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Kulkarni S, Rubio MAT, Hegedűsová E, Ross RL, Limbach PA, Alfonzo JD, Paris Z. Preferential import of queuosine-modified tRNAs into Trypanosoma brucei mitochondrion is critical for organellar protein synthesis. Nucleic Acids Res 2021; 49:8247-8260. [PMID: 34244755 PMCID: PMC8373054 DOI: 10.1093/nar/gkab567] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 05/28/2021] [Accepted: 06/21/2021] [Indexed: 11/13/2022] Open
Abstract
Transfer RNAs (tRNAs) are key players in protein synthesis. To be fully active, tRNAs undergo extensive post-transcriptional modifications, including queuosine (Q), a hypermodified 7-deaza-guanosine present in the anticodon of several tRNAs in bacteria and eukarya. Here, molecular and biochemical approaches revealed that in the protozoan parasite Trypanosoma brucei, Q-containing tRNAs have a preference for the U-ending codons for asparagine, aspartate, tyrosine and histidine, analogous to what has been described in other systems. However, since a lack of tRNA genes in T. brucei mitochondria makes it essential to import a complete set from the cytoplasm, we surprisingly found that Q-modified tRNAs are preferentially imported over their unmodified counterparts. In turn, their absence from mitochondria has a pronounced effect on organellar translation and affects function. Although Q modification in T. brucei is globally important for codon selection, it is more so for mitochondrial protein synthesis. These results provide a unique example of the combined regulatory effect of codon usage and wobble modifications on protein synthesis; all driven by tRNA intracellular transport dynamics.
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Affiliation(s)
- Sneha Kulkarni
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic.,Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Mary Anne T Rubio
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic.,Department of Microbiology and The Center for RNA Biology, The Ohio State University, Columbus, OH, USA
| | - Eva Hegedűsová
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Robert L Ross
- Metabolomics Mass Spectrometry Core, Department of Cancer Biology, University of Cincinnati, Cincinnati, OH, USA
| | - Patrick A Limbach
- Rieveschl Laboratories for Mass Spectrometry, Department of Chemistry, University of Cincinnati, Cincinnati, OH, USA
| | - Juan D Alfonzo
- Department of Microbiology and The Center for RNA Biology, The Ohio State University, Columbus, OH, USA
| | - Zdeněk Paris
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic.,Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
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2
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Niazi AK, Mileshina D, Cosset A, Val R, Weber-Lotfi F, Dietrich A. Targeting nucleic acids into mitochondria: progress and prospects. Mitochondrion 2012; 13:548-58. [PMID: 22609422 DOI: 10.1016/j.mito.2012.05.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Accepted: 05/14/2012] [Indexed: 12/18/2022]
Abstract
Given the essential functions of these organelles in cell homeostasis, their involvement in incurable diseases and their potential in biotechnological applications, genetic transformation of mitochondria has been a long pursued goal that has only been reached in a couple of unicellular organisms. The challenge led scientists to explore a wealth of different strategies for mitochondrial delivery of DNA or RNA in living cells. These are the subject of the present review. Targeting DNA into the organelles currently shows promise but remarkably a number of alternative approaches based on RNA trafficking were also established and will bring as well major contributions.
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Affiliation(s)
- Adnan Khan Niazi
- Institut de Biologie Moléculaire des Plantes, CNRS and Université de Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France
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3
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Tubulin polymerization promoting protein (TPPP) ortholog from Suberites domuncula and comparative analysis of TPPP/p25 gene family. Biologia (Bratisl) 2010. [DOI: 10.2478/s11756-010-0147-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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4
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Lynn MA, McMaster WR. Leishmania: conserved evolution--diverse diseases. Trends Parasitol 2008; 24:103-5. [PMID: 18255339 DOI: 10.1016/j.pt.2007.11.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2007] [Revised: 11/23/2007] [Accepted: 11/28/2007] [Indexed: 10/22/2022]
Abstract
The landmark completion of the Leishmania major genome sequence and the recent publication of the L. infantum and L. braziliensis genomes revealed the surprising result that, although separated by 15-50 million years of evolution, the Leishmania genomes are highly conserved and have less than 1% species-specific genes. Yet, these three species of Leishmania cause distinctive and diverse diseases in humans. Here, we discuss these findings together with recent microarray and proteomics studies and highlight their importance in understanding Leishmania disease phenotypes.
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Affiliation(s)
- Miriam A Lynn
- Immunity and Infection Research Centre, Vancouver Coastal Health Institute, and the Department of Medical Genetics, University of British Columbia, 2660 Oak Street, Vancouver, V6H 3Z6 BC, Canada
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5
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Kolesnikova OA, Entelis NS, Jacquin-Becker C, Goltzene F, Chrzanowska-Lightowlers ZM, Lightowlers RN, Martin RP, Tarassov I. Nuclear DNA-encoded tRNAs targeted into mitochondria can rescue a mitochondrial DNA mutation associated with the MERRF syndrome in cultured human cells. Hum Mol Genet 2004; 13:2519-34. [PMID: 15317755 DOI: 10.1093/hmg/ddh267] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Mitochondrial DNA (mtDNA) mutations are an important cause of human disease for which there is no efficient treatment. Our aim was to determine whether the A8344G mitochondrial tRNA(Lys) mutation, which can cause the MERRF (myoclonic epilepsy with ragged-red fibers) syndrome, could be complemented by targeting tRNAs into mitochondria from the cytosol. Import of small RNAs into mitochondria has been demonstrated in many organisms, including protozoans, plants, fungi and animals. Although human mitochondria do not import tRNAs in vivo, we previously demonstrated that some yeast tRNA derivatives can be imported into isolated human mitochondria. We show here that yeast tRNALys derivatives expressed in immortalized human cells and in primary human fibroblasts are partially imported into mitochondria. Imported tRNAs are correctly aminoacylated and are able to participate in mitochondrial translation. In transmitochondrial cybrid cells and in patient-derived fibroblasts bearing the MERRF mutation, import of tRNALys is accompanied by a partial rescue of mitochondrial functions affected by the mutation such as mitochondrial translation, activity of respiratory complexes, electrochemical potential across the mitochondrial membrane and respiration rate. Import of a tRNALys with a mutation in the anticodon preventing recognition of the lysine codons does not lead to any rescue, whereas downregulation of the transgenic tRNAs by small interfering RNA (siRNA) transiently abolishes the functional rescue, showing that this rescue is due to the import. These findings prove for the first time the functionality of imported tRNAs in human mitochondria in vivo and highlight the potential for exploiting the RNA import pathway to treat patients with mtDNA diseases.
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Affiliation(s)
- Olga A Kolesnikova
- CNRS-FRE 2375, Institute of Physiology and Biological Chemistry, Université Louis Pasteur, 21 René Descartes, 67084 Strasbourg, France
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6
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Tan THP, Pach R, Crausaz A, Ivens A, Schneider A. tRNAs in Trypanosoma brucei: genomic organization, expression, and mitochondrial import. Mol Cell Biol 2002; 22:3707-17. [PMID: 11997507 PMCID: PMC133840 DOI: 10.1128/mcb.22.11.3707-3716.2002] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The mitochondrial genome of Trypanosoma brucei does not encode tRNAs. Consequently, all mitochondrial tRNAs are imported from the cytosol and originate from nucleus-encoded genes. Analysis of all currently available T. brucei sequences revealed that its genome carries 50 tRNA genes representing 40 different isoacceptors. The identified set is expected to be nearly complete since all but four codons are accounted for. The number of tRNA genes in T. brucei is very low for a eukaryote and lower than those of many prokaryotes. Using quantitative Northern analysis we have determined the absolute abundance in the cell and the mitochondrion of a group of 15 tRNAs specific for 12 amino acids. Except for the initiator type tRNA(Met), which is cytosol specific, the cytosolic and the mitochondrial sets of tRNAs were qualitatively identical. However, the extent of mitochondrial localization was variable for the different tRNAs, ranging from 1 to 7.5% per cell. Finally, by using transgenic cell lines in combination with quantitative Northern analysis it was shown that import of tRNA(Leu)(CAA) is independent of its 5'-genomic context, suggesting that the in vivo import substrate corresponds to the mature, fully processed tRNA.
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Affiliation(s)
- Timothy H P Tan
- Department of Biology/Zoology, University of Fribourg, CH-1700 Fribourg, Switzerland
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Crain PF, Alfonzo JD, Rozenski J, Kapushoc ST, McCloskey JA, Simpson L. Modification of the universally unmodified uridine-33 in a mitochondria-imported edited tRNA and the role of the anticodon arm structure on editing efficiency. RNA (NEW YORK, N.Y.) 2002; 8:752-761. [PMID: 12088148 PMCID: PMC1370294 DOI: 10.1017/s1355838202022045] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Editing of tRNA has a wide phylogenetic distribution among eukaryotes and in some cases serves to expand the decoding capacity of the target tRNA. We previously described C-to-U editing of the wobble position of the imported tRNA(Trp) in Leishmania mitochondria, which is essential for decoding UGA codons as tryptophan. Here we show the complete set of nucleotide modifications in the anticodon arm of the mitochondrial and cytosolic tRNA(Trp) as determined by electrospray ionization mass spectrometry. This analysis revealed extensive mitochondria-specific posttranscriptional modifications, including the first example of thiolation of U33, the "universally unmodified" uridine. In light of the known rigidity imparted on sugar conformation by thiolation, our discovery of a thiolated U33 suggests that conformational flexibility is not a universal feature of the anticodon structural signature. In addition, the in vivo analysis of tRNA(Trp) variants presented shows a single base-pair reversal in the anticodon stem of tRNA(Trp) is sufficient to abrogate editing in vivo, indicating that subtle changes in anticodon structure can have drastic effects on editing efficiency.
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Affiliation(s)
- Pamela F Crain
- Department of Medicinal Chemistry, University of Utah, Salt Lake City 84112, USA
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Abstract
Mitochondria, though containing their own genome, import the vast majority of their macromolecular components from the cytoplasm. If the mechanisms of pre-protein import are well understood, the import of nuclear-coded RNAs into mitochondria was investigated to a much lesser extent. This targeting, if not universal, is widely spread among species. The origin and the mechanisms of RNA import seem to differ from one system to another and striking differences are observed even in closely related species. We describe data concerning the various experimental systems of studying RNA import with emphasis on the model of the yeast Saccharomyces cerevisiae, which was studied in our laboratory. We compare various requirements of RNA import into mitochondria in different species and demonstrate that this pathway can be transferred from yeast to human cells, in which tRNAs normally are not imported. We speculate on the possibility to use RNA import for biomedical purposes.
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Affiliation(s)
- N S Entelis
- FRE 2168 CNRS, 21, rue René Descartes, 67084 Strasbourg, France
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9
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Abstract
Sequence information from an increasing number of complete mitochondrial genomes indicates that a large number of evolutionary distinct organisms import nucleus-encoded tRNAs. In the past five years, much research has been initiated on the features of imported tRNAs, the mechanism and the energetics of the process as well as on the components of the import machinery. In summary, these studies show that the import systems of different species exhibit some unique features, suggesting that more than one mechanism might exist to import tRNAs.
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Affiliation(s)
- A Schneider
- André Schneider is at the University of Fribourg, Institute of Zoology, Dept of Biology, Pérolles, CH-1700, Fribourg, Switzerland.
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Kapushoc ST, Alfonzo JD, Rubio MA, Simpson L. End processing precedes mitochondrial importation and editing of tRNAs in Leishmania tarentolae. J Biol Chem 2000; 275:37907-14. [PMID: 10993905 DOI: 10.1074/jbc.m007838200] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
All mitochondrial tRNAs in Leishmania tarentolae are encoded in the nuclear genome and imported into the mitochondrion from the cytosol. One imported tRNA (tRNA(Trp)) is edited by a C to U modification at the first position of the anticodon. To determine the in vivo substrates for mitochondrial tRNA importation as well as tRNA editing, we examined the subcellular localization and extent of 5'- and 3'-end maturation of tRNA(Trp)(CCA), tRNA(Ile)(UAU), tRNA(Gln)(CUG), tRNA(Lys)(UUU), and tRNA(Val)(CAC). Nuclear, cytosolic, and mitochondrial fractions were obtained with little cross-contamination, as determined by Northern analysis of specific marker RNAs. tRNA(Gln) was mainly cytosolic in localization; tRNA(Ile) and tRNA(Lys) were mainly mitochondrial; and tRNA(Trp) and tRNA(Val) were shared between the two compartments. 5'- and 3'-extended precursors of all five tRNAs were present only in the nuclear fraction, suggesting that the mature tRNAs represent the in vivo substrates for importation into the mitochondrion. Consistent with this model, T7-transcribed mature tRNA(Ile) underwent importation in vitro into isolated mitochondria more efficiently than 5'-extended precursor tRNA(Ile). 5'-Extended precursor tRNA(Trp) was found to be unedited, which is consistent with a mitochondrial localization of this editing reaction. T7-transcribed unedited tRNA(Trp) was imported in vitro more efficiently than edited tRNA(Trp), suggesting the presence of importation determinants in the anticodon.
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Affiliation(s)
- S T Kapushoc
- Departments of Molecular, Cell, and Developmental Biology and Microbiology, Immunology, and Molecular Genetics and the Howard Hughes Medical Institute, University of California, Los Angeles, California 90095, USA
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11
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Rubio MA, Liu X, Yuzawa H, Alfonzo JD, Simpson L. Selective importation of RNA into isolated mitochondria from Leishmania tarentolae. RNA (NEW YORK, N.Y.) 2000; 6:988-1003. [PMID: 10917595 PMCID: PMC1369975 DOI: 10.1017/s1355838200991519] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
All mitochondrial tRNAs in kinetoplastid protozoa are encoded in the nucleus and imported from the cytosol. Incubation of two in vitro-transcribed tRNAs, tRNA(Ile)(UAU) and tRNA(Gln)(CUG), with isolated mitochondria from Leishmania tarentolae, in the absence of any added cytosolic fraction, resulted in a protease-sensitive, ATP-dependent importation, as measured by nuclease protection. Evidence that nuclease protection represents importation was obtained by the finding that Bacillus subtilis pre-tRNA(Asp) was protected from nuclease digestion and was also cleaved by an intramitochondrial RNase P-like activity to produce the mature tRNA. The presence of a membrane potential is not required for in vitro importation. A variety of small synthetic RNAs were also found to be efficiently imported in vitro. The data suggest that there is a structural requirement for importation of RNAs greater than approximately 17 nt, and that smaller RNAs are apparently nonspecifically imported. The signals for importation of folded RNAs have not been determined, but the specificity of the process was illustrated by the higher saturation level of importation of the mainly mitochondria-localized tRNA(Ile) as compared to the level of importation of the mainly cytosol-localized tRNA(Gln). Furthermore, exchanging the D-arm between the tRNA(Ile) and the tRNA(Gln) resulted in a reversal of the in vitro importation behavior and this could also be interpreted in terms of tertiary structure specificity.
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Affiliation(s)
- M A Rubio
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, School of Medicine, 90095, USA
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12
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Nabholz CE, Horn EK, Schneider A. tRNAs and proteins are imported into mitochondria of Trypanosoma brucei by two distinct mechanisms. Mol Biol Cell 1999; 10:2547-57. [PMID: 10436011 PMCID: PMC25487 DOI: 10.1091/mbc.10.8.2547] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Import of tRNA into the mitochondrial matrix of Trypanosoma brucei was reconstituted in vitro. Efficient import required the hydrolysis of externally added ATP and was shown to be a carrier-mediated process depending on proteinaceous receptors on the surface of mitochondria. A partly synthetic tRNA(Tyr) as well as a physiological tRNA(Lys) were imported along the same pathway. Contrary to import of all matrix-localized proteins, tRNA import does not require a membrane potential. Furthermore, addition of an excess of import-competent tRNA had no effect on import of a mitochondrial matrix protein. In summary, these results show that tRNAs and proteins in T. brucei are imported by fundamentally different mechanisms.
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MESH Headings
- Adenosine Triphosphate/metabolism
- Aldehyde Oxidoreductases/metabolism
- Animals
- Base Sequence
- Biological Transport
- Exoribonucleases/chemistry
- Exoribonucleases/metabolism
- Mitochondria/metabolism
- Molecular Biology/methods
- Molecular Sequence Data
- Protozoan Proteins/metabolism
- RNA, Protozoan/metabolism
- RNA, Transfer/metabolism
- RNA, Transfer, Lys/metabolism
- RNA, Transfer, Tyr/chemistry
- RNA, Transfer, Tyr/metabolism
- Ribonuclease, Pancreatic/chemistry
- Ribonuclease, Pancreatic/metabolism
- Trypanosoma brucei brucei/metabolism
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Affiliation(s)
- C E Nabholz
- University of Fribourg, Institute of Zoology, Pérolles, CH-1700 Fribourg, Switzerland
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