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Cruz E, Vargas-Rodriguez O. The role of tRNA identity elements in aminoacyl-tRNA editing. Front Microbiol 2024; 15:1437528. [PMID: 39101037 PMCID: PMC11295145 DOI: 10.3389/fmicb.2024.1437528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2024] [Accepted: 06/18/2024] [Indexed: 08/06/2024] Open
Abstract
The rules of the genetic code are implemented by the unique features that define the amino acid identity of each transfer RNA (tRNA). These features, known as "identity elements," mark tRNAs for recognition by aminoacyl-tRNA synthetases (ARSs), the enzymes responsible for ligating amino acids to tRNAs. While tRNA identity elements enable stringent substrate selectivity of ARSs, these enzymes are prone to errors during amino acid selection, leading to the synthesis of incorrect aminoacyl-tRNAs that jeopardize the fidelity of protein synthesis. Many error-prone ARSs have evolved specialized domains that hydrolyze incorrectly synthesized aminoacyl-tRNAs. These domains, known as editing domains, also exist as free-standing enzymes and, together with ARSs, safeguard protein synthesis fidelity. Here, we discuss how the same identity elements that define tRNA aminoacylation play an integral role in aminoacyl-tRNA editing, synergistically ensuring the correct translation of genetic information into proteins. Moreover, we review the distinct strategies of tRNA selection used by editing enzymes and ARSs to avoid undesired hydrolysis of correctly aminoacylated tRNAs.
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Affiliation(s)
| | - Oscar Vargas-Rodriguez
- Department of Molecular Biology and Biophysics, University of Connecticut School of Medicine, Farmington, CT, United States
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2
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Watkins RR, Vradi A, Shulgina I, Musier-Forsyth K. Trypanosoma brucei multi-aminoacyl-tRNA synthetase complex formation limits promiscuous tRNA proofreading. Front Microbiol 2024; 15:1445687. [PMID: 39081885 PMCID: PMC11286415 DOI: 10.3389/fmicb.2024.1445687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2024] [Accepted: 07/03/2024] [Indexed: 08/02/2024] Open
Abstract
Faithful mRNA decoding depends on the accuracy of aminoacyl-tRNA synthetases (ARSs). Aminoacyl-tRNA proofreading mechanisms have been well-described in bacteria, humans, and plants. However, our knowledge of translational fidelity in protozoans is limited. Trypanosoma brucei (Tb) is a eukaryotic, protozoan pathogen that causes Human African Trypanosomiasis, a fatal disease if untreated. Tb undergoes many physiological changes that are dictated by nutrient availability throughout its insect-mammal lifecycle. In the glucose-deprived insect vector, the tsetse fly, Tb use proline to make ATP via mitochondrial respiration. Alanine is one of the major by-products of proline consumption. We hypothesize that the elevated alanine pool challenges Tb prolyl-tRNA synthetase (ProRS), an ARS known to misactivate alanine in all three domains of life, resulting in high levels of misaminoacylated Ala-tRNAPro. Tb encodes two domains that are members of the INS superfamily of aminoacyl-tRNA deacylases. One homolog is appended to the N-terminus of Tb ProRS, and a second is the major domain of multi-aminoacyl-tRNA synthetase complex (MSC)-associated protein 3 (MCP3). Both ProRS and MCP3 are housed in the Tb MSC. Here, we purified Tb ProRS and MCP3 and observed robust Ala-tRNAPro deacylation activity from both enzymes in vitro. Size-exclusion chromatography multi-angle light scattering used to probe the oligomerization state of MCP3 revealed that although its unique N-terminal extension confers homodimerization in the absence of tRNA, the protein binds to tRNA as a monomer. Kinetic assays showed MCP3 alone has relaxed tRNA specificity and promiscuously hydrolyzes cognate Ala-tRNAAla; this activity is significantly reduced in the presence of Tb alanyl-tRNA synthetase, also housed in the MSC. Taken together, our results provide insight into translational fidelity mechanisms in Tb and lay the foundation for exploring MSC-associated proteins as novel drug targets.
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Affiliation(s)
| | | | | | - Karin Musier-Forsyth
- Department of Chemistry and Biochemistry, Center for RNA Biology, Ohio State University, Columbus, OH, United States
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Bhowal P, Roy B, Ganguli S, Igloi GL, Banerjee R. Elucidating the structure-function attributes of a trypanosomal arginyl-tRNA synthetase. Mol Biochem Parasitol 2023; 256:111597. [PMID: 37852416 DOI: 10.1016/j.molbiopara.2023.111597] [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: 08/06/2023] [Revised: 09/20/2023] [Accepted: 10/10/2023] [Indexed: 10/20/2023]
Abstract
Aminoacyl-tRNA synthetases (aaRSs) are fundamental components of the protein translation machinery. In light of their pivotal role in protein synthesis and structural divergence among species, they have always been considered potential targets for the development of antimicrobial compounds. Arginyl-tRNA synthetase from Trypanosoma cruzi (TcArgRS), the parasite responsible for causing Chagas Disease, contains a 100-amino acid insertion that was found to be completely absent in the human counterpart of similar length, as ascertained from multiple sequence alignment results. Thus, we were prompted to perform a preliminary characterization of TcArgRS using biophysical, biochemical, and bioinformatics tools. We expressed the protein in E. coli and validated its in-vitro enzymatic activity. Additionally, analysis of DTNB kinetics, Circular dichroism (CD) spectra, and ligand-binding studies using intrinsic tryptophan fluorescence measurements aided us to understand some structural features in the absence of available crystal structures. Our study indicates that TcArgRS can discriminate between L-arginine and its analogues. Among the many tested substrates, only L-canavanine and L-thioarginine, a synthetic arginine analogue exhibited notable activation. The binding of various substrates was also determined using in silico methods. This study may provide a viable foundation for studying small compounds that can be targeted against TcArgRS.
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Affiliation(s)
- Pratyasha Bhowal
- Department of Biotechnology and Dr. B. C. Guha Centre for Genetic Engineering and Biotechnology, University of Calcutta, 35, Ballygunge Circular Road, Kolkata 700 019, India
| | - Bappaditya Roy
- Department of Microbiology, The Ohio State University, 318 West 12th Avenue, Columbus, OH 43210, USA; Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Sayak Ganguli
- Post Graduate Department of Biotechnology, St. Xavier's College (Autonomous), 30, Park Street, Mullick Bazar, Kolkata 700 016, India.
| | - Gabor L Igloi
- Institute of Biology III, University of Freiburg, Schänzlestr 1, D-79104 Freiburg, Germany
| | - Rajat Banerjee
- Department of Biotechnology and Dr. B. C. Guha Centre for Genetic Engineering and Biotechnology, University of Calcutta, 35, Ballygunge Circular Road, Kolkata 700 019, India.
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Jacobs HT. A century of mitochondrial research, 1922-2022. Enzymes 2023; 54:37-70. [PMID: 37945177 DOI: 10.1016/bs.enz.2023.07.002] [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] [Indexed: 11/12/2023]
Abstract
Although recognized earlier as subcellular entities by microscopists, mitochondria have been the subject of functional studies since 1922, when their biochemical similarities with bacteria were first noted. In this overview I trace the history of research on mitochondria from that time up to the present day, focussing on the major milestones of the overlapping eras of mitochondrial biochemistry, genetics, pathology and cell biology, and its explosion into new areas in the past 25 years. Nowadays, mitochondria are considered to be fully integrated into cell physiology, rather than serving specific functions in isolation.
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Affiliation(s)
- Howard T Jacobs
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland; Department of Environment and Genetics, La Trobe University, Melbourne, VIC, Australia.
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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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Nasim F, Qureshi IA. Aminoacyl tRNA Synthetases: Implications of Structural Biology in Drug Development against Trypanosomatid Parasites. ACS OMEGA 2023; 8:14884-14899. [PMID: 37151504 PMCID: PMC10157851 DOI: 10.1021/acsomega.3c00826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 03/29/2023] [Indexed: 05/09/2023]
Abstract
The ensemble of aminoacyl tRNA synthetases is regarded as a key component of the protein translation machinery. With the progressive increase in structure-based studies on tRNA synthetase-ligand complexes, the detailed picture of these enzymes is becoming clear. Having known their critical role in deciphering the genetic code in a living system, they have always been chosen as one of the important targets for development of antimicrobial drugs. Later on, the role of aminoacyl tRNA synthetases (aaRSs) on the survivability of trypanosomatids has also been validated. It became evident through several gene knockout studies that targeting even one of these enzymes affected parasitic growth drastically. Such successful studies have inspired researchers to search for inhibitors that could specifically target trypanosomal aaRSs, and their never-ending efforts have provided fruitful results. Taking all such studies into consideration, these macromolecules of prime importance deserve further investigation for the development of drugs that cure spectrum of infections caused by trypanosomatids. In this review, we have compiled advancements of over a decade that have taken place in the pursuit of devising drugs by using trypanosomatid aaRSs as a major target of interest. Several of these inhibitors work on an exemplary low concentration range without posing any threat to the mammalian cells which is a very critical aspect of the drug discovery process. Advancements have been made in terms of using structural biology as an important tool to analyze the architecture of the trypanosomatids aaRSs and concoction of inhibitors with augmented specificities toward their targets. Some of the inhibitors that have been tested on other parasites successfully but their efficacy has so far not been validated against these trypanosomatids have also been appended.
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Bernard F, Dargère D, Rechavi O, Dupuy D. Quantitative analysis of C. elegans transcripts by Nanopore direct-cDNA sequencing reveals terminal hairpins in non trans-spliced mRNAs. Nat Commun 2023; 14:1229. [PMID: 36869073 PMCID: PMC9984361 DOI: 10.1038/s41467-023-36915-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 02/23/2023] [Indexed: 03/05/2023] Open
Abstract
In nematodes and kinetoplastids, mRNA processing involves a trans-splicing step through which a short sequence from a snRNP replaces the original 5' end of the primary transcript. It has long been held that 70% of C. elegans mRNAs are submitted to trans-splicing. Our recent work suggested that the mechanism is more pervasive but not fully captured by mainstream transcriptome sequencing methods. Here we use Oxford Nanopore's long-read amplification-free sequencing technology to perform a comprehensive analysis of trans-splicing in worms. We demonstrate that spliced leader (SL) sequences at the 5' end of the mRNAs affect library preparation and generate sequencing artefacts due to their self-complementarity. Consistent with our previous observations, we find evidence of trans-splicing for most genes. However, a subset of genes appears to be only marginally trans-spliced. These mRNAs all share the capacity to generate a 5' terminal hairpin structure mimicking the SL structure and offering a mechanistic explanation for their non conformity. Altogether, our data provide a comprehensive quantitative analysis of SL usage in C. elegans.
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Affiliation(s)
- Florian Bernard
- Université de Bordeaux, Inserm U1212, CNRS UMR5320, Institut Européen de Chimie et Biologie (IECB), 2, rue Robert Escarpit, 33607, Pessac, France.,Department of Neurobiology, Wise Faculty of Life Sciences & Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Delphine Dargère
- Université de Bordeaux, Inserm U1212, CNRS UMR5320, Institut Européen de Chimie et Biologie (IECB), 2, rue Robert Escarpit, 33607, Pessac, France
| | - Oded Rechavi
- Department of Neurobiology, Wise Faculty of Life Sciences & Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Denis Dupuy
- Université de Bordeaux, Inserm U1212, CNRS UMR5320, Institut Européen de Chimie et Biologie (IECB), 2, rue Robert Escarpit, 33607, Pessac, France.
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Kushwaha V, Capalash N. Aminoacyl-tRNA synthetase (AARS) as an attractive drug target in neglected tropical trypanosomatid diseases-Leishmaniasis, Human African Trypanosomiasis and Chagas disease. Mol Biochem Parasitol 2022; 251:111510. [PMID: 35988745 DOI: 10.1016/j.molbiopara.2022.111510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 08/09/2022] [Accepted: 08/16/2022] [Indexed: 10/15/2022]
Abstract
TriTryp diseases (Leishmaniasis, Human African Trypanosomiasis (HAT), and Chagas disease) are devastating parasitic neglected tropical diseases (NTDs) that affect billions of people in developing countries, cause high mortality in humans, and impose a large socio-economic burden. The current treatment options against tritryp diseases are suboptimal and challenging due to the emergence of resistance against available tritryp drugs. Hence, designing and developing effective anti-tritryp drugs with novel targets are required. Aminoacyl-tRNA synthetases (AARSs) involved in specific aminoacylation of transfer RNAs (tRNAs), interrupt protein synthesis through inhibitors, and retard the parasite growth. AaRSs have long been studied as therapeutic targets in bacteria, and three aaRS inhibitors, mupirocin (against IleRS), tavaborole AN2690 (against LeuRS), and halofuginone (against ProRS), are already in clinical practice. The structural differences between tritryp and human aaRSs and the presence of unique sequences (N-terminal domain/C-terminal domain/catalytic domain) make them potential target for developing selective inhibitors. Drugs based on a single aaRS target developed by high-throughput screening (HTS) are less effective due to the emergence of resistance. However, designing multi-targeted drugs may be a better strategy for resistance development. In this perspective, we discuss the characteristics of tritryp aaRSs, sequence conservation in their orthologs and their peculiarities, recent advancements towards the single-target and multi-target aaRS inhibitors developed through rational design.
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Affiliation(s)
- Vikas Kushwaha
- Department of Biotechnology, Panjab University, Sector-25, South Campus, Chandigarh 160025, India.
| | - Neena Capalash
- Department of Biotechnology, Panjab University, Sector-25, South Campus, Chandigarh 160025, India.
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