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Giordano C, Morea V, Perli E, d'Amati G. The phenotypic expression of mitochondrial tRNA-mutations can be modulated by either mitochondrial leucyl-tRNA synthetase or the C-terminal domain thereof. Front Genet 2015; 6:113. [PMID: 25852750 PMCID: PMC4370040 DOI: 10.3389/fgene.2015.00113] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 03/04/2015] [Indexed: 11/23/2022] Open
Abstract
Mutations in mitochondrial (mt) DNA determine important human diseases. The majority of the known pathogenic mutations are located in transfer RNA (tRNA) genes and are responsible for a wide range of currently untreatable disorders. Experimental evidence both in yeast and in human cells has shown that the detrimental effects of mt-tRNA point mutations can be attenuated by increasing the expression of the cognate mt-aminoacyl-tRNA synthetases (aaRSs). In addition, constitutive high levels of isoleucyl-tRNA syntethase have been shown to reduce the penetrance of a homoplasmic mutation in mt-tRNAIle in a small kindred. More recently, we showed that the isolated carboxy-terminal domain of human mt-leucyl tRNA synthetase (LeuRS-Cterm) localizes to mitochondria and ameliorates the energetic defect in transmitochondrial cybrids carrying mutations either in the cognate mt-tRNALeu(UUR) or in the non-cognate mt-tRNAIle gene. Since the mt-LeuRS-Cterm does not possess catalytic activity, its rescuing ability is most likely mediated by a chaperon-like effect, consisting in the stabilization of the tRNA structure altered by the mutation. All together, these observations open potential therapeutic options for mt-tRNA mutations-associated diseases.
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Affiliation(s)
- Carla Giordano
- Department of Radiological, Oncological and Pathological Sciences, Sapienza University of Rome Rome, Italy
| | - Veronica Morea
- National Research Council of Italy, Institute of Molecular Biology and Pathology, Department of Biochemical Sciences, Sapienza University of Rome Rome, Italy
| | - Elena Perli
- Department of Radiological, Oncological and Pathological Sciences, Sapienza University of Rome Rome, Italy
| | - Giulia d'Amati
- Department of Radiological, Oncological and Pathological Sciences, Sapienza University of Rome Rome, Italy ; Pasteur Institute-Cenci Bolognetti Foundation Rome, Italy
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2
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Di Micco P, Fazzi D'Orsi M, Morea V, Frontali L, Francisci S, Montanari A. The yeast model suggests the use of short peptides derived from mt LeuRS for the therapy of diseases due to mutations in several mt tRNAs. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1843:3065-74. [PMID: 25261707 DOI: 10.1016/j.bbamcr.2014.09.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 09/09/2014] [Accepted: 09/11/2014] [Indexed: 01/23/2023]
Abstract
We have previously established a yeast model of mitochondrial (mt) diseases. We showed that defective respiratory phenotypes due to point-mutations in mt tRNA(Leu(UUR)), tRNA(Ile) and tRNA(Val) could be relieved by overexpression of both cognate and non-cognate nuclearly encoded mt aminoacyl-tRNA synthetases (aaRS) LeuRS, IleRS and ValRS. More recently, we showed that the isolated carboxy-terminal domain (Cterm) of yeast mt LeuRS, and even short peptides derived from the human Cterm, have the same suppressing abilities as the whole enzymes. In this work, we extend these results by investigating the activity of a number of mt aaRS from either class I or II towards a panel of mt tRNAs. The Cterm of both human and yeast mt LeuRS has the same spectrum of activity as mt aaRS belonging to class I and subclass a, which is the most extensive among the whole enzymes. Yeast Cterm is demonstrated to be endowed with mt targeting activity. Importantly, peptide fragments β30_31 and β32_33, derived from the human Cterm, have even higher efficiency as well as wider spectrum of activity, thus opening new avenues for therapeutic intervention. Bind-shifting experiments show that the β30_31 peptide directly interacts with human mt tRNA(Leu(UUR)) and tRNA(Ile), suggesting that the rescuing activity of isolated peptide fragments is mediated by a chaperone-like mechanism. Wide-range suppression appears to be idiosyncratic of LeuRS and its fragments, since it is not shared by Cterminal regions derived from human mt IleRS or ValRS, which are expected to have very different structures and interactions with tRNAs.
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Affiliation(s)
- Patrizio Di Micco
- Department of Biochemical Sciences "A. Rossi Fanelli", Sapienza University of Rome, Piazzale A. Moro 5, 00185 Rome, Italy
| | - Mario Fazzi D'Orsi
- Department of Biology and Biotechnologies "C. Darwin", Sapienza University of Rome, Piazzale A. Moro 5, 00185 Rome, Italy
| | - Veronica Morea
- National Research Council of Italy (CNR) - Institute of Biology, Molecular Medicine and Nanobiotechnology (IBMN), Sapienza University of Rome, Piazzale A. Moro 5, 00185 Rome, Italy
| | - Laura Frontali
- Department of Biology and Biotechnologies "C. Darwin", Sapienza University of Rome, Piazzale A. Moro 5, 00185 Rome, Italy; Pasteur Institute - Cenci Bolognetti Foundation, Sapienza University of Rome, Piazzale A. Moro 5, 00185 Rome, Italy
| | - Silvia Francisci
- Department of Biology and Biotechnologies "C. Darwin", Sapienza University of Rome, Piazzale A. Moro 5, 00185 Rome, Italy; Pasteur Institute - Cenci Bolognetti Foundation, Sapienza University of Rome, Piazzale A. Moro 5, 00185 Rome, Italy
| | - Arianna Montanari
- Department of Biology and Biotechnologies "C. Darwin", Sapienza University of Rome, Piazzale A. Moro 5, 00185 Rome, Italy.
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3
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Perli E, Giordano C, Pisano A, Montanari A, Campese AF, Reyes A, Ghezzi D, Nasca A, Tuppen HA, Orlandi M, Di Micco P, Poser E, Taylor RW, Colotti G, Francisci S, Morea V, Frontali L, Zeviani M, d'Amati G. The isolated carboxy-terminal domain of human mitochondrial leucyl-tRNA synthetase rescues the pathological phenotype of mitochondrial tRNA mutations in human cells. EMBO Mol Med 2014; 6:169-82. [PMID: 24413190 PMCID: PMC3927953 DOI: 10.1002/emmm.201303198] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 09/16/2013] [Accepted: 10/17/2013] [Indexed: 11/16/2022] Open
Abstract
Mitochondrial (mt) diseases are multisystem disorders due to mutations in nuclear or mtDNA genes. Among the latter, more than 50% are located in transfer RNA (tRNA) genes and are responsible for a wide range of syndromes, for which no effective treatment is available at present. We show that three human mt aminoacyl-tRNA syntethases, namely leucyl-, valyl-, and isoleucyl-tRNA synthetase are able to improve both viability and bioenergetic proficiency of human transmitochondrial cybrid cells carrying pathogenic mutations in the mt-tRNA(Ile) gene. Importantly, we further demonstrate that the carboxy-terminal domain of human mt leucyl-tRNA synthetase is both necessary and sufficient to improve the pathologic phenotype associated either with these "mild" mutations or with the "severe" m.3243A>G mutation in the mt-tRNA(L)(eu(UUR)) gene. Furthermore, we provide evidence that this small, non-catalytic domain is able to directly and specifically interact in vitro with human mt-tRNA(Leu(UUR)) with high affinity and stability and, with lower affinity, with mt-tRNA(Ile). Taken together, our results sustain the hypothesis that the carboxy-terminal domain of human mt leucyl-tRNA synthetase can be used to correct mt dysfunctions caused by mt-tRNA mutations.
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Affiliation(s)
- Elena Perli
- Department of Radiology, Oncology and Pathology, Sapienza University of RomeRome, Italy
- Pasteur Institute-Cenci Bolognetti FoundationRome, Italy
| | - Carla Giordano
- Department of Radiology, Oncology and Pathology, Sapienza University of RomeRome, Italy
| | - Annalinda Pisano
- Department of Radiology, Oncology and Pathology, Sapienza University of RomeRome, Italy
- Department of Internal Medicine and Medical Specialties, Sapienza University of RomeRome, Italy
| | - Arianna Montanari
- Department of Radiology, Oncology and Pathology, Sapienza University of RomeRome, Italy
- Pasteur Institute-Cenci Bolognetti FoundationRome, Italy
- Department of Biology and Biotechnologies ‘Charles Darwin’, Sapienza University of RomeRome, Italy
| | - Antonio F Campese
- Department of Molecular Medicine, Sapienza University of RomeRome, Italy
| | | | - Daniele Ghezzi
- Unit of Molecular Neurogenetics, The Foundation “Carlo Besta” Institute of Neurology IRCCSMilan, Italy
| | - Alessia Nasca
- Unit of Molecular Neurogenetics, The Foundation “Carlo Besta” Institute of Neurology IRCCSMilan, Italy
| | - Helen A Tuppen
- Wellcome Trust Center for Mitochondrial Research, Institute for Ageing and Health, Newcastle UniversityNewcastle upon Tyne, UK
| | - Maurizia Orlandi
- Department of Radiology, Oncology and Pathology, Sapienza University of RomeRome, Italy
- Department of Molecular Medicine, Sapienza University of RomeRome, Italy
| | - Patrizio Di Micco
- Department of Biochemical Sciences “A. Rossi Fanelli”, Sapienza University of RomeRome, Italy
| | - Elena Poser
- Department of Biochemical Sciences “A. Rossi Fanelli”, Sapienza University of RomeRome, Italy
| | - Robert W Taylor
- Wellcome Trust Center for Mitochondrial Research, Institute for Ageing and Health, Newcastle UniversityNewcastle upon Tyne, UK
| | - Gianni Colotti
- National Research Council of Italy, Institute of Molecular Biology and PathologyRome, Italy
| | - Silvia Francisci
- Pasteur Institute-Cenci Bolognetti FoundationRome, Italy
- Department of Biology and Biotechnologies ‘Charles Darwin’, Sapienza University of RomeRome, Italy
| | - Veronica Morea
- National Research Council of Italy, Institute of Molecular Biology and PathologyRome, Italy
| | - Laura Frontali
- Pasteur Institute-Cenci Bolognetti FoundationRome, Italy
- Department of Biology and Biotechnologies ‘Charles Darwin’, Sapienza University of RomeRome, Italy
| | | | - Giulia d'Amati
- Department of Radiology, Oncology and Pathology, Sapienza University of RomeRome, Italy
- Pasteur Institute-Cenci Bolognetti FoundationRome, Italy
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4
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Yao YN, Wang L, Wu XF, Wang ED. The processing of human mitochondrial leucyl-tRNA synthetase in the insect cells. FEBS Lett 2003; 534:139-42. [PMID: 12527375 DOI: 10.1016/s0014-5793(02)03833-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A His-tagged full-length cDNA of human mitochondrial leucyl-tRNA synthetase was expressed in a baculovirus system. The N-terminal sequence of the enzyme isolated from the mitochondria of insect cells was found to be IYSATGKWTKEYTL, indicating that the mitochondrial targeting signal peptide was cleaved between Ser39 and Ile40 after the enzyme precursor was translocated into mitochondria. The enzyme purified from mitochondria catalyzed the leucylation of Escherichia coli tRNA(1)(Leu)(CAG) and Aquifex aeolicus tRNA(Leu)(GAG) with higher catalytic activity in the leucylation of E. coli tRNA(Leu) than that previously expressed in E. coli without the N-terminal 21 residues.
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Affiliation(s)
- Yong Neng Yao
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, the Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, PR China
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5
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Bullard JM, Cai YC, Spremulli LL. Expression and characterization of the human mitochondrial leucyl-tRNA synthetase. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1490:245-58. [PMID: 10684970 DOI: 10.1016/s0167-4781(99)00240-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A cDNA clone encoding the human mitochondrial leucyl-tRNA synthetase (mtLeuRS) has been identified from the EST databases. Analysis of the protein encoded by this cDNA indicates that the protein is 903 amino acids in length and contains a mitochondrial signal sequence that is predicted to encompass the first 21 amino acids. Sequence analysis shows that this protein contains the characteristic motifs of class I aminoacyl-tRNA synthetases and regions of high homology to other mitochondrial and bacterial LeuRS proteins. The mature form of this protein has been cloned and expressed in Escherichia coli. Gel filtration indicates that human mtLeuRS is active in a monomeric state, with an apparent molecular mass of 101 kDa. The human mtLeuRS is capable of aminoacylating E. coli tRNA(Leu). Its activity is inhibited at high levels of either monovalent or divalent cations. K(M) and k(cat) values for ATP:PP(i) exchange and for the aminoacylation reaction have been determined.
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Affiliation(s)
- J M Bullard
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599-3290, USA
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6
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Landrieu I, Vandenbol M, Härtlein M, Portetelle D. Mitochondrial asparaginyl-tRNA synthetase is encoded by the yeast nuclear gene YCR24c. EUROPEAN JOURNAL OF BIOCHEMISTRY 1997; 243:268-73. [PMID: 9030748 DOI: 10.1111/j.1432-1033.1997.0268a.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
One of the open reading frames located on yeast Saccharomyces cerevisiae chromosome III, YCR24c, appeared to code for a protein of unknown function, but the predicted sequence showed similarity with asparaginyl-tRNA synthetase from Escherichia coli, with 38% amino acid identity. There is a putative mitochondrial targeting signal at the N-terminus of the YCR24c product. Northern blot analysis of total RNA from a wild-type strain sigma1278b confirmed that YCR24c was transcribed. Disruption of the chromosomal copy of YCR24c in a respiratory-competent haploid cell induced a petite phenotype, but did not affect cell viability. This respiratory-defective phenotype is typical for a mutation in a nuclear gene that induces a non-functional mitochondrial protein synthesis system. The protein encoded by YCR24c was expressed in Escherichia coli in a histidine-tagged form and isolated. The enzyme aminoacylated unfractionated Escherichia coli tRNA with asparagine. These results identified YCR24c as the structural gene for yeast mitochondrial asparaginyl-tRNA synthetase.
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Affiliation(s)
- I Landrieu
- Unité de Microbiologie, Faculté Universitaire des Sciences Agronomiques de Gembloux, Belgium
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7
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Li GY, Bécam AM, Slonimski PP, Herbert CJ. In vitro mutagenesis of the mitochondrial leucyl tRNA synthetase of Saccharomyces cerevisiae shows that the suppressor activity of the mutant proteins is related to the splicing function of the wild-type protein. MOLECULAR & GENERAL GENETICS : MGG 1996; 252:667-75. [PMID: 8917309 DOI: 10.1007/bf02173972] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The NAM2 gene of Saccharomyces cerevisiae encodes the mitochondrial leucyl tRNA synthetase (mLRS), which is necessary for the excision of the fourth intron of the mitochondrial cytb gene (bI4) and the fourth intron of the mitochondrial coxI gene (aI4), as well as for mitochondrial protein synthesis. Some dominant mutant alleles of the gene are able to suppress mutations that inactivate the bI4 maturase, which is essential for the excision of the introns aI4 and bI4. Here we report mutagenesis studies which focus on the splicing and suppressor functions of the protein. Small deletions in the C-terminal region of the protein preferentially reduce the splicing, but not the synthetase activity; and all the C-terminal deletions tested abolish the suppressor activity. Mutations which increase the volume of the residue at position 240 in the wild-type mLRS without introducing a charge, lead to a suppressor activity. The mutant 238C, which is located in the suppressor region, has a reduced synthetase activity and no detectable splicing activity. These data show that the splicing and suppressor functions are linked and that the suppressor activity of the mutant alleles results from a modification of the wild-type splicing activity.
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Affiliation(s)
- G Y Li
- Centre de Génétique Moléculaire, Laboratoire propre du CNRS associé á I'Université Pierre et Marie Curie, Gif-sur-Yvette, France
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8
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Abstract
All proteins encoded by mitochondrial DNA (mtDNA) are dependent on proteins encoded by nuclear genes for their synthesis and function. Recent developments in the identification of these genes and the elucidation of the roles their products play at various stages of mitochondrial gene expression are covered in this review, which focuses mainly on work with the yeast Saccharomyces cerevisiae. The high degree of evolutionary conservation of many cellular processes between this yeast and higher eukaryotes, the ease with which mitochondrial biogenesis can be manipulated both genetically and physiologically, and the fact that it will be the first organism for which a complete genomic sequence will be available within the next 2 to 3 years makes it the organism of choice for drawing up an inventory of all nuclear genes involved in mitochondrial biogenesis and for the identification of their counterparts in other organisms.
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Affiliation(s)
- L A Grivell
- Department of Molecular Cell Biology, University of Amsterdam, Netherlands
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9
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Dieckmann CL, Staples RR. Regulation of mitochondrial gene expression in Saccharomyces cerevisiae. INTERNATIONAL REVIEW OF CYTOLOGY 1994; 152:145-81. [PMID: 8206703 DOI: 10.1016/s0074-7696(08)62556-5] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- C L Dieckmann
- Department of Biochemistry, University of Arizona, Tucson 85721
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10
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Affiliation(s)
- H J Pel
- Department of Molecular Cell Biology, University of Amsterdam, The Netherlands
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11
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Monteilhet C, Lachacinski N, Aggerbeck LP. Cytoplasmic and periplasmic production of human apolipoprotein E in Escherichia coli using natural and bacterial signal peptides. Gene 1993; 125:223-8. [PMID: 8462877 DOI: 10.1016/0378-1119(93)90333-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
To understand the toxicity of high levels of heterologous human serum apolipoprotein E (ApoE) in Escherichia coli, as well as to prepare a system for producing the structural domains of this protein, plasmids were constructed in which the coding sequence of the N-terminal domain or all of ApoE followed E. coli or human apolipoprotein signal peptides (SP) or the N-terminal eleven amino acids (f10) of the gene 10-encoded protein of phage T7. High levels of production of the 22-kDa N-terminal domain (22K) of ApoE were obtained either as an f10::22K fusion protein, or using the natural SP, or SP derived from the periplasmic protein, alkaline phosphatase (PhoA), or from the outer membrane protein A (OmpA). Microsequencing showed that the SP of sPhoA::22K and sOmpA::22K, but not sApoE::22K, were correctly processed and, in the former cases, the protein could be released from the cells by osmotic shock. The extent of maturation of sPhoA::22K depended upon the host strain; with JM109, about 50% of the protein was not processed. Microsequencing of the f10::22K fusion protein, which could easily be purified following lysis of the cells, showed that the N-terminal methionine had been removed in agreement with the length parameter rule. Although considerable levels of the f10::ApoE fusion protein could be produced in the cytoplasm, production was markedly less using the PhoA signal peptide and the protein was not easily isolated following osmotic shock. The recombinant protein was biologically active after reconstitution with lipids in spite of the N-terminal modifications introduced.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- C Monteilhet
- Centre de Génétique Moléculaire, Centre National de la Recherche Scientifique, Gif-sur-Yvette, France
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