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Gupta S, Jani J, Vijayasurya, Mochi J, Tabasum S, Sabarwal A, Pappachan A. Aminoacyl-tRNA synthetase - a molecular multitasker. FASEB J 2023; 37:e23219. [PMID: 37776328 DOI: 10.1096/fj.202202024rr] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 08/31/2023] [Accepted: 09/12/2023] [Indexed: 10/02/2023]
Abstract
Aminoacyl-tRNA synthetases (AaRSs) are valuable "housekeeping" enzymes that ensure the accurate transmission of genetic information in living cells, where they aminoacylated tRNA molecules with their cognate amino acid and provide substrates for protein biosynthesis. In addition to their translational or canonical function, they contribute to nontranslational/moonlighting functions, which are mediated by the presence of other domains on the proteins. This was supported by several reports which claim that AaRS has a significant role in gene transcription, apoptosis, translation, and RNA splicing regulation. Noncanonical/ nontranslational functions of AaRSs also include their roles in regulating angiogenesis, inflammation, cancer, and other major physio-pathological processes. Multiple AaRSs are also associated with a broad range of physiological and pathological processes; a few even serve as cytokines. Therefore, the multifunctional nature of AaRSs suggests their potential as viable therapeutic targets as well. Here, our discussion will encompass a range of noncanonical functions attributed to Aminoacyl-tRNA Synthetases (AaRSs), highlighting their links with a diverse array of human diseases.
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Affiliation(s)
- Swadha Gupta
- School of Life Sciences, Central University of Gujarat, Gandhinagar, India
| | - Jaykumar Jani
- School of Life Sciences, Central University of Gujarat, Gandhinagar, India
| | - Vijayasurya
- School of Life Sciences, Central University of Gujarat, Gandhinagar, India
| | - Jigneshkumar Mochi
- School of Life Sciences, Central University of Gujarat, Gandhinagar, India
| | - Saba Tabasum
- Dana Farber Cancer Institute, Boston, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
| | - Akash Sabarwal
- Harvard Medical School, Boston, Massachusetts, USA
- Boston Children's Hospital, Boston, Massachusetts, USA
| | - Anju Pappachan
- School of Life Sciences, Central University of Gujarat, Gandhinagar, India
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2
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Oakley AJ. Hidden Glutathione Transferases in the Human Genome. Biomolecules 2023; 13:1240. [PMID: 37627305 PMCID: PMC10452860 DOI: 10.3390/biom13081240] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 08/08/2023] [Accepted: 08/08/2023] [Indexed: 08/27/2023] Open
Abstract
With the development of accurate protein structure prediction algorithms, artificial intelligence (AI) has emerged as a powerful tool in the field of structural biology. AI-based algorithms have been used to analyze large amounts of protein sequence data including the human proteome, complementing experimental structure data found in resources such as the Protein Data Bank. The EBI AlphaFold Protein Structure Database (for example) contains over 230 million structures. In this study, these data have been analyzed to find all human proteins containing (or predicted to contain) the cytosolic glutathione transferase (cGST) fold. A total of 39 proteins were found, including the alpha-, mu-, pi-, sigma-, zeta- and omega-class GSTs, intracellular chloride channels, metaxins, multisynthetase complex components, elongation factor 1 complex components and others. Three broad themes emerge: cGST domains as enzymes, as chloride ion channels and as protein-protein interaction mediators. As the majority of cGSTs are dimers, the AI-based structure prediction algorithm AlphaFold-multimer was used to predict structures of all pairwise combinations of these cGST domains. Potential homo- and heterodimers are described. Experimental biochemical and structure data is used to highlight the strengths and limitations of AI-predicted structures.
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Affiliation(s)
- Aaron J Oakley
- School of Chemistry and Molecular Bioscience, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW 2522, Australia
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3
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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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4
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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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Hei Z, Wu S, Zheng L, Zhou J, Liu Z, Wang J, Fang P. Crystal structures reveal a novel dimer of the RWD domain of human general control nonderepressible 2. Biochem Biophys Res Commun 2021; 549:164-170. [PMID: 33676185 DOI: 10.1016/j.bbrc.2021.02.111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 02/23/2021] [Indexed: 10/22/2022]
Abstract
General control nonderepressible 2 (GCN2) is a serine/threonine protein kinase, detecting a variety of stresses including amino acid starvation, reactive oxygen species, etc. in eukaryotic cells. Activation of GCN2 requires the interaction of the N-terminal RWD domain with the upstream GCN1 protein and the dimerization by the kinase domain. In this study, we determined two crystal structures of the RWD domain of human GCN2 in two different crystal packing modes. These two different crystal structures reveal a same dimer of the RWD domain, which has not been reported in previous studies. We further confirmed this novel dimer interaction in solution using gel filtration experiments, and in human embryonic kidney (HEK) 293 cells using bimolecular fluorescence complementation (BiFC) and co-immunoprecipitation (co-IP) assays. Together, this study discovers a potential protein-protein interface on the RWD domain of human GCN2, and suggests a possible regulation between the interaction of GCN1 and the formation of GCN2 dimer.
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Affiliation(s)
- Zhoufei Hei
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China
| | - Siqi Wu
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China
| | - Li Zheng
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China; School of Chemistry and Materials Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, 1 Sub-lane Xiangshan, Hangzhou, 310024, China
| | - Jintong Zhou
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China
| | - Zaizhou Liu
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China
| | - Jing Wang
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China; School of Chemistry and Materials Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, 1 Sub-lane Xiangshan, Hangzhou, 310024, China
| | - Pengfei Fang
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China; School of Chemistry and Materials Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, 1 Sub-lane Xiangshan, Hangzhou, 310024, China.
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6
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Williams EA, Sharaf R, Decker B, Werth AJ, Toma H, Montesion M, Sokol ES, Pavlick DC, Shah N, Williams KJ, Venstrom JM, Alexander BM, Ross JS, Albacker LA, Lin DI, Ramkissoon SH, Elvin JA. CDKN2C-Null Leiomyosarcoma: A Novel, Genomically Distinct Class of TP53/ RB1-Wild-Type Tumor With Frequent CIC Genomic Alterations and 1p/19q-Codeletion. JCO Precis Oncol 2020; 4:PO.20.00040. [PMID: 33015533 PMCID: PMC7529542 DOI: 10.1200/po.20.00040] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/24/2020] [Indexed: 11/20/2022] Open
Abstract
PURPOSE Leiomyosarcoma (LMS) harbors frequent mutations in TP53 and RB1 but few actionable genomic alterations. Here, we searched for recurrent actionable genomic alterations in LMS that occur in the absence of common untreatable oncogenic drivers. METHODS Tissues from 276,645 unique advanced cancers, including 2,570 uterine and soft tissue LMS, were sequenced by hybrid-capture-based next-generation DNA and RNA sequencing/comprehensive genomic profiling of up to 406 genes. We characterized clinicopathologic features of relevant patient cases. RESULTS Overall, 77 LMS exhibited homozygous copy loss of CDKN2C at chromosome 1p32.3 (3.0% of LMS). Genomic alterations (GAs) in TP53, RB1, and ATRX were rare compared with the remainder of the LMS cohort (11.7% v 73.4%, 0% v 54.5%, 2.6% v 24.5%, respectively; all P < .0001). CDKN2C-null LMS patient cases were significantly enriched for GAs in CIC (40.3% v 1.4%) at 19q13.2, CDKN2A (46.8% v 7.0%), and RAD51B (16.9% v 1.7%; all P < .0001). Chromosome arm-level aneuploidy analysis of available LMS patient cases (n = 1,284) found that 81% (58 of 72) of CDKN2C-null LMS exhibited 1p/19q-codeletion, a significant enrichment compared with 5.1% in the remainder of the LMS cohort (P < .0001). In total, 99% of CDKN2C-null LMS were in women; the median age was 61 years at surgery (range, 36-81 years). Fifty-five patient cases were uterine primary, four were nonuterine, and the remaining 18 were of uncertain primary site. Sixty percent of cases showed at least focal epithelioid variant histology. Most patients had advanced-stage disease, with 62% of confirmed uterine primary LMS at International Federation of Gynecology and Obstetrics stage IVB. We further validated our findings in two publicly available datasets: The Cancer Genome Atlas and the Project GENIE initiative. CONCLUSION CDKN2C-null LMS defines a genomically distinct tumor that may have prognostic and/or therapeutic clinical implications, including possible use of specific cyclin-dependent kinase inhibitors.
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Affiliation(s)
| | | | - Brennan Decker
- Department of Pathology, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA
| | - Adrienne J. Werth
- Christiana Hospital, Department of Obstetrics and Gynecology, Newark, DE
| | - Helen Toma
- Christiana Hospital, Department of Obstetrics and Gynecology, Newark, DE
| | | | | | | | | | - Kevin Jon Williams
- Department of Physiology, Department of Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA
| | | | | | - Jeffrey S. Ross
- Foundation Medicine, Cambridge, MA
- Department of Pathology, State University of New York Upstate Medical University, Syracuse, NY
| | | | | | - Shakti H. Ramkissoon
- Foundation Medicine, Cambridge, MA
- Wake Forest Comprehensive Cancer Center and Department of Pathology, Wake Forest School of Medicine, Winston-Salem, NC
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7
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Roles of aminoacyl-tRNA synthetase-interacting multi-functional proteins in physiology and cancer. Cell Death Dis 2020; 11:579. [PMID: 32709848 PMCID: PMC7382500 DOI: 10.1038/s41419-020-02794-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 07/03/2020] [Accepted: 07/06/2020] [Indexed: 12/15/2022]
Abstract
Aminoacyl-tRNA synthetases (ARSs) are an important class of enzymes with an evolutionarily conserved mechanism for protein synthesis. In higher eukaryotic systems, eight ARSs and three ARS-interacting multi-functional proteins (AIMPs) form a multi-tRNA synthetase complex (MSC), which seems to contribute to cellular homeostasis. Of these, AIMPs are generally considered as non-enzyme factors, playing a scaffolding role during MSC assembly. Although the functions of AIMPs are not fully understood, increasing evidence indicates that these scaffold proteins usually exert tumor-suppressive activities. In addition, endothelial monocyte-activating polypeptide II (EMAP II), as a cleavage product of AIMP1, and AIMP2-DX2, as a splice variant of AIMP2 lacking exon 2, also have a pivotal role in regulating tumorigenesis. In this review, we summarize the biological functions of AIMP1, EMAP II, AIMP2, AIMP2-DX2, and AIMP3. Also, we systematically introduce their emerging roles in cancer, aiming to provide new ideas for the treatment of cancer.
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8
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Cho HY, Lee HJ, Choi YS, Kim DK, Jin KS, Kim S, Kang BS. Symmetric Assembly of a Decameric Subcomplex in Human Multi-tRNA Synthetase Complex Via Interactions between Glutathione Transferase-Homology Domains and Aspartyl-tRNA Synthetase. J Mol Biol 2019; 431:4475-4496. [PMID: 31473157 DOI: 10.1016/j.jmb.2019.08.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 08/21/2019] [Accepted: 08/21/2019] [Indexed: 11/29/2022]
Abstract
Aminoacyl-tRNA synthetases (AARSs) ligate amino acids to their cognate tRNAs during protein synthesis. In humans, eight AARSs and three non-enzymatic AARS-interacting multifunctional proteins (AIMP1-3), which are involved in various biological processes, form a multi-tRNA synthetase complex (MSC). Elucidation of the structures and multiple functions of individual AARSs and AIMPs has aided current understanding of the structural arrangement of MSC components and their assembly processes. Here, we report the crystal structure of a complex comprising a motif from aspartyl-tRNA synthetase (DRS) and the glutathione transferase (GST)-homology domains of methionyl-tRNA synthetase (MRS), glutamyl-prolyl-tRNA synthetase (EPRS), AIMP2, and AIMP3. In the crystal structure, the four GST domains are assembled in the order of MRS-AIMP3-EPRS-AIMP2, and the GST domain of AIMP2 binds DRS through the β-sheet in the GST domain. The C-terminus of AIMP3 enhances the binding of DRS to the tetrameric GST complex. A DRS dimer and two GST tetramers binding to the dimer with 2-fold symmetry complete a decameric complex. The formation of this complex enhances the stability of DRS and enables it to retain its reaction intermediate, aspartyl adenylate. Since the catalytic domains of MRS and EPRS are connected to the decameric complex through their flexible linker peptides, and lysyl-tRNA synthetase and AIMP1 are also linked to the complex via the N-terminal region of AIMP2, the DRS-GST tetramer complex functions as a frame in the MSC.
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Affiliation(s)
- Ha Yeon Cho
- School of Life Science and Biotechnology, KNU Creative BioResearch Group, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Hyun Joo Lee
- School of Life Science and Biotechnology, KNU Creative BioResearch Group, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Yoon Seo Choi
- School of Life Science and Biotechnology, KNU Creative BioResearch Group, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Dong Kyu Kim
- School of Life Science and Biotechnology, KNU Creative BioResearch Group, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Kyeong Sik Jin
- Pohang Accelerator Laboratory, Pohang University of Science and Technology, 80 Jigokro-127-beongil, Nam-Gu, Pohang, Kyungbuk 37673, Republic of Korea
| | - Sunghoon Kim
- Medicinal Bioconvergence Research Center, Seoul National University, Suwon 16229, Republic of Korea; College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
| | - Beom Sik Kang
- School of Life Science and Biotechnology, KNU Creative BioResearch Group, Kyungpook National University, Daegu 41566, Republic of Korea.
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Mousavian Z, Nowzari-Dalini A, Rahmatallah Y, Masoudi-Nejad A. Differential network analysis and protein-protein interaction study reveals active protein modules in glucocorticoid resistance for infant acute lymphoblastic leukemia. Mol Med 2019; 25:36. [PMID: 31370801 PMCID: PMC6676637 DOI: 10.1186/s10020-019-0106-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 07/24/2019] [Indexed: 01/24/2023] Open
Abstract
Background Acute lymphoblastic leukemia (ALL) is the most common type of cancer diagnosed in children and Glucocorticoids (GCs) form an essential component of the standard chemotherapy in most treatment regimens. The category of infant ALL patients carrying a translocation involving the mixed lineage leukemia (MLL) gene (gene KMT2A) is characterized by resistance to GCs and poor clinical outcome. Although some studies examined GC-resistance in infant ALL patients, the understanding of this phenomenon remains limited and impede the efforts to improve prognosis. Methods This study integrates differential co-expression (DC) and protein-protein interaction (PPI) networks to find active protein modules associated with GC-resistance in MLL-rearranged infant ALL patients. A network was constructed by linking differentially co-expressed gene pairs between GC-resistance and GC-sensitive samples and later integrated with PPI networks by keeping the links that are also present in the PPI network. The resulting network was decomposed into two sub-networks, specific to each phenotype. Finally, both sub-networks were clustered into modules using weighted gene co-expression network analysis (WGCNA) and further analyzed with functional enrichment analysis. Results Through the integration of DC analysis and PPI network, four protein modules were found active under the GC-resistance phenotype but not under the GC-sensitive. Functional enrichment analysis revealed that these modules are related to proteasome, electron transport chain, tRNA-aminoacyl biosynthesis, and peroxisome signaling pathways. These findings are in accordance with previous findings related to GC-resistance in other hematological malignancies such as pediatric ALL. Conclusions Differential co-expression analysis is a promising approach to incorporate the dynamic context of gene expression profiles into the well-documented protein interaction networks. The approach allows the detection of relevant protein modules that are highly enriched with DC gene pairs. Functional enrichment analysis of detected protein modules generates new biological hypotheses and may help in explaining the GC-resistance in MLL-rearranged infant ALL patients. Electronic supplementary material The online version of this article (10.1186/s10020-019-0106-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Zaynab Mousavian
- School of Mathematics, Statistics, and Computer Science, College of Science, University of Tehran, Tehran, Iran. .,Laboratory of Systems Biology and Bioinformatics (LBB), Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran.
| | - Abbas Nowzari-Dalini
- School of Mathematics, Statistics, and Computer Science, College of Science, University of Tehran, Tehran, Iran
| | - Yasir Rahmatallah
- Department of Biomedical Informatics, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
| | - Ali Masoudi-Nejad
- Laboratory of Systems Biology and Bioinformatics (LBB), Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran.
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Kim C, Park JM, Song Y, Kim S, Moon J. HIF1α-mediated AIMP3 suppression delays stem cell aging via the induction of autophagy. Aging Cell 2019; 18:e12909. [PMID: 30706629 PMCID: PMC6413650 DOI: 10.1111/acel.12909] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Accepted: 01/03/2019] [Indexed: 12/31/2022] Open
Abstract
Senescence in stem cells, which occurs as a consequence of chronic responses to the environment, defines the capacity of stem cells for proliferation and differentiation as well as their potential for tissue regeneration and homeostasis maintenance. Although stem cells reside under low oxygen pressure and the availability of oxygen is known to be a crucial determinant in their fate, the key modulators in stem cell aging and the underlying mechanism have yet to be unraveled. Human placenta‐derived mesenchymal stem cells (hpMSCs) were cultured under hypoxia (3% O2) or normoxia (21% O2) to investigate the key factors that regulate stem cell senescence under hypoxic conditions. RNA sequencing results suggested that the expression of aminoacyl‐tRNA synthetase‐interacting multifunctional protein 3 (AIMP3, EEF1E1), an aging inducer, in the hpMSCs was dramatically repressed under hypoxia with concurrent suppression of the aging marker p16INK4a. The hpMSCs that overexpressed AIMP3 under hypoxic conditions displayed significantly decreased proliferation and fewer stem cell characteristics, whereas the downregulation of AIMP3 ameliorated the age‐related senescence of MSCs. Consistent with the results of the hpMSCs, MSCs isolated from the adipose tissue of AIMP3‐overexpressing mice exhibited decreased stem cell functions. Interestingly, AIMP3‐induced senescence is negatively regulated by hypoxia‐inducible factor 1α (HIF1α) and positively regulated by Notch3. Furthermore, we showed that AIMP3 enhanced mitochondrial respiration and suppressed autophagic activity, indicating that the AIMP3‐associated modulation of metabolism and autophagy is a key mechanism in the senescence of stem cells and further suggesting a novel target for interventions against aging.
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Affiliation(s)
- Chul Kim
- Department of Biotechnology, College of Life Science; CHA University; Pocheon-si Korea
| | - Ji-Min Park
- Department of Biotechnology, College of Life Science; CHA University; Pocheon-si Korea
| | - Youngsook Song
- Department of Biotechnology, College of Life Science; CHA University; Pocheon-si Korea
| | - Sunghoon Kim
- Medicinal Bioconvergence Research Center; Seoul National University; Seoul Korea
- Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Technology; Seoul National University; Suwon Korea
| | - Jisook Moon
- Department of Biotechnology, College of Life Science; CHA University; Pocheon-si Korea
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11
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Kim SS, Hur SY, Kim YR, Yoo NJ, Lee SH. Expression of AIMP1, 2 and 3, the scaffolds for the multi-tRNA synthetase complex, is downregulated in gastric and colorectal cancer. TUMORI JOURNAL 2018; 97:380-5. [DOI: 10.1177/030089161109700321] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Aminoacyl-tRNA synthetase-interacting multifunctional proteins (AIMPs) form a protein complex with aminoacyl-tRNA synthetases. In addition to protein translation, AIMPs play a role in diverse biological processes. Earlier studies suggested that AIMPs may act as tumor suppressors. However, the expression status of the AIMP proteins in human cancer tissues is largely unknown. In this study, we analyzed the expression of AIMP members (AIMP1, AIMP2 and AIMP3) in gastric cancer (GC) and colorectal cancer (CRC) tissues. We analyzed the expression of these proteins in 100 GC and 103 CRC tissues by immunohistochemistry using a tissue microarray method. Normal gastric and colon mucosa expressed AIMP1, AIMP2 and AIMP3 in nearly all of the cases (95–100%). However, the expression of AIMP1, AIMP2 and AIMP3 was significantly decreased in the GC samples (60%, 52% and 70% of the cases, respectively) and in the CRC samples (66%, 53% and 81% of the cases, respectively) (P <0.01). Expression of AIMP1, AIMP2 or AIMP3 was not associated with clinicopathological parameters including differentiation, depth of invasion and TNM stage. The decreased expression of AIMP1, AIMP2 and AIMP3 in the GC and CRC tissues compared to the corresponding normal tissues suggested that downregulation of these proteins may be related to inactivation of the tumor suppressor functions of AIMP proteins and might play a role in the development of GC and CRC.
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Affiliation(s)
- Sung Soo Kim
- Departments of Internal Medicine, The Catholic University of Korea, Seoul, Korea
| | - Soo Young Hur
- Departments of Obstetrics/Gynecology, The Catholic University of Korea, Seoul, Korea
| | - Yoo Ri Kim
- Departments of Pathology, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Nam Jin Yoo
- Departments of Pathology, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Sug Hyung Lee
- Departments of Pathology, College of Medicine, The Catholic University of Korea, Seoul, Korea
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Tao Y, Fang P, Kim S, Guo M, Young NL, Marshall AG. Mapping the contact surfaces in the Lamin A:AIMP3 complex by hydrogen/deuterium exchange FT-ICR mass spectrometry. PLoS One 2017; 12:e0181869. [PMID: 28797100 PMCID: PMC5552228 DOI: 10.1371/journal.pone.0181869] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 07/07/2017] [Indexed: 11/23/2022] Open
Abstract
Aminoacyl-tRNA synthetases-interacting multifunctional protein3 (AIMP3/p18) is involved in the macromolecular tRNA synthetase complex via its interaction with several aminoacyl-tRNA synthetases. Recent reports reveal a novel function of AIMP3 as a tumor suppressor by accelerating cellular senescence and causing defects in nuclear morphology. AIMP3 specifically mediates degradation of mature Lamin A (LmnA), a major component of the nuclear envelope matrix; however, the mechanism of how AIMP3 interacts with LmnA is unclear. Here we report solution-phase hydrogen/deuterium exchange (HDX) for AIMP3, LmnA, and AIMP3 in association with the LmnA C-terminus. Reversed-phase LC coupled with LTQ 14.5 T Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) results in high mass accuracy and resolving power for comparing the D-uptake profiles for AIMP3, LmnA, and their complex. The results show that the AIMP3-LmnA interaction involves one of the two putative binding sites and an adjacent novel interface on AIMP3. LmnA binds AIMP3 via its extreme C-terminus. Together these findings provide a structural insight for understanding the interaction between AIMP3 and LmnA in AIMP3 degradation.
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Affiliation(s)
- Yeqing Tao
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida, United States of America
| | - Pengfei Fang
- Department of Cancer Biology, The Scripps Research Institute, Scripps Florida, Jupiter, Florida, United States of America
| | - Sunghoon Kim
- Medicinal Bioconvergence Research Center, College of Pharmacy, Seoul National University, Seoul, South Korea
| | - Min Guo
- Department of Cancer Biology, The Scripps Research Institute, Scripps Florida, Jupiter, Florida, United States of America
| | - Nicolas L. Young
- Verna & Marrs McLean Department of Biochemistry & Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Alan G. Marshall
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida, United States of America
- Ion Cyclotron Resonance Program, National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida, United States of America
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13
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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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14
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Cho HY, Maeng SJ, Cho HJ, Choi YS, Chung JM, Lee S, Kim HK, Kim JH, Eom CY, Kim YG, Guo M, Jung HS, Kang BS, Kim S. Assembly of Multi-tRNA Synthetase Complex via Heterotetrameric Glutathione Transferase-homology Domains. J Biol Chem 2015; 290:29313-28. [PMID: 26472928 DOI: 10.1074/jbc.m115.690867] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Indexed: 01/27/2023] Open
Abstract
Many multicomponent protein complexes mediating diverse cellular processes are assembled through scaffolds with specialized protein interaction modules. The multi-tRNA synthetase complex (MSC), consisting of nine different aminoacyl-tRNA synthetases and three non-enzymatic factors (AIMP1-3), serves as a hub for many signaling pathways in addition to its role in protein synthesis. However, the assembly process and structural arrangement of the MSC components are not well understood. Here we show the heterotetrameric complex structure of the glutathione transferase (GST) domains shared among the four MSC components, methionyl-tRNA synthetase (MRS), glutaminyl-prolyl-tRNA synthetase (EPRS), AIMP2 and AIMP3. The MRS-AIMP3 and EPRS-AIMP2 using interface 1 are bridged via interface 2 of AIMP3 and EPRS to generate a unique linear complex of MRS-AIMP3:EPRS-AIMP2 at the molar ratio of (1:1):(1:1). Interestingly, the affinity at interface 2 of AIMP3:EPRS can be varied depending on the occupancy of interface 1, suggesting the dynamic nature of the linear GST tetramer. The four components are optimally arranged for maximal accommodation of additional domains and proteins. These characteristics suggest the GST tetramer as a unique and dynamic structural platform from which the MSC components are assembled. Considering prevalence of the GST-like domains, this tetramer can also provide a tool for the communication of the MSC with other GST-containing cellular factors.
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Affiliation(s)
- Ha Yeon Cho
- From the School of Life Science and Biotechnology, KNU Creative BioResearch Group, Kyungpook National University, Daegu 702-701, Korea
| | - Seo Jin Maeng
- From the School of Life Science and Biotechnology, KNU Creative BioResearch Group, Kyungpook National University, Daegu 702-701, Korea
| | - Hyo Je Cho
- From the School of Life Science and Biotechnology, KNU Creative BioResearch Group, Kyungpook National University, Daegu 702-701, Korea
| | - Yoon Seo Choi
- From the School of Life Science and Biotechnology, KNU Creative BioResearch Group, Kyungpook National University, Daegu 702-701, Korea
| | - Jeong Min Chung
- the Department of Biochemistry, College of Natural Sciences, Kangwon National University, Chuncheon 200-701, Korea
| | - Sangmin Lee
- the Department of Biochemistry, College of Natural Sciences, Kangwon National University, Chuncheon 200-701, Korea
| | - Hoi Kyoung Kim
- the Department of Molecular Medicine and Biopharmaceutical Sciences, Medicinal Bioconvergence Research Center, Graduate School of Convergence Technology, Seoul National University, Seoul 151-742, Korea
| | - Jong Hyun Kim
- the Department of Molecular Medicine and Biopharmaceutical Sciences, Medicinal Bioconvergence Research Center, Graduate School of Convergence Technology, Seoul National University, Seoul 151-742, Korea
| | - Chi-Yong Eom
- the NanoBio Convergence Research Team, Western Seoul Center, Korea Basic Science Institute, Seoul 120-750, Korea
| | - Yeon-Gil Kim
- the Pohang Accelerator Laboratory, Pohang University of Science and Technology, Pohang 790-834, Korea
| | - Min Guo
- the Department of Cancer Biology, The Scripps Research Institute, Jupiter, Florida 33458, and
| | - Hyun Suk Jung
- the Department of Biochemistry, College of Natural Sciences, Kangwon National University, Chuncheon 200-701, Korea
| | - Beom Sik Kang
- From the School of Life Science and Biotechnology, KNU Creative BioResearch Group, Kyungpook National University, Daegu 702-701, Korea,
| | - Sunghoon Kim
- the Department of Molecular Medicine and Biopharmaceutical Sciences, Medicinal Bioconvergence Research Center, Graduate School of Convergence Technology, Seoul National University, Seoul 151-742, Korea, the The National Center for Drug Screening, Shanghai Institute of Materia Medica, Shanghai 201203, China
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15
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Aminoacyl-tRNA synthetase complexes in evolution. Int J Mol Sci 2015; 16:6571-94. [PMID: 25807264 PMCID: PMC4394549 DOI: 10.3390/ijms16036571] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 02/17/2015] [Accepted: 03/11/2015] [Indexed: 11/23/2022] Open
Abstract
Aminoacyl-tRNA synthetases are essential enzymes for interpreting the genetic code. They are responsible for the proper pairing of codons on mRNA with amino acids. In addition to this canonical, translational function, they are also involved in the control of many cellular pathways essential for the maintenance of cellular homeostasis. Association of several of these enzymes within supramolecular assemblies is a key feature of organization of the translation apparatus in eukaryotes. It could be a means to control their oscillation between translational functions, when associated within a multi-aminoacyl-tRNA synthetase complex (MARS), and nontranslational functions, after dissociation from the MARS and association with other partners. In this review, we summarize the composition of the different MARS described from archaea to mammals, the mode of assembly of these complexes, and their roles in maintenance of cellular homeostasis.
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16
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Gurung PMS, Veerakumarasivam A, Williamson M, Counsell N, Douglas J, Tan WS, Feber A, Crabb SJ, Short SC, Freeman A, Powles T, Hoskin PJ, West CM, Kelly JD. Loss of expression of the tumour suppressor gene AIMP3 predicts survival following radiotherapy in muscle-invasive bladder cancer. Int J Cancer 2014; 136:709-20. [PMID: 24917520 DOI: 10.1002/ijc.29022] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2013] [Revised: 05/05/2014] [Accepted: 05/08/2014] [Indexed: 11/10/2022]
Abstract
The aim of this study was to test the utility of AIMP3, an upstream regulator of DNA damage response following genotoxic stress, as a clinical biomarker in muscle-invasive bladder cancer (MIBC). AIMP3 was identified from a meta-analysis of a global gene-expression dataset. AIMP3 protein expression was determined by immunohistochemistry on a customised bladder cancer tissue-microarray (TMA). The mechanism of gene silencing was probed using methylation-specific PCR. The association between AIMP3 expression, Tp53 transactivity and genomic stability was analysed. In vitro AIMP3 translocation to the nucleus in response to ionising radiation was demonstrated using immunofluorescence. Radiosensitisation effects of siRNA-mediated AIMP3-knockdown were measured using colony forming assays. TMAs derived from patients enrolled in BCON, a Phase III multicentre radiotherapy trial in bladder cancer (ISRCTN45938399) were used to evaluate the association between AIMP3 expression and survival. The prognostic value of AIMP3 expression was determined in a TMA derived from patients treated by radical cystectomy. Loss of AIMP3 expression was frequent in MIBC and associated with impaired Tp53 transactivity and genomic instability. AIMP3-knockdown was associated with an increase in radioresistance. Loss of AIMP3 expression was associated with survival in MIBC patients following radiotherapy (HR = 0.53; 95% CI: 0.36 to 0.78, p = 0.002) but was not prognostic in the cystectomy set. In conclusion, AIMP3 expression is lost in a subset of bladder cancers and is significantly predictive of survival following radiotherapy in MIBC patients.
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Affiliation(s)
- Pratik M S Gurung
- Division of Surgery and Interventional Science, University College London (UCL), London, United Kingdom
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17
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Pang YLJ, Poruri K, Martinis SA. tRNA synthetase: tRNA aminoacylation and beyond. WILEY INTERDISCIPLINARY REVIEWS-RNA 2014; 5:461-80. [PMID: 24706556 DOI: 10.1002/wrna.1224] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2010] [Revised: 01/14/2014] [Accepted: 02/06/2014] [Indexed: 01/20/2023]
Abstract
The aminoacyl-tRNA synthetases are prominently known for their classic function in the first step of protein synthesis, where they bear the responsibility of setting the genetic code. Each enzyme is exquisitely adapted to covalently link a single standard amino acid to its cognate set of tRNA isoacceptors. These ancient enzymes have evolved idiosyncratically to host alternate activities that go far beyond their aminoacylation role and impact a wide range of other metabolic pathways and cell signaling processes. The family of aminoacyl-tRNA synthetases has also been suggested as a remarkable scaffold to incorporate new domains that would drive evolution and the emergence of new organisms with more complex function. Because they are essential, the tRNA synthetases have served as pharmaceutical targets for drug and antibiotic development. The recent unfolding of novel important functions for this family of proteins offers new and promising pathways for therapeutic development to treat diverse human diseases.
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Affiliation(s)
- Yan Ling Joy Pang
- Department of Biochemistry, University of Illinois at Urbana, Urbana, IL, USA
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18
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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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19
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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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20
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Guo M, Schimmel P. Essential nontranslational functions of tRNA synthetases. Nat Chem Biol 2013; 9:145-53. [PMID: 23416400 DOI: 10.1038/nchembio.1158] [Citation(s) in RCA: 282] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 11/28/2012] [Indexed: 12/25/2022]
Abstract
Nontranslational functions of vertebrate aminoacyl tRNA synthetases (aaRSs), which catalyze the production of aminoacyl-tRNAs for protein synthesis, have recently been discovered. Although these new functions were thought to be 'moonlighting activities', many are as critical for cellular homeostasis as their activity in translation. New roles have been associated with their cytoplasmic forms as well as with nuclear and secreted extracellular forms that affect pathways for cardiovascular development and the immune response and mTOR, IFN-γ and p53 signaling. The associations of aaRSs with autoimmune disorders, cancers and neurological disorders further highlight nontranslational functions of these proteins. New architecture elaborations of the aaRSs accompany their functional expansion in higher organisms and have been associated with the nontranslational functions for several aaRSs. Although a general understanding of how these functions developed is limited, the expropriation of aaRSs for essential nontranslational functions may have been initiated by co-opting the amino acid-binding site for another purpose.
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Affiliation(s)
- Min Guo
- Department of Cancer Biology, The Scripps Research Institute, Jupiter, Florida, USA
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21
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Ku MJ, Lee SY. Contributions of aminoacyl-tRNA synthetase-interacting multifunctional protein-3 to mammalian translation initiation. Amino Acids 2013; 44:1241-5. [PMID: 23306449 DOI: 10.1007/s00726-012-1447-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2012] [Accepted: 12/12/2012] [Indexed: 10/27/2022]
Abstract
Aminoacyl-tRNA synthetase-interacting multifunctional protein-3 (AIMP3) stabilizes and protects mammalian methionyl-tRNA synthetase (MRS) and eukaryotic initiation factor 2 subunit gamma (eIF2γ), factors involved in the formation and the delivery of Met-tRNA(i)Met respectively, through the binding interactions. Due to the protections that MRS and eIF2γ are provided from the interactions with AIMP3, cellular levels of MRS and eIF2γ may be able to be maintained high enough for their canonical and/or non-canonical functions.
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Affiliation(s)
- Min Jeong Ku
- Department of Life Science, Gachon University, San 65, Bokjeong-Dong, Sujeong-Gu, Seongnam-Si, 461-701, Kyeonggi-Do, Korea
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22
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Abstract
Although aminoacyl-tRNA synthetases (ARSs) and ARS-interacting multi-functional proteins (AIMPs) have long been recognized as housekeeping proteins, evidence indicating that they play a key role in regulating cancer is now accumulating. In this chapter we will review the conventional and non-conventional functions of ARSs and AIMPs with respect to carcinogenesis. First, we will address how ARSs and AIMPs are altered in terms of expression, mutation, splicing, and post-translational modifications. Second, the molecular mechanisms for ARSs' and AIMPs' involvement in the initiation, maintenance, and progress of carcinogenesis will be covered. Finally, we will introduce the development of therapeutic approaches that target ARSs and AIMPs with the goal of treating cancer.
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23
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Dual role of methionyl-tRNA synthetase in the regulation of translation and tumor suppressor activity of aminoacyl-tRNA synthetase-interacting multifunctional protein-3. Proc Natl Acad Sci U S A 2011; 108:19635-40. [PMID: 22106287 DOI: 10.1073/pnas.1103922108] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Mammalian methionyl-tRNA synthetase (MRS) plays an essential role in initiating translation by transferring Met to initiator tRNA (tRNA(i)(Met)). MRS also provides a cytosolic anchoring site for aminoacyl-tRNA synthetase-interacting multifunctional protein-3 (AIMP3)/p18, a potent tumor suppressor that is translocated to the nucleus for DNA repair upon DNA damage. However, the mechanism by which this enzyme mediates these two seemingly unrelated functions is unknown. Here we demonstrate that AIMP3 is released from MRS by UV irradiation-induced stress. Dissociation was induced by phosphorylation of MRS at Ser662 by general control nonrepressed-2 (GCN2) following UV irradiation. Substitution of Ser662 to Asp (S662D) induced a conformational change in MRS and significantly reduced its interaction with AIMP3. This mutant possessed significantly reduced MRS catalytic activity because of loss of tRNA(Met) binding, resulting in down-regulation of global translation. According to the Met incorporation assay using stable HeLa cells expressing MRS S662A or eukaryotic initiation factor-2 subunit-α (eIF2α) S51A, inactivation of GCN2-induced phosphorylation at eIF2α or MRS augmented the role of the other, suggesting a cross-talk between MRS and eIF2α for efficient translational inhibition. This work reveals a unique mode of regulation of global translation as mediated by aminoacyl-tRNA synthetase, specifically MRS, which we herein identified as a previously unidentified GCN2 substrate. In addition, our research suggests a dual role for MRS: (i) as a coregulator with eIF2α for GCN2-mediated translational inhibition; and (ii) as a coupler of translational inhibition and DNA repair following DNA damage by releasing bound tumor suppressor AIMP3 for its nuclear translocation.
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Abstract
Over the past decade, the identification of cancer-associated factors has been a subject of primary interest not only for understanding the basic mechanisms of tumorigenesis but also for discovering the associated therapeutic targets. However, aminoacyl-tRNA synthetases (ARSs) have been overlooked, mostly because many assumed that they were simply 'housekeepers' that were involved in protein synthesis. Mammalian ARSs have evolved many additional domains that are not necessarily linked to their catalytic activities. With these domains, they interact with diverse regulatory factors. In addition, the expression of some ARSs is dynamically changed depending on various cellular types and stresses. This Analysis article addresses the potential pathophysiological implications of ARSs in tumorigenesis.
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Affiliation(s)
- Sunghoon Kim
- Medicinal Bioconvergence Research Center, WCU Department of Molecular Medicine and Biopharmaceutical Sciences, Seoul National University, Seoul 151-742, Republic of Korea.
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25
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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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26
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Choi JW, Kim DG, Lee AE, Kim HR, Lee JY, Kwon NH, Shin YK, Hwang SK, Chang SH, Cho MH, Choi YL, Kim J, Oh SH, Kim B, Kim SY, Jeon HS, Park JY, Kang HP, Park BJ, Han JM, Kim S. Cancer-associated splicing variant of tumor suppressor AIMP2/p38: pathological implication in tumorigenesis. PLoS Genet 2011; 7:e1001351. [PMID: 21483803 PMCID: PMC3069106 DOI: 10.1371/journal.pgen.1001351] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Accepted: 02/23/2011] [Indexed: 11/26/2022] Open
Abstract
Although ARS-interacting multifunctional protein 2 (AIMP2, also named as MSC p38) was first found as a component for a macromolecular tRNA synthetase complex, it was recently discovered to dissociate from the complex and work as a potent tumor suppressor. Upon DNA damage, AIMP2 promotes apoptosis through the protective interaction with p53. However, it was not demonstrated whether AIMP2 was indeed pathologically linked to human cancer. In this work, we found that a splicing variant of AIMP2 lacking exon 2 (AIMP2-DX2) is highly expressed by alternative splicing in human lung cancer cells and patient's tissues. AIMP2-DX2 compromised pro-apoptotic activity of normal AIMP2 through the competitive binding to p53. The cells with higher level of AIMP2-DX2 showed higher propensity to form anchorage-independent colonies and increased resistance to cell death. Mice constitutively expressing this variant showed increased susceptibility to carcinogen-induced lung tumorigenesis. The expression ratio of AIMP2-DX2 to normal AIMP2 was increased according to lung cancer stage and showed a positive correlation with the survival of patients. Thus, this work identified an oncogenic splicing variant of a tumor suppressor, AIMP2/p38, and suggests its potential for anti-cancer target. Lung cancer is one of the most common cancers and a leading cause of death resulting from cancer. Despite intensive investigation, effective therapeutic targets and reliable biomarkers are still limited. Here we found that a tumor suppressor, AIMP2 (MSC p38), produces a variant lacking a part of its structure in cancer tissues. We designated it AIMP2-DX2. This smaller version of AIMP2 compromises the normal tumor suppressive activity of AIMP2 and induces tumor formation. We also found that the expression of AIMP2-DX2 was increased according to cancer progression. In addition, the patients with higher expression of AIMP2-DX2 showed lower survival than those with lower levels of this variant. Suppression of AIMP2-DX2 slowed tumor growth, suggesting it as a new therapeutic target. In summary, this work newly identified a tumor-inducing factor, AIMP2-DX2, that can be used as a therapeutic target and biomarker associated with lung cancer.
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Affiliation(s)
- Jin Woo Choi
- Medicinal Bioconvergence Research Center, Seoul National University, Seoul, Korea
| | - Dae Gyu Kim
- Medicinal Bioconvergence Research Center, Seoul National University, Seoul, Korea
| | - Al-Eum Lee
- Medicinal Bioconvergence Research Center, Seoul National University, Seoul, Korea
| | - Hye Rim Kim
- Medicinal Bioconvergence Research Center, Seoul National University, Seoul, Korea
| | - Jin Young Lee
- Medicinal Bioconvergence Research Center, Seoul National University, Seoul, Korea
| | - Nam Hoon Kwon
- Medicinal Bioconvergence Research Center, Seoul National University, Seoul, Korea
| | - Young Kee Shin
- Laboratory of Molecular Pathology, College of Pharmacy, Seoul National University, Seoul, Korea
| | - Soon-Kyung Hwang
- College of Veterinary Medicine, Seoul National University, Seoul, Korea
| | - Seung-Hee Chang
- College of Veterinary Medicine, Seoul National University, Seoul, Korea
| | - Myung-Haing Cho
- College of Veterinary Medicine, Seoul National University, Seoul, Korea
| | - Yoon-La Choi
- Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Jhingook Kim
- Department of Thoracic and Cardiovascular Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Seung Hyun Oh
- National Cancer Center, Research Institute, Goyang, Korea
| | - Bora Kim
- National Cancer Center, Research Institute, Goyang, Korea
| | - Soo-Youl Kim
- National Cancer Center, Research Institute, Goyang, Korea
| | - Hyo-Sung Jeon
- Department of Biochemistry, School of Medicine, Kyungpook National University, Daegu, Korea
| | - Jae Yong Park
- Department of Internal Medicine, School of Medicine, Kyungpook National University, Daegu, Korea
| | - Hyunseok Peter Kang
- Department of Pathology and Laboratory Medicine, Roswell Cancer Park Institute, Buffalo, New York, United States of America
| | - Bum Joon Park
- Department of Molecular Biology, Pusan National University, Pusan, Korea
| | - Jung Min Han
- Medicinal Bioconvergence Research Center, Seoul National University, Seoul, Korea
- WCU Department of Molecular Medicine and Biopharmaceutical Sciences, Seoul National University, Suwon, Korea
| | - Sunghoon Kim
- Medicinal Bioconvergence Research Center, Seoul National University, Seoul, Korea
- WCU Department of Molecular Medicine and Biopharmaceutical Sciences, Seoul National University, Suwon, Korea
- * E-mail:
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27
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Oh YS, Kim DG, Kim G, Choi EC, Kennedy BK, Suh Y, Park BJ, Kim S. Downregulation of lamin A by tumor suppressor AIMP3/p18 leads to a progeroid phenotype in mice. Aging Cell 2010; 9:810-22. [PMID: 20726853 DOI: 10.1111/j.1474-9726.2010.00614.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Although AIMP3/p18 is normally associated with the macromolecular tRNA synthetase complex, recent reports have revealed a new role of AIMP3 in tumor suppression. In this study, we generated a transgenic mouse that overexpresses AIMP3 and characterized the associated phenotype in vivo and in vitro. Surprisingly, the AIMP3 transgenic mouse exhibited a progeroid phenotype, and the cells that overexpressed AIMP3 showed accelerated senescence and defects in nuclear morphology. We found that overexpression of AIMP3 resulted in proteasome-dependent degradation of mature lamin A, but not of lamin C, prelamin A, or progerin. The resulting imbalance in the protein levels of lamin A isoforms, namely altered stoichiometry of prelamin A and progerin to lamin A, appeared to be responsible for a phenotype that resembled progeria. An increase in the level of endogenous AIMP3 has been observed in aged human tissues and cells. The findings in this report suggest that AIMP3 is a specific regulator of mature lamin A and imply that enhanced expression of AIMP3 might be a factor driving cellular and/or organismal aging.
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Affiliation(s)
- Young Sun Oh
- Center for Medicinal Protein Network and Systems Biology, Seoul National University, Korea
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28
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Karanasios E, Simos G. Building arks for tRNA: Structure and function of the Arc1p family of non-catalytic tRNA-binding proteins. FEBS Lett 2010; 584:3842-9. [DOI: 10.1016/j.febslet.2010.08.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2010] [Revised: 08/14/2010] [Accepted: 08/16/2010] [Indexed: 11/16/2022]
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29
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Park SG, Choi EC, Kim S. Aminoacyl-tRNA synthetase-interacting multifunctional proteins (AIMPs): a triad for cellular homeostasis. IUBMB Life 2010; 62:296-302. [PMID: 20306515 DOI: 10.1002/iub.324] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Aminoacyl-tRNA synthetases (ARSs) are highly conserved for efficient and precise translation of genetic codes. In higher eukaryotic systems, several different ARSs including glutamyl-prolyl-, isoelucyl-, leucyl-, methionyl-, glutaminyl-, lysyl-, arginyl-, and aspartyl-tRNA synthetase form a macromolecular protein complex with three nonenzymatic cofactors (AIMP1/p43, AIMP2/p38, and AIMP3/p18). Although the structure and functional implications for this complex formation are not completely understood, rapidly accumulating evidences suggest that this complex would work as a molecular hub linked to the multiple signaling pathways that involve the components of enzymes and cofactors. In this article, the roles of three nonenzymatic components of the multi-tRNA synthetase complex in the assembly of the components and in cell regulation are addressed.
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Affiliation(s)
- Sang Gyu Park
- Department of Biomedical Science, CHA University, Yeoksam-dong, Kangnam-gu, Seoul, Korea
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30
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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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31
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Li CJ, Chang JK, Chou CH, Wang GJ, Ho ML. The PI3K/Akt/FOXO3a/p27Kip1 signaling contributes to anti-inflammatory drug-suppressed proliferation of human osteoblasts. Biochem Pharmacol 2009; 79:926-37. [PMID: 19883628 DOI: 10.1016/j.bcp.2009.10.019] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2009] [Revised: 10/21/2009] [Accepted: 10/21/2009] [Indexed: 12/17/2022]
Abstract
Akt has been reported to suppress p27(Kip1) promoter activity through Forkhead box O (FOXO) in different kinds of cells. Previous studies indicated that anti-inflammatory drugs up-regulated p27(Kip1), and this effect might play an important role in anti-inflammatory drug-induced cell cycle arrest of human osteoblasts (hOBs). In this study, we hypothesized that these drugs might increase p27(Kip1) expression in hOBs by altering the Akt/FOXO signaling. We tested this hypothesis by examining the influences of three anti-inflammatory drugs on the levels and/or activities of Akt, FOXO and p27(Kip1) as well as the relationship between these factors and proliferation of hOBs. We tested the effects of indomethacin (10(-5) and 10(-4)M), celecoxib (10(-6) and 10(-5)M), and dexamethasone (10(-7) and 10(-6)M) using PI3K inhibitor, LY294002 (10(-5)M) as the basis of comparison. The three drugs suppressed the canonical level of phosphorylated Akt in hOBs. This was accompanied by elevated FOXO3a level and increased promoter activity, mRNA expression and protein level of p27(Kip1). Furthermore, the anti-inflammatory drugs suppressed the EGF-induced increases in proliferation, phosphorylation, and nucleus translocation of Akt. Simultaneously, they suppressed EGF-induced decreases of FOXO3a nucleus accumulation and p27(Kip1) mRNA expression. On the other hand, FOXO silencing significantly attenuated the drug-induced up-regulation of p27(Kip1) and suppression of proliferation in hOBs. To the best of our knowledge, this study represents the first to demonstrate that Akt/FOXO3a/p27(Kip1) pathway contributes to suppression of hOB proliferation by anti-inflammatory drugs. We suggest that anti-inflammatory drugs suppress hOB proliferation, at least partly, through inactivating Akt, activating FOXO3a, and eventually up-regulating p27(Kip1) expression.
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Affiliation(s)
- Ching-Ju Li
- Department of Physiology, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
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32
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Choi JW, Um JY, Kundu JK, Surh YJ, Kim S. Multidirectional tumor-suppressive activity of AIMP2/p38 and the enhanced susceptibility of AIMP2 heterozygous mice to carcinogenesis. Carcinogenesis 2009; 30:1638-44. [PMID: 19622630 DOI: 10.1093/carcin/bgp170] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Aminoacyl-transfer ribonucleic acid (tRNA) synthetases-interacting multifunctional protein (AIMP) 2 is a factor associated with the macromolecular protein synthesis machinery consisting of nine different aminoacyl-tRNA synthetases and three non-enzymatic factors. However, it was shown to work as a multifaceted regulator through the versatile interactions with diverse signal mediators. For instance, it can mediate pro-apoptotic response to DNA damage and tumor necrosis factor-alpha (TNF-alpha) stimulus and growth-arresting signal by transforming growth factor (TGF)-beta. Considering that these pathways are critically implicated in the control of tumorigenesis, AIMP2 is expected to work as a potent tumor suppressor with broad coverage against different cancer types. Here we investigated whether AIMP2 would give gene dosage effect on its pro-apoptotic and anti-proliferative activities using the wild-type, hetero- and homozygous AIMP2 cells and whether AIMP2 would be critical in preventing tumorigenesis using different in vivo tumor models. Both the apoptotic responses to DNA damage and TNF-alpha and sensitivity to growth arresting TGF-beta signal were reduced in AIMP2 hetero- and homozygous cells compared with the wild-type cells in dose-dependent manner. In all the in vivo carcinogenesis experiments, reduction of AIMP2 level in heterozygous AIMP2 mice provided higher susceptibility to tumor formation. Thus, this work proves the functional significance of AIMP2 in determination of cell proliferation and death, and as a haploinsufficient tumor suppressor.
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Affiliation(s)
- Jin Woo Choi
- Center for Medicinal Protein Network and Systems Biology, College of Pharmacy, Seoul National University, Seoul 151-742, Korea
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33
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Choi JW, Kim DG, Park MC, Um JY, Han JM, Park SG, Choi EC, Kim S. AIMP2 promotes TNFalpha-dependent apoptosis via ubiquitin-mediated degradation of TRAF2. J Cell Sci 2009; 122:2710-5. [PMID: 19584093 DOI: 10.1242/jcs.049767] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
AIMP2 (aminoacyl-tRNA synthetase interacting multifunctional protein 2; also known as JTV-1) was first identified as p38 in a macromolecular protein complex that consisted of nine different aminoacyl-tRNA synthetases and two other auxiliary factors. AIMP2 also plays pivotal roles in the regulation of cell proliferation and death. Although AIMP2 was previously shown to augment TNFalpha-induced cell death, its working mechanism in this signal pathway was not understood. Here, we investigate the functional significance and mode of action of AIMP2 in TNFalpha signaling. TNFalpha-induced cell death was compromised in AIMP2-deficient or -suppressed cells and exogenous supplementation of AIMP2 augmented apoptotic sensitivity to TNFalpha signaling. This activity was confirmed by the AIMP2-dependent increase of IkappaB and suppression of NFkappaB. We found binding of AIMP2 to TRAF2, a key player in the TNFalpha signaling pathway. AIMP2 augmented the association of an E3 ubiquitin ligase, c-IAP1, with TRAF2, causing ubiquitin-dependent degradation of TRAF2. These findings suggest that AIMP2 can mediate the pro-apoptotic activity of TNFalpha via the downregulation of TRAF2 expression.
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Affiliation(s)
- Jin Woo Choi
- Center for Medicinal Protein Network and Systems Biology, Department of Molecular Medicine, College of Pharmacy, Seoul National University, Seoul 151-742, Korea
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Lee WG, Demirci U, Khademhosseini A. Microscale electroporation: challenges and perspectives for clinical applications. Integr Biol (Camb) 2009; 1:242-51. [PMID: 20023735 DOI: 10.1039/b819201d] [Citation(s) in RCA: 126] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Microscale engineering plays a significant role in developing tools for biological applications by miniaturizing devices and providing controllable microenvironments for in vitro cell research. Miniaturized devices offer numerous benefits in comparison to their macroscale counterparts, such as lower use of expensive reagents, biomimetic environments, and the ability to manipulate single cells. Microscale electroporation is one of the main beneficiaries of microscale engineering as it provides spatial and temporal control of various electrical parameters. Microscale electroporation devices can be used to reduce limitations associated with the conventional electroporation approaches such as variations in the local pH, electric field distortion, sample contamination, and the difficulties in transfecting and maintaining the viability of desired cell types. Here, we present an overview of recent advances of the microscale electroporation methods and their applications in biology, as well as current challenges for its use for clinical applications. We categorize microscale electroporation into microchannel and microcapillary electroporation. Microchannel-based electroporation can be used for transfecting cells within microchannels under dynamic flow conditions in a controlled and high-throughput fashion. In contrast, microcapillary-based electroporation can be used for transfecting cells within controlled reaction chambers under static flow conditions. Using these categories we examine the use of microscale electroporation for clinical applications related to HIV-1, stem cells, cancer and other diseases and discuss the challenges in further advancing this technology for use in clinical medicine and biology.
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Affiliation(s)
- Won Gu Lee
- Center for Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
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35
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Nechushtan H, Kim S, Kay G, Razin E. Chapter 1 The Physiological Role of Lysyl tRNA Synthetase in the Immune System. Adv Immunol 2009; 103:1-27. [DOI: 10.1016/s0065-2776(09)03001-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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36
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Abstract
Aminoacylation of transfer RNAs establishes the rules of the genetic code. The reactions are catalyzed by an ancient group of 20 enzymes (one for each amino acid) known as aminoacyl tRNA synthetases (AARSs). Surprisingly, the etiology of specific diseases-including cancer, neuronal pathologies, autoimmune disorders, and disrupted metabolic conditions-is connected to specific aminoacyl tRNA synthetases. These connections include heritable mutations in the genes for tRNA synthetases that are causally linked to disease, with both dominant and recessive disease-causing mutations being annotated. Because some disease-causing mutations do not affect aminoacylation activity or apparent enzyme stability, the mutations are believed to affect functions that are distinct from aminoacylation. Examples include enzymes that are secreted as procytokines that, after activation, operate in pathways connected to the immune system or angiogenesis. In addition, within cells, synthetases form multiprotein complexes with each other or with other regulatory factors and in that way control diverse signaling pathways. Although much has been uncovered in recent years, many novel functions, disease connections, and interpathway connections of tRNA synthetases have yet to be worked out.
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