), 08010 Barcelona, Catalonia, Spain
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10
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Dixit S, Henderson JC, Alfonzo JD. Multi-Substrate Specificity and the Evolutionary Basis for Interdependence in tRNA Editing and Methylation Enzymes. Front Genet 2019; 10:104. [PMID: 30838029 PMCID: PMC6382703 DOI: 10.3389/fgene.2019.00104] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 01/30/2019] [Indexed: 12/12/2022] Open
Abstract
Among tRNA modification enzymes there is a correlation between specificity for multiple tRNA substrates and heteromultimerization. In general, enzymes that modify a conserved residue in different tRNA sequences adopt a heterodimeric structure. Presumably, such changes in the oligomeric state of enzymes, to gain multi-substrate recognition, are driven by the need to accommodate and catalyze a particular reaction in different substrates while maintaining high specificity. This review focuses on two classes of enzymes where the case for multimerization as a way to diversify molecular recognition can be made. We will highlight several new themes with tRNA methyltransferases and will also discuss recent findings with tRNA editing deaminases. These topics will be discussed in the context of several mechanisms by which heterodimerization may have been achieved during evolution and how these mechanisms might impact modifications in different systems.
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Affiliation(s)
| | | | - Juan D. Alfonzo
- Department of Microbiology, The Ohio State Biochemistry Program, The Center for RNA Biology, The Ohio State University, Columbus, OH, United States
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11
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de Freitas Nascimento J, Kelly S, Sunter J, Carrington M. Codon choice directs constitutive mRNA levels in trypanosomes. eLife 2018; 7:e32467. [PMID: 29543152 PMCID: PMC5896880 DOI: 10.7554/elife.32467] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 02/27/2018] [Indexed: 11/13/2022] Open
Abstract
Selective transcription of individual protein coding genes does not occur in trypanosomes and the cellular copy number of each mRNA must be determined post-transcriptionally. Here, we provide evidence that codon choice directs the levels of constitutively expressed mRNAs. First, a novel codon usage metric, the gene expression codon adaptation index (geCAI), was developed that maximised the relationship between codon choice and the measured abundance for a transcriptome. Second, geCAI predictions of mRNA levels were tested using differently coded GFP transgenes and were successful over a 25-fold range, similar to the variation in endogenous mRNAs. Third, translation was necessary for the accelerated mRNA turnover resulting from codon choice. Thus, in trypanosomes, the information determining the levels of most mRNAs resides in the open reading frame and translation is required to access this information.
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Affiliation(s)
| | - Steven Kelly
- Department of Plant SciencesUniversity of OxfordOxfordUnited Kingdom
| | - Jack Sunter
- Department of BiochemistryUniversity of CambridgeCambridgeUnited Kingdom
| | - Mark Carrington
- Department of BiochemistryUniversity of CambridgeCambridgeUnited Kingdom
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12
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McKenney KM, Rubio MAT, Alfonzo JD. Binding synergy as an essential step for tRNA editing and modification enzyme codependence in Trypanosoma brucei. RNA (NEW YORK, N.Y.) 2018; 24:56-66. [PMID: 29042505 PMCID: PMC5733570 DOI: 10.1261/rna.062893.117] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 10/02/2017] [Indexed: 05/10/2023]
Abstract
Transfer RNAs acquire a variety of naturally occurring chemical modifications during their maturation; these fine-tune their structure and decoding properties in a manner critical for protein synthesis. We recently reported that in the eukaryotic parasite, Trypanosoma brucei, a methylation and deamination event are unexpectedly interconnected, whereby the tRNA adenosine deaminase (TbADAT2/3) and the 3-methylcytosine methyltransferase (TbTrm140) strictly rely on each other for activity, leading to formation of m3C and m3U at position 32 in several tRNAs. Still however, it is not clear why these two enzymes, which work independently in other systems, are strictly codependent in T. brucei Here, we show that these enzymes exhibit binding synergism, or a mutual increase in binding affinity, that is more than the sum of the parts, when added together in a reaction. Although these enzymes interact directly with each other, tRNA binding assays using enzyme variants mutated in critical binding and catalytic sites indicate that the observed binding synergy stems from contributions from tRNA-binding domains distal to their active sites. These results provide a rationale for the known interactions of these proteins, while also speaking to the modulation of substrate specificity between seemingly unrelated enzymes. This information should be of value in furthering our understanding of how tRNA modification enzymes act together to regulate gene expression at the post-transcriptional level and provide a basis for the interdependence of such activities.
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Affiliation(s)
- Katherine M McKenney
- Department of Microbiology, Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA
- Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio 43210, USA
| | - Mary Anne T Rubio
- Department of Microbiology, Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA
| | - Juan D Alfonzo
- Department of Microbiology, Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA
- Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio 43210, USA
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13
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Abstract
All types of nucleic acids in cells undergo naturally occurring chemical modifications, including DNA, rRNA, mRNA, snRNA, and most prominently tRNA. Over 100 different modifications have been described and every position in the purine and pyrimidine bases can be modified; often the sugar is also modified [1]. In tRNA, the function of modifications varies; some modulate global and/or local RNA structure, and others directly impact decoding and may be essential for viability. Whichever the case, the overall importance of modifications is highlighted by both their evolutionary conservation and the fact that organisms use a substantial portion of their genomes to encode modification enzymes, far exceeding what is needed for the de novo synthesis of the canonical nucleotides themselves [2]. Although some modifications occur at exactly the same nucleotide position in tRNAs from the three domains of life, many can be found at various positions in a particular tRNA and their location may vary between and within different tRNAs. With this wild array of chemical diversity and substrate specificities, one of the big challenges in the tRNA modification field has been to better understand at a molecular level the modes of substrate recognition by the different modification enzymes; in this realm RNA binding rests at the heart of the problem. This chapter will focus on several examples of modification enzymes where their mode of RNA binding is well understood; from these, we will try to draw general conclusions and highlight growing themes that may be applicable to the RNA modification field at large.
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14
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McKenney KM, Alfonzo JD. From Prebiotics to Probiotics: The Evolution and Functions of tRNA Modifications. Life (Basel) 2016; 6:E13. [PMID: 26985907 PMCID: PMC4810244 DOI: 10.3390/life6010013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 02/27/2016] [Accepted: 03/07/2016] [Indexed: 12/13/2022] Open
Abstract
All nucleic acids in cells are subject to post-transcriptional chemical modifications. These are catalyzed by a myriad of enzymes with exquisite specificity and that utilize an often-exotic array of chemical substrates. In no molecule are modifications more prevalent than in transfer RNAs. In the present document, we will attempt to take a chemical rollercoaster ride from prebiotic times to the present, with nucleoside modifications as key players and tRNA as the centerpiece that drove the evolution of biological systems to where we are today. These ideas will be put forth while touching on several examples of tRNA modification enzymes and their modus operandi in cells. In passing, we submit that the choice of tRNA is not a whimsical one but rather highlights its critical function as an essential invention for the evolution of protein enzymes.
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Affiliation(s)
- Katherine M McKenney
- The Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA.
- The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA.
| | - Juan D Alfonzo
- The Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA.
- The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA.
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA.
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15
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Abstract
tRNA modifications are crucial for efficient and accurate protein translation, with defects often linked to disease. There are 7 cytoplasmic tRNA modifications in the yeast Saccharomyces cerevisiae that are formed by an enzyme consisting of a catalytic subunit and an auxiliary protein, 5 of which require only a single subunit in bacteria, and 2 of which are not found in bacteria. These enzymes include the deaminase Tad2-Tad3, and the methyltransferases Trm6-Trm61, Trm8-Trm82, Trm7-Trm732, and Trm7-Trm734, Trm9-Trm112, and Trm11-Trm112. We describe the occurrence and biological role of each modification, evidence for a required partner protein in S. cerevisiae and other eukaryotes, evidence for a single subunit in bacteria, and evidence for the role of the non-catalytic binding partner. Although it is unclear why these eukaryotic enzymes require partner proteins, studies of some 2-subunit modification enzymes suggest that the partner proteins help expand substrate range or allow integration of cellular activities.
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Affiliation(s)
- Michael P Guy
- a Department of Biochemistry and Biophysics; Center for RNA Biology ; University of Rochester School of Medicine ; Rochester , NY USA
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16
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Torres AG, Piñeyro D, Filonava L, Stracker TH, Batlle E, Ribas de Pouplana L. A-to-I editing on tRNAs: biochemical, biological and evolutionary implications. FEBS Lett 2014; 588:4279-86. [PMID: 25263703 DOI: 10.1016/j.febslet.2014.09.025] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 09/16/2014] [Accepted: 09/16/2014] [Indexed: 12/13/2022]
Abstract
Inosine on transfer RNAs (tRNAs) are post-transcriptionally formed by a deamination mechanism of adenosines at positions 34, 37 and 57 of certain tRNAs. Despite its ubiquitous nature, the biological role of inosine in tRNAs remains poorly understood. Recent developments in the study of nucleotide modifications are beginning to indicate that the dynamics of such modifications are used in the control of specific genetic programs. Likewise, the essentiality of inosine-modified tRNAs in genome evolution and animal biology is becoming apparent. Here we review our current understanding on the role of inosine in tRNAs, the enzymes that catalyze the modification and the evolutionary link between such enzymes and other deaminases.
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Affiliation(s)
- Adrian Gabriel Torres
- Institute for Research in Biomedicine (IRB Barcelona), C/ Baldiri Reixac 10, Barcelona 08028, Catalonia, Spain
| | - David Piñeyro
- Institute for Research in Biomedicine (IRB Barcelona), C/ Baldiri Reixac 10, Barcelona 08028, Catalonia, Spain
| | - Liudmila Filonava
- Institute for Research in Biomedicine (IRB Barcelona), C/ Baldiri Reixac 10, Barcelona 08028, Catalonia, Spain
| | - Travis H Stracker
- Institute for Research in Biomedicine (IRB Barcelona), C/ Baldiri Reixac 10, Barcelona 08028, Catalonia, Spain
| | - Eduard Batlle
- Institute for Research in Biomedicine (IRB Barcelona), C/ Baldiri Reixac 10, Barcelona 08028, Catalonia, Spain; Catalan Institution for Research and Advanced Studies (ICREA), P/ Lluís Companys 23, Barcelona 08010, Catalonia, Spain
| | - Lluis Ribas de Pouplana
- Institute for Research in Biomedicine (IRB Barcelona), C/ Baldiri Reixac 10, Barcelona 08028, Catalonia, Spain; Catalan Institution for Research and Advanced Studies (ICREA), P/ Lluís Companys 23, Barcelona 08010, Catalonia, Spain.
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17
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Paris Z, Fleming IMC, Alfonzo JD. Determinants of tRNA editing and modification: avoiding conundrums, affecting function. Semin Cell Dev Biol 2011; 23:269-74. [PMID: 22024020 DOI: 10.1016/j.semcdb.2011.10.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 10/04/2011] [Accepted: 10/12/2011] [Indexed: 11/12/2022]
Abstract
In all organisms tRNAs play the essential role of connecting the genetic information found in DNA with the protein synthesis machinery ensuring fidelity during translation. Following transcription tRNAs undergo a number of processing events including numerous post-transcriptional modifications that render a tRNA molecule fully functional. The effects of some modifications go beyond simply affecting tRNA structure and can alter the meaning of the tRNA. This review will summarize the current state of the tRNA editing field, highlighting how editing affects tRNA structure and function in various organisms. It will also discuss recent data that hints at connections between editing and modification that may be exploited by cells to modulate a tRNA's role in translation.
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Affiliation(s)
- Zdeněk Paris
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA
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18
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Spears JL, Rubio MAT, Gaston KW, Wywial E, Strikoudis A, Bujnicki JM, Papavasiliou FN, Alfonzo JD. A single zinc ion is sufficient for an active Trypanosoma brucei tRNA editing deaminase. J Biol Chem 2011; 286:20366-74. [PMID: 21507956 DOI: 10.1074/jbc.m111.243568] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Editing of adenosine (A) to inosine (I) at the first anticodon position in tRNA is catalyzed by adenosine deaminases acting on tRNA (ADATs). This essential reaction in bacteria and eukarya permits a single tRNA to decode multiple codons. Bacterial ADATa is a homodimer with two bound essential Zn(2+). The ADATa crystal structure revealed residues important for substrate binding and catalysis; however, such high resolution structural information is not available for eukaryotic tRNA deaminases. Despite significant sequence similarity among deaminases, we continue to uncover unexpected functional differences between Trypanosoma brucei ADAT2/3 (TbADAT2/3) and its bacterial counterpart. Previously, we demonstrated that TbADAT2/3 is unique in catalyzing two different deamination reactions. Here we show by kinetic analyses and inductively coupled plasma emission spectrometry that wild type TbADAT2/3 coordinates two Zn(2+) per heterodimer, but unlike any other tRNA deaminase, mutation of one of the key Zn(2+)-coordinating cysteines in TbADAT2 yields a functional enzyme with a single-bound zinc. These data suggest that, at least, TbADAT3 may play a role in catalysis via direct coordination of the catalytic Zn(2+). These observations raise the possibility of an unusual Zn(2+) coordination interface with important implications for the function and evolution of editing deaminases.
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Affiliation(s)
- Jessica L Spears
- Department of Microbiology, The Ohio State Center for RNA Biology, Columbus, Ohio 43210, USA
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