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Liu Y, Luo Z, Chen X, Yang X, Qi Q, Alifu M, Tao C, Cui W, Liu M, Wang W. Determinants of the interaction between the 5'-leader of HIV-1 genome and human lysyl-tRNA synthetase in reverse transcription primer release process. Biochem Biophys Res Commun 2024; 725:150252. [PMID: 38878758 DOI: 10.1016/j.bbrc.2024.150252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2024] [Revised: 06/04/2024] [Accepted: 06/10/2024] [Indexed: 07/06/2024]
Abstract
Reverse transcription of human immunodeficiency virus type 1 (HIV-1) initiates from the 3' end of human tRNALys3. The primer tRNALys3 is selectively packaged into the virus in the form of a complex with human lysyl-tRNA synthetase (LysRS). To facilitate reverse transcription initiation, part of the 5' leader (5'L) of HIV-1 genomic RNA (gRNA) evolves a tRNA anticodon-like element (TLE), which binds LysRS and releases tRNALys3 for primer annealing and reverse transcription initiation. Although TLE has been identified as a key element in 5'L responsible for LysRS binding, how the conformations and various hairpin structures of 5'L regulate 5'L-LysRS interaction is not fully understood. Here, these factors have been individually investigated using direct and competitive fluorescence anisotropy binding experiments. Our data showed that the conformation of 5'L significantly influences its binding affinity with LysRS. The 5'L conformation favoring gRNA dimerization and packaging exhibits much weaker binding affinity with LysRS compared to the alternative 5'L conformation that is not selected for packaging. Additionally, dimerization of 5'L impairs LysRS-5'L interaction. Furthermore, among various regions of 5'L, both the primer binding site/TLE domain and the stem-loop 3 are important for LysRS interaction, whereas the dimerization initiation site and the splicing donor plays a minor role. In contrast, the presence of the transacting responsive and the polyadenylation signal hairpins slightly inhibit LysRS binding. These findings reveal that the conformation and various regions of the 5'L of HIV-1 genome regulate its interaction with human LysRS and the reverse transcription primer release process.
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Affiliation(s)
- Yong Liu
- Institute of Life Sciences, Chongqing Medical University, Chongqing, China
| | - Zhi Luo
- Institute of Life Sciences, Chongqing Medical University, Chongqing, China
| | - Xiang Chen
- Institute of Life Sciences, Chongqing Medical University, Chongqing, China
| | - Xin Yang
- Institute of Life Sciences, Chongqing Medical University, Chongqing, China
| | - Qi Qi
- Institute of Life Sciences, Chongqing Medical University, Chongqing, China
| | - Mailikezhati Alifu
- Institute of Life Sciences, Chongqing Medical University, Chongqing, China
| | - Chengcheng Tao
- Institute of Life Sciences, Chongqing Medical University, Chongqing, China
| | - Wen Cui
- Institute of Life Sciences, Chongqing Medical University, Chongqing, China
| | - Mengmeng Liu
- Institute of Life Sciences, Chongqing Medical University, Chongqing, China.
| | - Wei Wang
- Institute of Life Sciences, Chongqing Medical University, Chongqing, China.
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2
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Giegé R, Eriani G. The tRNA identity landscape for aminoacylation and beyond. Nucleic Acids Res 2023; 51:1528-1570. [PMID: 36744444 PMCID: PMC9976931 DOI: 10.1093/nar/gkad007] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 12/21/2022] [Accepted: 01/03/2023] [Indexed: 02/07/2023] Open
Abstract
tRNAs are key partners in ribosome-dependent protein synthesis. This process is highly dependent on the fidelity of tRNA aminoacylation by aminoacyl-tRNA synthetases and relies primarily on sets of identities within tRNA molecules composed of determinants and antideterminants preventing mischarging by non-cognate synthetases. Such identity sets were discovered in the tRNAs of a few model organisms, and their properties were generalized as universal identity rules. Since then, the panel of identity elements governing the accuracy of tRNA aminoacylation has expanded considerably, but the increasing number of reported functional idiosyncrasies has led to some confusion. In parallel, the description of other processes involving tRNAs, often well beyond aminoacylation, has progressed considerably, greatly expanding their interactome and uncovering multiple novel identities on the same tRNA molecule. This review highlights key findings on the mechanistics and evolution of tRNA and tRNA-like identities. In addition, new methods and their results for searching sets of multiple identities on a single tRNA are discussed. Taken together, this knowledge shows that a comprehensive understanding of the functional role of individual and collective nucleotide identity sets in tRNA molecules is needed for medical, biotechnological and other applications.
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Affiliation(s)
- Richard Giegé
- Correspondence may also be addressed to Richard Giegé.
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3
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Cantara WA, Pathirage C, Hatterschide J, Olson ED, Musier-Forsyth K. Phosphomimetic S207D Lysyl-tRNA Synthetase Binds HIV-1 5'UTR in an Open Conformation and Increases RNA Dynamics. Viruses 2022; 14:1556. [PMID: 35891536 PMCID: PMC9315659 DOI: 10.3390/v14071556] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 07/08/2022] [Accepted: 07/13/2022] [Indexed: 01/25/2023] Open
Abstract
Interactions between lysyl-tRNA synthetase (LysRS) and HIV-1 Gag facilitate selective packaging of the HIV-1 reverse transcription primer, tRNALys3. During HIV-1 infection, LysRS is phosphorylated at S207, released from a multi-aminoacyl-tRNA synthetase complex and packaged into progeny virions. LysRS is critical for proper targeting of tRNALys3 to the primer-binding site (PBS) by specifically binding a PBS-adjacent tRNA-like element (TLE), which promotes release of the tRNA proximal to the PBS. However, whether LysRS phosphorylation plays a role in this process remains unknown. Here, we used a combination of binding assays, RNA chemical probing, and small-angle X-ray scattering to show that both wild-type (WT) and a phosphomimetic S207D LysRS mutant bind similarly to the HIV-1 genomic RNA (gRNA) 5'UTR via direct interactions with the TLE and stem loop 1 (SL1) and have a modest preference for binding dimeric gRNA. Unlike WT, S207D LysRS bound in an open conformation and increased the dynamics of both the PBS region and SL1. A new working model is proposed wherein a dimeric phosphorylated LysRS/tRNA complex binds to a gRNA dimer to facilitate tRNA primer release and placement onto the PBS. Future anti-viral strategies that prevent this host factor-gRNA interaction are envisioned.
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Affiliation(s)
- William A. Cantara
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA; (C.P.); (J.H.); (E.D.O.)
- Center for Retrovirus Research, The Ohio State University, Columbus, OH 43210, USA
- Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Chathuri Pathirage
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA; (C.P.); (J.H.); (E.D.O.)
- Center for Retrovirus Research, The Ohio State University, Columbus, OH 43210, USA
- Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
| | - Joshua Hatterschide
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA; (C.P.); (J.H.); (E.D.O.)
- Center for Retrovirus Research, The Ohio State University, Columbus, OH 43210, USA
- Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Erik D. Olson
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA; (C.P.); (J.H.); (E.D.O.)
- Center for Retrovirus Research, The Ohio State University, Columbus, OH 43210, USA
- Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
| | - Karin Musier-Forsyth
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA; (C.P.); (J.H.); (E.D.O.)
- Center for Retrovirus Research, The Ohio State University, Columbus, OH 43210, USA
- Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
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4
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Ruzzenente B, Assouline Z, Barcia G, Rio M, Boddaert N, Munnich A, Rötig A, Metodiev MD. Inhibition of mitochondrial translation in fibroblasts from a patient expressing the KARS p.(Pro228Leu) variant and presenting with sensorineural deafness, developmental delay, and lactic acidosis. Hum Mutat 2018; 39:2047-2059. [PMID: 30252186 DOI: 10.1002/humu.23657] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Revised: 09/03/2018] [Accepted: 09/22/2018] [Indexed: 01/12/2023]
Abstract
Aminoacyl-tRNA synthetases are ubiquitous enzymes, which universally charge tRNAs with their cognate amino acids for use in cytosolic or organellar translation. In humans, mutations in mitochondrial tRNA synthetases have been linked to different tissue-specific pathologies. Mutations in the KARS gene, which encodes both the cytosolic and mitochondrial isoform of lysyl-tRNA synthetase, cause predominantly neurological diseases that often involve deafness, but have also been linked to cardiomyopathy, developmental delay, and lactic acidosis. Using whole exome sequencing, we identified two compound heterozygous mutations, NM_001130089.1:c.683C>T p.(Pro228Leu) and NM_001130089.1:c.1438del p.(Leu480TrpfsX3), in a patient presenting with sensorineural deafness, developmental delay, hypotonia, and lactic acidosis. Nonsense-mediated mRNA decay eliminated the truncated mRNA transcript, rendering the patient hemizygous for the missense mutation. The c.683C>T mutation was previously described, but its pathogenicity remained unexamined. Molecular characterization of patient fibroblasts revealed a multiple oxidative phosphorylation deficiency due to impaired mitochondrial translation, but no evidence of inhibition of cytosolic translation. Reintroduction of wild-type mitochondrial KARS, but not the cytosolic isoform, rescued this phenotype confirming the disease-causing nature of p.(Pro228Leu) exchange and demonstrating the mitochondrial etiology of the disease. We propose that mitochondrial translation deficiency is the probable disease culprit in this and possibly other patients with mutations in KARS.
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Affiliation(s)
- Benedetta Ruzzenente
- INSERM UMR1163, Université Paris Descartes - Sorbonne Paris Cité, Institut Imagine, Paris, France
| | - Zahra Assouline
- Departments of Pediatrics, Neurology and Genetics, Hôpital Necker-Enfants-Malades, Paris, France
| | - Giulia Barcia
- Departments of Pediatrics, Neurology and Genetics, Hôpital Necker-Enfants-Malades, Paris, France
| | - Marlène Rio
- Departments of Pediatrics, Neurology and Genetics, Hôpital Necker-Enfants-Malades, Paris, France
| | - Nathalie Boddaert
- Department of pediatric radiology, INSERM 1000 and INSERM UMR1136, Hôpital Necker-Enfants-Malades AP-HP, Université Paris Descartes - Sorbonne Paris Cité, Institut Imagine, Paris, France
| | - Arnold Munnich
- INSERM UMR1163, Université Paris Descartes - Sorbonne Paris Cité, Institut Imagine, Paris, France.,Departments of Pediatrics, Neurology and Genetics, Hôpital Necker-Enfants-Malades, Paris, France
| | - Agnès Rötig
- INSERM UMR1163, Université Paris Descartes - Sorbonne Paris Cité, Institut Imagine, Paris, France
| | - Metodi D Metodiev
- INSERM UMR1163, Université Paris Descartes - Sorbonne Paris Cité, Institut Imagine, Paris, France
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5
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A second RNA-binding protein is essential for ethanol tolerance provided by the bacterial OLE ribonucleoprotein complex. Proc Natl Acad Sci U S A 2018; 115:E6319-E6328. [PMID: 29915070 DOI: 10.1073/pnas.1803191115] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
OLE (ornate, large, extremophilic) RNAs comprise a class of structured noncoding RNAs (ncRNAs) found in many extremophilic bacteria species. OLE RNAs constitute one of the longest and most widespread bacterial ncRNA classes whose major biochemical function remains unknown. In the Gram-positive alkaliphile Bacillus halodurans, OLE RNA is abundant, and localizes to the cell membrane by association with the transmembrane OLE-associated protein called OapA (formerly OAP). These characteristics, along with the well-conserved sequence and structural features of OLE RNAs, suggest that the OLE ribonucleoprotein (RNP) complex performs important biological functions. B. halodurans strains lacking OLE RNA (∆ole) or OapA (∆oapA) are less tolerant of cold (20 °C) and short-chain alcohols (e.g., ethanol). Here, we describe the effects of a mutant OapA (called PM1) that more strongly inhibits growth under cold or ethanol stress compared with strains lacking the oapA gene, even when wild-type OapA is present. This dominant-negative effect of PM1 is reversed by mutations that render OLE RNA nonfunctional. This finding demonstrates that the deleterious PM1 phenotype requires an intact RNP complex, and suggests that the complex has one or more additional undiscovered components. A genetic screen uncovered PM1 phenotype suppressor mutations in the ybzG gene, which codes for a putative RNA-binding protein of unknown biological function. We observe that YbzG protein (also called OapB) selectively binds OLE RNA in vitro, whereas a mutant version of the protein is not observed to bind OLE RNA. Thus, YbzG/OapB is an important component of the functional OLE RNP complex in B. halodurans.
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6
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Liu S, Comandur R, Jones CP, Tsang P, Musier-Forsyth K. Anticodon-like binding of the HIV-1 tRNA-like element to human lysyl-tRNA synthetase. RNA (NEW YORK, N.Y.) 2016; 22:1828-1835. [PMID: 27852925 PMCID: PMC5113203 DOI: 10.1261/rna.058081.116] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 09/10/2016] [Indexed: 06/06/2023]
Abstract
A critical step in the HIV-1 lifecycle involves reverse transcription of the viral genomic RNA (gRNA). Human tRNALys3 serves as a primer for transcription initiation and is selectively enriched in virus particles. Human lysyl-tRNA synthetase (hLysRS) is also packaged into virions. Recently, a tRNA-like element (TLE) within the HIV-1 gRNA was shown to mimic the global tRNA fold and bind competitively to hLysRS, suggesting a mechanism of tRNA targeting to the primer binding site (PBS) and release from the synthetase. Here, we use NMR to investigate hLysRS anticodon-binding domain (ACB) binding to six RNA oligonucleotides, including a hairpin derived from the HIV-1 gRNA TLE. We show that ACB interacts with submicromolar affinity to U-rich RNA oligonucleotides-the tRNALys3 anticodon stem-loop (ACSL), the WT TLE, and a nonanucleotide, U9. In contrast, the ACB bound only weakly to two TLE loop mutants and a C9 nonanucleotide. NMR chemical shift perturbations induced by each RNA indicate that the ACSL and the WT TLE both interact with the ACB in a strikingly similar manner. Taken together, these findings support the conclusion that tRNA mimicry by the HIV-1 genome leads to a highly specific protein-RNA interaction that facilitates efficient primer release from hLysRS prior to reverse transcription.
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Affiliation(s)
- Sheng Liu
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172, USA
| | - Roopa Comandur
- Department of Chemistry and Biochemistry, Center for Retrovirus Research and Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA
| | - Christopher P Jones
- Department of Chemistry and Biochemistry, Center for Retrovirus Research and Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA
| | - Pearl Tsang
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172, USA
| | - Karin Musier-Forsyth
- Department of Chemistry and Biochemistry, Center for Retrovirus Research and Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA
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7
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Rogers HH, Griffiths-Jones S. tRNA anticodon shifts in eukaryotic genomes. RNA (NEW YORK, N.Y.) 2014; 20:269-281. [PMID: 24442610 PMCID: PMC3923123 DOI: 10.1261/rna.041681.113] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 11/30/2013] [Indexed: 06/03/2023]
Abstract
Embedded in the sequence of each transfer RNA are elements that promote specific interactions with its cognate aminoacyl tRNA-synthetase. Although many such "identity elements" are known, their detection is difficult since they rely on unique structural signatures and the combinatorial action of multiple elements spread throughout the tRNA molecule. Since the anticodon is often a major identity determinant itself, it is possible to switch between certain tRNA functional types by means of anticodon substitutions. This has been shown to have occurred during the evolution of some genomes; however, the scale and relevance of "anticodon shifts" to the evolution of the tRNA multigene family is unclear. Using a synteny-conservation-based method, we detected tRNA anticodon shifts in groups of closely related species: five primates, 12 Drosophila, six nematodes, 11 Saccharomycetes, and 61 Enterobacteriaceae. We found a total of 75 anticodon shifts: 31 involving switches of identity (alloacceptor shifts) and 44 between isoacceptors that code for the same amino acid (isoacceptor shifts). The relative numbers of shifts in each taxa suggest that tRNA gene redundancy is likely the driving factor, with greater constraint on changes of identity. Sites that frequently covary with alloacceptor shifts are located at the extreme ends of the molecule, in common with most known identity determinants. Isoacceptor shifts are associated with changes in the midsections of the tRNA sequence. However, the mutation patterns of anticodon shifts involving the same identities are often dissimilar, suggesting that alternate sets of mutation may achieve the same functional compensation.
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8
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Jones CP, Saadatmand J, Kleiman L, Musier-Forsyth K. Molecular mimicry of human tRNALys anti-codon domain by HIV-1 RNA genome facilitates tRNA primer annealing. RNA (NEW YORK, N.Y.) 2013; 19:219-29. [PMID: 23264568 PMCID: PMC3543088 DOI: 10.1261/rna.036681.112] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Accepted: 11/14/2012] [Indexed: 05/18/2023]
Abstract
The primer for initiating reverse transcription in human immunodeficiency virus type 1 (HIV-1) is tRNA(Lys3). Host cell tRNA(Lys) is selectively packaged into HIV-1 through a specific interaction between the major tRNA(Lys)-binding protein, human lysyl-tRNA synthetase (hLysRS), and the viral proteins Gag and GagPol. Annealing of the tRNA primer onto the complementary primer-binding site (PBS) in viral RNA is mediated by the nucleocapsid domain of Gag. The mechanism by which tRNA(Lys3) is targeted to the PBS and released from hLysRS prior to annealing is unknown. Here, we show that hLysRS specifically binds to a tRNA anti-codon-like element (TLE) in the HIV-1 genome, which mimics the anti-codon loop of tRNA(Lys) and is located proximal to the PBS. Mutation of the U-rich sequence within the TLE attenuates binding of hLysRS in vitro and reduces the amount of annealed tRNA(Lys3) in virions. Thus, LysRS binds specifically to the TLE, which is part of a larger LysRS binding domain in the viral RNA that includes elements of the Psi packaging signal. Our results suggest that HIV-1 uses molecular mimicry of the anti-codon of tRNA(Lys) to increase the efficiency of tRNA(Lys3) annealing to viral RNA.
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MESH Headings
- Base Pairing
- Electrophoretic Mobility Shift Assay
- Genome, Viral/genetics
- HIV Enhancer/genetics
- HIV-1/genetics
- HIV-1/physiology
- Humans
- Lysine-tRNA Ligase/genetics
- Lysine-tRNA Ligase/metabolism
- Molecular Mimicry
- Mutation
- Protein Structure, Tertiary
- RNA
- RNA, Transfer, Lys/chemistry
- RNA, Transfer, Lys/genetics
- RNA, Transfer, Lys/metabolism
- RNA, Viral/genetics
- RNA, Viral/metabolism
- Virus Assembly/genetics
- Virus Replication/genetics
- gag Gene Products, Human Immunodeficiency Virus/metabolism
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Affiliation(s)
- Christopher P. Jones
- Department of Chemistry and Biochemistry, Center for Retroviral Research, and Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA
| | - Jenan Saadatmand
- Lady Davis Institute for Medical Research, McGill AIDS Centre, Jewish General Hospital, Montreal, Quebec, Canada, H3T1E2
| | - Lawrence Kleiman
- Lady Davis Institute for Medical Research, McGill AIDS Centre, Jewish General Hospital, Montreal, Quebec, Canada, H3T1E2
| | - Karin Musier-Forsyth
- Department of Chemistry and Biochemistry, Center for Retroviral Research, and Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA
- Corresponding authorE-mail
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9
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Ofir-Birin Y, Fang P, Bennett SP, Zhang HM, Wang J, Rachmin I, Shapiro R, Song J, Dagan A, Pozo J, Kim S, Marshall AG, Schimmel P, Yang XL, Nechushtan H, Razin E, Guo M. Structural switch of lysyl-tRNA synthetase between translation and transcription. Mol Cell 2012; 49:30-42. [PMID: 23159739 DOI: 10.1016/j.molcel.2012.10.010] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 09/13/2012] [Accepted: 10/09/2012] [Indexed: 12/25/2022]
Abstract
Lysyl-tRNA synthetase (LysRS), a component of the translation apparatus, is released from the cytoplasmic multi-tRNA synthetase complex (MSC) to activate the transcription factor MITF in stimulated mast cells through undefined mechanisms. Here we show that Ser207 phosphorylation provokes a new conformer of LysRS that inactivates its translational function but activates its transcriptional function. The crystal structure of an MSC subcomplex established that LysRS is held in the MSC by binding to the N terminus of the scaffold protein p38/AIMP2. Phosphorylation-created steric clashes at the LysRS domain interface disrupt its binding grooves for p38/AIMP2, releasing LysRS and provoking its nuclear translocation. This alteration also exposes the C-terminal domain of LysRS to bind to MITF and triggers LysRS-directed production of the second messenger Ap(4)A that activates MITF. Thus our results establish that a single conformational change triggered by phosphorylation leads to multiple effects driving an exclusive switch of LysRS function from translation to transcription.
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Affiliation(s)
- Yifat Ofir-Birin
- Department of Biochemistry and Molecular Biology, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel
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10
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Chen SJ, Wu YH, Huang HY, Wang CC. Saccharomyces cerevisiae possesses a stress-inducible glycyl-tRNA synthetase gene. PLoS One 2012; 7:e33363. [PMID: 22438917 PMCID: PMC3306390 DOI: 10.1371/journal.pone.0033363] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Accepted: 02/13/2012] [Indexed: 12/04/2022] Open
Abstract
Aminoacyl-tRNA synthetases are a large family of housekeeping enzymes that are pivotal in protein translation and other vital cellular processes. Saccharomyces cerevisiae possesses two distinct nuclear glycyl-tRNA synthetase (GlyRS) genes, GRS1 and GRS2. GRS1 encodes both cytoplasmic and mitochondrial activities, while GRS2 is essentially silent and dispensable under normal conditions. We herein present evidence that expression of GRS2 was drastically induced upon heat shock, ethanol or hydrogen peroxide addition, and high pH, while expression of GRS1 was somewhat repressed under those conditions. In addition, GlyRS2 (the enzyme encoded by GRS2) had a higher protein stability and a lower KM value for yeast tRNAGly under heat shock conditions than under normal conditions. Moreover, GRS2 rescued the growth defect of a GRS1 knockout strain when highly expressed by a strong promoter at 37°C, but not at the optimal temperature of 30°C. These results suggest that GRS2 is actually an inducible gene that may function to rescue the activity of GRS1 under stress conditions.
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Affiliation(s)
| | | | | | - Chien-Chia Wang
- Department of Life Sciences, National Central University, Jung-li, Taiwan
- * E-mail:
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11
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Dias J, Octobre G, Kobbi L, Comisso M, Flisiak S, Mirande M. Activation of human mitochondrial lysyl-tRNA synthetase upon maturation of its premitochondrial precursor. Biochemistry 2012; 51:909-16. [PMID: 22235746 DOI: 10.1021/bi201337b] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The cytoplasmic and mitochondrial species of human lysyl-tRNA synthetase are encoded by a single gene by means of alternative splicing of the KARS1 gene. The cytosolic enzyme possesses a eukaryote-specific N-terminal polypeptide extension that confers on the native enzyme potent tRNA binding properties required for the vectorial transfer of tRNA from the synthetase to elongation factor EF1A within the eukaryotic translation machinery. The mitochondrial enzyme matures from its precursor upon being targeted to that organelle. To understand how the cytosolic and mitochondrial enzymes are adapted to participate in two distinct translation machineries, of eukaryotic or bacterial origin, we characterized the mitochondrial LysRS species. Here we report that cleavage of the precursor of mitochondrial LysRS leads to a mature enzyme with reduced tRNA binding properties compared to those of the cytoplasmic counterpart. This adaptation mechanism may prevent inhibition of translation through sequestration of lysyl-tRNA on the synthetase in a compartment where the bacterial-like elongation factor EF-Tu could not assist in its dissociation from the synthetase. We also observed that the RxxxKRxxK tRNA-binding motif of mitochondrial LysRS is not functional in the precursor form of that enzyme and becomes operational after cleavage of the mitochondrial targeting sequence. The finding that maturation of the precursor is needed to reveal the potent tRNA binding properties of this enzyme has strong implications for the spatiotemporal regulation of its activities and is consistent with previous studies suggesting that the only LysRS species able to promote packaging of tRNA(Lys) into HIV-1 viral particles is the mature form of the mitochondrial enzyme.
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Affiliation(s)
- José Dias
- Laboratoire d'Enzymologie et Biochimie Structurales, Centre de Recherche de Gif, CNRS, Gif-sur-Yvette, France
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12
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Guo M, Shapiro R, Morris GM, Yang XL, Schimmel P. Packaging HIV virion components through dynamic equilibria of a human tRNA synthetase. J Phys Chem B 2010; 114:16273-9. [PMID: 21058683 DOI: 10.1021/jp1082517] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Aminoacyl tRNA synthetases, components of the translation apparatus, have alternative functions outside of translation. The structural and mechanistic basis of these alternative functions is of great interest. As an example, reverse transcription of the HIV genome is primed by a human lysine-specific tRNA (tRNA(Lys3)) that is packaged (into the virion) by the HIV Gag protein with lysyl-tRNA synthetase (LysRS). Not understood is the structural basis for simultaneous packaging of tRNA(Lys3), LysRS, and Gag. Here, ab initio computational methods, together with our recent high-resolution 3-D structure of human LysRS, produced an energy-minimized model where Gag, tRNA(Lys), and LysRS form a ternary complex. Interestingly, the model requires normally homodimeric LysRS to dissociate into a monomer that bridges between Gag and tRNA(Lys3). Earlier experiments of others and new experiments presented here, which tested an engineered dissociated form of LysRS, were consistent with the ab initio "bridging monomer" model. The results support an emerging theme that alterative functions of tRNA synthetases may come, in part, from protein surfaces exposed by dynamic equilibria.
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Affiliation(s)
- Min Guo
- The Skaggs Institute for Chemical Biology, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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Chiu WC, Chang CP, Wen WL, Wang SW, Wang CC. Schizosaccharomyces pombe possesses two paralogous valyl-tRNA synthetase genes of mitochondrial origin. Mol Biol Evol 2010; 27:1415-24. [PMID: 20106903 DOI: 10.1093/molbev/msq025] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Previous studies showed that VAS1 of Saccharomyces cerevisiae encodes both cytosolic and mitochondrial forms of valyl-tRNA synthetase (ValRS) through alternative initiation of translation. We show herein that except for Schizosaccharomyces pombe, all yeast species studied contained a single ValRS gene encoding both forms, and all of the mature protein forms deduced from those genes possessed an N-terminal appended domain (Ad) that was absent from their bacterial relatives. In contrast, S. pombe contained two distinct nuclear ValRS genes, one encoding the mitochondrial form and the other its cytosolic counterpart. Although the cytosolic form closely resembles other yeast ValRS sequences (approximately 60% identity), the mitochondrial form exhibits significant divergence from others (approximately 35% identity). Both genes are active and essential for the survival of the yeast. Most conspicuously, the mitochondrial form lacks the characteristic Ad. A phylogenetic analysis further suggested that both forms of S. pombe ValRS are of mitochondrial origin, and the mitochondrial form is ancestral to the cytoplasmic form.
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Affiliation(s)
- Wen-Chih Chiu
- Department of Life Science, National Central University, Jung-li, Taiwan
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14
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tRNA mitochondrial import in yeast: Mapping of the import determinants in the carrier protein, the precursor of mitochondrial lysyl-tRNA synthetase. Mitochondrion 2010; 10:284-93. [PMID: 20064631 DOI: 10.1016/j.mito.2010.01.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2009] [Revised: 12/05/2009] [Accepted: 01/05/2010] [Indexed: 02/03/2023]
Abstract
Mitochondria of many species import of nuclear DNA-encoded tRNAs. This widely spread but poorly studied phenomenon proved to be a promising tool for mitochondrial transfection. In yeast Saccharomyces cerevisiae, one cytosolic tRNAs(Lys) is partially targeted into mitochondria. Previous studies have shown that binding of this tRNA to its putative protein carrier, the precursor of mitochondrial lysyl-tRNA synthetase (preMsk1p), IIb class aminoacyl-tRNA synthetase, was a pre-requisite of import. In this work, we identify the hinge region with two adjacent helices H5 and H7 to be responsible for mitochondrial targeting of the tRNA and characterize preMsk1p versions with altered tRK1 import capacities.
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15
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Processivity of translation in the eukaryote cell: role of aminoacyl-tRNA synthetases. FEBS Lett 2009; 584:443-7. [PMID: 19914240 DOI: 10.1016/j.febslet.2009.11.027] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2009] [Accepted: 11/10/2009] [Indexed: 11/21/2022]
Abstract
Several lines of evidence led to the conclusion that mammalian ribosomal protein synthesis is a highly organized biological process in vivo. A wealth of data support the concept according to which tRNA aminoacylation, formation of the ternary complex on EF1A and delivery of aminoacyl-tRNA to the ribosome is a processive mechanism where tRNA is vectorially transferred from one component to another. Polypeptide extensions, referred to as tRBDs (tRNA binding domains), are appended to mammalian and yeast aminoacyl-tRNA synthetases. The involvement of these domains in the capture of deacylated tRNA and in the sequestration of aminoacylated tRNA, suggests that cycling of tRNA in translation is mediated by the processivity of the consecutive steps. The possible origin of the tRBDs is discussed.
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16
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Ataide SF, Rogers TE, Ibba M. The CCA anticodon specifies separate functions inside and outside translation in Bacillus cereus. RNA Biol 2009; 6:479-87. [PMID: 19667754 DOI: 10.4161/rna.6.4.9332] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Bacillus cereus 14579 encodes two tRNAs with the CCA anticodon, tRNA(Trp) and tRNA(Other). tRNA(Trp) was separately aminoacylated by two enzymes, TrpRS1 and TrpRS2, which share only 34% similarity and display different catalytic capacities and specificities. TrpRS1 was 18-fold more proficient at aminoacylating tRNA(Trp) with Trp, while TrpRS2 more efficiently utilizes the Trp analog 5-hydroxy Trp. tRNA(Other) was not aminoacylated by either TrpRS but instead by the combined activity of LysRS1 and LysRS2, which recognized sequence elements absent from tRNA(Trp). Polysomes were found to contain tRNA(Trp), consistent with its role in translation, but not tRNA(Other) suggesting a function outside protein synthesis. Regulation of the genes encoding TrpRS1 and TrpRS2 (trpS1 and trpS2) is dependent on riboswitch-mediated recognition of the CCA anticodon, and the role of tRNA(Other) in this process was investigated. Deletion of tRNA(Other) led to up to a 50 fold drop in trpS1 expression, which resulted in the loss of differential regulation of the trpS1 and trpS2 genes in stationary phase. These findings reveal that sequence-specific interactions with a tRNA anticodon can be confined to processes outside translation, suggesting a means by which such RNAs may evolve non-coding functions.
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Affiliation(s)
- Sandro F Ataide
- Department of Microbiology, Ohio State University, Columbus, OH 43210-1292, USA
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17
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Chiu WC, Chang CP, Wang CC. Evolutionary basis of converting a bacterial tRNA synthetase into a yeast cytoplasmic or mitochondrial enzyme. J Biol Chem 2009; 284:23954-60. [PMID: 19574213 DOI: 10.1074/jbc.m109.031047] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Previous studies showed that cytoplasmic and mitochondrial forms of yeast valyl-tRNA synthetase (ValRS) are specified by the VAS1 gene through alternative initiation of translation. Sequence comparison suggests that the yeast cytoplasmic (or mature mitochondrial) ValRS contains an N-terminal appendage that acts in cis as a nonspecific tRNA-binding domain (TRBD) and is absent from its bacterial relatives. We show here that Escherichia coli ValRS can substitute for the mitochondrial and cytoplasmic functions of VAS1 by fusion of a mitochondrial targeting signal and a TRBD, respectively. In addition, the bacterial ValRS gene can be converted into a dual functional yeast gene encoding both cytoplasmic and mitochondrial activities by fusion of a DNA sequence specifying both the mitochondrial targeting signal and TRBD. In vitro assays suggested that fusion of a nonspecific TRBD to the bacterial enzyme significantly enhanced its yeast tRNA-binding and aminoacylation activities. These results not only underscore the necessity of retaining a TRBD for functioning of a tRNA synthetase in yeast cytoplasm, but also provide insights into the evolution of tRNA synthetase genes.
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Affiliation(s)
- Wen-Chih Chiu
- Department of Life Science, National Central University, Jung-li 32001, Taiwan
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18
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Chang CP, Lin G, Chen SJ, Chiu WC, Chen WH, Wang CC. Promoting the formation of an active synthetase/tRNA complex by a nonspecific tRNA-binding domain. J Biol Chem 2008; 283:30699-706. [PMID: 18755686 DOI: 10.1074/jbc.m805339200] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Previous studies showed that valyl-tRNA synthetase of Saccharomyces cerevisiae contains an N-terminal polypeptide extension of 97 residues, which is absent from its bacterial relatives, but is conserved in its mammalian homologues. We showed herein that this appended domain and its human counterpart are both nonspecific tRNA-binding domains (K(d) approximately 0.5 microm). Deletion of the appended domain from the yeast enzyme severely impaired its tRNA binding, aminoacylation, and complementation activities. This N-domain-deleted yeast valyl-tRNA synthetase mutant could be rescued by fusion of the equivalent domain from its human homologue. Moreover, fusion of the N-domain of the yeast enzyme or its human counterpart to Escherichia coli glutaminyl-tRNA synthetase enabled the otherwise "inactive" prokaryotic enzyme to function as a yeast enzyme in vivo. Different from the native yeast enzyme, which showed different affinities toward mixed tRNA populations, the fusion enzyme exhibited similar binding affinities for all yeast tRNAs. These results not only underscore the significance of nonspecific tRNA binding in aminoacylation, but also provide insights into the mechanism of the formation of aminoacyl-tRNAs.
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Affiliation(s)
- Chia-Pei Chang
- Department of Life Science, National Central University, Jung-li, 32001 Taiwan
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Lysyl-tRNA synthetase interacts with EF1alpha, aspartyl-tRNA synthetase and p38 in vitro. Biochem Biophys Res Commun 2007; 365:718-23. [PMID: 18029264 DOI: 10.1016/j.bbrc.2007.11.028] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2007] [Accepted: 11/12/2007] [Indexed: 11/21/2022]
Abstract
The functions of evolved mammalian supramolecular assemblies and extensions of enzymes are not well understood. Human lysyl-tRNA synthetase (hKRS) only upon the removal of the amino-terminal extension (hKRSDelta60) bound to EF1alpha and was stimulated by EF1alphain vitro. HKRS and hKRSDelta60 were also differentially stimulated by aspartyl-tRNA synthetase (AspRS) from the multi-synthetase complex. The non-synthetase protein from the multi-synthetase complex p38 alone did not affect hKRS lysylation but inhibited the AspRS-mediated stimulation of hKRS. These results revealed the functional interactions of hKRS and shed new lights on the functional significance of the structural evolution of multienzyme complexes and appended extensions.
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