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Jang SI, Nahm JH, Lee SY, Cho JH, Do MY, Park JS, Lee HS, Yang J, Kong J, Jung S, Kim S, Lee DK. Prediction of Prognosis in Pancreatic Cancer According to Methionyl-tRNA Synthetase 1 Expression as Determined by Immunohistochemical Staining. Cancers (Basel) 2023; 15:5413. [PMID: 38001673 PMCID: PMC10670752 DOI: 10.3390/cancers15225413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Revised: 11/07/2023] [Accepted: 11/13/2023] [Indexed: 11/26/2023] Open
Abstract
The serum level of CA 19-9 is a prognostic marker for pancreatic ductal adenocarcinoma (PDAC). We evaluated the ability of the expression level of methionyl-tRNA synthetase 1 (MARS1)-which facilitates cancer growth by modulating protein synthesis and the cell cycle-to predict the prognosis of PDAC. Immunohistochemical (IHC) staining was performed on pancreatic specimens obtained from patients with PDAC who were undergoing surgery. High MARS1 expression was defined as equal to, or greater than, that in normal acinar cells. Low MARS1 expression was defined as weaker than in normal acinar cells, and stronger than in the pancreatic duct epithelium. Univariate and multivariate analyses were performed on other factors related to prognosis. Among 137 PDAC patients, no significant differences in baseline characteristics were found between those with high (n = 82) and low (n = 55) MARS1 expression. The median overall survival time of patients with high MARS1 expression was shorter than that of those with low expression (15.2 versus 17.2 months, log-rank test p = 0.044). The median disease-free survival (DFS) was not significantly different between the two groups. However, the DFS was shorter in patients with high than in those with low MARS1 expression (8.9 versus 11.2 months, log-rank test p = 0.067). In a multivariate analysis, lymph node metastasis and high MARS1 expression were associated with a poor prognosis of PDAC. Elevated MARS1 expression detected by IHC staining is associated with a poor prognosis of PDAC, suggesting that MARS1 has potential as a prognostic marker.
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Affiliation(s)
- Sung Ill Jang
- Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Republic of Korea; (S.I.J.); (S.Y.L.); (J.H.C.); (M.-Y.D.)
| | - Ji Hae Nahm
- Department of Pathology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Republic of Korea;
| | - See Young Lee
- Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Republic of Korea; (S.I.J.); (S.Y.L.); (J.H.C.); (M.-Y.D.)
| | - Jae Hee Cho
- Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Republic of Korea; (S.I.J.); (S.Y.L.); (J.H.C.); (M.-Y.D.)
| | - Min-Young Do
- Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Republic of Korea; (S.I.J.); (S.Y.L.); (J.H.C.); (M.-Y.D.)
| | - Joon Seong Park
- Department of Surgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Republic of Korea;
| | - Hye Sun Lee
- Biostatistics Collaboration Unit, Yonsei University College of Medicine, Seoul 06273, Republic of Korea; (H.S.L.); (J.Y.)
| | - Juyeon Yang
- Biostatistics Collaboration Unit, Yonsei University College of Medicine, Seoul 06273, Republic of Korea; (H.S.L.); (J.Y.)
| | - Jiwon Kong
- Institute for Artificial Intelligence and Biomedical Research, Medicinal Bioconvergence Research Center, Yonsei University, Incheon 21983, Republic of Korea; (J.K.); (S.J.); (S.K.)
| | - Seunghwan Jung
- Institute for Artificial Intelligence and Biomedical Research, Medicinal Bioconvergence Research Center, Yonsei University, Incheon 21983, Republic of Korea; (J.K.); (S.J.); (S.K.)
| | - Sunghoon Kim
- Institute for Artificial Intelligence and Biomedical Research, Medicinal Bioconvergence Research Center, Yonsei University, Incheon 21983, Republic of Korea; (J.K.); (S.J.); (S.K.)
- Yonsei Institute of Pharmaceutical Sciences, College of Pharmacy, Yonsei University, Incheon 21983, Republic of Korea
| | - Dong Ki Lee
- Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Republic of Korea; (S.I.J.); (S.Y.L.); (J.H.C.); (M.-Y.D.)
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Multimodal cotranslational interactions direct assembly of the human multi-tRNA synthetase complex. Proc Natl Acad Sci U S A 2022; 119:e2205669119. [PMID: 36037331 PMCID: PMC9457175 DOI: 10.1073/pnas.2205669119] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Amino acid ligation to cognate transfer RNAs (tRNAs) is catalyzed by aminoacyl-tRNA synthetases (aaRSs)-essential interpreters of the genetic code during translation. Mammalian cells harbor 20 cytoplasmic aaRSs, out of which 9 (in 8 proteins), with 3 non-aaRS proteins, AIMPs 1 to 3, form the ∼1.25-MDa multi-tRNA synthetase complex (MSC). The function of MSC remains uncertain, as does its mechanism of assembly. Constituents of multiprotein complexes encounter obstacles during assembly, including inappropriate interactions, topological constraints, premature degradation of unassembled subunits, and suboptimal stoichiometry. To facilitate orderly and efficient complex formation, some complexes are assembled cotranslationally by a mechanism in which a fully formed, mature protein binds a nascent partner as it emerges from the translating ribosome. Here, we show out of the 121 possible interaction events between the 11 MSC constituents, 15 are cotranslational. AIMPs are involved in the majority of these cotranslational interactions, suggesting they are not only critical for MSC structure but also for assembly. Unexpectedly, several cotranslational events involve more than the usual dyad of interacting proteins. We show two modes of cotranslational interaction, namely a "multisite" mechanism in which two or more mature proteins bind the same nascent peptide at distinct sites and a second "piggy-back" mechanism in which a mature protein carries a second fully formed protein and binds to a single site on an emerging peptide. Multimodal mechanisms of cotranslational interaction offer a diversity of pathways for ordered, piecewise assembly of small subcomplexes into larger heteromultimeric complexes such as the mammalian MSC.
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Van Cauwelaert S, Stylemans D, D’Haenens A, Slabbynck H, Nieuwendijk R. Even if it looks like COVID-19, think again: the importance of differential diagnosis during a pandemic. Acta Clin Belg 2022; 77:416-420. [PMID: 33449840 DOI: 10.1080/17843286.2021.1872312] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Antisynthetase syndrome (ASSD) is a rare auto-immune condition that can present as interstitial lung disease (ILD) and progress into Acute Respiratory Distress Syndrome (ARDS). IMPORTANCE The purpose of this clinical case is to highlight the importance of considering less prevalent causes of ARDS amid the COVID-19 pandemic. CASE REPORT We present a 56-year-old Belgian female of African descent without past medical history who demonstrated typical signs of COVID-19 at the start of the pandemic. Based on the disease course as well as CT-scan findings, a diagnosis of COVID-19 was made. She progressed to ARDS for which she got intubated and was started on venovenous membrane oxygenation (VV-ECMO). Despite initial negative screening for antinuclear antibodies, further analysis revealed anti-Jo-antibodies. Diagnosis of ASSD was eventually retained and immunosuppressive therapy was started. However, pulmonary fibrosis had evolved too far and therapy was halted shortly after.
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Affiliation(s)
- Stefan Van Cauwelaert
- Department of Internal Medicine, Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium
| | - Dimitri Stylemans
- Department of Pulmonary Medicine, Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium
| | - Alexander D’Haenens
- Department of Pulmonary Medicine, Universitair Ziekenhuis Leuven (UZ Leuven), Leuven, Belgium
| | - Hans Slabbynck
- Department of Pulmonary Medicine, Ziekenhuis Netwerk Antwerpen Middelheim (ZNA Middelheim), Antwerp, Belgium
| | - Rogier Nieuwendijk
- Department of Intensive Care Medicine, Ziekenhuis Netwerk Antwerpen Middelheim (ZNA Middelheim), Antwerp, Belgium
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Khan K, Gogonea V, Fox PL. Aminoacyl-tRNA synthetases of the multi-tRNA synthetase complex and their role in tumorigenesis. Transl Oncol 2022; 19:101392. [PMID: 35278792 PMCID: PMC8914993 DOI: 10.1016/j.tranon.2022.101392] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 02/27/2022] [Accepted: 02/28/2022] [Indexed: 12/16/2022] Open
Abstract
In mammalian cells, 20 aminoacyl-tRNA synthetases (AARS) catalyze the ligation of amino acids to their cognate tRNAs to generate aminoacylated-tRNAs. In higher eukaryotes, 9 of the 20 AARSs, along with 3 auxiliary proteins, join to form the cytoplasmic multi-tRNA synthetase complex (MSC). The complex is absent in prokaryotes, but evolutionary expansion of MSC constituents, primarily by addition of novel interacting domains, facilitates formation of subcomplexes that join to establish the holo-MSC. In some cases, environmental cues direct the release of constituents from the MSC which enables the execution of non-canonical, i.e., "moonlighting", functions distinct from their essential activities in protein translation. These activities are generally beneficial, but can also be deleterious to the cell. Elucidation of the non-canonical activities of several AARSs residing in the MSC suggest they are potential therapeutic targets for cancer, as well as metabolic and neurologic diseases. Here, we describe the role of MSC-resident AARSs in cancer progression, and the factors that regulate their release from the MSC. Also, we highlight recent developments in therapeutic modalities that target MSC AARSs for cancer prevention and treatment.
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Affiliation(s)
- Krishnendu Khan
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, United States of America.
| | - Valentin Gogonea
- Department of Chemistry, Cleveland State University, Cleveland, OH 44115, United States of America
| | - Paul L Fox
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, United States of America.
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Liu S, Refaei M, Liu S, Decker A, Hinerman JM, Herr AB, Howell M, Musier-Forsyth K, Tsang P. Hairpin RNA-induced conformational change of a eukaryotic-specific lysyl-tRNA synthetase extension and role of adjacent anticodon-binding domain. J Biol Chem 2020; 295:12071-12085. [PMID: 32611767 PMCID: PMC7443506 DOI: 10.1074/jbc.ra120.013852] [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: 04/11/2020] [Revised: 06/26/2020] [Indexed: 11/06/2022] Open
Abstract
Human lysyl-tRNA synthetase (hLysRS) is essential for aminoacylation of tRNALys Higher eukaryotic LysRSs possess an N-terminal extension (Nterm) previously shown to facilitate high-affinity tRNA binding and aminoacylation. This eukaryote-specific appended domain also plays a critical role in hLysRS nuclear localization, thus facilitating noncanonical functions of hLysRS. The structure is intrinsically disordered and therefore remains poorly characterized. Findings of previous studies are consistent with the Nterm domain undergoing a conformational transition to an ordered structure upon nucleic acid binding. In this study, we used NMR to investigate how the type of RNA, as well as the presence of the adjacent anticodon-binding domain (ACB), influences the Nterm conformation. To explore the latter, we used sortase A ligation to produce a segmentally labeled tandem-domain protein, Nterm-ACB. In the absence of RNA, Nterm remained disordered regardless of ACB attachment. Both alone and when attached to ACB, Nterm structure remained unaffected by titration with single-stranded RNAs. The central region of the Nterm domain adopted α-helical structure upon titration of Nterm and Nterm-ACB with RNA hairpins containing double-stranded regions. Nterm binding to the RNA hairpins resulted in CD spectral shifts consistent with an induced helical structure. NMR and fluorescence anisotropy revealed that Nterm binding to hairpin RNAs is weak but that the binding affinity increases significantly upon covalent attachment to ACB. We conclude that the ACB domain facilitates induced-fit conformational changes and confers high-affinity RNA hairpin binding, which may be advantageous for functional interactions of LysRS with a variety of different binding partners.
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Affiliation(s)
- Sheng Liu
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio, USA
| | - Maryanne Refaei
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio, USA
| | - Shuohui Liu
- Department of Chemistry and Biochemistry, Center for RNA Biology, Ohio State University, Columbus, Ohio, USA
| | - Aaron Decker
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio, USA
| | - Jennifer M. Hinerman
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
- Division of Immunobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Andrew B. Herr
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
- Division of Immunobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Mike Howell
- Protein Express, Inc., Cincinnati, Ohio, USA
| | - Karin Musier-Forsyth
- Department of Chemistry and Biochemistry, Center for RNA Biology, Ohio State University, Columbus, Ohio, USA
| | - Pearl Tsang
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio, USA
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Jin Q, Liu G, Wang B, Li S, Ni K, Wang C, Ren J, Zhang S, Dai Y. High methionyl-tRNA synthetase expression predicts poor prognosis in patients with breast cancer. J Clin Pathol 2020; 73:803-812. [PMID: 32404475 PMCID: PMC7691814 DOI: 10.1136/jclinpath-2019-206175] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 04/07/2020] [Accepted: 04/10/2020] [Indexed: 01/03/2023]
Abstract
Aims Methionyl–tRNA synthetase (MARS) is known to play a critical role in initiating translation and protection against cellular damages in vivo. The aim of this study was to clarify the role of MARS in breast cancer (BC) progression. Methods The expressions of MARS messenger RNA (mRNA) and protein in human BC tissues and adjacent non-cancerous tissues were detected by quantitative real-time PCR, western blot and immunohistochemistry. The prognostic potential of MARS in patients with BC was assessed by univariate and multivariate survival analyses. The association between the MARS expression and BC progression was further evaluated by the bioinformatics database of UALCAN, Gene Expression Profiling Interactive Analysis (GEPIA) and Gene Expression Database of Normal and Tumor Tissues (GENT). The role of MARS in the proliferation, migration and epithelial-to-mesenchymal transition (EMT) of human breast cancer cell line (MCF-7 cells) was investigated after siRNA transfection. Results The expression level of MARS mRNA in the fresh BC tissues was significantly higher than that in the adjacent tissues. Immunohistochemistry showed that the expression level of MARS was closely associated with the clinicopathologial parameters of patients with BC, including the HER-2 status, Ki-67 status, molecular classification, tumour grade, N stage and tumour, node, metastasis (TNM) stage, and this finding was further confirmed by UALCAN database. The Kaplan-Meier analysis showed that high MARS expression and TNM stage were predictors of poor prognosis of patients with BC. The proliferation, migration and EMT capabilities of MCF-7 cells were significantly suppressed after MARS knockdown. An overview of UALCAN, GEPIA and GENT results suggested that MARS may be an oncogene of BC, as well as a potential therapeutic target of this malignant tumour. Conclusions High expression level of MARS in the human BC tissues was significantly associated with the unfavourable prognosis of patients with BC, suggesting that MARS may serve as a potential prognostic marker for the clinical diagnosis and prognostic prediction of BC.
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Affiliation(s)
- Qin Jin
- Department of Pathology, Affiliated Hospital of Nantong University, Nantong, China
| | - Gang Liu
- College of Life Science, Inner Mongolia University, Hohhot, Inner Mongolia, China.,Clinical Medicine Research Center of the Affiliated Hospital, Inner Mongolia Medical University, Hohhot, China
| | - Biao Wang
- College of Life Science, Inner Mongolia University, Hohhot, Inner Mongolia, China
| | - Shubin Li
- College of Life Science, Inner Mongolia University, Hohhot, Inner Mongolia, China
| | - Kan Ni
- Department of Thyroid and Breast Surgery, Affiliated Hospital of Nantong University, Nantong, China
| | - Chunyu Wang
- College of Life Science, Inner Mongolia University, Hohhot, Inner Mongolia, China
| | - Jingyu Ren
- College of Life Science, Inner Mongolia University, Hohhot, Inner Mongolia, China
| | - Shu Zhang
- Department of Pathology, Affiliated Hospital of Nantong University, Nantong, China
| | - Yanfeng Dai
- College of Life Science, Inner Mongolia University, Hohhot, Inner Mongolia, China
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Kwon SB, Yu JE, Park C, Lee J, Seong BL. Nucleic Acid-Dependent Structural Transition of the Intrinsically Disordered N-Terminal Appended Domain of Human Lysyl-tRNA Synthetase. Int J Mol Sci 2018; 19:ijms19103016. [PMID: 30282926 PMCID: PMC6213541 DOI: 10.3390/ijms19103016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 09/27/2018] [Accepted: 09/29/2018] [Indexed: 12/22/2022] Open
Abstract
Eukaryotic lysyl-tRNA synthetases (LysRS) have an N-terminal appended tRNA-interaction domain (RID) that is absent in their prokaryotic counterparts. This domain is intrinsically disordered and lacks stable structures. The disorder-to-order transition is induced by tRNA binding and has implications on folding and subsequent assembly into multi-tRNA synthetase complexes. Here, we expressed and purified RID from human LysRS (hRID) in Escherichia coli and performed a detailed mutagenesis of the appended domain. hRID was co-purified with nucleic acids during Ni-affinity purification, and cumulative mutations on critical amino acid residues abolished RNA binding. Furthermore, we identified a structural ensemble between disordered and helical structures in non-RNA-binding mutants and an equilibrium shift for wild-type into the helical conformation upon RNA binding. Since mutations that disrupted RNA binding led to an increase in non-functional soluble aggregates, a stabilized RNA-mediated structural transition of the N-terminal appended domain may have implications on the functional organization of human LysRS and multi-tRNA synthetase complexes in vivo.
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Affiliation(s)
- Soon Bin Kwon
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Korea.
| | - Ji Eun Yu
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Korea.
| | - Chan Park
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Korea.
| | - Jiseop Lee
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Korea.
| | - Baik L Seong
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Korea.
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Venkat S, Gregory C, Gan Q, Fan C. Biochemical Characterization of the Lysine Acetylation of Tyrosyl-tRNA Synthetase in Escherichia coli. Chembiochem 2017; 18:1928-1934. [PMID: 28741290 PMCID: PMC5629106 DOI: 10.1002/cbic.201700343] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Indexed: 12/21/2022]
Abstract
Aminoacyl-tRNA synthetases (aaRSs) play essential roles in protein synthesis. As a member of the aaRS family, the tyrosyl-tRNA synthetase (TyrRS) in Escherichia coli has been shown in proteomic studies to be acetylated at multiple lysine residues. However, these putative acetylation targets have not yet been biochemically characterized. In this study, we applied a genetic-code-expansion strategy to site-specifically incorporate Nϵ -acetyl-l-lysine into selected positions of TyrRS for in vitro characterization. Enzyme assays demonstrated that acetylation at K85, K235, and K238 could impair the enzyme activity. In vitro deacetylation experiments showed that most acetylated lysine residues in TyrRS were sensitive to the E. coli deacetylase CobB but not YcgC. In vitro acetylation assays indicated that 25 members of the Gcn5-related N-acetyltransferase family in E. coli, including YfiQ, could not acetylate TyrRS efficiently, whereas TyrRS could be acetylated chemically by acetyl-CoA or acetyl-phosphate (AcP) only. Our in vitro characterization experiments indicated that lysine acetylation could be a possible mechanism for modulating aaRS enzyme activities, thus affecting translation.
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Affiliation(s)
- Sumana Venkat
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR, 72701, USA
| | - Caroline Gregory
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR, 727011, USA
| | - Qinglei Gan
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR, 72701, USA
| | - Chenguang Fan
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR, 72701, USA
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Abstract
Aminoacyl-tRNA synthetases (AARSs) are essential enzymes that specifically aminoacylate one tRNA molecule by the cognate amino acid. They are a family of twenty enzymes, one for each amino acid. By coupling an amino acid to a specific RNA triplet, the anticodon, they are responsible for interpretation of the genetic code. In addition to this translational, canonical role, several aminoacyl-tRNA synthetases also fulfill nontranslational, moonlighting functions. In mammals, nine synthetases, those specific for amino acids Arg, Asp, Gln, Glu, Ile, Leu, Lys, Met and Pro, associate into a multi-aminoacyl-tRNA synthetase complex, an association which is believed to play a key role in the cellular organization of translation, but also in the regulation of the translational and nontranslational functions of these enzymes. Because the balance between their alternative functions rests on the assembly and disassembly of this supramolecular entity, it is essential to get precise insight into the structural organization of this complex. The high-resolution 3D-structure of the native particle, with a molecular weight of about 1.5 MDa, is not yet known. Low-resolution structures of the multi-aminoacyl-tRNA synthetase complex, as determined by cryo-EM or SAXS, have been reported. High-resolution data have been reported for individual enzymes of the complex, or for small subcomplexes. This review aims to present a critical view of our present knowledge of the aminoacyl-tRNA synthetase complex in 3D. These preliminary data shed some light on the mechanisms responsible for the balance between the translational and nontranslational functions of some of its components.
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Affiliation(s)
- Marc Mirande
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 1 avenue de la Terrasse, 91190, Gif-sur-Yvette, Paris, France.
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Cai SY, Yang T, Chen Y, Wang JW, Li L, Xu MJ. Gene expression profiling of ovarian carcinomas and prognostic analysis of outcome. J Ovarian Res 2015; 8:50. [PMID: 26228058 PMCID: PMC4521463 DOI: 10.1186/s13048-015-0176-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 07/07/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Ovarian cancer (OCA), the fifth leading deaths cancer to women, is famous for its low survival rate in epithelial ovarian cancer cases, which is very complicated and hard to be diagnosed from asymptomatic nature in the early stage. Thus, it is urgent to develop an effective genetic prognostic strategy. METHODS Current study using the Database for Annotation, Visualization and Integrated Discovery tool for the generation and analysis of quantitative gene expression profiles; all the annotated gene and biochemical pathway membership realized according to shared categorical data from Pathway and Kyoto Encyclopedia of Genes and Genomes; correlation networks based on current gene screening actualize by Weighted correlation network analysis to identify therapeutic targets gene and candidate bio-markers. RESULTS 3095 differentially expressed genes were collected from genome expression profiles of OCA patients (n = 53, 35 advanced, 8 early and 10 normal). By pathway enrichment, most genes showed contribution to cell cycle and chromosome maintenance.1073 differentially expression genes involved in the 4 dominant network modules are further generated for prognostic pattern establish, we divided a dataset with random OCA cases (n = 80) into 3 groups efficiently (p = 0.0323, 95% CIs in Kaplan-Meier). Finally, 6 prognosis related genes were selected out by COX regression analysis, TFCP2L1 related to cancer-stem cell, probably contributes to chemotherapy efficiency. CONCLUSIONS Our study presents an integrated original model of the differentially expression genes related to ovarian cancer progressing, providing the identification of genes relevant for its pathological physiology which can potentially be new clinical markers.
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Affiliation(s)
- Sheng-Yun Cai
- Department of Obstetrics & Gynecology, Changhai Hospital, Second Military Medical University, No.168, Changhai Road, Shanghai, 200433, China.
| | - Tian Yang
- Department of Hepatic Surgery, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, No.225, Changhai Road, Shanghai, 200438, China.
| | - Yu Chen
- Department of Obstetrics & Gynecology, Changhai Hospital, Second Military Medical University, No.168, Changhai Road, Shanghai, 200433, China.
| | - Jing-Wen Wang
- Department of Obstetrics & Gynecology, Changhai Hospital, Second Military Medical University, No.168, Changhai Road, Shanghai, 200433, China.
| | - Li Li
- Department of Obstetrics & Gynecology, Changhai Hospital, Second Military Medical University, No.168, Changhai Road, Shanghai, 200433, China.
| | - Ming-Juan Xu
- Department of Obstetrics & Gynecology, Changhai Hospital, Second Military Medical University, No.168, Changhai Road, Shanghai, 200433, China.
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Shin C, Hwang GS, Ahn HC, Kim S, Kim KS. (1)H, (13)C and (15)N resonance assignment of WHEP domains of human glutamyl-prolyl tRNA synthetase. BIOMOLECULAR NMR ASSIGNMENTS 2015; 9:25-30. [PMID: 24378977 DOI: 10.1007/s12104-013-9538-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 12/17/2013] [Indexed: 06/03/2023]
Abstract
Human bifunctional glutamyl-prolyl tRNA synthetase (EPRS) contains three WHEP domains (R123) linking two catalytic domains. These three WHEP domains have been shown to be involved in protein-protein and protein-nucleic acid interactions. In translational control of gene expression, R12 repeats is known to interact with 3'UTR element in mRNAs of inflammatory gene for translational control mechanisms. While, R23 repeats interacts with NSAP1, which inhibits mRNA binding. Here we present the NMR chemical shift assignments for R12 (128 amino acids) as a 14 kDa recombinant protein and whole WHEP domains R123 (208 amino acids) as a 21 kDa recombinant protein. 97% of backbone and 98% of side-chain assignments have been completed in R12 analysis and 93 and 92% of backbone and side-chain, respectively, assignments have been completed in R123 analysis based upon triple-resonance experiments.
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Affiliation(s)
- ChinHo Shin
- University of Science and Technology, Gajeong-ro 217, Yuseong-gu, Taejon, 305-333, Republic of Korea
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12
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Wang SH, Cheng CY, Chen CJ, Chen HH, Tang PC, Chen CF, Lee YP, Huang SY. Changes in protein expression in testes of L2 strain Taiwan country chickens in response to acute heat stress. Theriogenology 2014; 82:80-94. [DOI: 10.1016/j.theriogenology.2014.03.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 03/04/2014] [Accepted: 03/08/2014] [Indexed: 01/16/2023]
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Abstract
When compared to other conserved housekeeping protein families, such as ribosomal proteins, during the evolution of higher eukaryotes, aminoacyl-tRNA synthetases (aaRSs) show an apparent high propensity to add new sequences, and especially new domains. The stepwise emergence of those new domains is consistent with their involvement in a broad range of biological functions beyond protein synthesis, and correlates with the increasing biological complexity of higher organisms. These new domains have been extensively characterized based on their evolutionary origins and their sequence, structural, and functional features. While some of the domains are uniquely found in aaRSs and may have originated from nucleic acid binding motifs, others are common domain modules mediating protein-protein interactions that play a critical role in the assembly of the multi-synthetase complex (MSC). Interestingly, the MSC has emerged from a miniature complex in yeast to a large stable complex in humans. The human MSC consists of nine aaRSs (LysRS, ArgRS, GlnRS, AspRS, MetRS, IleRS, LeuRS, GluProRS, and bifunctional aaRs) and three scaffold proteins (AIMP1/p43, AIMP2/p38, and AIMP3/p18), and has a molecular weight of 1.5 million Dalton. The MSC has been proposed to have a functional dualism: facilitating protein synthesis and serving as a reservoir of non-canonical functions associated with its synthetase and non-synthetase components. Importantly, domain additions and functional expansions are not limited to the components of the MSC and are found in almost all aaRS proteins. From a structural perspective, multi-functionalities are represented by multiple conformational states. In fact, alternative conformations of aaRSs have been generated by various mechanisms from proteolysis to alternative splicing and posttranslational modifications, as well as by disease-causing mutations. Therefore, the metamorphosis between different conformational states is connected to the activation and regulation of the novel functions of aaRSs in higher eukaryotes.
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Affiliation(s)
- Min Guo
- Department of Cancer Biology, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33410, USA,
| | - Xiang-Lei Yang
- Department of Cancer Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA,
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Sun L, Yang Q, Wang P, Liu D, Liang W, Lin S, Yuan S. The influence of YS-1 on the Dll4-Notch1 signaling pathway. Acta Biochim Biophys Sin (Shanghai) 2013; 46:56-64. [PMID: 24274976 DOI: 10.1093/abbs/gmt125] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In this study, we investigated the role and molecular mechanism of p43 and YS-1 (recombinant human p43 protein) in Dll4-Notch1 signaling pathway. Active, small interfering RNA and recombinant plasmid targeting of p43 protein were used to infect human umbilical vein endothelial cells (HUVECs). Three-dimensional sprouting model, endothelial cell migration assay, and sprouting and tube formation assay were used to deduce the function of p43 and YS-1 in angiogenesis. Semi-quantitative reverse transcription-polymerase chain reaction and western blot analysis were performed to detect the efficiency of p43 in Dll4-Notch1 signaling in HUVECs. It was found that silencing and overexpression of p43 could upregulate Dll4-Notch and stimulate angiogenesis. p43 plays a complex role in angiogenesis. When the concentration is under 100 nM, it promotes angiogenesis; instead, when the concentration is over 100 nM, it inhibits angiogenesis. In this study, we found that the expression level of p43 was under 60 nM. However, recombinant human p43 protein, YS-1, inhibited endothelial cell sprouting, and 500 μg/ml of YS-1 attenuated the activation of Dll4-Notch1 signaling. These results suggested that YS-1 could directly inhibit angiogenesis through Dll4-Notch1 signal transduction pathway, while p43 plays a modulating role in this signaling pathway.
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Affiliation(s)
- Li Sun
- National Nanjing New Drug Screening Center, China Pharmaceutical University, Nanjing 210009, China
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15
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Dias J, Renault L, Pérez J, Mirande M. Small-angle X-ray solution scattering study of the multi-aminoacyl-tRNA synthetase complex reveals an elongated and multi-armed particle. J Biol Chem 2013; 288:23979-89. [PMID: 23836901 PMCID: PMC3745343 DOI: 10.1074/jbc.m113.489922] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Revised: 07/01/2013] [Indexed: 02/01/2023] Open
Abstract
In animal cells, nine aminoacyl-tRNA synthetases are associated with the three auxiliary proteins p18, p38, and p43 to form a stable and conserved large multi-aminoacyl-tRNA synthetase complex (MARS), whose molecular mass has been proposed to be between 1.0 and 1.5 MDa. The complex acts as a molecular hub for coordinating protein synthesis and diverse regulatory signal pathways. Electron microscopy studies defined its low resolution molecular envelope as an overall rather compact, asymmetric triangular shape. Here, we have analyzed the composition and homogeneity of the native mammalian MARS isolated from rabbit liver and characterized its overall internal structure, size, and shape at low resolution by hydrodynamic methods and small-angle x-ray scattering in solution. Our data reveal that the MARS exhibits a much more elongated and multi-armed shape than expected from previous reports. The hydrodynamic and structural features of the MARS are large compared with other supramolecular assemblies involved in translation, including ribosome. The large dimensions and non-compact structural organization of MARS favor a large protein surface accessibility for all its components. This may be essential to allow structural rearrangements between the catalytic and cis-acting tRNA binding domains of the synthetases required for binding the bulky tRNA substrates. This non-compact architecture may also contribute to the spatiotemporal controlled release of some of its components, which participate in non-canonical functions after dissociation from the complex.
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Affiliation(s)
- José Dias
- From the Laboratoire d'Enzymologie et Biochimie Structurales, Centre de Recherche de Gif, CNRS, 1 Avenue de la Terrasse, 91190 Gif-sur-Yvette, France and
| | - Louis Renault
- From the Laboratoire d'Enzymologie et Biochimie Structurales, Centre de Recherche de Gif, CNRS, 1 Avenue de la Terrasse, 91190 Gif-sur-Yvette, France and
| | - Javier Pérez
- SOLEIL Synchrotron, L'Orme des Merisiers Saint-Aubin, Gif-sur-Yvette, France
| | - Marc Mirande
- From the Laboratoire d'Enzymologie et Biochimie Structurales, Centre de Recherche de Gif, CNRS, 1 Avenue de la Terrasse, 91190 Gif-sur-Yvette, France and
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16
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Savytskyi OV, Yesylevskyy SO, Kornelyuk AI. Asymmetric structure and domain binding interfaces of human tyrosyl-tRNA synthetase studied by molecular dynamics simulations. J Mol Recognit 2013; 26:113-20. [DOI: 10.1002/jmr.2259] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Revised: 11/20/2012] [Accepted: 12/10/2012] [Indexed: 11/09/2022]
Affiliation(s)
- Oleksandr V. Savytskyi
- Institute of Molecular Biology and Genetics; National Academy of Sciences of Ukraine; Akademika Zabolotnogo Str., 150; Kyiv-03680; Ukraine
| | - Semen O. Yesylevskyy
- Institute of Physics; National Academy of Sciences of Ukraine; Prospect Nauki, 46; Kyiv-03039; Ukraine
| | - Alexander I. Kornelyuk
- Institute of Molecular Biology and Genetics; National Academy of Sciences of Ukraine; Akademika Zabolotnogo Str., 150; Kyiv-03680; Ukraine
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Liao CC, Lin CH, Chen SJ, Wang CC. Trans-kingdom rescue of Gln-tRNAGln synthesis in yeast cytoplasm and mitochondria. Nucleic Acids Res 2012; 40:9171-81. [PMID: 22821561 PMCID: PMC3467082 DOI: 10.1093/nar/gks689] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Aminoacylation of transfer RNAGln (tRNAGln) is performed by distinct mechanisms in different kingdoms and represents the most diverged route of aminoacyl-tRNA synthesis found in nature. In Saccharomyces cerevisiae, cytosolic Gln-tRNAGln is generated by direct glutaminylation of tRNAGln by glutaminyl-tRNA synthetase (GlnRS), whereas mitochondrial Gln-tRNAGln is formed by an indirect pathway involving charging by a non-discriminating glutamyl-tRNA synthetase and the subsequent transamidation by a specific Glu-tRNAGln amidotransferase. Previous studies showed that fusion of a yeast non-specific tRNA-binding cofactor, Arc1p, to Escherichia coli GlnRS enables the bacterial enzyme to substitute for its yeast homologue in vivo. We report herein that the same fusion enzyme, upon being imported into mitochondria, substituted the indirect pathway for Gln-tRNAGln synthesis as well, despite significant differences in the identity determinants of E. coli and yeast cytosolic and mitochondrial tRNAGln isoacceptors. Fusion of Arc1p to the bacterial enzyme significantly enhanced its aminoacylation activity towards yeast tRNAGln isoacceptors in vitro. Our study provides a mechanism by which trans-kingdom rescue of distinct pathways of Gln-tRNAGln synthesis can be conferred by a single enzyme.
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Affiliation(s)
- Chih-Chi Liao
- Department of Life Sciences, National Central University, Jung-li 32001, Taiwan, Republic of China
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18
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Bushnell EAC, Huang W, Llano J, Gauld JW. Molecular Dynamics Investigation into Substrate Binding and Identity of the Catalytic Base in the Mechanism of Threonyl-tRNA Synthetase. J Phys Chem B 2012; 116:5205-12. [DOI: 10.1021/jp302556e] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Eric A. C. Bushnell
- Department of Chemistry and
Biochemistry, University of Windsor, Windsor,
Ontario N9B 3P4, Canada
| | - WenJuan Huang
- Department of Chemistry and
Biochemistry, University of Windsor, Windsor,
Ontario N9B 3P4, Canada
| | - Jorge Llano
- Department of Physical Sciences, Grant MacEwan University, Edmonton, Alberta T5J 4S2,
Canada
| | - James W. Gauld
- Department of Chemistry and
Biochemistry, University of Windsor, Windsor,
Ontario N9B 3P4, Canada
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Chen SJ, Wu YH, Huang HY, Wang CC. Saccharomyces cerevisiae possesses a stress-inducible glycyl-tRNA synthetase gene. PLoS One 2012; 7:e33363. [PMID: 22438917 PMCID: PMC3306390 DOI: 10.1371/journal.pone.0033363] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Accepted: 02/13/2012] [Indexed: 12/04/2022] Open
Abstract
Aminoacyl-tRNA synthetases are a large family of housekeeping enzymes that are pivotal in protein translation and other vital cellular processes. Saccharomyces cerevisiae possesses two distinct nuclear glycyl-tRNA synthetase (GlyRS) genes, GRS1 and GRS2. GRS1 encodes both cytoplasmic and mitochondrial activities, while GRS2 is essentially silent and dispensable under normal conditions. We herein present evidence that expression of GRS2 was drastically induced upon heat shock, ethanol or hydrogen peroxide addition, and high pH, while expression of GRS1 was somewhat repressed under those conditions. In addition, GlyRS2 (the enzyme encoded by GRS2) had a higher protein stability and a lower KM value for yeast tRNAGly under heat shock conditions than under normal conditions. Moreover, GRS2 rescued the growth defect of a GRS1 knockout strain when highly expressed by a strong promoter at 37°C, but not at the optimal temperature of 30°C. These results suggest that GRS2 is actually an inducible gene that may function to rescue the activity of GRS1 under stress conditions.
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Affiliation(s)
| | | | | | - Chien-Chia Wang
- Department of Life Sciences, National Central University, Jung-li, Taiwan
- * E-mail:
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20
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Chen SJ, Lee CY, Lin ST, Wang CC. Rescuing a dysfunctional homologue of a yeast glycyl-tRNA synthetase gene. ACS Chem Biol 2011; 6:1182-7. [PMID: 21877692 DOI: 10.1021/cb200240a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The yeast Saccharomyces cerevisiae contains two distinct nuclear glycyl-tRNA synthetase (GlyRS) genes, GRS1 and GRS2. GRS1 is dual functional in that possesses both cytoplasmic and mitochondrial activities, whereas GRS2 is pseudogene-like. GlyRS1 and GlyRS2 are highly similar on the whole but are distinguished by a lysine-rich insertion domain of 44 amino acid residues, present only in GlyRS1. We herein present evidence that whereas the insertion domain is dispensable for the complementary activity of GRS1in vivo, deletion of this domain from GlyRS1 reduced its aminoacylation activity by up to 9-fold. On the other hand, fusion of a constitutive ADH promoter to GRS2 failed to confer a functional phenotype to the gene, but further fusion of ARC1 (a yeast gene encoding a tRNA-binding protein, Arc1p) to this hybrid gene successfully rescued its activity. Most intriguingly, purified GlyRS2 retained a substantial level of aminoacylation activity. Fusion of Arc1p to this enzyme further enhanced its activity and stability. These findings highlight not only the structural integrity of the pseudogene-encoded enzyme but also the necessity of obtaining an auxiliary tRNA-binding domain for functioning of a yeast tRNA synthetase.
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Affiliation(s)
- Shun-Jia Chen
- Department of Life Sciences, National Central University, 300 Jung-da Rd., Jung-li 32001, Taiwan
| | - Chih-Ying Lee
- Department of Life Sciences, National Central University, 300 Jung-da Rd., Jung-li 32001, Taiwan
| | - Szu-Ting Lin
- Department of Life Sciences, National Central University, 300 Jung-da Rd., Jung-li 32001, Taiwan
| | - Chien-Chia Wang
- Department of Life Sciences, National Central University, 300 Jung-da Rd., Jung-li 32001, Taiwan
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21
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Structural context for mobilization of a human tRNA synthetase from its cytoplasmic complex. Proc Natl Acad Sci U S A 2011; 108:8239-44. [PMID: 21536907 DOI: 10.1073/pnas.1100224108] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Human lysyl-tRNA synthetase is bound to the multi-tRNA synthetase complex (MSC) that maintains and regulates the aminoacylation and nuclear functions of LysRS. The p38 scaffold protein binds LysRS to the MSC and, only with the appropriate cue, mobilizes LysRS for redirection to the nucleus to interact with the microphthalmia associated transcription factor (MITF). In recent work, an (α(2))(2) LysRS tetramer crystallized to yield a high-resolution structure and raised the question of how LysRS is arranged (dimer or tetramer) in the MSC to interact with p38. To understand the structural organization of the LysRS-p38 complex that regulates LysRS mobilization, we investigated the complex by use of small angle X-ray scattering and hydrogen-deuterium exchange with mass spectrometry in solution. The structure revealed a surprising α(2)β(1):β(1)α(2) organization in which a dimeric p38 scaffold holds two LysRS α(2) dimers in a parallel configuration. Each of the N-terminal 48 residues of p38 binds one LysRS dimer and, in so doing, brings two copies of the LysRS dimer into the MSC. The results suggest that this unique geometry, which reconfigures the LysRS tetramer from α(2):α(2) to α(2)β(1):β(1)α(2), is designed to control both retention and mobilization of LysRS from the MSC.
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22
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Larson ET, Kim JE, Zucker FH, Kelley A, Mueller N, Napuli AJ, Verlinde CL, Fan E, Buckner FS, Van Voorhis WC, Merritt EA, Hol WG. Structure of Leishmania major methionyl-tRNA synthetase in complex with intermediate products methionyladenylate and pyrophosphate. Biochimie 2011; 93:570-82. [PMID: 21144880 PMCID: PMC3039092 DOI: 10.1016/j.biochi.2010.11.015] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Accepted: 11/29/2010] [Indexed: 01/07/2023]
Abstract
Leishmania parasites cause two million new cases of leishmaniasis each year with several hundreds of millions of people at risk. Due to the paucity and shortcomings of available drugs, we have undertaken the crystal structure determination of a key enzyme from Leishmania major in hopes of creating a platform for the rational design of new therapeutics. Crystals of the catalytic core of methionyl-tRNA synthetase from L. major (LmMetRS) were obtained with the substrates MgATP and methionine present in the crystallization medium. These crystals yielded the 2.0 Å resolution structure of LmMetRS in complex with two products, methionyladenylate and pyrophosphate, along with a Mg(2+) ion that bridges them. This is the first class I aminoacyl-tRNA synthetase (aaRS) structure with pyrophosphate bound. The residues of the class I aaRS signature sequence motifs, KISKS and HIGH, make numerous contacts with the pyrophosphate. Substantial differences between the LmMetRS structure and previously reported complexes of Escherichia coli MetRS (EcMetRS) with analogs of the methionyladenylate intermediate product are observed, even though one of these analogs only differs by one atom from the intermediate. The source of these structural differences is attributed to the presence of the product pyrophosphate in LmMetRS. Analysis of the LmMetRS structure in light of the Aquifex aeolicus MetRS-tRNA(Met) complex shows that major rearrangements of multiple structural elements of enzyme and/or tRNA are required to allow the CCA acceptor triplet to reach the methionyladenylate intermediate in the active site. Comparison with sequences of human cytosolic and mitochondrial MetRS reveals interesting differences near the ATP- and methionine-binding regions of LmMetRS, suggesting that it should be possible to obtain compounds that selectively inhibit the parasite enzyme.
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Affiliation(s)
- Eric T. Larson
- Department of Biochemistry, University of Washington, Seattle, WA 98195-7742, USA,Medical Structural Genomics of Pathogenic Protozoa (MSGPP), www.msgpp.org
| | - Jessica E. Kim
- Department of Biochemistry, University of Washington, Seattle, WA 98195-7742, USA,Medical Structural Genomics of Pathogenic Protozoa (MSGPP), www.msgpp.org
| | - Frank H. Zucker
- Department of Biochemistry, University of Washington, Seattle, WA 98195-7742, USA,Medical Structural Genomics of Pathogenic Protozoa (MSGPP), www.msgpp.org
| | - Angela Kelley
- Medical Structural Genomics of Pathogenic Protozoa (MSGPP), www.msgpp.org,Department of Medicine, University of Washington, Seattle, WA 98195-7185, USA
| | - Natascha Mueller
- Medical Structural Genomics of Pathogenic Protozoa (MSGPP), www.msgpp.org,Department of Medicine, University of Washington, Seattle, WA 98195-7185, USA
| | - Alberto J. Napuli
- Medical Structural Genomics of Pathogenic Protozoa (MSGPP), www.msgpp.org,Department of Medicine, University of Washington, Seattle, WA 98195-7185, USA
| | - Christophe L.M.J. Verlinde
- Department of Biochemistry, University of Washington, Seattle, WA 98195-7742, USA,Medical Structural Genomics of Pathogenic Protozoa (MSGPP), www.msgpp.org
| | - Erkang Fan
- Department of Biochemistry, University of Washington, Seattle, WA 98195-7742, USA,Medical Structural Genomics of Pathogenic Protozoa (MSGPP), www.msgpp.org
| | - Frederick S. Buckner
- Medical Structural Genomics of Pathogenic Protozoa (MSGPP), www.msgpp.org,Department of Medicine, University of Washington, Seattle, WA 98195-7185, USA
| | - Wesley C. Van Voorhis
- Medical Structural Genomics of Pathogenic Protozoa (MSGPP), www.msgpp.org,Department of Medicine, University of Washington, Seattle, WA 98195-7185, USA
| | - Ethan A. Merritt
- Department of Biochemistry, University of Washington, Seattle, WA 98195-7742, USA,Medical Structural Genomics of Pathogenic Protozoa (MSGPP), www.msgpp.org
| | - Wim G.J. Hol
- Department of Biochemistry, University of Washington, Seattle, WA 98195-7742, USA,Medical Structural Genomics of Pathogenic Protozoa (MSGPP), www.msgpp.org,Corresponding author.
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23
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Yesylevskyy S, Savytskyi O, Odynets K, Kornelyuk A. Interdomain compactization in human tyrosyl-tRNA synthetase studied by the hierarchical rotations technique. Biophys Chem 2011; 154:90-8. [DOI: 10.1016/j.bpc.2011.01.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2010] [Revised: 12/21/2010] [Accepted: 01/17/2011] [Indexed: 10/18/2022]
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24
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Lin CH, Lin G, Chang CP, Wang CC. A tryptophan-rich peptide acts as a transcription activation domain. BMC Mol Biol 2010; 11:85. [PMID: 21078206 PMCID: PMC2992532 DOI: 10.1186/1471-2199-11-85] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2010] [Accepted: 11/16/2010] [Indexed: 11/23/2022] Open
Abstract
Background Eukaryotic transcription activators normally consist of a sequence-specific DNA-binding domain (DBD) and a transcription activation domain (AD). While many sequence patterns and motifs have been defined for DBDs, ADs do not share easily recognizable motifs or structures. Results We report herein that the N-terminal domain of yeast valyl-tRNA synthetase can function as an AD when fused to a DNA-binding protein, LexA, and turn on reporter genes with distinct LexA-responsive promoters. The transcriptional activity was mainly attributed to a five-residue peptide, WYDWW, near the C-terminus of the N domain. Remarkably, the pentapeptide per se retained much of the transcriptional activity. Mutations which substituted tryptophan residues for both of the non-tryptophan residues in the pentapeptide (resulting in W5) significantly enhanced its activity (~1.8-fold), while mutations which substituted aromatic residues with alanine residues severely impaired its activity. Accordingly, a much more active peptide, pentatryptophan (W7), was produced, which elicited ~3-fold higher activity than that of the native pentapeptide and the N domain. Further study indicated that W7 mediates transcription activation through interacting with the general transcription factor, TFIIB. Conclusions Since W7 shares no sequence homology or features with any known transcription activators, it may represent a novel class of AD.
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Affiliation(s)
- Chen-Huan Lin
- Department of Life Science, National Central University, Jung-li 32001, Taiwan
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25
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Panwar B, Raghava GPS. Prediction and classification of aminoacyl tRNA synthetases using PROSITE domains. BMC Genomics 2010; 11:507. [PMID: 20860794 PMCID: PMC2997003 DOI: 10.1186/1471-2164-11-507] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2010] [Accepted: 09/22/2010] [Indexed: 12/02/2022] Open
Abstract
Background Aminoacyl tRNA synthetases (aaRSs) catalyse the first step of protein synthesis in all organisms. They are responsible for the precise attachment of amino acids to their cognate transfer RNAs. There are twenty different types of aaRSs, unique for each amino acid. These aaRSs have been divided into two classes, each comprising ten enzymes. It is important to predict and classify aaRSs in order to understand protein synthesis. Results In this study, all models were developed on a non-redundant dataset containing 117 aaRSs and an equal number of non-aaRSs, in which no two sequences have more than 30% similarity. First, we applied the similarity search technique, BLAST, and achieved a maximum accuracy of 67.52%. We observed that 62% of tRNA synthetases contain one or more domains from amongst the following four PROSITE domains: PS50862, PS00178, PS50860 and PS50861. An SVM-based model was developed to discriminate between aaRSs, and non-aaRSs, and achieved a maximum MCC of 0.68 with accuracy of 83.73%, using selective dipeptide composition. We developed a hybrid approach and achieved a maximum MCC of 0.72 with accuracy of 85.49%, where SVM model developed using selected dipeptide composition and information of four PROSITE domains. We further developed an SVM-based model for classifying the aaRSs into class-1 and class-2, using selective dipeptide composition and achieved an MCC of 0.79. We also observed that two domains (PS00178, PS50889) in class-1 and three domains (PS50862, PS50860, PS50861) in class-2 were preferred. A hybrid method was developed using these domains as descriptor, along with selected dipeptide composition, and achieved an MCC of 0.87 with a sensitivity of 94.55% and an accuracy of 93.19%. All models were evaluated using a five-fold cross-validation technique. Conclusions We have analyzed protein sequences of aaRSs (class-1 and class-2) and non-aaRSs and identified interesting patterns. The high accuracy achieved by our SVM models using selected dipeptide composition demonstrates that certain types of dipeptide are preferred in aaRSs. We were able to identify PROSITE domains that are preferred in aaRSs and their classes, providing interesting insights into tRNA synthetases. The method developed in this study will be useful for researchers studying aaRS enzymes and tRNA biology. The web-server based on the above study, is available at http://www.imtech.res.in/raghava/icaars/.
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Affiliation(s)
- Bharat Panwar
- Bioinformatics Centre, Institute of Microbial Technology, Chandigarh, India
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26
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Structure of human cytosolic phenylalanyl-tRNA synthetase: evidence for kingdom-specific design of the active sites and tRNA binding patterns. Structure 2010; 18:343-53. [PMID: 20223217 DOI: 10.1016/j.str.2010.01.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Revised: 01/10/2010] [Accepted: 01/19/2010] [Indexed: 11/23/2022]
Abstract
The existence of three types of phenylalanyl-tRNA synthetase (PheRS), bacterial (alphabeta)(2), eukaryotic/archaeal cytosolic (alphabeta)(2), and mitochondrial alpha, is a prominent example of structural diversity within the aaRS family. PheRSs have considerably diverged in primary sequences, domain compositions, and subunit organizations. Loss of the anticodon-binding domain B8 in human cytosolic PheRS (hcPheRS) is indicative of variations in the tRNA(Phe) binding and recognition as compared to bacterial PheRSs. We report herein the crystal structure of hcPheRS in complex with phenylalanine at 3.3 A resolution. A novel structural module has been revealed at the N terminus of the alpha subunit. It stretches out into the solvent of approximately 80 A and is made up of three structural domains (DBDs) possessing DNA-binding fold. The dramatic reduction of aminoacylation activity for truncated N terminus variants coupled with structural data and tRNA-docking model testify that DBDs play crucial role in hcPheRS activity.
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Chiu WC, Chang CP, Wen WL, Wang SW, Wang CC. Schizosaccharomyces pombe possesses two paralogous valyl-tRNA synthetase genes of mitochondrial origin. Mol Biol Evol 2010; 27:1415-24. [PMID: 20106903 DOI: 10.1093/molbev/msq025] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Previous studies showed that VAS1 of Saccharomyces cerevisiae encodes both cytosolic and mitochondrial forms of valyl-tRNA synthetase (ValRS) through alternative initiation of translation. We show herein that except for Schizosaccharomyces pombe, all yeast species studied contained a single ValRS gene encoding both forms, and all of the mature protein forms deduced from those genes possessed an N-terminal appended domain (Ad) that was absent from their bacterial relatives. In contrast, S. pombe contained two distinct nuclear ValRS genes, one encoding the mitochondrial form and the other its cytosolic counterpart. Although the cytosolic form closely resembles other yeast ValRS sequences (approximately 60% identity), the mitochondrial form exhibits significant divergence from others (approximately 35% identity). Both genes are active and essential for the survival of the yeast. Most conspicuously, the mitochondrial form lacks the characteristic Ad. A phylogenetic analysis further suggested that both forms of S. pombe ValRS are of mitochondrial origin, and the mitochondrial form is ancestral to the cytoplasmic form.
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Affiliation(s)
- Wen-Chih Chiu
- Department of Life Science, National Central University, Jung-li, Taiwan
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28
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Ul-Haq Z, Khan W, Zarina S, Sattar R, Moin ST. Template-based structure prediction and molecular dynamics simulation study of two mammalian Aspartyl-tRNA synthetases. J Mol Graph Model 2010; 28:401-12. [DOI: 10.1016/j.jmgm.2009.09.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2009] [Revised: 09/14/2009] [Accepted: 09/23/2009] [Indexed: 10/20/2022]
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Guo M, Schimmel P, Yang XL. Functional expansion of human tRNA synthetases achieved by structural inventions. FEBS Lett 2009; 584:434-42. [PMID: 19932696 DOI: 10.1016/j.febslet.2009.11.064] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Revised: 11/17/2009] [Accepted: 11/17/2009] [Indexed: 02/06/2023]
Abstract
Known as an essential component of the translational apparatus, the aminoacyl-tRNA synthetase family catalyzes the first step reaction in protein synthesis, that is, to specifically attach each amino acid to its cognate tRNA. While preserving this essential role, tRNA synthetases developed other roles during evolution. Human tRNA synthetases, in particular, have diverse functions in different pathways involving angiogenesis, inflammation and apoptosis. The functional diversity is further illustrated in the association with various diseases through genetic mutations that do not affect aminoacylation or protein synthesis. Here we review the accumulated knowledge on how human tRNA synthetases used structural inventions to achieve functional expansions.
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Affiliation(s)
- Min Guo
- The Skaggs Institute for Chemical Biology, Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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Processivity of translation in the eukaryote cell: role of aminoacyl-tRNA synthetases. FEBS Lett 2009; 584:443-7. [PMID: 19914240 DOI: 10.1016/j.febslet.2009.11.027] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2009] [Accepted: 11/10/2009] [Indexed: 11/21/2022]
Abstract
Several lines of evidence led to the conclusion that mammalian ribosomal protein synthesis is a highly organized biological process in vivo. A wealth of data support the concept according to which tRNA aminoacylation, formation of the ternary complex on EF1A and delivery of aminoacyl-tRNA to the ribosome is a processive mechanism where tRNA is vectorially transferred from one component to another. Polypeptide extensions, referred to as tRBDs (tRNA binding domains), are appended to mammalian and yeast aminoacyl-tRNA synthetases. The involvement of these domains in the capture of deacylated tRNA and in the sequestration of aminoacylated tRNA, suggests that cycling of tRNA in translation is mediated by the processivity of the consecutive steps. The possible origin of the tRBDs is discussed.
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Bhatt TK, Kapil C, Khan S, Jairajpuri MA, Sharma V, Santoni D, Silvestrini F, Pizzi E, Sharma A. A genomic glimpse of aminoacyl-tRNA synthetases in malaria parasite Plasmodium falciparum. BMC Genomics 2009; 10:644. [PMID: 20042123 PMCID: PMC2813244 DOI: 10.1186/1471-2164-10-644] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2009] [Accepted: 12/31/2009] [Indexed: 12/14/2022] Open
Abstract
Background Plasmodium parasites are causative agents of malaria which affects >500 million people and claims ~2 million lives annually. The completion of Plasmodium genome sequencing and availability of PlasmoDB database has provided a platform for systematic study of parasite genome. Aminoacyl-tRNA synthetases (aaRSs) are pivotal enzymes for protein translation and other vital cellular processes. We report an extensive analysis of the Plasmodium falciparum genome to identify and classify aaRSs in this organism. Results Using various computational and bioinformatics tools, we have identified 37 aaRSs in P. falciparum. Our key observations are: (i) fraction of proteome dedicated to aaRSs in P. falciparum is very high compared to many other organisms; (ii) 23 out of 37 Pf-aaRS sequences contain signal peptides possibly directing them to different cellular organelles; (iii) expression profiles of Pf-aaRSs vary considerably at various life cycle stages of the parasite; (iv) several PfaaRSs posses very unusual domain architectures; (v) phylogenetic analyses reveal evolutionary relatedness of several parasite aaRSs to bacterial and plants aaRSs; (vi) three dimensional structural modelling has provided insights which could be exploited in inhibitor discovery against parasite aaRSs. Conclusion We have identified 37 Pf-aaRSs based on our bioinformatics analysis. Our data reveal several unique attributes in this protein family. We have annotated all 37 Pf-aaRSs based on predicted localization, phylogenetics, domain architectures and their overall protein expression profiles. The sets of distinct features elaborated in this work will provide a platform for experimental dissection of this family of enzymes, possibly for the discovery of novel drugs against malaria.
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Affiliation(s)
- Tarun Kumar Bhatt
- Structural and Computational Biology Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, India.
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Chiu WC, Chang CP, Wang CC. Evolutionary basis of converting a bacterial tRNA synthetase into a yeast cytoplasmic or mitochondrial enzyme. J Biol Chem 2009; 284:23954-60. [PMID: 19574213 DOI: 10.1074/jbc.m109.031047] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Previous studies showed that cytoplasmic and mitochondrial forms of yeast valyl-tRNA synthetase (ValRS) are specified by the VAS1 gene through alternative initiation of translation. Sequence comparison suggests that the yeast cytoplasmic (or mature mitochondrial) ValRS contains an N-terminal appendage that acts in cis as a nonspecific tRNA-binding domain (TRBD) and is absent from its bacterial relatives. We show here that Escherichia coli ValRS can substitute for the mitochondrial and cytoplasmic functions of VAS1 by fusion of a mitochondrial targeting signal and a TRBD, respectively. In addition, the bacterial ValRS gene can be converted into a dual functional yeast gene encoding both cytoplasmic and mitochondrial activities by fusion of a DNA sequence specifying both the mitochondrial targeting signal and TRBD. In vitro assays suggested that fusion of a nonspecific TRBD to the bacterial enzyme significantly enhanced its yeast tRNA-binding and aminoacylation activities. These results not only underscore the necessity of retaining a TRBD for functioning of a tRNA synthetase in yeast cytoplasm, but also provide insights into the evolution of tRNA synthetase genes.
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Affiliation(s)
- Wen-Chih Chiu
- Department of Life Science, National Central University, Jung-li 32001, Taiwan
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Herzog W, Müller K, Huisken J, Stainier DYR. Genetic evidence for a noncanonical function of seryl-tRNA synthetase in vascular development. Circ Res 2009; 104:1260-6. [PMID: 19423847 DOI: 10.1161/circresaha.108.191718] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
In a recent genetic screen, we identified mutations in genes important for vascular development and maintenance in zebrafish (Jin et al. Dev Biol. 2007;307:29-42). Mutations [corrected] at the adrasteia (adr) locus cause a pronounced dilatation of the aortic arch vessels as well as aberrant patterning of the hindbrain capillaries and, to a lesser extent, intersomitic vessels. This dilatation of the aortic arch vessels does not appear to be caused by increased cell proliferation but is dependent on vascular endothelial growth factor (Vegf) signaling. By positional cloning, we isolated seryl-tRNA synthetase (sars) as the gene affected by the adr mutations. Small interfering RNA knockdown experiments in human umbilical vein endothelial cell cultures indicate that SARS also regulates endothelial sprouting. These analyses of zebrafish and human endothelial cells reveal a new noncanonical function of Sars in endothelial development.
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Affiliation(s)
- Wiebke Herzog
- Department of Biochemistry and Biophysics and the Cardiovascular Research Institute, Programs in Developmental Biology, Genetics, and Human Genetics, University of California, San Francisco, San Francisco, CA 94158, USA
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Malde AK, Mark AE. Binding and Enantiomeric Selectivity of Threonyl-tRNA Synthetase. J Am Chem Soc 2009; 131:3848-9. [DOI: 10.1021/ja9002124] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alpeshkumar K. Malde
- School of Chemistry and Molecular Biosciences and Institute of Molecular Biosciences, University of Queensland, St. Lucia, QLD 4072, Australia
| | - Alan E. Mark
- School of Chemistry and Molecular Biosciences and Institute of Molecular Biosciences, University of Queensland, St. Lucia, QLD 4072, Australia
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36
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Finarov I, Moor N, Kessler N, Safro M. Crystallization and X-ray analysis of human cytoplasmic phenylalanyl-tRNA synthetase. Acta Crystallogr Sect F Struct Biol Cryst Commun 2009; 65:93-7. [PMID: 19193993 DOI: 10.1107/s1744309108042425] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2008] [Accepted: 12/12/2008] [Indexed: 11/11/2022]
Abstract
Human cytosolic phenylalanyl-tRNA synthetase (hcPheRS) is responsible for the covalent attachment of phenylalanine to its cognate tRNA(Phe). Significant differences between the amino-acid sequences of eukaryotic and prokaryotic PheRSs indicate that the domain composition of hcPheRS differs from that of the Thermus thermophilus analogue. As a consequence of the absence of the anticodon-recognizing B8 domain, the binding mode of tRNA(Phe) to hcPheRS is expected to differ from that in prokaryotes. Recombinant hcPheRS protein was purified to homogeneity and crystallized. The crystals used for structure determination diffracted to 3.3 A resolution and belonged to space group C2, with unit-cell parameters a = 362.9, b = 213.6, c = 212.7 A, beta = 125.2 degrees . The structure of hcPheRS was determined by the molecular-replacement method in combination with phase information from multiwavelength anomalous dispersion.
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Affiliation(s)
- Igal Finarov
- Department of Structural Biology, Weizmann Institute of Science, 76100 Rehovot, Israel
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37
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He R, Zu LD, Yao P, Chen X, Wang ED. Two non-redundant fragments in the N-terminal peptide of human cytosolic methionyl-tRNA synthetase were indispensable for the multi-synthetase complex incorporation and enzyme activity. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2008; 1794:347-54. [PMID: 19064003 DOI: 10.1016/j.bbapap.2008.11.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2008] [Revised: 11/03/2008] [Accepted: 11/04/2008] [Indexed: 10/21/2022]
Abstract
In human cytoplasm, nine aminoacyl-tRNA synthetases (aaRSs) and three protein factors form a multi-synthetase complex (MSC). Human cytosolic methionyl-tRNA synthetase (hcMetRS) is a component of the MSC. Sequence alignment revealed that hcMetRS has an N-terminal extension of 267 amino acid residues. This extension can be divided into three sub-domains: GST-like, GN, and GC sub-domains. The effect of each sub-domain in the N-terminal extension of hcMetRS on enzymatic activity and incorporation into the MSC was studied. The results of cellular assay showed that the GST-like sub-domain was responsible for the incorporation of hcMetRS into the MSC. The entire N-terminal extension of hcMetRS is indispensable for the enzymatic activity. Deletion mutagenesis revealed that a seven-amino acid motif within the sub-domain GC was important for the activity of amino acid activation. A conserved proline residue within the seven-amino acid motif was crucial, while the other six residues were moderately important for the amino acid activation activity. Thus, the last 15 residues of previously defined N-terminal extension of hcMetRS was a part of the catalytic domain; whereas the first 252 residues of hcMetRS constitute the N-terminal extended domain of hcMetRS. The formerly defined N-terminal extension of hcMetRS possesses two functions of two different domains.
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Affiliation(s)
- Ran He
- Shanghai Institutes for Biological Sciences, The Chinese Academy of Sciences, Shanghai 200031, China
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38
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Chang CP, Lin G, Chen SJ, Chiu WC, Chen WH, Wang CC. Promoting the formation of an active synthetase/tRNA complex by a nonspecific tRNA-binding domain. J Biol Chem 2008; 283:30699-706. [PMID: 18755686 DOI: 10.1074/jbc.m805339200] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Previous studies showed that valyl-tRNA synthetase of Saccharomyces cerevisiae contains an N-terminal polypeptide extension of 97 residues, which is absent from its bacterial relatives, but is conserved in its mammalian homologues. We showed herein that this appended domain and its human counterpart are both nonspecific tRNA-binding domains (K(d) approximately 0.5 microm). Deletion of the appended domain from the yeast enzyme severely impaired its tRNA binding, aminoacylation, and complementation activities. This N-domain-deleted yeast valyl-tRNA synthetase mutant could be rescued by fusion of the equivalent domain from its human homologue. Moreover, fusion of the N-domain of the yeast enzyme or its human counterpart to Escherichia coli glutaminyl-tRNA synthetase enabled the otherwise "inactive" prokaryotic enzyme to function as a yeast enzyme in vivo. Different from the native yeast enzyme, which showed different affinities toward mixed tRNA populations, the fusion enzyme exhibited similar binding affinities for all yeast tRNAs. These results not only underscore the significance of nonspecific tRNA binding in aminoacylation, but also provide insights into the mechanism of the formation of aminoacyl-tRNAs.
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Affiliation(s)
- Chia-Pei Chang
- Department of Life Science, National Central University, Jung-li, 32001 Taiwan
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39
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Hausmann CD, Ibba M. Structural and functional mapping of the archaeal multi-aminoacyl-tRNA synthetase complex. FEBS Lett 2008; 582:2178-82. [PMID: 18538672 DOI: 10.1016/j.febslet.2008.05.043] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2008] [Revised: 05/20/2008] [Accepted: 05/26/2008] [Indexed: 10/22/2022]
Abstract
Methanothermobacter thermautotrophicus contains a multi-aminoacyl-tRNA synthetase complex (MSC) of LysRS, LeuRS and ProRS. Elongation factor (EF) 1A also associates to the MSC, with LeuRS possibly acting as a core protein. Analysis of the MSC revealed that LysRS and ProRS specifically interact with the idiosyncratic N- and C- termini of LeuRS, respectively. EF-1A instead interacts with the inserted CP1 proofreading domain, consistent with models for post-transfer editing by class I synthetases such as LeuRS. Together with previous genetic data, these findings show that LeuRS plays a central role in mediating interactions within the archaeal MSC by acting as a core scaffolding protein.
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Affiliation(s)
- Corinne D Hausmann
- Department of Microbiology, The Ohio State University, 484 West 12th Avenue, Columbus, OH 43210-1292, USA
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40
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Hausmann CD, Ibba M. Aminoacyl-tRNA synthetase complexes: molecular multitasking revealed. FEMS Microbiol Rev 2008; 32:705-21. [PMID: 18522650 DOI: 10.1111/j.1574-6976.2008.00119.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The accurate synthesis of proteins, dictated by the corresponding nucleotide sequence encoded in mRNA, is essential for cell growth and survival. Central to this process are the aminoacyl-tRNA synthetases (aaRSs), which provide amino acid substrates for the growing polypeptide chain in the form of aminoacyl-tRNAs. The aaRSs are essential for coupling the correct amino acid and tRNA molecules, but are also known to associate in higher order complexes with proteins involved in processes beyond translation. Multiprotein complexes containing aaRSs are found in all three domains of life playing roles in splicing, apoptosis, viral assembly, and regulation of transcription and translation. An overview of the complexes aaRSs form in all domains of life is presented, demonstrating the extensive network of connections between the translational machinery and cellular components involved in a myriad of essential processes beyond protein synthesis.
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Affiliation(s)
- Corinne D Hausmann
- Department of Microbiology, The Ohio State University, Columbus, OH 43210-1292, USA
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41
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Kaminska M, Francin M, Shalak V, Mirande M. Role of HIV-1 Vpr-induced apoptosis on the release of mitochondrial lysyl-tRNA synthetase. FEBS Lett 2007; 581:3105-10. [PMID: 17560997 DOI: 10.1016/j.febslet.2007.05.076] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2007] [Revised: 05/24/2007] [Accepted: 05/28/2007] [Indexed: 11/25/2022]
Abstract
Mitochondrial lysyl-tRNA synthetase (LysRS) is thought to be involved in the specific packaging of tRNA(3)(Lys) into HIV-1 viral particles. The HIV-1 auxiliary viral protein Vpr is an apoptogenic protein that affects the integrity of the mitochondrial membrane and has also been reported to interact with LysRS. In the present study, we show that HIV-1 Vpr expressed in E. coli and purified to homogeneity does not interact specifically with LysRS and does not impact its aminoacylation activity. However, we also show that the mitochondrial localization of LysRS in HeLa cells is altered after addition of Vpr in the culture medium. These results suggest that HIV-1 Vpr fulfills an essential role in the process of packaging of mitochondrial LysRS.
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Affiliation(s)
- Monika Kaminska
- Laboratoire d'Enzymologie et Biochimie Structurales, Gif-sur-Yvette, France
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42
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Godinic V, Mocibob M, Rocak S, Ibba M, Weygand-Durasevic I. Peroxin Pex21p interacts with the C-terminal noncatalytic domain of yeast seryl-tRNA synthetase and forms a specific ternary complex with tRNA(Ser). FEBS J 2007; 274:2788-99. [PMID: 17451428 DOI: 10.1111/j.1742-4658.2007.05812.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The seryl-tRNA synthetase from Saccharomyces cerevisiae interacts with the peroxisome biogenesis-related factor Pex21p. Several deletion mutants of seryl-tRNA synthetase were constructed and inspected for their ability to interact with Pex21p in a yeast two-hybrid assay, allowing mapping of the synthetase domain required for complex assembly. Deletion of the 13 C-terminal amino acids abolished Pex21p binding to seryl-tRNA synthetase. The catalytic parameters of purified truncated seryl-tRNA synthetase, determined in the serylation reaction, were found to be almost identical to those of the native enzyme. In vivo loss of interaction with Pex21p was confirmed in vitro by coaffinity purification. These data indicate that the C-terminally appended domain of yeast seryl-tRNA synthetase does not participate in substrate binding, but instead is required for association with Pex21p. We further determined that Pex21p does not directly bind tRNA, and nor does it possess a tRNA-binding motif, but it instead participates in the formation of a specific ternary complex with seryl-tRNA synthetase and tRNA(Ser), strengthening the interaction of seryl-tRNA synthetase with its cognate tRNA(Ser).
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Affiliation(s)
- Vlatka Godinic
- Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, 10000 Zagreb, Croatia
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43
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Djekic UV, Morrow CD. Analysis of the replication of HIV-1 forced to use tRNAMet(i) supports a link between primer selection, translation and encapsidation. Retrovirology 2007; 4:10. [PMID: 17274824 PMCID: PMC1797187 DOI: 10.1186/1742-4690-4-10] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2006] [Accepted: 02/02/2007] [Indexed: 11/18/2022] Open
Abstract
Background Previous studies have suggested that the process of HIV-1 tRNA primer selection and encapsidation of genomic RNA might be coupled with viral translation. In order to further investigate this relationship, proviruses were constructed in which the primer-binding site (PBS) was altered to be complementary to elongator tRNAMet (tRNAMet(e)) (HXB2-Met(e)) or initiator tRNAMet (tRNAMet(i)) (HXB2-Met(i)). These tRNAMet not only differ with respect to the 3' terminal 18-nucleotides, but also with respect to interaction with host cell proteins during protein synthesis. Results Consistent with previous studies, HXB2-Met(e) were infectious and maintained this PBS following short-term in vitro culture in SupT1 cells. In contrast, transfection of HBX2-Met(i) produced reduced amounts of virus (as determined by p24) and did not establish a productive infection in SupT1 cells. The low infectivity of the virus with the PBS complementary to tRNAMet(i) was not due to differences in endogenous levels of cellular tRNAMet(i) compared to tRNAMet(e); tRNAMet(i) was also capable of being selected as the primer for reverse transcription as determined by the endogenous reverse transcription reaction. The PBS of HXB2-Met(i) contains an ATG, which could act as an upstream AUG and syphon scanning ribosomes thereby reducing initiation of translation at the authentic AUG of Gag. To investigate this possibility, a provirus with an A to G change was constructed (HXB2-Met(i)AG). Transfection of HXB2-Met(i)AG resulted in increased production of virus, similar to that for the wild type virus. In contrast to HXB2-Met(i), HXB2-Met(i)AG was able to establish a productive infection in SupT1 cells. Analysis of the PBS following replication revealed the virus favored the genome with the repaired PBS (A to G) even though tRNAMet(i) was continuously selected as the primer for reverse transcription. Conclusion The results of these studies suggest that HIV-1 has access to both tRNAMet for selection as the replication primer and supports a co-ordination between primer selection, translation and encapsidation during virus replication.
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Affiliation(s)
- Uros V Djekic
- Department of Cell Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - Casey D Morrow
- Department of Cell Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
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Golinelli-Cohen MP, Mirande M. Arc1p is required for cytoplasmic confinement of synthetases and tRNA. Mol Cell Biochem 2006; 300:47-59. [PMID: 17131041 DOI: 10.1007/s11010-006-9367-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2006] [Accepted: 10/25/2006] [Indexed: 02/07/2023]
Abstract
In yeast, Arc1p interacts with ScMetRS and ScGluRS and operates as a tRNA-Interacting Factor (tIF) in trans of these two synthetases. Its N-terminal domain (N-Arc1p) binds the two synthetases and its C-terminal domain is an EMAPII-like domain organized around an OB-fold-based tIF. ARC1 is not an essential gene but its deletion (arc1- cells) is accompanied by a growth retardation phenotype. Here, we show that expression of N-Arc1p or of C-Arc1p alone palliates the growth defect of arc1- cells, and that bacterial Trbp111 or human p43, two proteins containing EMAPII-like domains, also improve the growth of an arc1- strain. The synthetic lethality of an arc1-los1- strain can be complemented with either ARC1 or LOS1. Expression of N-Arc1p or C-Arc1p alone does not complement an arc1-los1- phenotype, but coexpression of the two domains does. Our data demonstrate that Trbp111 or p43 may replace C-Arc1p to complement an arc1-los1- strain. The two functional domains of Arc1p (N-Arc1p and C-Arc1p) are required to get rid of the synthetic lethal phenotype but do not need to be physically linked. To get some clues to the discrete functions of N-Arc1p and C-Arc1p, we targeted ScMetRS or tIF domains to the nuclear compartment and analyzed their cellular localization by using GFP fusions, and their ability to sustain growth. Our results are consistent with a model according to which Arc1p is a bifunctional protein involved in the subcellular localization of ScMetRS and ScGluRS via its N-terminal domain and of tRNA via its C-terminal domain.
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Affiliation(s)
- Marie-Pierre Golinelli-Cohen
- Laboratoire d'Enzymologie et Biochimie Structurales, Centre National de la Recherche Scientifique, 1 Avenue de la Terrasse, Gif-sur-Yvette 91190, France
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45
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Kaminska M, Shalak V, Francin M, Mirande M. Viral hijacking of mitochondrial lysyl-tRNA synthetase. J Virol 2006; 81:68-73. [PMID: 17050605 PMCID: PMC1797232 DOI: 10.1128/jvi.01267-06] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The primer for reverse transcription of the human immunodeficiency virus type 1 (HIV-1) genome is tRNA3(Lys). During assembly of HIV-1 particles, tRNA3(Lys) is taken up from the host cell along with lysyl-tRNA synthetase (LysRS), the tRNA binding protein that specifically aminoacylates the different tRNA(Lys) isoacceptors. In humans, the cytoplasmic and mitochondrial species of LysRS are encoded by a single gene by means of alternative splicing. Here, we show that polyclonal antibodies directed to the full-length cytoplasmic enzyme equally recognized the two enzyme species. We raised antibodies against synthetic peptides that allowed discrimination between the two enzymes and found that mitochondrial LysRS is the only cellular source of LysRS detected in the virions. These results open new routes for understanding the molecular mechanisms involved in the specific packaging of tRNA3(Lys) into viral particles.
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Affiliation(s)
- Monika Kaminska
- Laboratoire d'Enzymologie et Biochimie Structurales, CNRS, 1 Avenue de la Terrasse, 91190 Gif-sur-Yvette, France
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46
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Kordysh M, Kornelyuk A. Conformational Flexibility of Cytokine-Like C-Module of Tyrosyl-tRNA Synthetase Monitored by Trp144 Intrinsic Fluorescence. J Fluoresc 2006; 16:705-11. [PMID: 16955364 DOI: 10.1007/s10895-006-0113-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2006] [Accepted: 07/21/2006] [Indexed: 10/24/2022]
Abstract
The non-catalytic COOH-terminal module formed after proteolytic cleavage of full-length mammalian tyrosyl-tRNA synthetase displays dual function: tRNA binding ability and cytokine activity. With the aim to explore the intramolecular dynamics of C-module in solution we used fluorescence spectroscopy to study conformational changes of isolated protein. We used information from fluorescence spectra and computational model for characterization of a microenvironment of a single tryptophan residue (Trp144). Its fluorescence parameters and protection from quenching by Cs+ ions indicate the internal localization--buried into protein globule. The fluorescence quenching of Trp144 by acrylamide suggests rapid conformation dynamics of the C-module in nanosecond time scale. The temperature-induced conformational changes in the C-module were monitored by the fluorescence measurements of Trp144 emission and by red-edge excitation shift. An emission maximum shift up to approximately 349 nm and significant decrease of the red-edge shift effect at 37-52 degrees C indicated a major conformational transition of Trp144 from buried native state into highly relaxing polar solvent environment.
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Affiliation(s)
- Mariya Kordysh
- Department of Protein Engineering, Institute of Molecular Biology and Genetics, National Academy of Science of Ukraine, 150, Acad. Zabolotnogo Str., Kiev, Kyiv 03143, Ukraine.
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van Horssen R, Eggermont AMM, ten Hagen TLM. Endothelial monocyte-activating polypeptide-II and its functions in (patho)physiological processes. Cytokine Growth Factor Rev 2006; 17:339-48. [PMID: 16945568 DOI: 10.1016/j.cytogfr.2006.08.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Endothelial monocyte-activating polypeptide-II (EMAP-II) is a pro-inflammatory cytokine with anti-angiogenic properties. Its precursor, proEMAP, is identical to the p43 auxiliary component of the tRNA multisynthetase complex and therefore involved in protein translation. Although most of the activities have been ascribed to the active form EMAP-II, also p43 has reported cytokine properties. ProEMAP/p43 and EMAP-II act on many levels and on many cell types including endothelial cells, immune cells and fibroblasts. In this review we summarize all available data on isolation, expression and functions of EMAP-II both in physiological processes as well as in pathological settings, like cancer. We also discuss the different reported mechanisms for processing of proEMAP/p43 into EMAP-II. Finally, we speculate on the possible applications of this cytokine for (cancer) therapy.
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Affiliation(s)
- Remco van Horssen
- Laboratory of Experimental Surgical Oncology, Department of Surgical Oncology, Erasmus University MC - Daniel den Hoed Cancer Center, Rotterdam, The Netherlands.
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Wolfson A, Knight R. Occurrence of the aminoacyl-tRNA synthetases in high-molecular weight complexes correlates with the size of substrate amino acids. FEBS Lett 2005; 579:3467-72. [PMID: 15963508 DOI: 10.1016/j.febslet.2005.05.038] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2005] [Revised: 05/06/2005] [Accepted: 05/11/2005] [Indexed: 11/16/2022]
Abstract
One of the distinctive and mysterious features of mammalian aminoacyl-tRNA synthetases (AARSs) is the existence of stable high-molecular weight complexes containing 10 out of 20 AARSs. The composition and structure of these complexes are conserved among multicellular animals. No specific function associated with these structures has been found, and there is no evident rationale for a particular separation of AARSs in "complex-bound" and "free" forms. We have demonstrated a strong association between the occurrence of AARSs in the complexes and the volume of their substrate amino acids. The significance of this association is discussed in terms of the structural organization of translation in the living cell.
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Affiliation(s)
- Alexey Wolfson
- Department of Chemistry and Biochemistry, University of Colorado, UCB 215, Boulder, CO 80309, USA.
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Kelly NJ, Morrow CD. Structural elements of the tRNA TPsiC loop critical for nucleocytoplasmic transport are important for human immunodeficiency virus type 1 primer selection. J Virol 2005; 79:6532-9. [PMID: 15858038 PMCID: PMC1091683 DOI: 10.1128/jvi.79.10.6532-6539.2005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) selects a host cell tRNA as the primer for the initiation of reverse transcription. In a previous study, transport of the intact tRNA from the nucleus to the cytoplasm during tRNA biogenesis was shown to be a requirement for the selection of the tRNA primer by HIV-1. To further examine the importance of tRNA structure for transport and the selection of the primer, yeast tRNA(Phe) mutants were designed such that the native tRNA structure would be disrupted to various extents. The capacity of the mutant tRNA(Phe) to complement a defective HIV-1 provirus that relies on the expression of yeast tRNA(Phe) for infectivity was determined. We found a direct relationship between intact tRNA conformation and the capacity to be selected by HIV-1 for use in reverse transcription. tRNA(Phe) mutants that retained the capacity for nucleocytoplasmic transport, indicative of overall intact conformation, complemented the defective provirus. The mutant tRNAs were not aminoacylated, and the levels of complementation were lower than that for wild-type tRNA(Phe), which did undergo transport and aminoacylation. Taken together, these results demonstrate that HIV-1 primer selection is most dependent on a tRNA structure necessary for nucleocytoplasmic transport, consistent with primer selection occurring in the cytoplasm at or near the site of protein synthesis.
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Affiliation(s)
- Nathan J Kelly
- Department of Cell Biology, University of Alabama at Birmingham, 802 Kaul Building, 720 20th Street South, Birmingham, AL 35294, USA.
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Lee SW, Cho BH, Park SG, Kim S. Aminoacyl-tRNA synthetase complexes: beyond translation. J Cell Sci 2005; 117:3725-34. [PMID: 15286174 DOI: 10.1242/jcs.01342] [Citation(s) in RCA: 194] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Although aminoacyl-tRNA synthetases (ARSs) are housekeeping enzymes essential for protein synthesis, they can play non-catalytic roles in diverse biological processes. Some ARSs are capable of forming complexes with each other and additional proteins. This characteristic is most pronounced in mammals, which produce a macromolecular complex comprising nine different ARSs and three additional factors: p43, p38 and p18. We have been aware of the existence of this complex for a long time, but its structure and function have not been well understood. The only apparent distinction between the complex-forming ARSs and those that do not form complexes is their ability to interact with the three non-enzymatic factors. These factors are required not only for the catalytic activity and stability of the associated ARSs, such as isoleucyl-, methionyl-, and arginyl-tRNA synthetase, but also for diverse signal transduction pathways. They may thus have joined the ARS community to coordinate protein synthesis with other biological processes.
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Affiliation(s)
- Sang Won Lee
- National Creative Research Initiatives Center for ARS Network, College of Pharmacy, Seoul National University, Seoul 151-742, Korea
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