1
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Li ZH, Zhou XL. Eukaryotic AlaX provides multiple checkpoints for quality and quantity of aminoacyl-tRNAs in translation. Nucleic Acids Res 2024; 52:7825-7842. [PMID: 38869066 PMCID: PMC11260482 DOI: 10.1093/nar/gkae486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 05/27/2024] [Indexed: 06/14/2024] Open
Abstract
Translational fidelity relies critically on correct aminoacyl-tRNA supply. The trans-editing factor AlaX predominantly hydrolyzes Ser-tRNAAla, functioning as a third sieve of alanyl-tRNA synthetase (AlaRS). Despite extensive studies in bacteria and archaea, the mechanism of trans-editing in mammals remains largely unknown. Here, we show that human AlaX (hAlaX), which is exclusively distributed in the cytoplasm, is an active trans-editing factor with strict Ser-specificity. In vitro, both hAlaX and yeast AlaX (ScAlaX) were capable of hydrolyzing nearly all Ser-mischarged cytoplasmic and mitochondrial tRNAs; and robustly edited cognate Ser-charged cytoplasmic and mitochondrial tRNASers. In vivo or cell-based studies revealed that loss of ScAlaX or hAlaX readily induced Ala- and Thr-to-Ser misincorporation. Overexpression of hAlaX impeded the decoding efficiency of consecutive Ser codons, implying its regulatory role in Ser codon decoding. Remarkably, yeast cells with ScAlaX deletion responded differently to translation inhibitor treatment, with a gain in geneticin resistance, but sensitivity to cycloheximide, both of which were rescued by editing-capable ScAlaX, alanyl- or threonyl-tRNA synthetase. Altogether, our results demonstrated the previously undescribed editing peculiarities of eukaryotic AlaXs, which provide multiple checkpoints to maintain the speed and fidelity of genetic decoding.
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Affiliation(s)
- Zi-Han Li
- Key Laboratory of RNA Innovation, Science and Engineering, 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 Yue Yang Road, Shanghai 200031, China
| | - Xiao-Long Zhou
- Key Laboratory of RNA Innovation, Science and Engineering, 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 Yue Yang Road, Shanghai 200031, China
- Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
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2
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Sigal M, Matsumoto S, Beattie A, Katoh T, Suga H. Engineering tRNAs for the Ribosomal Translation of Non-proteinogenic Monomers. Chem Rev 2024; 124:6444-6500. [PMID: 38688034 PMCID: PMC11122139 DOI: 10.1021/acs.chemrev.3c00894] [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: 12/01/2023] [Revised: 02/21/2024] [Accepted: 04/10/2024] [Indexed: 05/02/2024]
Abstract
Ribosome-dependent protein biosynthesis is an essential cellular process mediated by transfer RNAs (tRNAs). Generally, ribosomally synthesized proteins are limited to the 22 proteinogenic amino acids (pAAs: 20 l-α-amino acids present in the standard genetic code, selenocysteine, and pyrrolysine). However, engineering tRNAs for the ribosomal incorporation of non-proteinogenic monomers (npMs) as building blocks has led to the creation of unique polypeptides with broad applications in cellular biology, material science, spectroscopy, and pharmaceuticals. Ribosomal polymerization of these engineered polypeptides presents a variety of challenges for biochemists, as translation efficiency and fidelity is often insufficient when employing npMs. In this Review, we will focus on the methodologies for engineering tRNAs to overcome these issues and explore recent advances both in vitro and in vivo. These efforts include increasing orthogonality, recruiting essential translation factors, and creation of expanded genetic codes. After our review on the biochemical optimizations of tRNAs, we provide examples of their use in genetic code manipulation, with a focus on the in vitro discovery of bioactive macrocyclic peptides containing npMs. Finally, an analysis of the current state of tRNA engineering is presented, along with existing challenges and future perspectives for the field.
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Affiliation(s)
- Maxwell Sigal
- Department of Chemistry,
Graduate School of Science, The University
of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Satomi Matsumoto
- Department of Chemistry,
Graduate School of Science, The University
of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Adam Beattie
- Department of Chemistry,
Graduate School of Science, The University
of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Takayuki Katoh
- Department of Chemistry,
Graduate School of Science, The University
of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hiroaki Suga
- Department of Chemistry,
Graduate School of Science, The University
of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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3
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Landerer C, Poehls J, Toth-Petroczy A. Fitness Effects of Phenotypic Mutations at Proteome-Scale Reveal Optimality of Translation Machinery. Mol Biol Evol 2024; 41:msae048. [PMID: 38421032 PMCID: PMC10939442 DOI: 10.1093/molbev/msae048] [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] [Received: 09/04/2023] [Revised: 01/30/2024] [Accepted: 02/23/2024] [Indexed: 03/02/2024] Open
Abstract
Errors in protein translation can lead to non-genetic, phenotypic mutations, including amino acid misincorporations. While phenotypic mutations can increase protein diversity, the systematic characterization of their proteome-wide frequencies and their evolutionary impact has been lacking. Here, we developed a mechanistic model of translation errors to investigate how selection acts on protein populations produced by amino acid misincorporations. We fitted the model to empirical observations of misincorporations obtained from over a hundred mass spectrometry datasets of E. coli and S. cerevisiae. We found that on average 20% to 23% of proteins synthesized in the cell are expected to harbor at least one amino acid misincorporation, and that deleterious misincorporations are less likely to occur. Combining misincorporation probabilities and the estimated fitness effects of amino acid substitutions in a population genetics framework, we found 74% of mistranslation events in E. coli and 94% in S. cerevisiae to be neutral. We further show that the set of available synonymous tRNAs is subject to evolutionary pressure, as the presence of missing tRNAs would increase codon-anticodon cross-reactivity and misincorporation error rates. Overall, we find that the translation machinery is likely optimal in E. coli and S. cerevisiae and that both local solutions at the level of codons and a global solution such as the tRNA pool can mitigate the impact of translation errors. We provide a framework to study the evolutionary impact of codon-specific translation errors and a method for their proteome-wide detection across organisms and conditions.
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Affiliation(s)
- Cedric Landerer
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
- Center for Systems Biology Dresden, 01307 Dresden, Germany
| | - Jonas Poehls
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
- Center for Systems Biology Dresden, 01307 Dresden, Germany
| | - Agnes Toth-Petroczy
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
- Center for Systems Biology Dresden, 01307 Dresden, Germany
- Cluster of Excellence Physics of Life, TU Dresden, 01062 Dresden, Germany
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4
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Wright DE, O’Donoghue P. Biosynthesis, Engineering, and Delivery of Selenoproteins. Int J Mol Sci 2023; 25:223. [PMID: 38203392 PMCID: PMC10778597 DOI: 10.3390/ijms25010223] [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] [Received: 11/15/2023] [Revised: 12/14/2023] [Accepted: 12/18/2023] [Indexed: 01/12/2024] Open
Abstract
Selenocysteine (Sec) was discovered as the 21st genetically encoded amino acid. In nature, site-directed incorporation of Sec into proteins requires specialized biosynthesis and recoding machinery that evolved distinctly in bacteria compared to archaea and eukaryotes. Many organisms, including higher plants and most fungi, lack the Sec-decoding trait. We review the discovery of Sec and its role in redox enzymes that are essential to human health and important targets in disease. We highlight recent genetic code expansion efforts to engineer site-directed incorporation of Sec in bacteria and yeast. We also review methods to produce selenoproteins with 21 or more amino acids and approaches to delivering recombinant selenoproteins to mammalian cells as new applications for selenoproteins in synthetic biology.
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Affiliation(s)
- David E. Wright
- Department of Biochemistry, The University of Western Ontario, London, ON N6A 5C1, Canada;
| | - Patrick O’Donoghue
- Department of Biochemistry, The University of Western Ontario, London, ON N6A 5C1, Canada;
- Department of Chemistry, The University of Western Ontario, London, ON N6A 5C1, Canada
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5
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Blomquist VG, Niu J, Choudhury P, Al Saneh A, Colecraft HM, Ahern CA. Transfer RNA-mediated restoration of potassium current and electrical correction in premature termination long-QT syndrome hERG mutants. MOLECULAR THERAPY. NUCLEIC ACIDS 2023; 34:102032. [PMID: 37842167 PMCID: PMC10568093 DOI: 10.1016/j.omtn.2023.102032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 09/14/2023] [Indexed: 10/17/2023]
Abstract
Disease-causing premature termination codons (PTCs) individually disrupt the functional expression of hundreds of genes and represent a pernicious clinical challenge. In the heart, loss-of-function mutations in the hERG potassium channel account for approximately 30% of long-QT syndrome arrhythmia, a lethal cardiac disorder with limited treatment options. Premature termination of ribosomal translation produces a truncated and, for potassium channels, a potentially dominant-negative protein that impairs the functional assembly of the wild-type homotetrameric hERG channel complex. We used high-throughput flow cytometry and patch-clamp electrophysiology to assess the trafficking and voltage-dependent activity of hERG channels carrying patient PTC variants that have been corrected by anticodon engineered tRNA. Adenoviral-mediated expression of mutant hERG channels in cultured adult guinea pig cardiomyocytes prolonged action potential durations, and this deleterious effect was corrected upon adenoviral delivery of a human ArgUGA tRNA to restore full-length hERG protein. The results demonstrate mutation-specific, context-agnostic PTC correction and elevate the therapeutic potential of this approach for rare genetic diseases caused by stop codons.
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Affiliation(s)
- Viggo G. Blomquist
- Department of Physiology and Cellular Biophysics, Columbia University Medical Center, New York, NY 10032, USA
| | - Jacqueline Niu
- Department of Physiology and Cellular Biophysics, Columbia University Medical Center, New York, NY 10032, USA
| | - Papiya Choudhury
- Department of Physiology and Cellular Biophysics, Columbia University Medical Center, New York, NY 10032, USA
| | - Ahmad Al Saneh
- Department of Molecular Physiology and Biophysics, University of Iowa Carver College of Medicine, Iowa City, IA, USA
| | - Henry M. Colecraft
- Department of Physiology and Cellular Biophysics, Columbia University Medical Center, New York, NY 10032, USA
| | - Christopher A. Ahern
- Department of Molecular Physiology and Biophysics, University of Iowa Carver College of Medicine, Iowa City, IA, USA
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6
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Schuntermann DB, Fischer JT, Bile J, Gaier SA, Shelley BA, Awawdeh A, Jahn M, Hoffman KS, Westhof E, Söll D, Clarke CR, Vargas-Rodriguez O. Mistranslation of the genetic code by a new family of bacterial transfer RNAs. J Biol Chem 2023; 299:104852. [PMID: 37224963 PMCID: PMC10404621 DOI: 10.1016/j.jbc.2023.104852] [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] [Received: 04/05/2023] [Revised: 05/16/2023] [Accepted: 05/18/2023] [Indexed: 05/26/2023] Open
Abstract
The correct coupling of amino acids with transfer RNAs (tRNAs) is vital for translating genetic information into functional proteins. Errors during this process lead to mistranslation, where a codon is translated using the wrong amino acid. While unregulated and prolonged mistranslation is often toxic, growing evidence suggests that organisms, from bacteria to humans, can induce and use mistranslation as a mechanism to overcome unfavorable environmental conditions. Most known cases of mistranslation are caused by translation factors with poor substrate specificity or when substrate discrimination is sensitive to molecular changes such as mutations or posttranslational modifications. Here we report two novel families of tRNAs, encoded by bacteria from the Streptomyces and Kitasatospora genera, that adopted dual identities by integrating the anticodons AUU (for Asn) or AGU (for Thr) into the structure of a distinct proline tRNA. These tRNAs are typically encoded next to a full-length or truncated version of a distinct isoform of bacterial-type prolyl-tRNA synthetase. Using two protein reporters, we showed that these tRNAs translate asparagine and threonine codons with proline. Moreover, when expressed in Escherichia coli, the tRNAs cause varying growth defects due to global Asn-to-Pro and Thr-to-Pro mutations. Yet, proteome-wide substitutions of Asn with Pro induced by tRNA expression increased cell tolerance to the antibiotic carbenicillin, indicating that Pro mistranslation can be beneficial under certain conditions. Collectively, our results significantly expand the catalog of organisms known to possess dedicated mistranslation machinery and support the concept that mistranslation is a mechanism for cellular resiliency against environmental stress.
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Affiliation(s)
- Dominik B Schuntermann
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA; Department of Microbiology, Technical University of Braunschweig, Braunschweig, Germany
| | - Jonathan T Fischer
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Jonmatthew Bile
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Sarah A Gaier
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Brett A Shelley
- Genetic Improvement for Fruits and Vegetables Lab, Beltsville Agricultural Research Center, Agricultural Research Service, USDA, Beltsville, Maryland, USA
| | - Aya Awawdeh
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Martina Jahn
- Department of Microbiology, Technical University of Braunschweig, Braunschweig, Germany
| | | | - Eric Westhof
- Université de Strasbourg, Institut de Biologie Moléculaire et Cellulaire du CNRS, Strasbourg, France
| | - Dieter Söll
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA; Department of Chemistry, Yale University, New Haven, Connecticut, USA.
| | - Christopher R Clarke
- Genetic Improvement for Fruits and Vegetables Lab, Beltsville Agricultural Research Center, Agricultural Research Service, USDA, Beltsville, Maryland, USA
| | - Oscar Vargas-Rodriguez
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA.
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7
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Guo M, Qiao X, Wang Y, Li ZH, Shi C, Chen Y, Kang L, Chen C, Zhou XL. Mitochondrial translational defect extends lifespan in C. elegans by activating UPR mt. Redox Biol 2023; 63:102722. [PMID: 37167879 DOI: 10.1016/j.redox.2023.102722] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 04/26/2023] [Indexed: 05/13/2023] Open
Abstract
Aminoacyl-tRNA synthetases (aaRSs) are indispensable players in translation. Usually, two or three genes encode cytoplasmic and mitochondrial threonyl-tRNA synthetases (ThrRSs) in eukaryotes. Here, we reported that Caenorhabditis elegans harbors only one tars-1, generating cytoplasmic and mitochondrial ThrRSs via translational reinitiation. Mitochondrial tars-1 knockdown decreased mitochondrial tRNAThr charging and translation and caused pleotropic phenotypes of delayed development, decreased motor ability and prolonged lifespan, which could be rescued by replenishing mitochondrial tars-1. Mitochondrial tars-1 deficiency leads to compromised mitochondrial functions including the decrease in oxygen consumption rate, complex Ⅰ activity and the activation of the mitochondrial unfolded protein response (UPRmt), which contributes to longevity. Furthermore, deficiency of other eight mitochondrial aaRSs in C. elegans and five in mammal also caused activation of the UPRmt. In summary, we deciphered the mechanism of one tars-1, generating two aaRSs, and elucidated the biochemical features and physiological function of C. elegans tars-1. We further uncovered a conserved connection between mitochondrial translation deficiency and UPRmt.
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Affiliation(s)
- Miaomiao Guo
- University of Chinese Academy of Sciences, Beijing, 100049, China; National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xinhua Qiao
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yuanyuan Wang
- University of Chinese Academy of Sciences, Beijing, 100049, China; National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Zi-Han Li
- University of Chinese Academy of Sciences, Beijing, 100049, China; State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Chang Shi
- University of Chinese Academy of Sciences, Beijing, 100049, China; National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yun Chen
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Lu Kang
- University of Chinese Academy of Sciences, Beijing, 100049, China; National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Chang Chen
- University of Chinese Academy of Sciences, Beijing, 100049, China; National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Xiao-Long Zhou
- University of Chinese Academy of Sciences, Beijing, 100049, China; State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, 200031, China; Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024, China.
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8
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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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9
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Al-Kafaji G, Alwehaidah MS, Alsabbagh MM, Alharbi MA, Bakhiet M. Mitochondrial DNA haplogroup analysis in Saudi Arab patients with multiple sclerosis. PLoS One 2022; 17:e0279237. [PMID: 36534684 PMCID: PMC9762579 DOI: 10.1371/journal.pone.0279237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Accepted: 12/03/2022] [Indexed: 12/24/2022] Open
Abstract
Previous studies have suggested that mitochondrial DNA (mtDNA) variants are associated with multiple sclerosis (MS), a complex neurodegenerative immune-mediated disease of the central nervous system. Since mtDNA is maternally inherited without recombination, specific mtDNA variants defining genetic background are associated with the susceptibility to human diseases. To assess the contribution of mtDNA haplogroups to the predisposition of MS in an Arab population, we analysed sequencing data of mitochondrial genomes from 47 native Saudi Arab individuals including 23 patients with relapsing-remitting MS (RRMS) and 24 healthy controls. All patients and controls could be classified into ten haplogroups. The European-specific haplogroup U was more prevalent in patients than in the controls (26.1% vs. 4.2%), whereas haplogroup T was only present in patients and haplogroups HV and N were only found in controls. Haplogroup U was significantly association with increased risk of MS (odds ratio = 6.26, p<0.05), although the association did not maintain significance after adjustment for multiple comparisons. Haplotype U was more prevalent in patients with younger age of onset (p = 0.006), but there was no relationship between haplotype U and disease severity, disease duration or EDSS and age-matched carriers and non-carriers of haplogroup U (p>0.05). Definition site of haplogroup U include the variant m.12308A>G in MT-TL2 gene which was found to affect highly conserved position within the variable arm of tRNALeu(CUN) and thus may impact mitochondrial protein synthesis, and two other variants namely m.11467A>G in MT-ND4 gene and m.12372G>A in MT-ND5 gene which were previously linked with mitochondrial function. Despite the small number of subjects, which may limit the statistical power of the study, our results showed for the first time a possible contribution of haplogroup U to the predisposition to MS in an Arab population. These findings warrant further validation in a large cohort to distinguish a genuine effect specific to MS from a chance finding due to small sampling.
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Affiliation(s)
- Ghada Al-Kafaji
- Department of Molecular Medicine and Al-Jawhara Centre for Molecular Medicine, Genetics, and Inherited Disorders, College of Medicine and Medical Sciences, Arabian Gulf University, Manama, Kingdom of Bahrain
- * E-mail:
| | - Materah Salem Alwehaidah
- Department of Medical Laboratory, Faculty of Allied Health, Kuwait University, Kuwait City, Kuwait
| | - Manahel Mahmood Alsabbagh
- Department of Molecular Medicine and Al-Jawhara Centre for Molecular Medicine, Genetics, and Inherited Disorders, College of Medicine and Medical Sciences, Arabian Gulf University, Manama, Kingdom of Bahrain
| | - Maram A. Alharbi
- College of Forensic Sciences, Naif Arab University for Security Sciences, Riyadh, Kingdom of Saudi Arabia
| | - Moiz Bakhiet
- Department of Molecular Medicine and Al-Jawhara Centre for Molecular Medicine, Genetics, and Inherited Disorders, College of Medicine and Medical Sciences, Arabian Gulf University, Manama, Kingdom of Bahrain
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10
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Byun JK, Vu JA, He SL, Jang JC, Musier-Forsyth K. Plant-exclusive domain of trans-editing enzyme ProXp-ala confers dimerization and enhanced tRNA binding. J Biol Chem 2022; 298:102255. [PMID: 35835222 PMCID: PMC9425024 DOI: 10.1016/j.jbc.2022.102255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 07/06/2022] [Accepted: 07/08/2022] [Indexed: 11/26/2022] Open
Abstract
Faithful translation of the genetic code is critical for the viability of all living organisms. The trans-editing enzyme ProXp-ala prevents Pro to Ala mutations during translation by hydrolyzing misacylated Ala-tRNAPro that has been synthesized by prolyl-tRNA synthetase. Plant ProXp-ala sequences contain a conserved C-terminal domain (CTD) that is absent in other organisms; the origin, structure, and function of this extra domain are unknown. To characterize the plant-specific CTD, we performed bioinformatics and computational analyses that provided a model consistent with a conserved α-helical structure. We also expressed and purified wildtype Arabidopsis thaliana (At) ProXp-ala in Escherichia coli, as well as variants lacking the CTD or containing only the CTD. Circular dichroism spectroscopy confirmed a loss of α-helical signal intensity upon CTD truncation. Size-exclusion chromatography with multiangle laser-light scattering revealed that wildtype At ProXp-ala was primarily dimeric and CTD truncation abolished dimerization in vitro. Furthermore, bimolecular fluorescence complementation assays in At protoplasts support a role for the CTD in homodimerization in vivo. The deacylation rate of Ala-tRNAPro by At ProXp-ala was also significantly reduced in the absence of the CTD, and kinetic assays indicated that the reduction in activity is primarily due to a tRNA binding defect. Overall, these results broaden our understanding of eukaryotic translational fidelity in the plant kingdom. Our study reveals that the plant-specific CTD plays a significant role in substrate binding and canonical editing function. Through its ability to facilitate protein-protein interactions, we propose the CTD may also provide expanded functional potential for trans-editing enzymes in plants.
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Affiliation(s)
- Jun-Kyu Byun
- Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA; Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, USA
| | - John A Vu
- Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA; Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, USA
| | - Siou-Luan He
- Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA; Department of Horticulture and Crop Science and Center for Applied Plant Sciences, The Ohio State University, Columbus, Ohio, USA
| | - Jyan-Chyun Jang
- Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA; Department of Horticulture and Crop Science and Center for Applied Plant Sciences, The Ohio State University, Columbus, Ohio, USA.
| | - Karin Musier-Forsyth
- Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA; Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, USA.
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11
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Duplicated ribosomal protein paralogs promote alternative translation and drug resistance. Nat Commun 2022; 13:4938. [PMID: 35999447 PMCID: PMC9399092 DOI: 10.1038/s41467-022-32717-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 08/12/2022] [Indexed: 11/28/2022] Open
Abstract
Ribosomes are often seen as monolithic machines produced from uniformly regulated genes. However, in yeast most ribosomal proteins come from duplicated genes. Here, we demonstrate that gene duplication may serve as a stress-adaptation mechanism modulating the global proteome through the differential expression of ribosomal protein paralogs. Our data indicate that the yeast paralog pair of the ribosomal protein L7/uL30 produces two differentially acetylated proteins. Under normal conditions most ribosomes incorporate the hypo-acetylated major form favoring the translation of genes with short open reading frames. Exposure to drugs, on the other hand, increases the production of ribosomes carrying the hyper-acetylated minor paralog that increases translation of long open reading frames. Many of these paralog-dependent genes encode cell wall proteins that could promote tolerance to drugs as their translation increases after exposure to drugs. Together our data suggest a mechanism of translation control that functions through a differential use of near-identical ribosomal protein isoforms. Most yeast ribosomal protein genes are duplicated but the functional significance of this duplication remains unclear. This study identifies a natural program where changing the ratio of proteins produced from duplicated genes modifies translation in response to drugs regardless of ribosome number.
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12
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Sun M, Zhang J. Preferred synonymous codons are translated more accurately: Proteomic evidence, among-species variation, and mechanistic basis. SCIENCE ADVANCES 2022; 8:eabl9812. [PMID: 35857447 PMCID: PMC9258949 DOI: 10.1126/sciadv.abl9812] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 05/20/2022] [Indexed: 06/15/2023]
Abstract
A commonly stated cause of unequal uses of synonymous codons is their differential translational accuracies. A key prediction of this long-standing translational accuracy hypothesis (TAH) of codon usage bias is higher translational accuracies of more frequently used synonymous codons, which, however, has had no direct evidence beyond case studies. Analyzing proteomic data from Escherichia coli, we present direct, global evidence for this prediction. The experimentally measured codon-specific translational accuracies validate a sequence-based proxy; this proxy provides support for the TAH from the vast majority of over 1000 taxa surveyed in all domains of life. We find that the relative translational accuracies of synonymous codons vary substantially among taxa and are strongly correlated with the amounts of cognate transfer RNAs (tRNAs) relative to those of near-cognate tRNAs. These and other observations suggest a model in which selections for translational efficiency and accuracy drive codon usage bias and its coevolution with the tRNA pool.
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13
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Jani J, Pappachan A. A review on quality control agents of protein translation - The role of Trans-editing proteins. Int J Biol Macromol 2022; 199:252-263. [PMID: 34995670 DOI: 10.1016/j.ijbiomac.2021.12.176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2021] [Revised: 12/18/2021] [Accepted: 12/27/2021] [Indexed: 11/16/2022]
Abstract
Translation of RNA to protein is a key feature of cellular life. The fidelity of this process mainly depends on the availability of correctly charged tRNAs. Different domains of tRNA synthetase (aaRS) maintain translation quality by ensuring the proper attachment of particular amino acid with respective tRNA, thus it establishes the rule of genetic code. However occasional errors by aaRS generate mischarged tRNAs, which can become lethal to the cells. Accurate protein synthesis necessitates hydrolysis of mischarged tRNAs. Various cis and trans-editing proteins are identified which recognize these mischarged products and correct them by hydrolysis. Trans-editing proteins are homologs of cis-editing domains of aaRS. The trans-editing proteins work in close association with aaRS, Ef-Tu, and ribosome to prevent global mistranslation and ensures correct charging of tRNA. In this review, we discuss the major trans-editing proteins and compared them with their cis-editing counterparts. We also discuss their structural features, biochemical activity and role in maintaining cellular protein homeostasis.
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Affiliation(s)
- Jaykumar Jani
- School of Life Sciences, Central University of Gujarat, Sector 30, Gandhinagar 382030, Gujarat, India
| | - Anju Pappachan
- School of Life Sciences, Central University of Gujarat, Sector 30, Gandhinagar 382030, Gujarat, India.
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14
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Upadhyay A. Natural compounds in the regulation of proteostatic pathways: An invincible artillery against stress, ageing, and diseases. Acta Pharm Sin B 2021; 11:2995-3014. [PMID: 34729300 PMCID: PMC8546668 DOI: 10.1016/j.apsb.2021.01.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 10/12/2020] [Accepted: 11/03/2020] [Indexed: 01/13/2023] Open
Abstract
Cells have different sets of molecules for performing an array of physiological functions. Nucleic acids have stored and carried the information throughout evolution, whereas proteins have been attributed to performing most of the cellular functions. To perform these functions, proteins need to have a unique conformation and a definite lifespan. These attributes are achieved by a highly coordinated protein quality control (PQC) system comprising chaperones to fold the proteins in a proper three-dimensional structure, ubiquitin-proteasome system for selective degradation of proteins, and autophagy for bulk clearance of cell debris. Many kinds of stresses and perturbations may lead to the weakening of these protective cellular machinery, leading to the unfolding and aggregation of cellular proteins and the occurrence of numerous pathological conditions. However, modulating the expression and functional efficiency of molecular chaperones, E3 ubiquitin ligases, and autophagic proteins may diminish cellular proteotoxic load and mitigate various pathological effects. Natural medicine and small molecule-based therapies have been well-documented for their effectiveness in modulating these pathways and reestablishing the lost proteostasis inside the cells to combat disease conditions. The present article summarizes various similar reports and highlights the importance of the molecules obtained from natural sources in disease therapeutics.
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Key Words
- 17-AAG, 17-allylamino-geldanamycin
- APC, anaphase-promoting complex
- Ageing
- Autophagy
- BAG, BCL2-associated athanogene
- CAP, chaperone-assisted proteasomal degradation
- CASA, chaperone-assisted selective autophagy
- CHIP, carboxy-terminus of HSC70 interacting protein
- CMA, chaperone-mediated autophagy
- Cancer
- Chaperones
- DUBs, deubiquitinases
- Drug discovery
- EGCG, epigallocatechin-3-gallate
- ESCRT, endosomal sorting complexes required for transport
- HECT, homologous to the E6-AP carboxyl terminus
- HSC70, heat shock cognate 70
- HSF1, heat shock factor 1
- HSP, heat shock protein
- KFERQ, lysine-phenylalanine-glutamate-arginine-glutamine
- LAMP2a, lysosome-associated membrane protein 2a
- LC3, light chain 3
- NBR1, next to BRCA1 gene 1
- Natural molecules
- Neurodegeneration
- PQC, protein quality control
- Proteinopathies
- Proteostasis
- RING, really interesting new gene
- UPS, ubiquitin–proteasome system
- Ub, ubiquitin
- Ubiquitin proteasome system
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Affiliation(s)
- Arun Upadhyay
- Department of Biochemistry, Central University of Rajasthan, Bandar Sindari, Kishangarh, Ajmer, Rajasthan 305817, India
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15
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Caulfield TR, Hayes KE, Qiu Y, Coban M, Seok Oh J, Lane AL, Yoshimitsu T, Hazlehurst L, Copland JA, Tun HW. A Virtual Screening Platform Identifies Chloroethylagelastatin A as a Potential Ribosomal Inhibitor. Biomolecules 2020; 10:E1407. [PMID: 33027969 PMCID: PMC7599554 DOI: 10.3390/biom10101407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 09/11/2020] [Accepted: 09/29/2020] [Indexed: 12/03/2022] Open
Abstract
Chloroethylagelastatin A (CEAA) is an analogue of agelastatin A (AA), a natural alkaloid derived from a marine sponge. It is under development for therapeutic use against brain tumors as it has excellent central nervous system (CNS) penetration and pre-clinical therapeutic activity against brain tumors. Recently, AA was shown to inhibit protein synthesis by binding to the ribosomal A-site. In this study, we developed a novel virtual screening platform to perform a comprehensive screening of various AA analogues showing that AA analogues with proven therapeutic activity including CEAA have significant ribosomal binding capacity whereas therapeutically inactive analogues show poor ribosomal binding and revealing structural fingerprint features essential for drug-ribosome interactions. In particular, CEAA was found to have greater ribosomal binding capacity than AA. Biological tests showed that CEAA binds the ribosome and contributes to protein synthesis inhibition. Our findings suggest that CEAA may possess ribosomal inhibitor activity and that our virtual screening platform may be a useful tool in discovery and development of novel ribosomal inhibitors.
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Affiliation(s)
- Thomas R. Caulfield
- Department of Cancer Biology, Mayo Clinic, Jacksonville, FL 32224, USA; (Y.Q.); (M.C.); (A.L.L.); (J.A.C.)
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA
- Department of Neurosurgery, Mayo Clinic, Jacksonville, FL 32224, USA
- Department of Health Sciences Research, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Karen E. Hayes
- Modulation Therapeutics, Inc., Morgantown, WV 26506, USA;
| | - Yushi Qiu
- Department of Cancer Biology, Mayo Clinic, Jacksonville, FL 32224, USA; (Y.Q.); (M.C.); (A.L.L.); (J.A.C.)
| | - Mathew Coban
- Department of Cancer Biology, Mayo Clinic, Jacksonville, FL 32224, USA; (Y.Q.); (M.C.); (A.L.L.); (J.A.C.)
| | - Joon Seok Oh
- Department of Chemistry, University of North Florida, Jacksonville, FL 32224, USA;
| | - Amy L. Lane
- Department of Cancer Biology, Mayo Clinic, Jacksonville, FL 32224, USA; (Y.Q.); (M.C.); (A.L.L.); (J.A.C.)
- Department of Chemistry, University of North Florida, Jacksonville, FL 32224, USA;
| | - Takehiko Yoshimitsu
- Division of Pharmaceutical Sciences, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan;
| | - Lori Hazlehurst
- Department of Pharmaceutical Sciences, West Virginia University, Morgantown, WV 26506, USA;
| | - John A. Copland
- Department of Cancer Biology, Mayo Clinic, Jacksonville, FL 32224, USA; (Y.Q.); (M.C.); (A.L.L.); (J.A.C.)
| | - Han W. Tun
- Department of Cancer Biology, Mayo Clinic, Jacksonville, FL 32224, USA; (Y.Q.); (M.C.); (A.L.L.); (J.A.C.)
- Department of Hematology/Oncology, Mayo Clinic, Jacksonville, FL 32224, USA
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16
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Guo J, Chen B, Yu Y, Cheng B, Ju Y, Tang J, Cai Z, Gu Q, Xu J, Zhou H. Structure-guided optimization and mechanistic study of a class of quinazolinone-threonine hybrids as antibacterial ThrRS inhibitors. Eur J Med Chem 2020; 207:112848. [PMID: 32980741 DOI: 10.1016/j.ejmech.2020.112848] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 08/12/2020] [Accepted: 09/12/2020] [Indexed: 11/20/2022]
Abstract
Aminoacyl-tRNA synthetases (aaRSs) are an attractive class of antibacterial drug targets due to their essential roles in protein translation. While most traditional aaRS inhibitors target the binding pockets of substrate amino acids and/or ATP, we recently developed a class of novel tRNA-amino acid dual-site inhibitors including inhibitor 3 ((2S,3R)-2-amino-N-((E)-4-(6,7-dichloro-4-oxoquinazolin-3(4H)-yl)but-2-en-1-yl)-3-hydroxybutanamide) against threonyl-tRNA synthetase (ThrRS). Here, the binding modes and structure-activity relationships (SARs) of these inhibitors were analyzed by the crystal structures of Salmonella enterica ThrRS (SeThrRS) in complex with three of them. Based on the cocrystal structures, twelve quinazolinone-threonine hybrids were designed and synthesized, and their affinities, enzymatic inhibitory activities, and cellular potencies were evaluated. The best derivative 8g achieved a Kd value of 0.40 μM, an IC50 value of 0.50 μM against SeThrRS and MIC values of 16-32 μg/mL against the tested bacterial strains. The cocrystal structure of the SeThrRS-8g complex revealed that 8g induced a bended conformation for Met332 by forming hydrophobic interactions, which better mimicked the binding of tRNAThr to ThrRS. Moreover, the inhibitory potency of 8g was less impaired than a reported ATP competitive inhibitor at high concentrations of ATP, supporting our hypothesis that tRNA site inhibitors are likely superior to ATP site inhibitors in vivo, where ATP typically reaches millimolar concentrations.
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Affiliation(s)
- Junsong Guo
- Research Center for Drug Discovery and Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Bingyi Chen
- Research Center for Drug Discovery and Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Ying Yu
- Research Center for Drug Discovery and Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Bao Cheng
- Research Center for Drug Discovery and Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Yingchen Ju
- Research Center for Drug Discovery and Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Jieyu Tang
- Research Center for Drug Discovery and Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Zhengjun Cai
- Research Center for Drug Discovery and Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Qiong Gu
- Research Center for Drug Discovery and Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Jun Xu
- Research Center for Drug Discovery and Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Huihao Zhou
- Research Center for Drug Discovery and Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China.
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17
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Kuzmishin Nagy AB, Bakhtina M, Musier-Forsyth K. Trans-editing by aminoacyl-tRNA synthetase-like editing domains. Enzymes 2020; 48:69-115. [PMID: 33837712 DOI: 10.1016/bs.enz.2020.07.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Aminoacyl-tRNA synthetases (aaRS) are ubiquitous enzymes responsible for aminoacyl-tRNA (aa-tRNA) synthesis. Correctly formed aa-tRNAs are necessary for proper decoding of mRNA and accurate protein synthesis. tRNAs possess specific nucleobases that promote selective recognition by cognate aaRSs. Selecting the cognate amino acid can be more challenging because all amino acids share the same peptide backbone and several are isosteric or have similar side chains. Thus, aaRSs can misactivate non-cognate amino acids and produce mischarged aa-tRNAs. If left uncorrected, mischarged aa-tRNAs deliver their non-cognate amino acid to the ribosome resulting in misincorporation into the nascent polypeptide chain. This changes the primary protein sequence and potentially causes misfolding or formation of non-functional proteins that impair cell survival. A variety of proofreading or editing pathways exist to prevent and correct mistakes in aa-tRNA formation. Editing may occur before the amino acid transfer step of aminoacylation via hydrolysis of the aminoacyl-adenylate. Alternatively, post-transfer editing, which occurs after the mischarged aa-tRNA is formed, may be carried out via a distinct editing site on the aaRS where the mischarged aa-tRNA is deacylated. In recent years, it has become clear that most organisms also encode factors that lack aminoacylation activity but resemble aaRS editing domains and function to clear mischarged aa-tRNAs in trans. This review focuses on these trans-editing factors, which are encoded in all three domains of life and function together with editing domains present within aaRSs to ensure that the accuracy of protein synthesis is sufficient for cell survival.
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Affiliation(s)
- Alexandra B Kuzmishin Nagy
- Department of Chemistry and Biochemistry and Center for RNA Biology, The Ohio State University, Columbus, OH, United States
| | - Marina Bakhtina
- Department of Chemistry and Biochemistry and Center for RNA Biology, The Ohio State University, Columbus, OH, United States
| | - Karin Musier-Forsyth
- Department of Chemistry and Biochemistry and Center for RNA Biology, The Ohio State University, Columbus, OH, United States.
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18
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Momtaz S, Memariani Z, El-Senduny FF, Sanadgol N, Golab F, Katebi M, Abdolghaffari AH, Farzaei MH, Abdollahi M. Targeting Ubiquitin-Proteasome Pathway by Natural Products: Novel Therapeutic Strategy for Treatment of Neurodegenerative Diseases. Front Physiol 2020; 11:361. [PMID: 32411012 PMCID: PMC7199656 DOI: 10.3389/fphys.2020.00361] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 03/27/2020] [Indexed: 12/11/2022] Open
Abstract
Misfolded proteins are the main common feature of neurodegenerative diseases, thereby, normal proteostasis is an important mechanism to regulate the neural survival and the central nervous system functionality. The ubiquitin-proteasome system (UPS) is a non-lysosomal proteolytic pathway involved in numerous normal functions of the nervous system, modulation of neurotransmitter release, synaptic plasticity, and recycling of membrane receptors or degradation of damaged and regulatory intracellular proteins. Aberrant accumulation of intracellular ubiquitin-positive inclusions has been implicated to a variety of neurodegenerative disorders such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington disease (HD), Amyotrophic Lateral Sclerosis (ALS), and Multiple Myeloma (MM). Genetic mutation in deubiquitinating enzyme could disrupt UPS and results in destructive effects on neuron survival. To date, various agents were characterized with proteasome-inhibitory potential. Proteins of the ubiquitin-proteasome system, and in particular, E3 ubiquitin ligases, may be promising molecular targets for neurodegenerative drug discovery. Phytochemicals, specifically polyphenols (PPs), were reported to act as proteasome-inhibitors or may modulate the proteasome activity. PPs modify the UPS by means of accumulation of ubiquitinated proteins, suppression of neuronal apoptosis, reduction of neurotoxicity, and improvement of synaptic plasticity and transmission. This is the first comprehensive review on the effect of PPs on UPS. Here, we review the recent findings describing various aspects of UPS dysregulation in neurodegenerative disorders. This review attempts to summarize the latest reports on the neuroprotective properties involved in the proper functioning of natural polyphenolic compounds with implication for targeting ubiquitin-proteasome pathway in the neurodegenerative diseases. We highlight the evidence suggesting that polyphenolic compounds have a dose and disorder dependent effects in improving neurological dysfunctions, and so their mechanism of action could stimulate the UPS, induce the protein degradation or inhibit UPS and reduce protein degradation. Future studies should focus on molecular mechanisms by which PPs can interfere this complex regulatory system at specific stages of the disease development and progression.
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Affiliation(s)
- Saeideh Momtaz
- Medicinal Plants Research Center, Institute of Medicinal Plants, ACECR, Karaj, Iran.,Pharmaceutical Sciences Research Center (PSRC), The Institute of Pharmaceutical Sciences (TIPS), Tehran University of Medical Sciences, Tehran, Iran.,Gastrointestinal Pharmacology Interest Group, Universal Scientific Education and Research Network, Tehran, Iran
| | - Zahra Memariani
- Traditional Medicine and History of Medical Sciences Research Center, Health Research Center, Babol University of Medical Sciences, Babol, Iran
| | | | - Nima Sanadgol
- Department of Biology, Faculty of Sciences, University of Zabol, Zabol, Iran.,Department of Biomolecular Sciences, School of Pharmaceutical Sciences, University of São Paulo, Ribeirão Preto, Brazil
| | - Fereshteh Golab
- Cellular and Molecular Research Center, Iran University of Medical Science, Tehran, Iran
| | - Majid Katebi
- Department of Anatomy, Faculty of Medicine, Hormozgan University of Medical Sciences, Hormozgan, Iran
| | - Amir Hossein Abdolghaffari
- Medicinal Plants Research Center, Institute of Medicinal Plants, ACECR, Karaj, Iran.,Pharmaceutical Sciences Research Center (PSRC), The Institute of Pharmaceutical Sciences (TIPS), Tehran University of Medical Sciences, Tehran, Iran.,Gastrointestinal Pharmacology Interest Group, Universal Scientific Education and Research Network, Tehran, Iran.,Department of Toxicology & Pharmacology, Faculty of Pharmacy, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Mohammad Hosein Farzaei
- Pharmaceutical Sciences Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran.,Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Mohammad Abdollahi
- Pharmaceutical Sciences Research Center (PSRC), The Institute of Pharmaceutical Sciences (TIPS), Tehran University of Medical Sciences, Tehran, Iran.,Department of Toxicology and Pharmacology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
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19
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Rational Design of an Activatable Reporter for Quantitative Imaging of RNA Aberrant Splicing In Vivo. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2020; 17:904-911. [PMID: 32405512 PMCID: PMC7210378 DOI: 10.1016/j.omtm.2020.04.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 04/13/2020] [Indexed: 02/02/2023]
Abstract
Pre-mRNA splicing, the process of removing introns from pre-mRNA and the arrangement of exons to produce mature transcripts, is a crucial step in the expression of most eukaryote genes. However, the splicing kinetics remain poorly characterized in living cells, mainly because current methods cannot provide the dynamic information of splicing events. Here, we developed a genetically encoded bioluminescence reporter for real-time imaging of the pre-mRNA splicing process in living subjects. We showed that the bioluminescence reporter is able to visualize the pre-mRNA aberrant splicing process in living cells in a dose- and time-dependent manner. Moreover, this reporter could provide quantitative and longitudinal information of splicing activity in response to exogenous splicing inhibitors in living animals. Our data suggest that this activatable reporter could serve as a promising tool for the high-throughput screening of splicing modulators, which would facilitate the drug development for human diseases caused by the abnormal splicing of mRNA.
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20
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Wang Y, Zeng QY, Zheng WQ, Ji QQ, Zhou XL, Wang ED. A natural non-Watson-Crick base pair in human mitochondrial tRNAThr causes structural and functional susceptibility to local mutations. Nucleic Acids Res 2019; 46:4662-4676. [PMID: 29648639 PMCID: PMC5961198 DOI: 10.1093/nar/gky243] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 03/26/2018] [Indexed: 12/20/2022] Open
Abstract
Six pathogenic mutations have been reported in human mitochondrial tRNAThr (hmtRNAThr); however, the pathogenic molecular mechanism remains unclear. Previously, we established an activity assay system for human mitochondrial threonyl-tRNA synthetase (hmThrRS). In the present study, we surveyed the structural and enzymatic effects of pathogenic mutations in hmtRNAThr and then focused on m.15915 G > A (G30A) and m.15923A > G (A38G). The harmful evolutionary gain of non-Watson–Crick base pair A29/C41 caused hmtRNAThr to be highly susceptible to mutations disrupting the G30–C40 base pair in various ways; for example, structural integrity maintenance, modification and aminoacylation of tRNAThr, and editing mischarged tRNAThr. A similar phenomenon was observed for hmtRNATrp with an A29/C41 non-Watson–Crick base pair, but not in bovine mtRNAThr with a natural G29–C41 base pair. The A38G mutation caused a severe reduction in Thr-acceptance and editing of hmThrRS. Importantly, A38 is a nucleotide determinant for the t6A modification at A37, which is essential for the coding properties of hmtRNAThr. In summary, our results revealed the crucial role of the G30–C40 base pair in maintaining the proper structure and function of hmtRNAThr because of A29/C41 non-Watson–Crick base pair and explained the molecular outcome of pathogenic G30A and A38G mutations.
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Affiliation(s)
- Yong 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, ShanghaiTech University, 100 Haike Road, Shanghai 201210, P.R. China
| | - Qi-Yu Zeng
- 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
| | - Wen-Qiang Zheng
- School of Life Science and Technology, ShanghaiTech University, 100 Haike Road, Shanghai 201210, P.R. China
| | - 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
| | - Xiao-Long Zhou
- 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, ShanghaiTech University, 100 Haike Road, Shanghai 201210, P.R. China
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21
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Advani VM, Ivanov P. Translational Control under Stress: Reshaping the Translatome. Bioessays 2019; 41:e1900009. [PMID: 31026340 PMCID: PMC6541386 DOI: 10.1002/bies.201900009] [Citation(s) in RCA: 95] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 03/06/2019] [Indexed: 01/01/2023]
Abstract
Adequate reprogramming of cellular metabolism in response to stresses or suboptimal growth conditions involves a myriad of coordinated changes that serve to promote cell survival. As protein synthesis is an energetically expensive process, its regulation under stress is of critical importance. Reprogramming of messenger RNA (mRNA) translation involves well-understood stress-activated kinases that target components of translation initiation machinery, resulting in the robust inhibition of general translation and promotion of the translation of stress-responsive proteins. Translational arrest of mRNAs also results in the accumulation of transcripts in cytoplasmic foci called stress granules. Recent studies focus on the key roles of transfer RNA (tRNA) in stress-induced translational reprogramming. These include stress-specific regulation of tRNA pools, codon-biased translation influenced by tRNA modifications, tRNA miscoding, and tRNA cleavage. In combination, signal transduction pathways and tRNA metabolism changes regulate translation during stress, resulting in adaptation and cell survival. This review examines molecular mechanisms that regulate protein synthesis in response to stress.
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Affiliation(s)
- Vivek M. Advani
- Division of Rheumatology, Immunology and Allergy, Brigham and Women’s Hospital, Boston, Massachusetts, United States of America
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Pavel Ivanov
- Division of Rheumatology, Immunology and Allergy, Brigham and Women’s Hospital, Boston, Massachusetts, United States of America
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, United States of America
- The Broad Institute of Harvard and M.I.T., Cambridge, Massachusetts, United States of America
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22
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Chaudhuri S, Li L, Zimmerman M, Chen Y, Chen YX, Toosky MN, Gardner M, Pan M, Li YY, Kawaji Q, Zhu JH, Su HW, Martinot AJ, Rubin EJ, Dartois VA, Javid B. Kasugamycin potentiates rifampicin and limits emergence of resistance in Mycobacterium tuberculosis by specifically decreasing mycobacterial mistranslation. eLife 2018; 7:36782. [PMID: 30152756 PMCID: PMC6160228 DOI: 10.7554/elife.36782] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 08/27/2018] [Indexed: 12/23/2022] Open
Abstract
Most bacteria use an indirect pathway to generate aminoacylated glutamine and/or asparagine tRNAs. Clinical isolates of Mycobacterium tuberculosis with increased rates of error in gene translation (mistranslation) involving the indirect tRNA-aminoacylation pathway have increased tolerance to the first-line antibiotic rifampicin. Here, we identify that the aminoglycoside kasugamycin can specifically decrease mistranslation due to the indirect tRNA pathway. Kasugamycin but not the aminoglycoside streptomycin, can limit emergence of rifampicin resistance in vitro and increases mycobacterial susceptibility to rifampicin both in vitro and in a murine model of infection. Moreover, despite parenteral administration of kasugamycin being unable to achieve the in vitro minimum inhibitory concentration, kasugamycin alone was able to significantly restrict growth of Mycobacterium tuberculosis in mice. These data suggest that pharmacologically reducing mistranslation may be a novel mechanism for targeting bacterial adaptation. A bacterium called Mycobacterium tuberculosis is responsible for nearly 98% of cases of tuberculosis, which kills more people worldwide than any other infectious disease. This is due, in part, to the time it takes to cure individuals of the disease: patients have to take antibiotics continuously for at least six months to eradicate M. tuberculosis in the body. Bacteria, like all cells, make proteins using instructions contained within their genetic code. Cell components called ribosomes are responsible for translating these instructions and assembling the new proteins. Sometimes the ribosomes produce proteins that are slightly different to what the cell’s genetic code specified. These ‘incorrect proteins’ may not work properly so it is generally thought that cells try to prevent the mistakes from happening. However, scientists have recently found that the ribosomes in M. tuberculosis often assemble incorrect proteins. The more mistakes the ribosomes let happen, the more likely the bacteria are to survive when they are exposed to rifampicin, an antibiotic which is often used to treat tuberculosis infections. This suggests that it may be possible to make antibiotics more effective against M. tuberculosis by using them alongside a second drug that decreases the number of ribosome mistakes. Chaudhuri, Li et al. investigated the effect of a drug called kasugamycin on M. tuberculosis when the bacterium is cultured in the lab, and when it infects mice. The experiments found that Kasugamycin decreased the number of incorrect proteins assembled by the M. tuberculosis bacterium. When the drug was present, rifampicin also killed M. tuberculosis cells more efficiently. Furthermore, in the mice but not the cell cultures, kasugamycin alone was able to restrict the growth of the bacteria. This implies that M. tuberculosis cells may use ribosome mistakes as a strategy to survive in humans and other hosts. When it was given with rifampicin, kasugamycin caused several unwanted side effects in the mice, including weight loss; this may mean that the drug is currently not suitable to use in humans. Further studies may be able to find safer ways to decrease ribosome mistakes in M. tuberculosis, which could speed up the treatment of tuberculosis.
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Affiliation(s)
- Swarnava Chaudhuri
- Centre for Global Health and Infectious Diseases, Collaborative Innovation Centre for the Diagnosis and Treatment of Infectious Diseases, Tsinghua University School of Medicine, Beijing, China
| | - Liping Li
- Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, United States
| | - Matthew Zimmerman
- Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, United States
| | - Yuemeng Chen
- Centre for Global Health and Infectious Diseases, Collaborative Innovation Centre for the Diagnosis and Treatment of Infectious Diseases, Tsinghua University School of Medicine, Beijing, China
| | - Yu-Xiang Chen
- Centre for Global Health and Infectious Diseases, Collaborative Innovation Centre for the Diagnosis and Treatment of Infectious Diseases, Tsinghua University School of Medicine, Beijing, China
| | - Melody N Toosky
- Centre for Global Health and Infectious Diseases, Collaborative Innovation Centre for the Diagnosis and Treatment of Infectious Diseases, Tsinghua University School of Medicine, Beijing, China.,Department of Immunology and Infectious Diseases, Harvard TH Chan School of Public Health, Boston, United States
| | - Michelle Gardner
- Department of Immunology and Infectious Diseases, Harvard TH Chan School of Public Health, Boston, United States
| | - Miaomiao Pan
- Centre for Global Health and Infectious Diseases, Collaborative Innovation Centre for the Diagnosis and Treatment of Infectious Diseases, Tsinghua University School of Medicine, Beijing, China
| | - Yang-Yang Li
- Centre for Global Health and Infectious Diseases, Collaborative Innovation Centre for the Diagnosis and Treatment of Infectious Diseases, Tsinghua University School of Medicine, Beijing, China
| | - Qingwen Kawaji
- Centre for Global Health and Infectious Diseases, Collaborative Innovation Centre for the Diagnosis and Treatment of Infectious Diseases, Tsinghua University School of Medicine, Beijing, China
| | - Jun-Hao Zhu
- Centre for Global Health and Infectious Diseases, Collaborative Innovation Centre for the Diagnosis and Treatment of Infectious Diseases, Tsinghua University School of Medicine, Beijing, China
| | - Hong-Wei Su
- Centre for Global Health and Infectious Diseases, Collaborative Innovation Centre for the Diagnosis and Treatment of Infectious Diseases, Tsinghua University School of Medicine, Beijing, China
| | - Amanda J Martinot
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, United States
| | - Eric J Rubin
- Department of Immunology and Infectious Diseases, Harvard TH Chan School of Public Health, Boston, United States
| | - Veronique Anne Dartois
- Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, United States
| | - Babak Javid
- Centre for Global Health and Infectious Diseases, Collaborative Innovation Centre for the Diagnosis and Treatment of Infectious Diseases, Tsinghua University School of Medicine, Beijing, China.,Department of Immunology and Infectious Diseases, Harvard TH Chan School of Public Health, Boston, United States
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23
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Abstract
Aminoacyl-tRNA synthetases (aaRSs) establish the rules to express the universal genetic code. During aminoacylation, each of the 20 aaRSs associates 1 of 20 amino acids with a specific trinucleotide known as anticodon. Remarkably, for alanyl-tRNAs, the synthetase makes no contact with the anticodon. Instead, it uses a “second genetic code” by picking out a single G3:U70 base pair in the tRNA acceptor stem, which is close to the amino acid attachment site, but 76 Å away from the anticodon. Here, we show that, while in the three kingdoms of life, alanyl-tRNA synthetases use G3:U70 to identify alanyl-tRNAs, surprisingly, they use three different mechanisms to achieve this. We thus suggest that, in evolution, the genetic code had a powerful and persistent preference for associating G:U with alanine. Throughout three domains of life, alanyl-tRNA synthetases (AlaRSs) recognize a G3:U70 base pair in the acceptor stem of tRNAAla as the major identity determinant of tRNAAla. The crystal structure of the archaeon Archaeoglobus fulgidus AlaRS in complex with tRNAAla provided the basis for G3:U70 recognition with residues (Asp and Asn) that are conserved in the three domains [Naganuma M, et al. (2014) Nature 510:507–511]. The recognition mode is unprecedented, with specific accommodation of the dyad asymmetry of the G:U wobble pair and exclusion of the dyad symmetry of a Watson–Crick pair. With this conserved mode, specificity is based more on “fit” than on direct recognition of specific atomic groups. Here, we show that, in contrast to the archaeal complex, the Escherichia coli enzyme uses direct positive (energetically favorable) minor groove recognition of the unpaired 2-amino of G3 by Asp and repulsion of a competing base pair by Asn. Strikingly, mutations that disrupted positive recognition by the E. coli enzyme had little or no effect on G:U recognition by the human enzyme. Alternatively, Homo sapiens AlaRS selects G:U without positive recognition and uses Asp instead to repel a competitor. Thus, the widely conserved Asp-plus-Asn architecture of AlaRSs can select G:U in a straightforward (bacteria) or two different unconventional (eukarya/archaea) ways. The adoption of different modes for recognition of a widely conserved G:U pair in alanine tRNAs suggests an early and insistent role for G:U in the development of the genetic code.
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24
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The TRPV4 channel links calcium influx to DDX3X activity and viral infectivity. Nat Commun 2018; 9:2307. [PMID: 29899501 PMCID: PMC5998047 DOI: 10.1038/s41467-018-04776-7] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 05/22/2018] [Indexed: 12/11/2022] Open
Abstract
Ion channels are well placed to transduce environmental cues into signals used by cells to generate a wide range of responses, but little is known about their role in the regulation of RNA metabolism. Here we show that the TRPV4 cation channel binds the DEAD-box RNA helicase DDX3X and regulates its function. TRPV4-mediated Ca2+ influx releases DDX3X from the channel and drives DDX3X nuclear translocation, a process that involves calmodulin (CaM) and the CaM-dependent kinase II. Genetic depletion or pharmacological inhibition of TRPV4 diminishes DDX3X-dependent functions, including nuclear viral export and translation. Furthermore, TRPV4 mediates Ca2+ influx and nuclear accumulation of DDX3X in cells exposed to the Zika virus or the purified viral envelope protein. Consequently, targeting of TRPV4 reduces infectivity of dengue, hepatitis C and Zika viruses. Together, our results highlight the role of TRPV4 in the regulation of DDX3X-dependent control of RNA metabolism and viral infectivity. The ion channel TRPV4 senses many environmental cues, but its role in virus infection is not known. Here, Doñate-Macián et al. show that Zika virus induces TRPV4-mediated Ca2+ influx into cells, resulting in the nuclear accumulation of the DDX3X RNA helicase, which increases virus replication.
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25
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Vo MN, Terrey M, Lee JW, Roy B, Moresco JJ, Sun L, Fu H, Liu Q, Weber TG, Yates JR, Fredrick K, Schimmel P, Ackerman SL. ANKRD16 prevents neuron loss caused by an editing-defective tRNA synthetase. Nature 2018; 557:510-515. [PMID: 29769718 PMCID: PMC5973781 DOI: 10.1038/s41586-018-0137-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Accepted: 04/09/2018] [Indexed: 11/29/2022]
Abstract
Editing domains of aminoacyl tRNA synthetases correct tRNA charging errors to maintain translational fidelity. A mutation in the editing domain of alanyl tRNA synthetase (AlaRS) in Aars sti mutant mice results in an increase in the production of serine-mischarged tRNAAla and the degeneration of cerebellar Purkinje cells. Here, using positional cloning, we identified Ankrd16, a gene that acts epistatically with the Aars sti mutation to attenuate neurodegeneration. ANKRD16, a vertebrate-specific protein that contains ankyrin repeats, binds directly to the catalytic domain of AlaRS. Serine that is misactivated by AlaRS is captured by the lysine side chains of ANKRD16, which prevents the charging of serine adenylates to tRNAAla and precludes serine misincorporation in nascent peptides. The deletion of Ankrd16 in the brains of Aarssti/sti mice causes widespread protein aggregation and neuron loss. These results identify an amino-acid-accepting co-regulator of tRNA synthetase editing as a new layer of the machinery that is essential to the prevention of severe pathologies that arise from defects in editing.
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Affiliation(s)
- My-Nuong Vo
- The Skaggs Institute for Chemical Biology, Department of Molecular Medicine, Scripps Research Institute, La Jolla, CA, USA
| | - Markus Terrey
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, School of Medicine, University of California San Diego, La Jolla, CA, USA
- Section of Neurobiology, University of California San Diego, La Jolla, CA, USA
- Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, ME, USA
- The Jackson Laboratory, Bar Harbor, ME, USA
| | - Jeong Woong Lee
- The Jackson Laboratory, Bar Harbor, ME, USA
- Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
| | - Bappaditya Roy
- Department of Microbiology, The Ohio State University, Columbus, OH, USA
- Center for RNA Biology, The Ohio State University, Columbus, OH, USA
| | - James J Moresco
- Department of Chemical Physiology, Scripps Research Institute, La Jolla, CA, USA
- Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Litao Sun
- The Skaggs Institute for Chemical Biology, Department of Molecular Medicine, Scripps Research Institute, La Jolla, CA, USA
| | - Hongjun Fu
- The Jackson Laboratory, Bar Harbor, ME, USA
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY, USA
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, New York, NY, USA
| | - Qi Liu
- Department of Microbiology, The Ohio State University, Columbus, OH, USA
- Center for RNA Biology, The Ohio State University, Columbus, OH, USA
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH, USA
- Sharklet Technologies, Aurora, CO, USA
| | | | - John R Yates
- Department of Chemical Physiology, Scripps Research Institute, La Jolla, CA, USA
| | - Kurt Fredrick
- Department of Microbiology, The Ohio State University, Columbus, OH, USA
- Center for RNA Biology, The Ohio State University, Columbus, OH, USA
| | - Paul Schimmel
- The Skaggs Institute for Chemical Biology, Department of Molecular Medicine, Scripps Research Institute, La Jolla, CA, USA.
- The Scripps Research Institute, Jupiter, FL, USA.
| | - Susan L Ackerman
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, School of Medicine, University of California San Diego, La Jolla, CA, USA.
- Section of Neurobiology, University of California San Diego, La Jolla, CA, USA.
- Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, ME, USA.
- The Jackson Laboratory, Bar Harbor, ME, USA.
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26
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Abstract
Inhibition of tRNA aminoacylation has proven to be an effective antimicrobial strategy, impeding an essential step of protein synthesis. Mupirocin, the well-known selective inhibitor of bacterial isoleucyl-tRNA synthetase, is one of three aminoacylation inhibitors now approved for human or animal use. However, design of novel aminoacylation inhibitors is complicated by the steadfast requirement to avoid off-target inhibition of protein synthesis in human cells. Here we review available data regarding known aminoacylation inhibitors as well as key amino-acid residues in aminoacyl-tRNA synthetases (aaRSs) and nucleotides in tRNA that determine the specificity and strength of the aaRS-tRNA interaction. Unlike most ligand-protein interactions, the aaRS-tRNA recognition interaction represents coevolution of both the tRNA and aaRS structures to conserve the specificity of aminoacylation. This property means that many determinants of tRNA recognition in pathogens have diverged from those of humans-a phenomenon that provides a valuable source of data for antimicrobial drug development.
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Affiliation(s)
- Joanne M Ho
- a Department of BioSciences , Rice University , Houston , TX , United States
| | | | - Dieter Söll
- c Departments of Molecular Biophysics & Biochemistry , Yale University , New Haven , CT , United States.,d Department of Chemistry , Yale University , New Haven , CT , United States
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27
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Amanullah A, Upadhyay A, Joshi V, Mishra R, Jana NR, Mishra A. Progressing neurobiological strategies against proteostasis failure: Challenges in neurodegeneration. Prog Neurobiol 2017; 159:1-38. [DOI: 10.1016/j.pneurobio.2017.08.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Revised: 06/01/2017] [Accepted: 08/25/2017] [Indexed: 02/07/2023]
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28
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Jiang T, Song H, Slaney TR, Wu W, Langsdorf E, Gupta G, Ludwig R, Tao L, McVey D, Das TK. Codon-Directed Determination of the Biological Causes of Sequence Variants in Therapeutic Proteins. Anal Chem 2017; 89:12749-12755. [DOI: 10.1021/acs.analchem.7b02914] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Tao Jiang
- Department
of Chemistry, The University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Hangtian Song
- Analytical,
Cell Line and Process Development, Bristol-Myers Squibb Company, 311 Pennington-Rocky
Hill Road, Pennington, New
Jersey 08534, United States
| | - Thomas R. Slaney
- Analytical,
Cell Line and Process Development, Bristol-Myers Squibb Company, 311 Pennington-Rocky
Hill Road, Pennington, New
Jersey 08534, United States
| | - Wei Wu
- Analytical,
Cell Line and Process Development, Bristol-Myers Squibb Company, 311 Pennington-Rocky
Hill Road, Pennington, New
Jersey 08534, United States
| | - Erik Langsdorf
- Analytical,
Cell Line and Process Development, Bristol-Myers Squibb Company, 311 Pennington-Rocky
Hill Road, Pennington, New
Jersey 08534, United States
| | - Gargi Gupta
- Analytical,
Cell Line and Process Development, Bristol-Myers Squibb Company, 311 Pennington-Rocky
Hill Road, Pennington, New
Jersey 08534, United States
| | - Richard Ludwig
- Analytical,
Cell Line and Process Development, Bristol-Myers Squibb Company, 311 Pennington-Rocky
Hill Road, Pennington, New
Jersey 08534, United States
| | - Li Tao
- Analytical,
Cell Line and Process Development, Bristol-Myers Squibb Company, 311 Pennington-Rocky
Hill Road, Pennington, New
Jersey 08534, United States
| | - Duncan McVey
- Analytical,
Cell Line and Process Development, Bristol-Myers Squibb Company, 311 Pennington-Rocky
Hill Road, Pennington, New
Jersey 08534, United States
| | - Tapan K. Das
- Analytical,
Cell Line and Process Development, Bristol-Myers Squibb Company, 311 Pennington-Rocky
Hill Road, Pennington, New
Jersey 08534, United States
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29
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Leibovitch M, Topisirovic I. Dysregulation of mRNA translation and energy metabolism in cancer. Adv Biol Regul 2017; 67:30-39. [PMID: 29150352 DOI: 10.1016/j.jbior.2017.11.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 10/26/2017] [Accepted: 11/01/2017] [Indexed: 12/20/2022]
Abstract
Dysregulated mRNA translation and aberrant energy metabolism are frequent in cancer. Considering that mRNA translation is an energy demanding process, cancer cells must produce sufficient ATP to meet energy demand of hyperactive translational machinery. In recent years, the mammalian/mechanistic target of rapamycin (mTOR) emerged as a central regulatory node which coordinates energy consumption by the translation apparatus and ATP production in mitochondria. Aberrant mTOR signaling underpins the vast majority of cancers whereby increased mTOR activity is thought to be a major determinant of both malignant translatomes and metabolomes. Nonetheless, the role of mTOR and other related signaling nodes (e.g. AMPK) in orchestrating protein synthesis and cancer energetics is only recently being unraveled. In this review, we discuss recent findings that provide insights into the molecular underpinnings of coordination of translational and metabolic programs of cancer cells, and potential strategies to translate these findings into clinical treatments.
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Affiliation(s)
- Matthew Leibovitch
- Lady Davis Institute, SMBD JGH, McGill University, Montréal, QC, H3T 1E2, Canada.
| | - Ivan Topisirovic
- Gerald Bronfman Department of Oncology, Montréal, QC, H3A 1A3, Canada; Department of Biochemistry, Montréal, QC, H3A 1A3, Canada; Department of Experimental Medicine McGill University, Montréal, QC, H3A 1A3, Canada; Lady Davis Institute, SMBD JGH, McGill University, Montréal, QC, H3T 1E2, Canada
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30
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Holman KM, Puppala AK, Lee JW, Lee H, Simonović M. Insights into substrate promiscuity of human seryl-tRNA synthetase. RNA (NEW YORK, N.Y.) 2017; 23:1685-1699. [PMID: 28808125 PMCID: PMC5648036 DOI: 10.1261/rna.061069.117] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 08/08/2017] [Indexed: 06/07/2023]
Abstract
Seryl-tRNA synthetase (SerRS) attaches L-serine to the cognate serine tRNA (tRNASer) and the noncognate selenocysteine tRNA (tRNASec). The latter activity initiates the anabolic cycle of selenocysteine (Sec), proper decoding of an in-frame Sec UGA codon, and synthesis of selenoproteins across all domains of life. While the accuracy of SerRS is important for overall proteome integrity, it is its substrate promiscuity that is vital for the integrity of the selenoproteome. This raises a question as to what elements in the two tRNA species, harboring different anticodon sequences and adopting distinct folds, facilitate aminoacylation by a common aminoacyl-tRNA synthetase. We sought to answer this question by analyzing the ability of human cytosolic SerRS to bind and act on tRNASer, tRNASec, and 10 mutant and chimeric constructs in which elements of tRNASer were transposed onto tRNASec We show that human SerRS only subtly prefers tRNASer to tRNASec, and that discrimination occurs at the level of the serylation reaction. Surprisingly, the tRNA mutants predicted to adopt either the 7/5 or 8/5 fold are poor SerRS substrates. In contrast, shortening of the acceptor arm of tRNASec by a single base pair yields an improved SerRS substrate that adopts an 8/4 fold. We suggest that an optimal tertiary arrangement of structural elements within tRNASec and tRNASer dictate their utility for serylation. We also speculate that the extended acceptor-TΨC arm of tRNASec evolved as a compromise for productive binding to SerRS while remaining the major recognition element for other enzymes involved in Sec and selenoprotein synthesis.
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MESH Headings
- Base Sequence
- Binding Sites
- Cytosol/enzymology
- Humans
- Kinetics
- Models, Molecular
- Mutagenesis
- Nucleic Acid Conformation
- RNA Folding
- RNA, Transfer, Amino Acid-Specific/chemistry
- RNA, Transfer, Amino Acid-Specific/genetics
- RNA, Transfer, Amino Acid-Specific/metabolism
- RNA, Transfer, Ser/chemistry
- RNA, Transfer, Ser/genetics
- RNA, Transfer, Ser/metabolism
- Serine-tRNA Ligase/metabolism
- Substrate Specificity
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Affiliation(s)
- Kaitlyn M Holman
- Department of Biochemistry and Molecular Genetics, College of Medicine, The University of Illinois at Chicago, Chicago, Illinois 60607, USA
| | - Anupama K Puppala
- Department of Biochemistry and Molecular Genetics, College of Medicine, The University of Illinois at Chicago, Chicago, Illinois 60607, USA
| | - Jonathan W Lee
- College of Liberal Arts and Sciences, The University of Illinois at Chicago, Chicago, Illinois 60607, USA
| | - Hyun Lee
- Center for Biomolecular Sciences, Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The University of Illinois at Chicago, Chicago, Illinois 60607, USA
| | - Miljan Simonović
- Department of Biochemistry and Molecular Genetics, College of Medicine, The University of Illinois at Chicago, Chicago, Illinois 60607, USA
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31
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Fares MA, Sabater-Muñoz B, Toft C. Genome Mutational and Transcriptional Hotspots Are Traps for Duplicated Genes and Sources of Adaptations. Genome Biol Evol 2017; 9:1229-1240. [PMID: 28459980 PMCID: PMC5433386 DOI: 10.1093/gbe/evx085] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/26/2017] [Indexed: 12/23/2022] Open
Abstract
Gene duplication generates new genetic material, which has been shown to lead to major innovations in unicellular and multicellular organisms. A whole-genome duplication occurred in the ancestor of Saccharomyces yeast species but 92% of duplicates returned to single-copy genes shortly after duplication. The persisting duplicated genes in Saccharomyces led to the origin of major metabolic innovations, which have been the source of the unique biotechnological capabilities in the Baker’s yeast Saccharomyces cerevisiae. What factors have determined the fate of duplicated genes remains unknown. Here, we report the first demonstration that the local genome mutation and transcription rates determine the fate of duplicates. We show, for the first time, a preferential location of duplicated genes in the mutational and transcriptional hotspots of S. cerevisiae genome. The mechanism of duplication matters, with whole-genome duplicates exhibiting different preservation trends compared to small-scale duplicates. Genome mutational and transcriptional hotspots are rich in duplicates with large repetitive promoter elements. Saccharomyces cerevisiae shows more tolerance to deleterious mutations in duplicates with repetitive promoter elements, which in turn exhibit higher transcriptional plasticity against environmental perturbations. Our data demonstrate that the genome traps duplicates through the accelerated regulatory and functional divergence of their gene copies providing a source of novel adaptations in yeast.
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Affiliation(s)
- Mario A Fares
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas (CSIC), Universidad Politécnica de Valencia, Valencia, Spain.,Institute for Integrative Systems Biology, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valencia, Paterna, Spain.,Department of Genetics, Smurfit Institute of Genetics, University of Dublin, Trinity College, Dublin 2, Dublin, Ireland
| | - Beatriz Sabater-Muñoz
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas (CSIC), Universidad Politécnica de Valencia, Valencia, Spain.,Institute for Integrative Systems Biology, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valencia, Paterna, Spain.,Department of Genetics, Smurfit Institute of Genetics, University of Dublin, Trinity College, Dublin 2, Dublin, Ireland
| | - Christina Toft
- Institute for Integrative Systems Biology, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Valencia, Paterna, Spain.,Department of Genetics, University of Valencia, Burjasot, Spain.,Instituto de Agroquímica y Tecnología de los Alimentos, Consejo Superior de Investigaciones Científicas (CSIC), Burjasot, Valencia, Spain
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32
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Translational fidelity and mistranslation in the cellular response to stress. Nat Microbiol 2017; 2:17117. [PMID: 28836574 DOI: 10.1038/nmicrobiol.2017.117] [Citation(s) in RCA: 115] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 06/20/2017] [Indexed: 11/08/2022]
Abstract
Faithful translation of mRNA into the corresponding polypeptide is a complex multistep process, requiring accurate amino acid selection, transfer RNA (tRNA) charging and mRNA decoding on the ribosome. Key players in this process are aminoacyl-tRNA synthetases (aaRSs), which not only catalyse the attachment of cognate amino acids to their respective tRNAs, but also selectively hydrolyse incorrectly activated non-cognate amino acids and/or misaminoacylated tRNAs. This aaRS proofreading provides quality control checkpoints that exclude non-cognate amino acids during translation, and in so doing helps to prevent the formation of an aberrant proteome. However, despite the intrinsic need for high accuracy during translation, and the widespread evolutionary conservation of aaRS proofreading pathways, requirements for translation quality control vary depending on cellular physiology and changes in growth conditions, and translation errors are not always detrimental. Recent work has demonstrated that mistranslation can also be beneficial to cells, and some organisms have selected for a higher degree of mistranslation than others. The aims of this Review Article are to summarize the known mechanisms of protein translational fidelity and explore the diversity and impact of mistranslation events as a potentially beneficial response to environmental and cellular stress.
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33
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Aboelnga MM, Gauld JW. Roles of the Active Site Zn(II) and Residues in Substrate Discrimination by Threonyl-tRNA Synthetase: An MD and QM/MM Investigation. J Phys Chem B 2017; 121:6163-6174. [PMID: 28592109 DOI: 10.1021/acs.jpcb.7b03782] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Threonyl-tRNA synthetase (ThrRS) is a Zn(II) containing enzyme that catalyzes the activation of threonine and its subsequent transfer to the cognate tRNA. This process is accomplished with remarkable fidelity, with ThrRS being able to discriminate its cognate substrate from similar analogues such as serine and valine. Molecular dynamics (MD) simulations and hybrid quantum mechanics/molecular mechanics (QM/MM) methods have been used to elucidate the role of Zn(II) in the aminoacylation mechanism of ThrRS. More specifically, the role of Zn(II) and active site residues in ThrRS's ability to discriminate between its cognate substrate l-threonine and the noncognate l-serine, l-valine, and d-threonine has been examined. The present results suggest that a role of the Zn(II) ion, with its Lewis acidity, is to facilitate deprotonation of the side chain hydroxyl groups of the aminoacyl moieties of cognate Thr-AMP and noncognate Ser-AMP substrates. In their deprotonated forms, these substrates are able to adopt a conformation preferable for aminoacyl transfer from aa-AMP onto the Ado-3'OH of the tRNAThr cosubstrate. Relative to the neutral substrates, when the substrates are first deprotonated with the assistance of the Zn(II) ion, the barrier for the rate-limiting step is decreased significantly by 42.0 and 39.2 kJ mol-1 for l-Thr-AMP and l-Ser-AMP, respectively. An active site arginyl also plays a key role in stabilizing the buildup of negative charge on the substrate's bridging phosphate oxygen during the mechanism. For the enantiomeric substrate analogue d-Thr-AMP, product formation is highly disfavored, and as a result, the reverse reaction has a very low barrier of 16.0 kJ mol-1.
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Affiliation(s)
- Mohamed M Aboelnga
- Department of Chemistry and Biochemistry, University of Windsor , Windsor, Ontario, N9B 3P4, Canada.,Department of Chemistry, Faculty of Science, University of Damietta , New Damietta, Damietta Governorate 34511, Egypt
| | - James W Gauld
- Department of Chemistry and Biochemistry, University of Windsor , Windsor, Ontario, N9B 3P4, Canada
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Kamble AS, Fandilolu PM, Sambhare SB, Sonawane KD. Idiosyncratic recognition of UUG/UUA codons by modified nucleoside 5-taurinomethyluridine, τm5U present at 'wobble' position in anticodon loop of tRNALeu: A molecular modeling approach. PLoS One 2017; 12:e0176756. [PMID: 28453549 PMCID: PMC5409519 DOI: 10.1371/journal.pone.0176756] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 04/11/2017] [Indexed: 11/18/2022] Open
Abstract
Lack of naturally occurring modified nucleoside 5-taurinomethyluridine (τm5U) at the 'wobble' 34th position in tRNALeu causes mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS). The τm5U34 specifically recognizes UUG and UUA codons. Structural consequences of τm5U34 to read cognate codons have not been studied so far in detail at the atomic level. Hence, 50ns multiple molecular dynamics (MD) simulations of various anticodon stem loop (ASL) models of tRNALeu in presence and absence of τm5U34 along with UUG and UUA codons were performed to explore the dynamic behaviour of τm5U34 during codon recognition process. The MD simulation results revealed that τm5U34 recognizes G/A ending codons by 'wobble' as well as a novel 'single' hydrogen bonding interactions. RMSD and RMSF values indicate the comparative stability of the ASL models containing τm5U34 modification over the other models, lacking τm5U34. Another MD simulation study of 55S mammalian mitochondrial rRNA with tRNALeu showed crucial interactions between the A-site residues, A918, A919, G256 and codon-anticodon bases. Thus, these results could improve our understanding about the decoding efficiency of human mt tRNALeu with τm5U34 to recognize UUG and UUA codons.
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Affiliation(s)
- Asmita S. Kamble
- Structural Bioinformatics Unit, Department of Biochemistry, Shivaji University, Kolhapur, (M.S.), India
| | - Prayagraj M. Fandilolu
- Structural Bioinformatics Unit, Department of Biochemistry, Shivaji University, Kolhapur, (M.S.), India
| | - Susmit B. Sambhare
- Structural Bioinformatics Unit, Department of Biochemistry, Shivaji University, Kolhapur, (M.S.), India
| | - Kailas D. Sonawane
- Structural Bioinformatics Unit, Department of Biochemistry, Shivaji University, Kolhapur, (M.S.), India
- Department of Microbiology, Shivaji University, Kolhapur, (M.S.), India
- * E-mail:
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Fislage M, Wauters L, Versées W. Invited review: MnmE, a GTPase that drives a complex tRNA modification reaction. Biopolymers 2017; 105:568-79. [PMID: 26832457 DOI: 10.1002/bip.22813] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2015] [Revised: 01/19/2016] [Accepted: 01/27/2016] [Indexed: 01/30/2023]
Abstract
MnmE is a multi-domain GTPase that is conserved from bacteria to man. Together with its partner protein MnmG it is involved in the synthesis of a tRNA wobble uridine modification. The orthologues of these proteins in eukaryotes are targeted to mitochondria and mutations in the encoding genes are associated with severe mitochondrial diseases. While classical small GTP-binding proteins are regulated via auxiliary GEFs and GAPs, the GTPase activity of MnmE is activated via potassium-dependent homodimerization of its G domains. In this review we focus on the catalytic mechanism of GTP hydrolysis by MnmE and the large scale conformational changes that are triggered throughout the GTPase cycle. We also discuss how these conformational changes might be used to drive and tune the complex tRNA modification reaction. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 568-579, 2016.
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Affiliation(s)
- Marcus Fislage
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, 10032.,Howard Hughes Medical Institute, Columbia University, New York, NY, 10032
| | - Lina Wauters
- Department of Cell Biochemistry, University of Groningen, Nijenborgh 7, Groningen, 9747 AG, Netherlands.,Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, Brussel, 1050, Belgium.,Structural Biology Research Center, VIB, Pleinlaan 2, Brussel, 1050, Belgium
| | - Wim Versées
- Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, Brussel, 1050, Belgium.,Structural Biology Research Center, VIB, Pleinlaan 2, Brussel, 1050, Belgium
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Schwartz MH, Pan T. Function and origin of mistranslation in distinct cellular contexts. Crit Rev Biochem Mol Biol 2017; 52:205-219. [PMID: 28075177 DOI: 10.1080/10409238.2016.1274284] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Mistranslation describes errors during protein synthesis that prevent the amino acid sequences specified in the genetic code from being reflected within proteins. For a long time, mistranslation has largely been considered an aberrant cellular process that cells actively avoid at all times. However, recent evidence has demonstrated that cells from all three domains of life not only tolerate certain levels and forms of mistranslation, but actively induce mistranslation under certain circumstances. To this end, dedicated biological mechanisms have recently been found to reduce translational fidelity, which indicates that mistranslation is not exclusively an erroneous process and can even benefit cells in particular cellular contexts. There currently exists a spectrum of mistranslational processes that differ not only in their origins, but also in their molecular and cellular effects. These findings suggest that the optimal degree of translational fidelity largely depends on a specific cellular context. This review aims to conceptualize the basis and functional consequence of the diverse types of mistranslation that have been described so far.
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Affiliation(s)
- Michael H Schwartz
- a Department of Biochemistry and Molecular Biology , University of Chicago, Chicago , IL , USA
| | - Tao Pan
- a Department of Biochemistry and Molecular Biology , University of Chicago, Chicago , IL , USA
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Aboelnga MM, Hayward JJ, Gauld JW. A water-mediated and substrate-assisted aminoacylation mechanism in the discriminating aminoacyl-tRNA synthetase GlnRS and non-discriminating GluRS. Phys Chem Chem Phys 2017; 19:25598-25609. [DOI: 10.1039/c7cp02969a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Computational methods have been used to elucidate key differences and similarities between the distinct aminoacyl-tRNA synthetases (aaRS) GlnRS and non-discriminating-GluRS.
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Affiliation(s)
- Mohamed M. Aboelnga
- Department of Chemistry and Biochemistry
- University of Windsor
- Windsor
- Canada
- Department of Chemistry and Biochemistry
| | - John J. Hayward
- Department of Chemistry and Biochemistry
- University of Windsor
- Windsor
- Canada
| | - James W. Gauld
- Department of Chemistry and Biochemistry
- University of Windsor
- Windsor
- Canada
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Kabra A, Fatma F, Shahid S, Pathak PP, Yadav R, Pulavarti SK, Tripathi S, Jain A, Arora A. Structural characterization of peptidyl-tRNA hydrolase from Mycobacterium smegmatis by NMR spectroscopy. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2016; 1864:1304-14. [DOI: 10.1016/j.bbapap.2016.06.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 06/24/2016] [Accepted: 06/28/2016] [Indexed: 10/21/2022]
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Schwartz MH, Waldbauer JR, Zhang L, Pan T. Global tRNA misacylation induced by anaerobiosis and antibiotic exposure broadly increases stress resistance in Escherichia coli. Nucleic Acids Res 2016; 44:10292-10303. [PMID: 27672035 PMCID: PMC5137444 DOI: 10.1093/nar/gkw856] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 09/14/2016] [Accepted: 09/16/2016] [Indexed: 12/22/2022] Open
Abstract
High translational fidelity is commonly considered a requirement for optimal cellular health and protein function. However, recent findings have shown that inducible mistranslation specifically with methionine engendered at the tRNA charging level occurs in mammalian cells, yeast and archaea, yet it was unknown whether bacteria were capable of mounting a similar response. Here, we demonstrate that Escherichia coli misacylates non-methionyl-tRNAs with methionine in response to anaerobiosis and antibiotic exposure via the methionyl–tRNA synthetase (MetRS). Two MetRS succinyl-lysine modifications independently confer high tRNA charging fidelity to the otherwise promiscuous, unmodified enzyme. Strains incapable of tRNA mismethionylation are less adept at growth in the presence of antibiotics and stressors. The presence of tRNA mismethionylation and its potential role in mistranslation within the bacterial domain establishes this response as a pervasive biological mechanism and connects it to diverse cellular functions and modes of fitness.
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Affiliation(s)
- Michael H Schwartz
- Department of Biochemistry and Molecular Biology, University of Chicago, 929 E. 57th St., Chicago, IL 60637, USA.,Committee on Microbiology, University of Chicago, 929 E. 57th St., Chicago, IL 60637, USA
| | - Jacob R Waldbauer
- Department of Geophysical Sciences, University of Chicago, 5734 S. Ellis Ave., Chicago, IL 60637, USA
| | - Lichun Zhang
- Department of Geophysical Sciences, University of Chicago, 5734 S. Ellis Ave., Chicago, IL 60637, USA
| | - Tao Pan
- Department of Biochemistry and Molecular Biology, University of Chicago, 929 E. 57th St., Chicago, IL 60637, USA .,Committee on Microbiology, University of Chicago, 929 E. 57th St., Chicago, IL 60637, USA
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Jelinek T, Kryukova E, Kufova Z, Kryukov F, Hajek R. Proteasome inhibitors in AL amyloidosis: focus on mechanism of action and clinical activity. Hematol Oncol 2016; 35:408-419. [PMID: 27647123 DOI: 10.1002/hon.2351] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Revised: 08/08/2016] [Accepted: 08/10/2016] [Indexed: 11/11/2022]
Abstract
Proteasome inhibitors are the backbone in the treatment of multiple myeloma with 3 of its representatives (bortezomib, carfilzomib, and ixazomib) having already been approved. There is a different situation altogether in the treatment of amyloid light chain (AL) amyloidosis where owing to the rarity of this entity neither of these drugs has currently gained approval. Amyloid light chain plasma cells are possibly more vulnerable to bortezomib than myeloma plasmocytes because of a slightly distinct mechanism of action, which is described in depth in this manuscript. Bortezomib is highly active and rapidly effective as a single agent and even more potent in combination with dexamethasone and alkylators. Bortezomib-based regimens have become a standard part of the initial treatment of AL amyloidosis in the majority of centers. We have reviewed all available data on bortezomib in various combinations and settings. Carfilzomib seems to be effective but also toxic in these fragile patients with a high rate of cardiac events. Oral ixazomib has shown a surprisingly high efficacy with manageable toxicity and has received the Food and Drug Administration Breakthrough Therapy designation in 2014 for relapsed AL amyloidosis patients. In this review we have comprehensively described the current available knowledge of these 3 proteasome inhibitors and their use in AL amyloidosis.
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Affiliation(s)
- T Jelinek
- Department of Haematooncology, University Hospital Ostrava, Ostrava, Czech Republic.,Faculty of Medicine, University of Ostrava, Ostrava, Czech Republic
| | - E Kryukova
- Faculty of Medicine, University of Ostrava, Ostrava, Czech Republic
| | - Z Kufova
- Department of Haematooncology, University Hospital Ostrava, Ostrava, Czech Republic.,Faculty of Medicine, University of Ostrava, Ostrava, Czech Republic
| | - F Kryukov
- Faculty of Medicine, University of Ostrava, Ostrava, Czech Republic
| | - R Hajek
- Department of Haematooncology, University Hospital Ostrava, Ostrava, Czech Republic.,Faculty of Medicine, University of Ostrava, Ostrava, Czech Republic
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Wang X, Pan T. Stress Response and Adaptation Mediated by Amino Acid Misincorporation during Protein Synthesis. Adv Nutr 2016; 7:773S-9S. [PMID: 27422514 PMCID: PMC4942860 DOI: 10.3945/an.115.010991] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Translation of genetic information into functional proteins is critical for all cellular life. Accurate protein synthesis relies on proper aminoacylation of transfer RNAs (tRNAs) and decoding of mRNAs by the ribosome with the use of aminoacyl-tRNAs. Mistranslation can lead to pathologic consequences. All cells contain elaborate quality control mechanisms in translation, although translational fidelity may be regulated by various factors such as nutrient limitation or reactive oxygen species. Translation fidelity is maintained via the accuracy of tRNA aminoacylation by the aminoacyl-tRNA synthetases and matching of the mRNA codon with the tRNA anticodon by the ribosome. Stringent substrate discrimination and proofreading are critical in aminoacylating tRNAs with their cognate amino acid to maintain high accuracy of translation. Although the composition of the cellular proteome generally adheres to the genetic code, accumulating evidence indicates that cells can also deliberately mistranslate; they synthesize mutant proteins that deviate from the genetic code in response to stress or environmental changes. Mistranslation with tRNA charged with noncognate amino acids can expand the proteome to enhance stress response and help adaptation. Here, we review current knowledge on mistranslation through tRNA misacylation and describe advances in our understanding of translational control in the regulation of stress response and human diseases.
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Affiliation(s)
- Xiaoyun Wang
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL
| | - Tao Pan
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL
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42
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Aleksandrov A, Palencia A, Cusack S, Field M. Aminoacetylation Reaction Catalyzed by Leucyl-tRNA Synthetase Operates via a Self-Assisted Mechanism Using a Conserved Residue and the Aminoacyl Substrate. J Phys Chem B 2016; 120:4388-98. [PMID: 27115861 DOI: 10.1021/acs.jpcb.6b02387] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Leucyl-tRNA synthetase catalyzes attachment of leucine amino acid to its cognate tRNA. During the second, aminoacetylation, step of the reaction, the leucyl moiety is transferred from leucyl-adenylate to the terminal A76 adenosine of tRNA. In this work, we have investigated the aminoacetylation step catalyzed by leucyl-tRNA synthase, using ab initio quantum chemical/molecular mechanical hybrid potentials in conjunction with reaction-path-location algorithms and molecular dynamics free energy simulations. We have modeled reaction mechanisms arising from both crystallographic studies and computational work. We invoke various groups as potential proton acceptors-namely, the phosphate and leucyl amino groups of leucyl-adenylate, the A76 base of tRNA, and the Asp80 and Glu532 residues of the protein-and consider both metal-assisted and metal-free reactions. Free energy calculations indicate that both the phosphate group of leucyl adenylate and Glu532 are not strong bases. This agrees with the results of the quantum chemical/molecular mechanical reaction path calculations which give high free energy barriers for the studied pathways involving these groups. A self-assisted mechanism with the leucyl amino group and Asp80 as proton acceptors is the most likely. Furthermore, in this mechanism the presence of a metal ion coordinated by the phosphate group and Glu532 strongly activates the reaction.
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Affiliation(s)
- Alexey Aleksandrov
- Laboratoire de Biochimie, UMR 7654, Ecole Polytechnique, CNRS , F-91128 Palaiseau Cedex, France
| | - Andrés Palencia
- European Molecular Biology Laboratory (EMBL), Grenoble Outstation and Unit of Virus Host-Cell Interactions, University of Grenoble-EMBL-CNRS , 38044 Grenoble, France
| | - Stephen Cusack
- European Molecular Biology Laboratory (EMBL), Grenoble Outstation and Unit of Virus Host-Cell Interactions, University of Grenoble-EMBL-CNRS , 38044 Grenoble, France
| | - Martin Field
- Dynamo Team, DYNAMOP Group, UMR 5075, Université Grenoble 1, CNRS, CEA, Institut de Biologie Structurale , 71 Avenue des Martyrs, CS 10090, 38044 Grenoble Cedex 9, France
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Abstract
Aminoacyl-tRNA synthetases (aaRSs) are modular enzymes globally conserved in the three kingdoms of life. All catalyze the same two-step reaction, i.e., the attachment of a proteinogenic amino acid on their cognate tRNAs, thereby mediating the correct expression of the genetic code. In addition, some aaRSs acquired other functions beyond this key role in translation. Genomics and X-ray crystallography have revealed great structural diversity in aaRSs (e.g., in oligomery and modularity, in ranking into two distinct groups each subdivided in 3 subgroups, by additional domains appended on the catalytic modules). AaRSs show huge structural plasticity related to function and limited idiosyncrasies that are kingdom or even species specific (e.g., the presence in many Bacteria of non discriminating aaRSs compensating for the absence of one or two specific aaRSs, notably AsnRS and/or GlnRS). Diversity, as well, occurs in the mechanisms of aaRS gene regulation that are not conserved in evolution, notably between distant groups such as Gram-positive and Gram-negative Bacteria. The review focuses on bacterial aaRSs (and their paralogs) and covers their structure, function, regulation, and evolution. Structure/function relationships are emphasized, notably the enzymology of tRNA aminoacylation and the editing mechanisms for correction of activation and charging errors. The huge amount of genomic and structural data that accumulated in last two decades is reviewed, showing how the field moved from essentially reductionist biology towards more global and integrated approaches. Likewise, the alternative functions of aaRSs and those of aaRS paralogs (e.g., during cell wall biogenesis and other metabolic processes in or outside protein synthesis) are reviewed. Since aaRS phylogenies present promiscuous bacterial, archaeal, and eukaryal features, similarities and differences in the properties of aaRSs from the three kingdoms of life are pinpointed throughout the review and distinctive characteristics of bacterium-like synthetases from organelles are outlined.
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Affiliation(s)
- Richard Giegé
- Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, IBMC, 67084 Strasbourg, France
| | - Mathias Springer
- Université Paris Diderot, Sorbonne Cité, UPR9073 CNRS, IBPC, 75005 Paris, France
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Bhatt TK, Soni R, Sharma D. Recent Updates on DTD (D-Tyr-tRNA(Tyr) Deacylase): An Enzyme Essential for Fidelity and Quality of Protein Synthesis. Front Cell Dev Biol 2016; 4:32. [PMID: 27200345 PMCID: PMC4844752 DOI: 10.3389/fcell.2016.00032] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 04/12/2016] [Indexed: 12/03/2022] Open
Abstract
During protein synthesis, there are several checkpoints in the cell to ensure that the information encoded within genetic material is decoded correctly. Charging of tRNA with its cognate amino acid is one of the important steps in protein synthesis and is carried out by aminoacyl-tRNA synthetase (aaRS) with great accuracy. However, due to presence of D-amino acids in the cell, sometimes aaRS charges tRNA with D-amino acids resulting in the hampering of protein translational process, which is lethal to the cell. Every species has some mechanism in order to prevent the formation of D-amino acid-tRNA complex, for instance DTD (D-Tyr-tRNA deacylase) is an enzyme responsible for the cleavage of ester bond formed between D-amino acid and tRNA leading to error free translation process. In this review, structure, function, and enzymatic mechanism of DTD are discussed. The role of DTD as a drug target is also considered.
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Affiliation(s)
- Tarun K Bhatt
- Department of Biotechnology, School of Life Sciences, Central University of Rajasthan Bandar sindri, India
| | - Rani Soni
- Department of Biotechnology, School of Life Sciences, Central University of Rajasthan Bandar sindri, India
| | - Drista Sharma
- Department of Biotechnology, School of Life Sciences, Central University of Rajasthan Bandar sindri, India
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45
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Khan S. Recent advances in the biology and drug targeting of malaria parasite aminoacyl-tRNA synthetases. Malar J 2016; 15:203. [PMID: 27068331 PMCID: PMC4828885 DOI: 10.1186/s12936-016-1247-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 03/30/2016] [Indexed: 11/22/2022] Open
Abstract
Escalating drug resistance in malaria parasites and lack of vaccine entails the discovery of novel drug targets and inhibitor molecules. The multi-component protein translation machinery is a rich source of such drug targets. Malaria parasites contain three translational compartments: the cytoplasm, apicoplast and mitochondrion, of which the latter two are of the prokaryotic type. Recent explorations by many groups into the malaria parasite protein translation enzymes, aminoacyl-tRNA synthetases (aaRSs), have yielded many promising inhibitors. The understanding of the biology of this unique set of 36 enzymes has become much clearer in recent times. Current review discusses the advances made in understanding of crucial aaRSs from Plasmodium and also the specific inhibitors found against malaria aaRSs.
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Affiliation(s)
- Sameena Khan
- Drug Discovery Research Centre, Translational Health Science and Technology Institute (THSTI), NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, PO box #04, Faridabad, 121001, India.
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46
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Quaternionic representation of the genetic code. Biosystems 2016; 141:10-9. [PMID: 26751396 DOI: 10.1016/j.biosystems.2015.12.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 12/04/2015] [Accepted: 12/28/2015] [Indexed: 11/23/2022]
Abstract
A heuristic diagram of the evolution of the standard genetic code is presented. It incorporates, in a way that resembles the energy levels of an atom, the physical notion of broken symmetry and it is consistent with original ideas by Crick on the origin and evolution of the code as well as with the chronological order of appearance of the amino acids along the evolution as inferred from work that mixtures known experimental results with theoretical speculations. Suggested by the diagram we propose a Hamilton quaternions based mathematical representation of the code as it stands now-a-days. The central object in the description is a codon function that assigns to each amino acid an integer quaternion in such a way that the observed code degeneration is preserved. We emphasize the advantages of a quaternionic representation of amino acids taking as an example the folding of proteins. With this aim we propose an algorithm to go from the quaternions sequence to the protein three dimensional structure which can be compared with the corresponding experimental one stored at the Protein Data Bank. In our criterion the mathematical representation of the genetic code in terms of quaternions merits to be taken into account because it describes not only most of the known properties of the genetic code but also opens new perspectives that are mainly derived from the close relationship between quaternions and rotations.
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47
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Fiedler M, Rossmanith W, Wahle E, Rammelt C. Mitochondrial poly(A) polymerase is involved in tRNA repair. Nucleic Acids Res 2015; 43:9937-49. [PMID: 26354863 PMCID: PMC4787750 DOI: 10.1093/nar/gkv891] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 08/26/2015] [Indexed: 11/12/2022] Open
Abstract
Transcription of the mitochondrial genome results in polycistronic precursors, which are processed mainly by the release of tRNAs interspersed between rRNAs and mRNAs. In many metazoan mitochondrial genomes some tRNA genes overlap with downstream genes; in the case of human mitochondria the genes for tRNATyr and tRNACys overlap by one nucleotide. It has previously been shown that processing of the common precursor releases an incomplete tRNATyr lacking the 3′-adenosine. The 3′-terminal adenosine has to be added before addition of the CCA end and subsequent aminoacylation. We show that the mitochondrial poly(A) polymerase (mtPAP) is responsible for this A addition. In vitro, a tRNATyr lacking the discriminator is a substrate for mtPAP. In vivo, an altered mtPAP protein level affected tRNATyr maturation, as shown by sequencing the 3′ ends of mitochondrial tRNAs. Complete repair could be reconstituted in vitro with three enzymes: mtPAP frequently added more than one A to the 3′ end of the truncated tRNA, and either the mitochondrial deadenylase PDE12 or the endonuclease RNase Z trimmed the oligo(A) tail to a single A before CCA addition. An enzyme machinery that evolved primarily for other purposes thus allows to tolerate the frequent evolutionary occurrence of gene overlaps.
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Affiliation(s)
- Mario Fiedler
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
| | - Walter Rossmanith
- Center for Anatomy & Cell Biology, Medical University of Vienna, 1090 Vienna, Austria
| | - Elmar Wahle
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
| | - Christiane Rammelt
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
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48
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Fortowsky GB, Simard DJ, Aboelnga MM, Gauld JW. Substrate-Assisted and Enzymatic Pretransfer Editing of Nonstandard Amino Acids by Methionyl-tRNA Synthetase. Biochemistry 2015; 54:5757-65. [PMID: 26322377 DOI: 10.1021/acs.biochem.5b00588] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Aminoacyl-tRNA synthetases (aaRSs) are central to a number of physiological processes, including protein biosynthesis. In particular, they activate and then transfer their corresponding amino acid to the cognate tRNA. This is achieved with a generally remarkably high fidelity by editing against incorrect standard and nonstandard amino acids. Using docking, molecular dynamics (MD), and hybrid quantum mechanical/molecular mechanics methods, we have investigated mechanisms by which methionyl-tRNA synthetase (MetRS) may edit against the highly toxic, noncognate, amino acids homocysteine (Hcy) and its oxygen analogue, homoserine (Hse). Substrate-assisted editing of Hcy-AMP in which its own phosphate acts as the mechanistic base occurs with a rate-limiting barrier of 98.2 kJ mol(-1). This step corresponds to nucleophilic attack of the Hcy side-chain sulfur at its own carbonyl carbon (CCarb). In contrast, a new possible editing mechanism is identified in which an active site aspartate (Asp259) acts as the base. The rate-limiting step is now rotation about the substrate's aminoacyl Cβ-Cγ bond with a barrier of 27.5 kJ mol(-1), while for Hse-AMP, the rate-limiting step is cleavage of the CCarb-OP bond with a barrier of 30.9 kJ mol(-1). A similarly positioned aspartate or glutamate also occurs in the homologous enzymes LeuRS, IleRS, and ValRS, which also discriminate against Hcy. Docking and MD studies suggest that at least in the case of LeuRS and ValRS, a similar editing mechanism may be possible.
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Affiliation(s)
- Grant B Fortowsky
- Department of Chemistry and Biochemistry, University of Windsor , Windsor, Ontario N9B 3P4, Canada
| | - Daniel J Simard
- Department of Chemistry and Biochemistry, University of Windsor , Windsor, Ontario N9B 3P4, Canada
| | - Mohamed M Aboelnga
- Department of Chemistry and Biochemistry, University of Windsor , Windsor, Ontario N9B 3P4, Canada
| | - James W Gauld
- Department of Chemistry and Biochemistry, University of Windsor , Windsor, Ontario N9B 3P4, Canada
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Structure of the Pseudomonas aeruginosa transamidosome reveals unique aspects of bacterial tRNA-dependent asparagine biosynthesis. Proc Natl Acad Sci U S A 2014; 112:382-7. [PMID: 25548166 DOI: 10.1073/pnas.1423314112] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Many prokaryotes lack a tRNA synthetase to attach asparagine to its cognate tRNA(Asn), and instead synthesize asparagine from tRNA(Asn)-bound aspartate. This conversion involves two enzymes: a nondiscriminating aspartyl-tRNA synthetase (ND-AspRS) that forms Asp-tRNA(Asn), and a heterotrimeric amidotransferase GatCAB that amidates Asp-tRNA(Asn) to form Asn-tRNA(Asn) for use in protein synthesis. ND-AspRS, GatCAB, and tRNA(Asn) may assemble in an ∼400-kDa complex, known as the Asn-transamidosome, which couples the two steps of asparagine biosynthesis in space and time to yield Asn-tRNA(Asn). We report the 3.7-Å resolution crystal structure of the Pseudomonas aeruginosa Asn-transamidosome, which represents the most common machinery for asparagine biosynthesis in bacteria. We show that, in contrast to a previously described archaeal-type transamidosome, a bacteria-specific GAD domain of ND-AspRS provokes a principally new architecture of the complex. Both tRNA(Asn) molecules in the transamidosome simultaneously serve as substrates and scaffolds for the complex assembly. This architecture rationalizes an elevated dynamic and a greater turnover of ND-AspRS within bacterial-type transamidosomes, and possibly may explain a different evolutionary pathway of GatCAB in organisms with bacterial-type vs. archaeal-type Asn-transamidosomes. Importantly, because the two-step pathway for Asn-tRNA(Asn) formation evolutionarily preceded the direct attachment of Asn to tRNA(Asn), our structure also may reflect the mechanism by which asparagine was initially added to the genetic code.
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Katagiri S, Hayashi T, Kondo M, Tsukitome H, Yoshitake K, Akahori M, Ikeo K, Tsuneoka H, Iwata T. RPE65 Mutations in Two Japanese Families with Leber Congenital Amaurosis. Ophthalmic Genet 2014; 37:161-9. [DOI: 10.3109/13816810.2014.991931] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Satoshi Katagiri
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan,
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan,
| | - Takaaki Hayashi
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan,
| | - Mineo Kondo
- Department of Ophthalmology, Mie University Graduate School of Medicine, Tsu, Japan,
- Department of Ophthalmology, Aichi Children’s Health and Medical Center, Obu, Japan, and
| | - Hideyuki Tsukitome
- Department of Ophthalmology, Mie University Graduate School of Medicine, Tsu, Japan,
| | - Kazutoshi Yoshitake
- Laboratory of DNA Data Analysis, National Institute of Genetics, Shizuoka, Japan
| | - Masakazu Akahori
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan,
| | - Kazuho Ikeo
- Laboratory of DNA Data Analysis, National Institute of Genetics, Shizuoka, Japan
| | - Hiroshi Tsuneoka
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan,
| | - Takeshi Iwata
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan,
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