51
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Huang HY, Hopper AK. Multiple Layers of Stress-Induced Regulation in tRNA Biology. Life (Basel) 2016; 6:life6020016. [PMID: 27023616 PMCID: PMC4931453 DOI: 10.3390/life6020016] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 03/14/2016] [Accepted: 03/17/2016] [Indexed: 01/28/2023] Open
Abstract
tRNAs are the fundamental components of the translation machinery as they deliver amino acids to the ribosomes during protein synthesis. Beyond their essential function in translation, tRNAs also function in regulating gene expression, modulating apoptosis and several other biological processes. There are multiple layers of regulatory mechanisms in each step of tRNA biogenesis. For example, tRNA 3′ trailer processing is altered upon nutrient stress; tRNA modification is reprogrammed under various stresses; nuclear accumulation of tRNAs occurs upon nutrient deprivation; tRNA halves accumulate upon oxidative stress. Here we address how environmental stresses can affect nearly every step of tRNA biology and we describe the possible regulatory mechanisms that influence the function or expression of tRNAs under stress conditions.
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Affiliation(s)
- Hsiao-Yun Huang
- Department of Biology, Indiana University, 915 E third St., Myers 300, Bloomington, IN 47405, USA.
| | - Anita K Hopper
- Department of Molecular Genetics and Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA.
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52
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Silent Polymorphisms: Can the tRNA Population Explain Changes in Protein Properties? Life (Basel) 2016; 6:life6010009. [PMID: 26901226 PMCID: PMC4810240 DOI: 10.3390/life6010009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 01/26/2016] [Accepted: 02/05/2016] [Indexed: 01/18/2023] Open
Abstract
Silent mutations are being intensively studied. We previously showed that the estrogen receptor alpha Ala87’s synonymous polymorphism affects its functional properties. Whereas a link has been clearly established between the effect of silent mutations, tRNA abundance and protein folding in prokaryotes, this connection remains controversial in eukaryotic systems. Although a synonymous polymorphism can affect mRNA structure or the interaction with specific ligands, it seems that the relative frequencies of isoacceptor tRNAs could play a key role in the protein-folding process, possibly through modulation of translation kinetics. Conformational changes could be subtle but enough to cause alterations in solubility, proteolysis profiles, functional parameters or intracellular targeting. Interestingly, recent advances describe dramatic changes in the tRNA population associated with proliferation, differentiation or response to chemical, physical or biological stress. In addition, several reports reveal changes in tRNAs’ posttranscriptional modifications in different physiological or pathological conditions. In consequence, since changes in the cell state imply quantitative and/or qualitative changes in the tRNA pool, they could increase the likelihood of protein conformational variants, related to a particular codon usage during translation, with consequences of diverse significance. These observations emphasize the importance of genetic code flexibility in the co-translational protein-folding process.
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53
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Exploiting tRNAs to Boost Virulence. Life (Basel) 2016; 6:life6010004. [PMID: 26797637 PMCID: PMC4810235 DOI: 10.3390/life6010004] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 01/08/2016] [Accepted: 01/14/2016] [Indexed: 01/22/2023] Open
Abstract
Transfer RNAs (tRNAs) are powerful small RNA entities that are used to translate nucleotide language of genes into the amino acid language of proteins. Their near-uniform length and tertiary structure as well as their high nucleotide similarity and post-transcriptional modifications have made it difficult to characterize individual species quantitatively. However, due to the central role of the tRNA pool in protein biosynthesis as well as newly emerging roles played by tRNAs, their quantitative assessment yields important information, particularly relevant for virus research. Viruses which depend on the host protein expression machinery have evolved various strategies to optimize tRNA usage—either by adapting to the host codon usage or encoding their own tRNAs. Additionally, several viruses bear tRNA-like elements (TLE) in the 5′- and 3′-UTR of their mRNAs. There are different hypotheses concerning the manner in which such structures boost viral protein expression. Furthermore, retroviruses use special tRNAs for packaging and initiating reverse transcription of their genetic material. Since there is a strong specificity of different viruses towards certain tRNAs, different strategies for recruitment are employed. Interestingly, modifications on tRNAs strongly impact their functionality in viruses. Here, we review those intersection points between virus and tRNA research and describe methods for assessing the tRNA pool in terms of concentration, aminoacylation and modification.
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54
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Abstract
tRNA molecules undergo extensive post-transcriptional processing to generate the mature functional tRNA species that are essential for translation in all organisms. These processing steps include the introduction of numerous specific chemical modifications to nucleotide bases and sugars; among these modifications, methylation reactions are by far the most abundant. The tRNA methyltransferases comprise a diverse enzyme superfamily, including members of multiple structural classes that appear to have arisen independently during evolution. Even among closely related family members, examples of unusual substrate specificity and chemistry have been observed. Here we review recent advances in tRNA methyltransferase mechanism and function with a particular emphasis on discoveries of alternative substrate specificities and chemistry associated with some methyltransferases. Although the molecular function for a specific tRNA methylation may not always be clear, mutations in tRNA methyltransferases have been increasingly associated with human disease. The impact of tRNA methylation on human biology is also discussed.
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Affiliation(s)
- William E Swinehart
- a Center for RNA Biology and Department of Chemistry and Biochemistry ; Ohio State University ; Columbus , OH USA
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55
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Melnik BC. Milk: an epigenetic amplifier of FTO-mediated transcription? Implications for Western diseases. J Transl Med 2015; 13:385. [PMID: 26691922 PMCID: PMC4687119 DOI: 10.1186/s12967-015-0746-z] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 12/04/2015] [Indexed: 12/14/2022] Open
Abstract
Single-nucleotide polymorphisms within intron 1 of the FTO (fat mass and obesity-associated) gene are associated with enhanced FTO expression, increased body weight, obesity and type 2 diabetes mellitus (T2DM). The N6-methyladenosine (m6A) demethylase FTO plays a pivotal regulatory role for postnatal growth and energy expenditure. The purpose of this review is to provide translational evidence that links milk signaling with FTO-activated transcription of the milk recipient. FTO-dependent demethylation of m6A regulates mRNA splicing required for adipogenesis, increases the stability of mRNAs, and affects microRNA (miRNA) expression and miRNA biosynthesis. FTO senses branched-chain amino acids (BCAAs) and activates the nutrient sensitive kinase mechanistic target of rapamycin complex 1 (mTORC1), which plays a key role in translation. Milk provides abundant BCAAs and glutamine, critical components increasing FTO expression. CpG hypomethylation in the first intron of FTO has recently been associated with T2DM. CpG methylation is generally associated with gene silencing. In contrast, CpG demethylation generally increases transcription. DNA de novo methylation of CpG sites is facilitated by DNA methyltransferases (DNMT) 3A and 3B, whereas DNA maintenance methylation is controlled by DNMT1. MiRNA-29s target all DNMTs and thus reduce DNA CpG methylation. Cow´s milk provides substantial amounts of exosomal miRNA-29s that reach the systemic circulation and target mRNAs of the milk recipient. Via DNMT suppression, milk exosomal miRNA-29s may reduce the magnitude of FTO methylation, thereby epigenetically increasing FTO expression in the milk consumer. High lactation performance with increased milk yield has recently been associated with excessive miRNA-29 expression of dairy cow mammary epithelial cells (DCMECs). Notably, the galactopoietic hormone prolactin upregulates the transcription factor STAT3, which induces miRNA-29 expression. In a retrovirus-like manner milk exosomes may transfer DCMEC-derived miRNA-29s and bovine FTO mRNA to the milk consumer amplifying FTO expression. There is compelling evidence that obesity, T2DM, prostate and breast cancer, and neurodegenerative diseases are all associated with increased FTO expression. Maximization of lactation performance by veterinary medicine with enhanced miRNA-29s and FTO expression associated with increased exosomal miRNA-29 and FTO mRNA transfer to the milk consumer may represent key epigenetic mechanisms promoting FTO/mTORC1-mediated diseases of civilization.
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Affiliation(s)
- Bodo C Melnik
- Department of Dermatology, Environmental Medicine and Health Theory, University of Osnabrück, Sedanstrasse 115, 49090, Osnabrück, Germany.
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56
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Machnicka MA, Olchowik A, Grosjean H, Bujnicki JM. Distribution and frequencies of post-transcriptional modifications in tRNAs. RNA Biol 2015; 11:1619-29. [PMID: 25611331 DOI: 10.4161/15476286.2014.992273] [Citation(s) in RCA: 136] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Functional tRNA molecules always contain a wide variety of post-transcriptionally modified nucleosides. These modifications stabilize tRNA structure, allow for proper interaction with other macromolecules and fine-tune the decoding of mRNAs during translation. Their presence in functionally important regions of tRNA is conserved in all domains of life. However, the identities of many of these modified residues depend much on the phylogeny of organisms the tRNAs are found in, attesting for domain-specific strategies of tRNA maturation. In this work we present a new tool, tRNAmodviz web server (http://genesilico.pl/trnamodviz) for easy comparative analysis and visualization of modification patterns in individual tRNAs, as well as in groups of selected tRNA sequences. We also present results of comparative analysis of tRNA sequences derived from 7 phylogenetically distinct groups of organisms: Gram-negative bacteria, Gram-positive bacteria, cytosol of eukaryotic single cell organisms, Fungi and Metazoa, cytosol of Viridiplantae, mitochondria, plastids and Euryarchaeota. These data update the study conducted 20 y ago with the tRNA sequences available at that time.
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57
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Cai WM, Chionh YH, Hia F, Gu C, Kellner S, McBee ME, Ng CS, Pang YLJ, Prestwich EG, Lim KS, Babu IR, Begley TJ, Dedon PC. A Platform for Discovery and Quantification of Modified Ribonucleosides in RNA: Application to Stress-Induced Reprogramming of tRNA Modifications. Methods Enzymol 2015; 560:29-71. [PMID: 26253965 DOI: 10.1016/bs.mie.2015.03.004] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Here we describe an analytical platform for systems-level quantitative analysis of modified ribonucleosides in any RNA species, with a focus on stress-induced reprogramming of tRNA as part of a system of translational control of cell stress response. This chapter emphasizes strategies and caveats for each of the seven steps of the platform workflow: (1) RNA isolation, (2) RNA purification, (3) RNA hydrolysis to individual ribonucleosides, (4) chromatographic resolution of ribonucleosides, (5) identification of the full set of modified ribonucleosides, (6) mass spectrometric quantification of ribonucleosides, (6) interrogation of ribonucleoside datasets, and (7) mapping the location of stress-sensitive modifications in individual tRNA molecules. We have focused on the critical determinants of analytical sensitivity, specificity, precision, and accuracy in an effort to ensure the most biologically meaningful data on mechanisms of translational control of cell stress response. The methods described here should find wide use in virtually any analysis involving RNA modifications.
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Affiliation(s)
- Weiling Maggie Cai
- Department of Microbiology, National University of Singapore, Singapore; Singapore-MIT Alliance for Research and Technology, Singapore
| | - Yok Hian Chionh
- Department of Microbiology, National University of Singapore, Singapore; Singapore-MIT Alliance for Research and Technology, Singapore
| | - Fabian Hia
- Singapore-MIT Alliance for Research and Technology, Singapore
| | - Chen Gu
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Stefanie Kellner
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Megan E McBee
- Singapore-MIT Alliance for Research and Technology, Singapore; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Chee Sheng Ng
- Singapore-MIT Alliance for Research and Technology, Singapore; School of Biological Sciences, Nanyang Technological Institute, Singapore
| | - Yan Ling Joy Pang
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Erin G Prestwich
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Kok Seong Lim
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - I Ramesh Babu
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Thomas J Begley
- College of Nanoscale Engineering and Science, State University of New York, Albany, New York, USA
| | - Peter C Dedon
- Singapore-MIT Alliance for Research and Technology, Singapore; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA; Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
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58
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Shanmugam R, Fierer J, Kaiser S, Helm M, Jurkowski TP, Jeltsch A. Cytosine methylation of tRNA-Asp by DNMT2 has a role in translation of proteins containing poly-Asp sequences. Cell Discov 2015; 1:15010. [PMID: 27462411 PMCID: PMC4860778 DOI: 10.1038/celldisc.2015.10] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 03/26/2015] [Indexed: 01/09/2023] Open
Abstract
The Dnmt2 RNA methyltransferase catalyses the methylation of C38 in the anticodon loop of tRNA-Asp, but the molecular role of this methylation is unknown. Here, we report that mouse aspartyl-tRNA synthetase shows a four to fivefold preference for C38-methylated tRNA-Asp. Consistently, a 30% reduced charging level of tRNA-Asp was observed in Dnmt2 knockout (KO) murine embryonic fibroblast cells. Gene expression analysis with fluorescent reporter proteins fused to an N-terminal poly-Asp sequence showed that protein synthesis of poly-Asp-tagged reporter proteins was reduced in Dnmt2 KO cells as well. The same effect was observed with endogenous proteins containing poly-Asp sequences, indicating that Dnmt2-mediated C38 methylation of tRNA-Asp regulates the translation of proteins containing poly-Asp sequences. Gene ontology searches for proteins containing poly-Asp sequences in the human proteome showed that a significant number of these proteins have roles in transcriptional regulation and gene expression. Hence, the Dnmt2-mediated methylation of tRNA-Asp exhibits a post-transcriptional regulatory role by controlling the synthesis of a group of target proteins containing poly-Asp sequences.
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Affiliation(s)
- Raghuvaran Shanmugam
- Institute of Biochemistry, Stuttgart University, Faculty of Chemistry , Stuttgart, Germany
| | - Jacob Fierer
- MoLife Program, School of Engineering and Science, Jacobs University Bremen , Bremen, Germany
| | - Steffen Kaiser
- Institute of Pharmacy and Biochemistry, Faculty of Chemistry, Pharmaceutical Sciences and Geoscience, Johannes Gutenberg-Universität Mainz , Mainz, Germany
| | - Mark Helm
- Institute of Pharmacy and Biochemistry, Faculty of Chemistry, Pharmaceutical Sciences and Geoscience, Johannes Gutenberg-Universität Mainz , Mainz, Germany
| | - Tomasz P Jurkowski
- Institute of Biochemistry, Stuttgart University, Faculty of Chemistry , Stuttgart, Germany
| | - Albert Jeltsch
- Institute of Biochemistry, Stuttgart University, Faculty of Chemistry , Stuttgart, Germany
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59
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Aravind L, Zhang D, Iyer LM. The TET/JBP Family of Nucleic Acid Base-Modifying 2-Oxoglutarate and Iron-Dependent Dioxygenases. 2-OXOGLUTARATE-DEPENDENT OXYGENASES 2015. [DOI: 10.1039/9781782621959-00289] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The TET/JBP family of enzymes includes 2-oxoglutarate- and Fe(ii)-dependent dioxygenases that oxidize 5-methylpyrimidines in nucleic acids. They include euglenozoan JBP enzymes that catalyse the first step in the biosynthesis of the hypermodified thymine, base J, and metazoan TET enzymes that generate oxidized 5-methylcytosines (hydroxy-, formyl- and carboxymethylcytosine) in DNA. Recent studies suggest that these modified bases function as epigenetic marks and/or as potential intermediates for DNA demethylation during resetting of epigenetic 5mC marks upon zygote formation and in primordial germ cell development. Studies in mammalian models also point to an important role for these enzymes in haematopoiesis, tumour suppression, cell differentiation and neural behavioural adaptation. The TET/JBP family has undergone extensive gene expansion in fungi, such as mushrooms, in conjunction with a novel class of transposons and might play a role in genomic plasticity and speciation. Certain versions from stramenopiles and chlorophytes are likely to modify RNA and often show fusions to other RNA-modifying enzymatic domains. The ultimate origin of the TET/JBP family lies in bacteriophages where the enzymes are likely to catalyse formation of modified bases with key roles in DNA packaging and evasion of host restriction.
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Affiliation(s)
- L. Aravind
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health Bethesda MD 20894 USA
| | - Dapeng Zhang
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health Bethesda MD 20894 USA
| | - Lakshminarayan M. Iyer
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health Bethesda MD 20894 USA
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60
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Chan CTY, Deng W, Li F, DeMott MS, Babu IR, Begley TJ, Dedon PC. Highly Predictive Reprogramming of tRNA Modifications Is Linked to Selective Expression of Codon-Biased Genes. Chem Res Toxicol 2015; 28:978-88. [PMID: 25772370 PMCID: PMC4438938 DOI: 10.1021/acs.chemrestox.5b00004] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
![]()
Cells respond to stress by controlling
gene expression at several
levels, with little known about the role of translation. Here, we
demonstrate a coordinated translational stress response system involving
stress-specific reprogramming of tRNA wobble modifications that leads
to selective translation of codon-biased mRNAs representing different
classes of critical response proteins. In budding yeast exposed to
four oxidants and five alkylating agents, tRNA modification patterns
accurately distinguished among chemically similar stressors, with
14 modified ribonucleosides forming the basis for a data-driven model
that predicts toxicant chemistry with >80% sensitivity and specificity.
tRNA modification subpatterns also distinguish SN1 from
SN2 alkylating agents, with SN2-induced increases
in m3C in tRNA mechanistically linked to selective translation
of threonine-rich membrane proteins from genes enriched with ACC and
ACT degenerate codons for threonine. These results establish tRNA
modifications as predictive biomarkers of exposure and illustrate
a novel regulatory mechanism for translational control of cell stress
response.
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Affiliation(s)
| | | | | | | | | | - Thomas J Begley
- ∥College of Nanoscale Science, State University of New York, Albany, New York 12203, United States
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61
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Rimbach K, Kaiser S, Helm M, Dalpke AH, Eigenbrod T. 2'-O-Methylation within Bacterial RNA Acts as Suppressor of TLR7/TLR8 Activation in Human Innate Immune Cells. J Innate Immun 2015; 7:482-93. [PMID: 25823462 DOI: 10.1159/000375460] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 01/23/2015] [Indexed: 12/25/2022] Open
Abstract
Microbial RNA is an important stimulator of innate immune responses. Differences in posttranscriptional RNA modification profiles enable the immune system to discriminate between self and non-self nucleic acids. This principle may be exploited by certain bacteria to circumvent immune cell activation. In this regard, 2'-O-methylation of Escherichia coli tRNATyr at position 18 (Gm18) has recently been described to inhibit TLR7-mediated IFN-α production in human plasmacytoid dendritic cells (pDCs). Extending these findings, we now demonstrate that Gm18 also potently inhibits TLR7-independent human monocyte activation by RNA derived from a variety of bacterial strains. The half minimal inhibitory concentration values were similar to those found for IFN-α inhibition in pDCs. Mechanistically, 2'-O-methylated RNA impaired upstream signalling events, including MAP kinase and NFx03BA;B activation. Our results suggest that antagonizing effects of Gm18-modified RNA are due to competition with stimulatory RNA for receptor binding. The antagonistic effect was specific for RNA because the small molecule TLR7/8 agonist R848 was not inhibited. Despite the striking phenotype in human cells, 2'-O-methylated RNA did not interfere with TLR13 activation by bacterial 23S rRNA in murine DC and BMDM. Thus, we identify here Gm18 in E. coli tRNA(Tyr) as a universal suppressor of innate immune activation in the human but not the murine system.
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Affiliation(s)
- Katharina Rimbach
- Department of Infectious Diseases, Medical Microbiology and Hygiene, University of Heidelberg, Heidelberg, Germany
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62
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Elhardt W, Shanmugam R, Jurkowski TP, Jeltsch A. Somatic cancer mutations in the DNMT2 tRNA methyltransferase alter its catalytic properties. Biochimie 2015; 112:66-72. [PMID: 25747896 DOI: 10.1016/j.biochi.2015.02.022] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 02/24/2015] [Indexed: 12/22/2022]
Abstract
Methylation of tRNA is an important post-transcriptional modification and aberrations in tRNA modification has been implicated in cancer. The DNMT2 protein methylates C38 of tRNA-Asp and it has a role in cellular physiology and stress response and its expression levels are altered in cancer tissues. Here we studied whether DNMT2 somatic mutations found in cancer tissues affect the activity of the enzyme. We have generated 13 DNMT2 variants and purified the corresponding proteins. All proteins were properly folded as determined by circular dichroism spectroscopy. We tested their RNA methylation activity using in vitro generated tRNA-Asp. One of the mutations (E63K) caused a twofold increase in activity, while two of them led to a strong (over fourfold) decrease in activity (G155S and L257V). Two additional mutant proteins were almost inactive (R371H and G155V). The strong effect of some of the somatic cancer mutations on DNMT2 activity suggests that these mutations have a functional role in tumorigenesis.
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Affiliation(s)
- Winfried Elhardt
- Institute of Biochemistry, Stuttgart University, 70569 Stuttgart, Germany
| | | | - Tomasz P Jurkowski
- Institute of Biochemistry, Stuttgart University, 70569 Stuttgart, Germany.
| | - Albert Jeltsch
- Institute of Biochemistry, Stuttgart University, 70569 Stuttgart, Germany.
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63
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Abstract
Methylation of N6-adenosine (m6A) has been observed in many different classes of RNA, but its prevalence in microRNAs (miRNAs) has not yet been studied. Here we show that a knockdown of the m6A demethylase FTO affects the steady-state levels of several miRNAs. Moreover, RNA immunoprecipitation with an anti-m6A-antibody followed by RNA-seq revealed that a significant fraction of miRNAs contains m6A. By motif searches we have discovered consensus sequences discriminating between methylated and unmethylated miRNAs. The epigenetic modification of an epigenetic modifier as described here adds a new layer to the complexity of the posttranscriptional regulation of gene expression.
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64
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Vetting MW, Al-Obaidi N, Zhao S, San Francisco B, Kim J, Wichelecki DJ, Bouvier JT, Solbiati JO, Vu H, Zhang X, Rodionov DA, Love JD, Hillerich BS, Seidel RD, Quinn RJ, Osterman AL, Cronan JE, Jacobson MP, Gerlt JA, Almo SC. Experimental strategies for functional annotation and metabolism discovery: targeted screening of solute binding proteins and unbiased panning of metabolomes. Biochemistry 2015; 54:909-31. [PMID: 25540822 PMCID: PMC4310620 DOI: 10.1021/bi501388y] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
![]()
The
rate at which genome sequencing data is accruing demands enhanced
methods for functional annotation and metabolism discovery. Solute
binding proteins (SBPs) facilitate the transport of the first reactant
in a metabolic pathway, thereby constraining the regions of chemical
space and the chemistries that must be considered for pathway reconstruction.
We describe high-throughput protein production and differential scanning
fluorimetry platforms, which enabled the screening of 158 SBPs against
a 189 component library specifically tailored for this class of proteins.
Like all screening efforts, this approach is limited by the practical
constraints imposed by construction of the library, i.e., we can study
only those metabolites that are known to exist and which can be made
in sufficient quantities for experimentation. To move beyond these
inherent limitations, we illustrate the promise of crystallographic-
and mass spectrometric-based approaches for the unbiased use of entire
metabolomes as screening libraries. Together, our approaches identified
40 new SBP ligands, generated experiment-based annotations for 2084
SBPs in 71 isofunctional clusters, and defined numerous metabolic
pathways, including novel catabolic pathways for the utilization of
ethanolamine as sole nitrogen source and the use of d-Ala-d-Ala as sole carbon source. These efforts begin to define an
integrated strategy for realizing the full value of amassing genome
sequence data.
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Affiliation(s)
- Matthew W Vetting
- Department of Biochemistry, Albert Einstein College of Medicine , Bronx, New York 10461, United States
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65
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Abstract
Heterocyclic nucleic acid bases and their analogs can adopt multiple tautomeric forms due to the presence of multiple solvent-exchangeable protons. In DNA, spontaneous formation of minor tautomers has been speculated to contribute to mutagenic mispairings during DNA replication, whereas in RNA, minor tautomeric forms have been proposed to enhance the structural and functional diversity of RNA enzymes and aptamers. This review summarizes the role of tautomerism in RNA biochemistry, specifically focusing on the role of tautomerism in catalysis of small self-cleaving ribozymes and recognition of ligand analogs by riboswitches. Considering that the presence of multiple tautomers of nucleic acid bases is a rare occurrence, and that tautomers typically interconvert on a fast time scale, methods for studying rapid tautomerism in the context of nucleic acids under biologically relevant aqueous conditions are also discussed.
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Affiliation(s)
- Vipender Singh
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Bogdan I Fedeles
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - John M Essigmann
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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66
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Dufour D, Marti-Renom MA. Software for predicting the 3D structure of RNA molecules. WILEY INTERDISCIPLINARY REVIEWS: COMPUTATIONAL MOLECULAR SCIENCE 2015. [DOI: 10.1002/wcms.1198] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- David Dufour
- Genome Biology Group, Centre Nacional d'Anàlisi Genòmica (CNAG) and Gene Regulacion, Stem Cells and Cancer Program; Centre de Regulació Genòmica (CRG); Barcelona Spain
| | - Marc A. Marti-Renom
- Institució Catalana de Recerca i Estudis Avançats (ICREA); Genome Biology Group, Centre Nacional d'Anàlisi Genòmica (CNAG) and Gene Regulacion, Stem Cells and Cancer Program, Centre de Regulació Genòmica (CRG); Barcelona Spain
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67
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Kirchner S, Ignatova Z. Emerging roles of tRNA in adaptive translation, signalling dynamics and disease. Nat Rev Genet 2014; 16:98-112. [DOI: 10.1038/nrg3861] [Citation(s) in RCA: 355] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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68
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Leszczynska G, Pięta J, Wozniak K, Malkiewicz A. Site-selected incorporation of 5-carboxymethylaminomethyl(-2-thio)uridine into RNA sequences by phosphoramidite chemistry. Org Biomol Chem 2014; 12:1052-6. [PMID: 24407195 DOI: 10.1039/c3ob42302f] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
5-Carboxymethylaminomethyluridine (cmnm(5)U) and 5-carboxymethylaminomethyl-2-thiouridine (cmnm(5)s(2)U) are located at the wobble position in several cytosolic and mitochondrial tRNA sequences. In this paper, we report the first site-selected incorporation of cmnm(5)U and cmnm(5)s(2)U into RNA sequences by phosphoramidite chemistry on a CPG solid support. Trifluoroacetyl and 2-(trimethylsilyl)ethyl were selected for the protection of the amine and carboxyl functions, respectively.
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69
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Gu C, Begley TJ, Dedon PC. tRNA modifications regulate translation during cellular stress. FEBS Lett 2014; 588:4287-96. [PMID: 25304425 DOI: 10.1016/j.febslet.2014.09.038] [Citation(s) in RCA: 119] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 09/29/2014] [Accepted: 09/29/2014] [Indexed: 12/20/2022]
Abstract
The regulation of gene expression in response to stress is an essential cellular protection mechanism. Recent advances in tRNA modification analysis and genome-based codon bias analytics have facilitated studies that lead to a novel model for translational control, with translation elongation dynamically regulated during stress responses. Stress-induced increases in specific anticodon wobble bases are required for the optimal translation of stress response transcripts that are significantly biased in the use of degenerate codons keyed to these modified tRNA bases. These findings led us to introduce the notion of tRNA modification tunable transcripts (MoTTs - transcripts whose translation is regulated by tRNA modifications), which are identifiable using genome-wide codon counting algorithms. In support of this general model of translational control of stress response, studies making use of detailed measures of translation, tRNA methyltransferase mutants, and computational and mass spectrometry approaches reveal that stress reprograms tRNA modifications to translationally regulate MoTTs linked to arginine and leucine codons, which helps cells survive insults by damaging agents. These studies highlight how tRNA methyltransferase activities and MoTTs are key components of the cellular stress response.
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Affiliation(s)
- Chen Gu
- Department of Biological Engineering and Center for Environmental Health Science, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Thomas J Begley
- State University of New York - College of Nanoscale Science and Engineering, Albany, NY, United States; The RNA Institute at the University at Albany, Albany, NY, United States.
| | - Peter C Dedon
- Department of Biological Engineering and Center for Environmental Health Science, Massachusetts Institute of Technology, Cambridge, MA, United States; Singapore-MIT Alliance for Research and Technology, Singapore, Singapore.
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70
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Panwar B, Raghava GPS. Prediction of uridine modifications in tRNA sequences. BMC Bioinformatics 2014; 15:326. [PMID: 25272949 PMCID: PMC4287530 DOI: 10.1186/1471-2105-15-326] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 09/24/2014] [Indexed: 12/31/2022] Open
Abstract
Background In past number of methods have been developed for predicting post-translational modifications in proteins. In contrast, limited attempt has been made to understand post-transcriptional modifications. Recently it has been shown that tRNA modifications play direct role in the genome structure and codon usage. This study is an attempt to understand kingdom-wise tRNA modifications particularly uridine modifications (UMs), as majority of modifications are uridine-derived. Results A three-steps strategy has been applied to develop an efficient method for the prediction of UMs. In the first step, we developed a common prediction model for all the kingdoms using a dataset from MODOMICS-2008. Support Vector Machine (SVM) based prediction models were developed and evaluated by five-fold cross-validation technique. Different approaches were applied and found that a hybrid approach of binary and structural information achieved highest Area under the curve (AUC) of 0.936. In the second step, we used newly added tRNA sequences (as independent dataset) of MODOMICS-2012 for the kingdom-wise prediction performance evaluation of previously developed (in the first step) common model and achieved performances between the AUC of 0.910 to 0.949. In the third and last step, we used different datasets from MODOMICS-2012 for the kingdom-wise individual prediction models development and achieved performances between the AUC of 0.915 to 0.987. Conclusions The hybrid approach is efficient not only to predict kingdom-wise modifications but also to classify them into two most prominent UMs: Pseudouridine (Y) and Dihydrouridine (D). A webserver called tRNAmod (http://crdd.osdd.net/raghava/trnamod/) has been developed, which predicts UMs from both tRNA sequences and whole genome. Electronic supplementary material The online version of this article (doi:10.1186/1471-2105-15-326) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Gajendra P S Raghava
- Bioinformatics Centre, CSIR-Institute of Microbial Technology, Sector 39A, Chandigarh, India.
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71
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Turowski TW, Tollervey D. Cotranscriptional events in eukaryotic ribosome synthesis. WILEY INTERDISCIPLINARY REVIEWS-RNA 2014; 6:129-39. [PMID: 25176256 DOI: 10.1002/wrna.1263] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 07/16/2014] [Accepted: 07/23/2014] [Indexed: 12/13/2022]
Abstract
Eukaryotic ribosomes are synthesized in a complex, multistep pathway. This begins with transcription of the rDNA genes by a specialized RNA polymerase, accompanied by the cotranscriptional binding of large numbers of ribosome synthesis factors, small nucleolar RNAs and ribosomal proteins. Cleavage of the nascent transcript releases the early pre-40S and pre-60S particles, which acquire export competence in the nucleoplasm prior to translocation through the nuclear pore complexes and final maturation to functional ribosomal subunits in the cytoplasm. This review will focus on the many and complex interactions occurring during pre-rRNA synthesis, particularly in budding yeast in which the pathway is best understood.
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Affiliation(s)
- Tomasz W Turowski
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh, UK
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72
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Dudley E, Bond L. Mass spectrometry analysis of nucleosides and nucleotides. MASS SPECTROMETRY REVIEWS 2014; 33:302-31. [PMID: 24285362 DOI: 10.1002/mas.21388] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Revised: 05/03/2013] [Accepted: 05/03/2013] [Indexed: 05/12/2023]
Abstract
Mass spectrometry has been widely utilised in the study of nucleobases, nucleosides and nucleotides as components of nucleic acids and as bioactive metabolites in their own right. In this review, the application of mass spectrometry to such analysis is overviewed in relation to various aspects regarding the analytical mass spectrometric and chromatographic techniques applied and also the various applications of such analysis.
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Affiliation(s)
- Ed Dudley
- Institute of Mass Spectrometry, College of Medicine, Swansea University, Singleton Park, Swansea, SA2 8PP, UK
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73
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Leszczynska G, Leonczak P, Dziergowska A, Malkiewicz A. mt-tRNA components: synthesis of (2-thio)uridines modified with blocked glycine/taurine moieties at C-5,1. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2014; 32:599-616. [PMID: 24138499 DOI: 10.1080/15257770.2013.838261] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
In this paper, we discuss the usefulness of reductive amination of 5-formyl-2',3'-O-isopropylidene(-2-thio)uridine with glycine or taurine esters in the presence of sodium triacetoxyborohydride (NaBH(OAc)3) for the synthesis of the native mitochondrial (mt) tRNA components 5-carboxymethylaminomethyl(-2-thio)uridine (cmnm(5)(s(2))U) and 5-taurinomethyl(-2-thio)uridine (τm(5)(s(2))U) with a blocked amino acid function. 2-(Trimethylsilyl)ethyl and 2-(p-nitrophenyl)ethyl esters of glycine and 2-(2,4,5-trifluorophenyl)ethyl ester of taurine were selected as protection of carboxylic and sulfonic acid residues, respectively. The first synthesis of 5-formyl-2',3'-O-isopropylidene-2-thiouridine is also reported.
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Affiliation(s)
- Grazyna Leszczynska
- a Institute of Organic Chemistry , Lodz University of Technology , Lodz , Poland
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74
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Abstract
Discoveries over the past decade portend a paradigm shift in molecular biology. Evidence suggests that RNA is not only functional as a messenger between DNA and protein but also involved in the regulation of genome organization and gene expression, which is increasingly elaborate in complex organisms. Regulatory RNA seems to operate at many levels; in particular, it plays an important part in the epigenetic processes that control differentiation and development. These discoveries suggest a central role for RNA in human evolution and ontogeny. Here, we review the emergence of the previously unsuspected world of regulatory RNA from a historical perspective.
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Affiliation(s)
- Kevin V Morris
- School of Biotechnology and Biomedical Sciences, University of New South Wales, Sydney, NSW 2052, Australia; and Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California 92037, USA
| | - John S Mattick
- Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW 2010, Australia; the School of Biotechnology and Biomedical Sciences, and St. Vincent's Clinical School, University of New South Wales, Sydney, NSW 2052, Australia
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75
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Su D, Chan CT, Gu C, Lim KS, Chionh YH, McBee ME, Russell BS, Babu IR, Begley TJ, Dedon PC. Quantitative analysis of ribonucleoside modifications in tRNA by HPLC-coupled mass spectrometry. Nat Protoc 2014; 9:828-41. [PMID: 24625781 PMCID: PMC4313537 DOI: 10.1038/nprot.2014.047] [Citation(s) in RCA: 187] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Post-transcriptional modification of RNA is an important determinant of RNA quality control, translational efficiency, RNA-protein interactions and stress response. This is illustrated by the observation of toxicant-specific changes in the spectrum of tRNA modifications in a stress-response mechanism involving selective translation of codon-biased mRNA for crucial proteins. To facilitate systems-level studies of RNA modifications, we developed a liquid chromatography-mass spectrometry (LC-MS) technique for the quantitative analysis of modified ribonucleosides in tRNA. The protocol includes tRNA purification by HPLC, enzymatic hydrolysis, reversed-phase HPLC resolution of the ribonucleosides, and identification and quantification of individual ribonucleosides by LC-MS via dynamic multiple reaction monitoring (DMRM). In this approach, the relative proportions of modified ribonucleosides are quantified in several micrograms of tRNA in a 15-min LC-MS run. This protocol can be modified to analyze other types of RNA by modifying the steps for RNA purification as appropriate. By comparison, traditional methods for detecting modified ribonucleosides are labor- and time-intensive, they require larger RNA quantities, they are modification-specific or require radioactive labeling.
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Affiliation(s)
- Dan Su
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA
| | - Clement T.Y. Chan
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA
| | - Chen Gu
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA
| | - Kok Seong Lim
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA
| | - Yok Hian Chionh
- Singapore-MIT Alliance for Research and Technology, CREATE, Singapore
| | - Megan E. McBee
- Singapore-MIT Alliance for Research and Technology, CREATE, Singapore
| | - Brandon S. Russell
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA
| | - I. Ramesh Babu
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA
| | - Thomas J. Begley
- College of Nanoscale Science and Engineering, University at Albany, State University of New York, Albany, NY
| | - Peter C. Dedon
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA
- Singapore-MIT Alliance for Research and Technology, CREATE, Singapore
- Center for Environmental Health Science, Massachusetts Institute of Technology, Cambridge, MA
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76
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Zhang W, Bryson DI, Crumpton JB, Wynn J, Santos WL. Targeting folded RNA: a branched peptide boronic acid that binds to a large surface area of HIV-1 RRE RNA. Org Biomol Chem 2014; 11:6263-71. [PMID: 23925474 DOI: 10.1039/c3ob41053f] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
On-bead high-throughput screening of a medium-sized (1000-2000 Da) branched peptide boronic acid (BPBA) library consisting of 46,656 unique sequences against HIV-1 RRE RNA generated peptides with binding affinities in the low micromolar range. In particular, BPBA1 had a K(d) of 1.4 μM with RRE IIB, preference for RNA over DNA (27 fold), and selectivity of up to >75 fold against a panel of RRE IIB variants. Structure-activity studies suggest that the boronic acid moiety and "branching" in peptides are key structural features for efficient binding and selectivity for the folded RNA target. BPBA1 was efficiently taken up by HeLa and A2780 cells. RNA-footprinting studies revealed that the BPBA1 binding site encompasses a large surface area that spans both the upper stem as well as the internal loop regions of RRE IIB.
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Affiliation(s)
- Wenyu Zhang
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, USA
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77
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Dedon PC, Begley TJ. A system of RNA modifications and biased codon use controls cellular stress response at the level of translation. Chem Res Toxicol 2014; 27:330-7. [PMID: 24422464 PMCID: PMC3997223 DOI: 10.1021/tx400438d] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Cells respond to environmental stressors and xenobiotic exposures using regulatory networks to control gene expression, and there is an emerging appreciation for the role of numerous postsynthetic chemical modifications of DNA, RNA, and proteins in controlling transcription and translation of the stress response. In this Perspective, we present a model for a new network that regulates the cellular response to xenobiotic exposures and other stresses in which stress-induced reprogramming of a system of dozens of post-transcriptional modifications on tRNA (tRNA) promotes selective translation of codon-biased mRNAs for critical response proteins. As a product of novel genomic and bioanalytical technologies, this model has strong parallels with the regulatory networks of DNA methylation in epigenetics and the variety of protein secondary modifications comprising signaling pathways and the histone code. When present at the tRNA wobble position, the modified ribonucleosides enhance the translation of mRNAs in which the cognate codons of the tRNAs are highly over-represented and that represent critical stress response proteins. A parallel system may also downregulate the translation of families of proteins. Notably, dysregulation of the tRNA methyltransferase enzymes in humans has also been implicated in cancer etiology, with demonstrated oncogenic and tumor-suppressive effects.
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Affiliation(s)
- Peter C Dedon
- Department of Biological Engineering, Center for Environmental Health Science, Infectious Disease Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
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78
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Ryvkin P, Leung YY, Silverman IM, Childress M, Valladares O, Dragomir I, Gregory BD, Wang LS. HAMR: high-throughput annotation of modified ribonucleotides. RNA (NEW YORK, N.Y.) 2013; 19:1684-92. [PMID: 24149843 PMCID: PMC3884653 DOI: 10.1261/rna.036806.112] [Citation(s) in RCA: 113] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 08/23/2013] [Indexed: 05/17/2023]
Abstract
RNA is often altered post-transcriptionally by the covalent modification of particular nucleotides; these modifications are known to modulate the structure and activity of their host RNAs. The recent discovery that an RNA methyl-6 adenosine demethylase (FTO) is a risk gene in obesity has brought to light the significance of RNA modifications to human biology. These noncanonical nucleotides, when converted to cDNA in the course of RNA sequencing, can produce sequence patterns that are distinguishable from simple base-calling errors. To determine whether these modifications can be detected in RNA sequencing data, we developed a method that can not only locate these modifications transcriptome-wide with single nucleotide resolution, but can also differentiate between different classes of modifications. Using small RNA-seq data we were able to detect 92% of all known human tRNA modification sites that are predicted to affect RT activity. We also found that different modifications produce distinct patterns of cDNA sequence, allowing us to differentiate between two classes of adenosine and two classes of guanine modifications with 98% and 79% accuracy, respectively. To show the robustness of this method to sample preparation and sequencing methods, as well as to organismal diversity, we applied it to a publicly available yeast data set and achieved similar levels of accuracy. We also experimentally validated two novel and one known 3-methylcytosine (3mC) sites predicted by HAMR in human tRNAs. Researchers can now use our method to identify and characterize RNA modifications using only RNA-seq data, both retrospectively and when asking questions specifically about modified RNA.
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Affiliation(s)
- Paul Ryvkin
- Genomics and Computational Biology Graduate Group, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Yuk Yee Leung
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Ian M. Silverman
- Cell and Molecular Biology Graduate Group, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
- Penn Genome Frontiers Institute, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Micah Childress
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Otto Valladares
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Isabelle Dragomir
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Brian D. Gregory
- Genomics and Computational Biology Graduate Group, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
- Cell and Molecular Biology Graduate Group, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
- Penn Genome Frontiers Institute, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
- Corresponding authorsE-mail E-mail
| | - Li-San Wang
- Genomics and Computational Biology Graduate Group, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
- Penn Genome Frontiers Institute, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
- Institute for Biomedical Informatics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
- Corresponding authorsE-mail E-mail
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79
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Baldridge KC, Contreras LM. Functional implications of ribosomal RNA methylation in response to environmental stress. Crit Rev Biochem Mol Biol 2013; 49:69-89. [PMID: 24261569 DOI: 10.3109/10409238.2013.859229] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The study of post-transcriptional RNA modifications has long been focused on the roles these chemical modifications play in maintaining ribosomal function. The field of ribosomal RNA modification has reached a milestone in recent years with the confirmation of the final unknown ribosomal RNA methyltransferase in Escherichia coli in 2012. Furthermore, the last 10 years have brought numerous discoveries in non-coding RNAs and the roles that post-transcriptional modification play in their functions. These observations indicate the need for a revitalization of this field of research to understand the role modifications play in maintaining cellular health in a dynamic environment. With the advent of high-throughput sequencing technologies, the time is ripe for leaps and bounds forward. This review discusses ribosomal RNA methyltransferases and their role in responding to external stress in Escherichia coli, with a specific focus on knockout studies and on analysis of transcriptome data with respect to rRNA methyltransferases.
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Affiliation(s)
- Kevin C Baldridge
- McKetta Department of Chemical Engineering, The University of Texas at Austin , Austin, TX , USA
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80
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Sheng J, Gan J, Soares AS, Salon J, Huang Z. Structural insights of non-canonical U*U pair and Hoogsteen interaction probed with Se atom. Nucleic Acids Res 2013; 41:10476-87. [PMID: 24013566 PMCID: PMC3905866 DOI: 10.1093/nar/gkt799] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Unlike DNA, in addition to the 2′-OH group, uracil nucleobase and its modifications play essential roles in structure and function diversities of non-coding RNAs. Non-canonical U•U base pair is ubiquitous in non-coding RNAs, which are highly diversified. However, it is not completely clear how uracil plays the diversifing roles. To investigate and compare the uracil in U-A and U•U base pairs, we have decided to probe them with a selenium atom by synthesizing the novel 4-Se-uridine (SeU) phosphoramidite and Se-nucleobase-modified RNAs (SeU-RNAs), where the exo-4-oxygen of uracil is replaced by selenium. Our crystal structure studies of U-A and U•U pairs reveal that the native and Se-derivatized structures are virtually identical, and both U-A and U•U pairs can accommodate large Se atoms. Our thermostability and crystal structure studies indicate that the weakened H-bonding in U-A pair may be compensated by the base stacking, and that the stacking of the trans-Hoogsteen U•U pairs may stabilize RNA duplex and its junction. Our result confirms that the hydrogen bond (O4…H-C5) of the Hoogsteen pair is weak. Using the Se atom probe, our Se-functionalization studies reveal more insights into the U•U interaction and U-participation in structure and function diversification of nucleic acids.
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Affiliation(s)
- Jia Sheng
- Department of Chemistry, Georgia State University, Atlanta, GA, 30303, USA and Department of Biology, Brookhaven National Laboratory, Upton, NY, 11973, USA
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81
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Russell SP, Limbach PA. Evaluating the reproducibility of quantifying modified nucleosides from ribonucleic acids by LC-UV-MS. J Chromatogr B Analyt Technol Biomed Life Sci 2013; 923-924:74-82. [PMID: 23500350 DOI: 10.1016/j.jchromb.2013.02.010] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 02/07/2013] [Accepted: 02/11/2013] [Indexed: 11/26/2022]
Abstract
Post-transcriptional chemical covalent modification of adenosine, guanosine, uridine and cytidine occurs frequently in all types of ribonucleic acids (RNAs). In ribosomal RNA (rRNA) and transfer RNA (tRNA) these modifications make important contributions to RNA structure and stability and to the accuracy and efficiency of protein translation. The functional dynamics, synergistic nature and regulatory roles of these posttranscriptional nucleoside modifications within the cell are not well characterized. These modifications are present at very low levels and isolation of individual nucleosides for analysis requires a complex multi-step approach. The focus of this study is to characterize the reproducibility of a liquid chromatography method used to isolate and quantitatively characterize modified nucleosides in tRNA and rRNA when nucleoside detection is performed using ultraviolet and mass spectrometric detection (UV and MS, respectively). Despite the analytical challenges of sample isolation and dynamic range, quantitative profiling of modified nucleosides obtained from bacterial tRNAs and rRNAs is feasible at relative standard deviations of 5% RSD or less.
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Affiliation(s)
- Susan P Russell
- Rieveschl Laboratories for Mass Spectrometry, Department of Chemistry, University of Cincinnati, Cincinnati, OH 45221-0172, United States
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82
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Swinehart WE, Henderson JC, Jackman JE. Unexpected expansion of tRNA substrate recognition by the yeast m1G9 methyltransferase Trm10. RNA (NEW YORK, N.Y.) 2013; 19:1137-46. [PMID: 23793893 PMCID: PMC3708533 DOI: 10.1261/rna.039651.113] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
N-1 Methylation of the nearly invariant purine residue found at position 9 of tRNA is a nucleotide modification found in multiple tRNA species throughout Eukarya and Archaea. First discovered in Saccharomyces cerevisiae, the tRNA methyltransferase Trm10 is a highly conserved protein both necessary and sufficient to catalyze all known instances of m1G9 modification in yeast. Although there are 19 unique tRNA species that contain a G at position 9 in yeast, and whose fully modified sequence is known, only 9 of these tRNA species are modified with m1G9 in wild-type cells. The elements that allow Trm10 to distinguish between structurally similar tRNA species are not known, and sequences that are shared between all substrate or all nonsubstrate tRNAs have not been identified. Here, we demonstrate that the in vitro methylation activity of yeast Trm10 is not sufficient to explain the observed pattern of modification in vivo, as additional tRNA species are substrates for Trm10 m1G9 methyltransferase activity. Similarly, overexpression of Trm10 in yeast yields m1G9 containing tRNA species that are ordinarily unmodified in vivo. Thus, yeast Trm10 has a significantly broader tRNA substrate specificity than is suggested by the observed pattern of modification in wild-type yeast. These results may shed light onto the suggested involvement of Trm10 in other pathways in other organisms, particularly in higher eukaryotes that contain up to three different genes with sequence similarity to the single TRM10 gene in yeast, and where these other enzymes have been implicated in pathways beyond tRNA processing.
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MESH Headings
- Genes, Fungal
- Guanosine/analogs & derivatives
- Guanosine/chemistry
- Humans
- Kinetics
- Methylation
- RNA Processing, Post-Transcriptional
- RNA, Fungal/chemistry
- RNA, Fungal/metabolism
- RNA, Transfer/chemistry
- RNA, Transfer/metabolism
- RNA, Transfer, Val/chemistry
- RNA, Transfer, Val/metabolism
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae/metabolism
- Saccharomyces cerevisiae Proteins/genetics
- Saccharomyces cerevisiae Proteins/metabolism
- Substrate Specificity
- tRNA Methyltransferases/genetics
- tRNA Methyltransferases/metabolism
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Affiliation(s)
- William E. Swinehart
- Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
- Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio 43210, USA
| | - Jeremy C. Henderson
- Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
| | - Jane E. Jackman
- Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
- Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio 43210, USA
- Corresponding authorE-mail
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83
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tRNA tKUUU, tQUUG, and tEUUC wobble position modifications fine-tune protein translation by promoting ribosome A-site binding. Proc Natl Acad Sci U S A 2013; 110:12289-94. [PMID: 23836657 DOI: 10.1073/pnas.1300781110] [Citation(s) in RCA: 121] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
tRNA modifications are crucial to ensure translation efficiency and fidelity. In eukaryotes, the URM1 and ELP pathways increase cellular resistance to various stress conditions, such as nutrient starvation and oxidative agents, by promoting thiolation and methoxycarbonylmethylation, respectively, of the wobble uridine of cytoplasmic (tK(UUU)), (tQ(UUG)), and (tE(UUC)). Although in vitro experiments have implicated these tRNA modifications in modulating wobbling capacity and translation efficiency, their exact in vivo biological roles remain largely unexplored. Using a combination of quantitative proteomics and codon-specific translation reporters, we find that translation of a specific gene subset enriched for AAA, CAA, and GAA codons is impaired in the absence of URM1- and ELP-dependent tRNA modifications. Moreover, in vitro experiments using native tRNAs demonstrate that both modifications enhance binding of tK(UUU) to the ribosomal A-site. Taken together, our data suggest that tRNA thiolation and methoxycarbonylmethylation regulate translation of genes with specific codon content.
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84
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Transcriptome-wide mapping of 5-methylcytidine RNA modifications in bacteria, archaea, and yeast reveals m5C within archaeal mRNAs. PLoS Genet 2013; 9:e1003602. [PMID: 23825970 PMCID: PMC3694839 DOI: 10.1371/journal.pgen.1003602] [Citation(s) in RCA: 243] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2012] [Accepted: 05/17/2013] [Indexed: 11/19/2022] Open
Abstract
The presence of 5-methylcytidine (m5C) in tRNA and rRNA molecules of a wide variety of organisms was first observed more than 40 years ago. However, detection of this modification was limited to specific, abundant, RNA species, due to the usage of low-throughput methods. To obtain a high resolution, systematic, and comprehensive transcriptome-wide overview of m5C across the three domains of life, we used bisulfite treatment on total RNA from both gram positive (B. subtilis) and gram negative (E. coli) bacteria, an archaeon (S. solfataricus) and a eukaryote (S. cerevisiae), followed by massively parallel sequencing. We were able to recover most previously documented m5C sites on rRNA in the four organisms, and identified several novel sites in yeast and archaeal rRNAs. Our analyses also allowed quantification of methylated m5C positions in 64 tRNAs in yeast and archaea, revealing stoichiometric differences between the methylation patterns of these organisms. Molecules of tRNAs in which m5C was absent were also discovered. Intriguingly, we detected m5C sites within archaeal mRNAs, and identified a consensus motif of AUCGANGU that directs methylation in S. solfataricus. Our results, which were validated using m5C-specific RNA immunoprecipitation, provide the first evidence for mRNA modifications in archaea, suggesting that this mode of post-transcriptional regulation extends beyond the eukaryotic domain. Ribonucleic acids are universally used to express genetic information in the form of gene transcripts. Although we envision RNA as a mere copy of the DNA four-base code, modification of specific RNA bases can expand the information code. Such modifications are abundant in transfer RNA (tRNA) and ribosomal RNA (rRNA), where they contribute to translation fidelity and ribosome assembly. Recent studies in eukaryotes have shown that mRNA modifications such as RNA-editing (conversion of an adenosine base to inosine), N6-adenine methylation (m6A), and 5-methylcytidine (m5C) can change the coding sequence, alter splicing patterns, or change RNA stability. However, no mRNA modifications in bacteria or archaea have been documented to date. We have used an approach that enables mapping of the m5C modifications across all expressed genes in a given organism. Applying this approach on model bacterial, archaeal, and fungal microorganisms enabled us to reveal the modified RNA bases in these organisms, and to provide an accurate and sensitive map of these modifications. In archaea, we documented multiple genes whose mRNAs are subject to RNA modification, suggesting that similar to eukaryotes, these organisms may utilize mRNA modifications as a mechanism for gene regulation.
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85
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Kim J, Xiao H, Bonanno JB, Kalyanaraman C, Brown S, Tang X, Al-Obaidi NF, Patskovsky Y, Babbitt PC, Jacobson MP, Lee YS, Almo SC. Structure-guided discovery of the metabolite carboxy-SAM that modulates tRNA function. Nature 2013; 498:123-6. [PMID: 23676670 PMCID: PMC3895326 DOI: 10.1038/nature12180] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Accepted: 04/12/2013] [Indexed: 02/07/2023]
Abstract
Identifying novel metabolites and characterizing their biological functions are major challenges of the post-genomic era. X-ray crystallography can reveal unanticipated ligands which persist through purification and crystallization. These adventitious protein:ligand complexes provide insights into new activities, pathways and regulatory mechanisms. We describe a new metabolite, carboxy-S-adenosylmethionine (Cx-SAM), its biosynthetic pathway and its role in tRNA modification. The structure of CmoA, a member of the SAM-dependent methyltransferase superfamily, revealed a ligand in the catalytic site consistent with Cx-SAM. Mechanistic analyses demonstrated an unprecedented role for prephenate as the carboxyl donor and the involvement of a unique ylide intermediate as the carboxyl acceptor in the CmoA-mediated conversion of SAM to Cx-SAM. A second member of the SAM-dependent methyltransferase superfamily, CmoB, recognizes Cx-SAM and acts as a carboxymethyltransferase to convert 5-hydroxyuridine (ho5U) into 5-oxyacetyl uridine (cmo5U) at the wobble position of multiple tRNAs in Gram negative bacteria1, resulting in expanded codon-recognition properties2,3. CmoA and CmoB represent the first documented synthase and transferase for Cx-SAM. These findings reveal new functional diversity in the SAM-dependent methyltransferase superfamily and expand the metabolic and biological contributions of SAM-based biochemistry. These discoveries highlight the value of structural genomics approaches for identifying ligands in the context of their physiologically relevant macromolecular binding partners and for aiding in functional assignment.
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Affiliation(s)
- Jungwook Kim
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
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86
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Ge J, Yu YT. RNA pseudouridylation: new insights into an old modification. Trends Biochem Sci 2013; 38:210-8. [PMID: 23391857 PMCID: PMC3608706 DOI: 10.1016/j.tibs.2013.01.002] [Citation(s) in RCA: 183] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Revised: 12/22/2012] [Accepted: 01/07/2013] [Indexed: 12/18/2022]
Abstract
Pseudouridine is the most abundant post-transcriptionally modified nucleotide in various stable RNAs of all organisms. Pseudouridine is derived from uridine via base-specific isomerization, resulting in an extra hydrogen-bond donor that distinguishes it from other nucleotides. In eukaryotes, uridine-to-pseudouridine isomerization is catalyzed primarily by box H/ACA RNPs, ribonucleoproteins that act as pseudouridylases. When introduced into RNA, pseudouridine contributes significantly to RNA-mediated cellular processes. It was recently discovered that pseudouridylation can be induced by stress, suggesting a regulatory role for pseudouridine. It has also been reported that pseudouridine can be artificially introduced into mRNA by box H/ACA RNPs and that such introduction can mediate nonsense-to-sense codon conversion, thus demonstrating a new means of generating coding or protein diversity.
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Affiliation(s)
- Junhui Ge
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, NY 14642, USA
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87
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Wu J, Huang HY, Hopper AK. A rapid and sensitive non-radioactive method applicable for genome-wide analysis of Saccharomyces cerevisiae genes involved in small RNA biology. Yeast 2013; 30:119-28. [PMID: 23417998 DOI: 10.1002/yea.2947] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 02/02/2013] [Accepted: 02/04/2013] [Indexed: 11/10/2022] Open
Abstract
Conventional isolation and detection methods for small RNAs from yeast cells have been designed for a limited number of samples. In order to be able to conduct a genome-wide assessment of how each gene product impacts upon small RNAs, we developed a rapid method for analysing small RNAs from Saccharomyces cerevisiae wild-type (wt) and mutants cells in the deletion and temperature-sensitive (ts) collections. Our method implements three optimized techniques: a procedure for growing small yeast cultures in 96-deepwell plates, a fast procedure for small RNA isolation from the plates, and a sensitive non-radioactive northern method for RNA detection. The RNA isolation procedure requires only 4 h for processing 96 samples, is highly reproducible and yields RNA of good quality and quantity. The non-radioactive northern method employs digoxigenin (DIG)-labelled DNA probes and chemiluminescence. It detects femtomole levels of small RNAs within 1 min exposure time. We minimized the processing time for large-scale analysis and optimized the stripping and reprobing procedures for analyses of multiple RNAs from a single membrane. The method described is rapid, sensitive, safe and cost-effective for genome-wide screens of novel genes involved in the biogenesis, subcellular trafficking and stability of small RNAs. Moreover, it will be useful to educational laboratory class venues and to research institutions with limited access to radioisotopes or robots.
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Affiliation(s)
- Jingyan Wu
- Department of Molecular Genetics, Ohio State University, Columbus, OH 43210, USA
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88
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Thomas B, Matson S, Chopra V, Sun L, Sharma S, Hersch S, Rosas HD, Scherzer C, Ferrante R, Matson W. A novel method for detecting 7-methyl guanine reveals aberrant methylation levels in Huntington disease. Anal Biochem 2013; 436:112-20. [PMID: 23416183 DOI: 10.1016/j.ab.2013.01.035] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Revised: 01/24/2013] [Accepted: 01/29/2013] [Indexed: 12/21/2022]
Abstract
Guanine methylation is a ubiquitous process affecting DNA and various RNA species. N-7 guanine methylation (7-MG), although relatively less studied, could have a significant role in normal transcriptional regulation as well as in the onset and development of pathological conditions. The lack of a sensitive method to accurately quantify trace amounts of altered bases such as 7-MG has been a major deterrent in delineating its biological function(s). Here we report the development of methods to detect trace amounts of 7-MG in biological samples using electrochemical detection combined with high-performance liquid chromatography (HPLC) separation of compounds. We further sought to assess global alterations in DNA methylation in Huntington disease (HD), where transcriptional dysregulation is a major factor in pathogenesis. The developed method was used to study guanine methylation in cytoplasmic and nuclear nucleic acids from human and transgenic mouse HD brain and controls. Significant differences were observed in the guanine methylation levels in mouse and human samples, consistent with the known transcriptional pathology of HD. The sensitivity of the method makes it capable of detecting subtle aberrations. Identification of changes in methylation pattern will provide insights into the molecular mechanism changes that translate into onset and/or development of symptoms in diseases such as HD.
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Affiliation(s)
- Beena Thomas
- Department of Systems Biochemistry, Bedford VA Medical Center, Bedford, MA 01730, USA
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89
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Dominissini D, Moshitch-Moshkovitz S, Salmon-Divon M, Amariglio N, Rechavi G. Transcriptome-wide mapping of N(6)-methyladenosine by m(6)A-seq based on immunocapturing and massively parallel sequencing. Nat Protoc 2013; 8:176-89. [PMID: 23288318 DOI: 10.1038/nprot.2012.148] [Citation(s) in RCA: 461] [Impact Index Per Article: 41.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
N(6)-methyladenosine-sequencing (m(6)A-seq) is an immunocapturing approach for the unbiased transcriptome-wide localization of m(6)A in high resolution. To our knowledge, this is the first protocol to allow a global view of this ubiquitous RNA modification, and it is based on antibody-mediated enrichment of methylated RNA fragments followed by massively parallel sequencing. Building on principles of chromatin immunoprecipitation-sequencing (ChIP-seq) and methylated DNA immunoprecipitation (MeDIP), read densities of immunoprecipitated RNA relative to untreated input control are used to identify methylated sites. A consensus motif is deduced, and its distance to the point of maximal enrichment is assessed; these measures further corroborate the success of the protocol. Identified locations are intersected in turn with gene architecture to draw conclusions regarding the distribution of m(6)A between and within gene transcripts. When applied to human and mouse transcriptomes, m(6)A-seq generated comprehensive methylation profiles revealing, for the first time, tenets governing the nonrandom distribution of m(6)A. The protocol can be completed within ~9 d for four different sample pairs (each consists of an immunoprecipitation and corresponding input).
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Affiliation(s)
- Dan Dominissini
- Cancer Research Center, Chaim Sheba Medical Center, Tel Hashomer, Israel
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90
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XIE YP, TIAN J, GAO P, XU GUOW, FEI X, WANG Y. Determination of Nucleosides in Escherichia coli by Rapid Resolution Liquid Chromatography–Tandem Quadrupole Mass Spectrometry. CHINESE JOURNAL OF ANALYTICAL CHEMISTRY 2013. [DOI: 10.1016/s1872-2040(13)60622-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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91
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Schomburg I, Chang A, Placzek S, Söhngen C, Rother M, Lang M, Munaretto C, Ulas S, Stelzer M, Grote A, Scheer M, Schomburg D. BRENDA in 2013: integrated reactions, kinetic data, enzyme function data, improved disease classification: new options and contents in BRENDA. Nucleic Acids Res 2013; 41:D764-72. [PMID: 23203881 PMCID: PMC3531171 DOI: 10.1093/nar/gks1049] [Citation(s) in RCA: 271] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Revised: 10/08/2012] [Accepted: 10/10/2012] [Indexed: 11/13/2022] Open
Abstract
The BRENDA (BRaunschweig ENzyme DAtabase) enzyme portal (http://www.brenda-enzymes.org) is the main information system of functional biochemical and molecular enzyme data and provides access to seven interconnected databases. BRENDA contains 2.7 million manually annotated data on enzyme occurrence, function, kinetics and molecular properties. Each entry is connected to a reference and the source organism. Enzyme ligands are stored with their structures and can be accessed via their names, synonyms or via a structure search. FRENDA (Full Reference ENzyme DAta) and AMENDA (Automatic Mining of ENzyme DAta) are based on text mining methods and represent a complete survey of PubMed abstracts with information on enzymes in different organisms, tissues or organelles. The supplemental database DRENDA provides more than 910 000 new EC number-disease relations in more than 510 000 references from automatic search and a classification of enzyme-disease-related information. KENDA (Kinetic ENzyme DAta), a new amendment extracts and displays kinetic values from PubMed abstracts. The integration of the EnzymeDetector offers an automatic comparison, evaluation and prediction of enzyme function annotations for prokaryotic genomes. The biochemical reaction database BKM-react contains non-redundant enzyme-catalysed and spontaneous reactions and was developed to facilitate and accelerate the construction of biochemical models.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Dietmar Schomburg
- Technische Universität Braunschweig, Dpt. for Bioinformatics and Biochemistry, Langer Kamp 19 B, 38106 Braunschweig, Germany
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92
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Niu Y, Zhao X, Wu YS, Li MM, Wang XJ, Yang YG. N6-methyl-adenosine (m6A) in RNA: an old modification with a novel epigenetic function. GENOMICS PROTEOMICS & BIOINFORMATICS 2012; 11:8-17. [PMID: 23453015 PMCID: PMC4357660 DOI: 10.1016/j.gpb.2012.12.002] [Citation(s) in RCA: 318] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Revised: 12/10/2012] [Accepted: 12/11/2012] [Indexed: 12/02/2022]
Abstract
N6-methyl-adenosine (m6A) is one of the most common and abundant modifications on RNA molecules present in eukaryotes. However, the biological significance of m6A methylation remains largely unknown. Several independent lines of evidence suggest that the dynamic regulation of m6A may have a profound impact on gene expression regulation. The m6A modification is catalyzed by an unidentified methyltransferase complex containing at least one subunit methyltransferase like 3 (METTL3). m6A modification on messenger RNAs (mRNAs) mainly occurs in the exonic regions and 3′-untranslated region (3′-UTR) as revealed by high-throughput m6A-seq. One significant advance in m6A research is the recent discovery of the first two m6A RNA demethylases fat mass and obesity-associated (FTO) gene and ALKBH5, which catalyze m6A demethylation in an α-ketoglutarate (α-KG)- and Fe2+-dependent manner. Recent studies in model organisms demonstrate that METTL3, FTO and ALKBH5 play important roles in many biological processes, ranging from development and metabolism to fertility. Moreover, perturbation of activities of these enzymes leads to the disturbed expression of thousands of genes at the cellular level, implicating a regulatory role of m6A in RNA metabolism. Given the vital roles of DNA and histone methylations in epigenetic regulation of basic life processes in mammals, the dynamic and reversible chemical m6A modification on RNA may also serve as a novel epigenetic marker of profound biological significances.
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Affiliation(s)
- Yamei Niu
- Disease Genomics and Individualized Medicine Laboratory, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China
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93
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Perrochia L, Crozat E, Hecker A, Zhang W, Bareille J, Collinet B, van Tilbeurgh H, Forterre P, Basta T. In vitro biosynthesis of a universal t6A tRNA modification in Archaea and Eukarya. Nucleic Acids Res 2012; 41:1953-64. [PMID: 23258706 PMCID: PMC3561968 DOI: 10.1093/nar/gks1287] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
N6-threonylcarbamoyladenosine (t6A) is a modified nucleotide found in all transfer RNAs (tRNAs) decoding codons starting with adenosine. Its role is to facilitate codon–anticodon pairing and to prevent frameshifting during protein synthesis. Genetic studies demonstrated that two universal proteins, Kae1/YgjD and Sua5/YrdC, are necessary for t6A synthesis in Saccharomyces cerevisiae and Escherichia coli. In Archaea and Eukarya, Kae1 is part of a conserved protein complex named kinase, endopeptidase and other proteins of small size (KEOPS), together with three proteins that have no bacterial homologues. Here, we reconstituted for the first time an in vitro system for t6A modification in Archaea and Eukarya, using purified KEOPS and Sua5. We demonstrated binding of tRNAs to archaeal KEOPS and detected two distinct adenosine triphosphate (ATP)-dependent steps occurring in the course of the synthesis. Our data, together with recent reconstitution of an in vitro bacterial system, indicated that t6A cannot be catalysed by Sua5/YrdC and Kae1/YgjD alone but requires accessory proteins that are not universal. Remarkably, we observed interdomain complementation when bacterial, archaeal and eukaryotic proteins were combined in vitro, suggesting a conserved catalytic mechanism for the biosynthesis of t6A in nature. These findings shed light on the reaction mechanism of t6A synthesis and evolution of molecular systems that promote translation fidelity in present-day cells.
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Affiliation(s)
- Ludovic Perrochia
- Institut de Génétique et Microbiologie, Université Paris-Sud, IFR115, UMR8621-CNRS, 91405 Orsay, France
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94
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El Yacoubi B, Bailly M, de Crécy-Lagard V. Biosynthesis and Function of Posttranscriptional Modifications of Transfer RNAs. Annu Rev Genet 2012; 46:69-95. [DOI: 10.1146/annurev-genet-110711-155641] [Citation(s) in RCA: 380] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Basma El Yacoubi
- Department of Microbiology and Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611-0700;
| | - Marc Bailly
- Department of Microbiology and Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611-0700;
| | - Valérie de Crécy-Lagard
- Department of Microbiology and Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611-0700;
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95
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Chujo T, Suzuki T. Trmt61B is a methyltransferase responsible for 1-methyladenosine at position 58 of human mitochondrial tRNAs. RNA (NEW YORK, N.Y.) 2012; 18:2269-76. [PMID: 23097428 PMCID: PMC3504677 DOI: 10.1261/rna.035600.112] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
In human mitochondria, 1-methyladenosine (m¹A) occurs at position 58 of tRNA(Leu(UUR)). In addition, partial m¹A58 modifications have been found in human mitochondrial tRNA(Lys) and tRNA(Ser(UCN)). We identified human Trmt61B, which encodes a mitochondria-specific tRNA methyltransferase responsible for m¹A58 in these three tRNAs. Trmt61B is dominantly localized to the mitochondria. m¹A58 formation in human mitochondrial tRNA(Leu(UUR)) could be reconstituted in vitro using recombinant Trmt61B in the presence of Ado-Met as a methyl donor. Unlike the cytoplasmic tRNA m¹A58 methyltransferase that consists of an α2β2 heterotetramer formed by Trmt61A and Trmt6, Trmt61B formed a homo-oligomer (presumably a homotetramer) that resembled the bacterial homotetrameric m¹A58 methyltransferase. The bacterial origin of Trmt61B is supported by the results of the phylogenetic analysis.
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Affiliation(s)
- Takeshi Chujo
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Tsutomu Suzuki
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
- Corresponding authorE-mail
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96
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Milanowska K, Mikolajczak K, Lukasik A, Skorupski M, Balcer Z, Machnicka MA, Nowacka M, Rother KM, Bujnicki JM. RNApathwaysDB--a database of RNA maturation and decay pathways. Nucleic Acids Res 2012; 41:D268-72. [PMID: 23155061 PMCID: PMC3531052 DOI: 10.1093/nar/gks1052] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Many RNA molecules undergo complex maturation, involving e.g. excision from primary transcripts, removal of introns, post-transcriptional modification and polyadenylation. The level of mature, functional RNAs in the cell is controlled not only by the synthesis and maturation but also by degradation, which proceeds via many different routes. The systematization of data about RNA metabolic pathways and enzymes taking part in RNA maturation and degradation is essential for the full understanding of these processes. RNApathwaysDB, available online at http://iimcb.genesilico.pl/rnapathwaysdb, is an online resource about maturation and decay pathways involving RNA as the substrate. The current release presents information about reactions and enzymes that take part in the maturation and degradation of tRNA, rRNA and mRNA, and describes pathways in three model organisms: Escherichia coli, Saccharomyces cerevisiae and Homo sapiens. RNApathwaysDB can be queried with keywords, and sequences of protein enzymes involved in RNA processing can be searched with BLAST. Options for data presentation include pathway graphs and tables with enzymes and literature data. Structures of macromolecular complexes involving RNA and proteins that act on it are presented as ‘potato models’ using DrawBioPath—a new javascript tool.
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Affiliation(s)
- Kaja Milanowska
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, Trojdena 4, PL-02-109 Warsaw, Poland
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97
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Machnicka MA, Milanowska K, Osman Oglou O, Purta E, Kurkowska M, Olchowik A, Januszewski W, Kalinowski S, Dunin-Horkawicz S, Rother KM, Helm M, Bujnicki JM, Grosjean H. MODOMICS: a database of RNA modification pathways--2013 update. Nucleic Acids Res 2012; 41:D262-7. [PMID: 23118484 PMCID: PMC3531130 DOI: 10.1093/nar/gks1007] [Citation(s) in RCA: 795] [Impact Index Per Article: 66.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
MODOMICS is a database of RNA modifications that provides comprehensive information concerning the chemical structures of modified ribonucleosides, their biosynthetic pathways, RNA-modifying enzymes and location of modified residues in RNA sequences. In the current database version, accessible at http://modomics.genesilico.pl, we included new features: a census of human and yeast snoRNAs involved in RNA-guided RNA modification, a new section covering the 5'-end capping process, and a catalogue of 'building blocks' for chemical synthesis of a large variety of modified nucleosides. The MODOMICS collections of RNA modifications, RNA-modifying enzymes and modified RNAs have been also updated. A number of newly identified modified ribonucleosides and more than one hundred functionally and structurally characterized proteins from various organisms have been added. In the RNA sequences section, snRNAs and snoRNAs with experimentally mapped modified nucleosides have been added and the current collection of rRNA and tRNA sequences has been substantially enlarged. To facilitate literature searches, each record in MODOMICS has been cross-referenced to other databases and to selected key publications. New options for database searching and querying have been implemented, including a BLAST search of protein sequences and a PARALIGN search of the collected nucleic acid sequences.
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Affiliation(s)
- Magdalena A Machnicka
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology, ul. Ks. Trojdena 4, PL-02-109 Warsaw, Poland
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98
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Kitamura A, Nishimoto M, Sengoku T, Shibata R, Jäger G, Björk GR, Grosjean H, Yokoyama S, Bessho Y. Characterization and structure of the Aquifex aeolicus protein DUF752: a bacterial tRNA-methyltransferase (MnmC2) functioning without the usually fused oxidase domain (MnmC1). J Biol Chem 2012; 287:43950-60. [PMID: 23091054 PMCID: PMC3527978 DOI: 10.1074/jbc.m112.409300] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Post-transcriptional modifications of the wobble uridine (U34) of tRNAs play a critical role in reading NNA/G codons belonging to split codon boxes. In a subset of Escherichia coli tRNA, this wobble uridine is modified to 5-methylaminomethyluridine (mnm5U34) through sequential enzymatic reactions. Uridine 34 is first converted to 5-carboxymethylaminomethyluridine (cmnm5U34) by the MnmE-MnmG enzyme complex. The cmnm5U34 is further modified to mnm5U by the bifunctional MnmC protein. In the first reaction, the FAD-dependent oxidase domain (MnmC1) converts cmnm5U into 5-aminomethyluridine (nm5U34), and this reaction is immediately followed by the methylation of the free amino group into mnm5U34 by the S-adenosylmethionine-dependent domain (MnmC2). Aquifex aeolicus lacks a bifunctional MnmC protein fusion and instead encodes the Rossmann-fold protein DUF752, which is homologous to the methyltransferase MnmC2 domain of Escherichia coli MnmC (26% identity). Here, we determined the crystal structure of the A. aeolicus DUF752 protein at 2.5 Å resolution, which revealed that it catalyzes the S-adenosylmethionine-dependent methylation of nm5U in vitro, to form mnm5U34 in tRNA. We also showed that naturally occurring tRNA from A. aeolicus contains the 5-mnm group attached to the C5 atom of U34. Taken together, these results support the recent proposal of an alternative MnmC1-independent shortcut pathway for producing mnm5U34 in tRNAs.
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Affiliation(s)
- Aya Kitamura
- RIKEN SPring-8 Center, Harima Institute, 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan
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99
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Vilardo E, Nachbagauer C, Buzet A, Taschner A, Holzmann J, Rossmanith W. A subcomplex of human mitochondrial RNase P is a bifunctional methyltransferase--extensive moonlighting in mitochondrial tRNA biogenesis. Nucleic Acids Res 2012; 40:11583-93. [PMID: 23042678 PMCID: PMC3526285 DOI: 10.1093/nar/gks910] [Citation(s) in RCA: 180] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Transfer RNAs (tRNAs) reach their mature functional form through several steps of processing and modification. Some nucleotide modifications affect the proper folding of tRNAs, and they are crucial in case of the non-canonically structured animal mitochondrial tRNAs, as exemplified by the apparently ubiquitous methylation of purines at position 9. Here, we show that a subcomplex of human mitochondrial RNase P, the endonuclease removing tRNA 5′ extensions, is the methyltransferase responsible for m1G9 and m1A9 formation. The ability of the mitochondrial tRNA:m1R9 methyltransferase to modify both purines is uncommon among nucleic acid modification enzymes. In contrast to all the related methyltransferases, the human mitochondrial enzyme, moreover, requires a short-chain dehydrogenase as a partner protein. Human mitochondrial RNase P, thus, constitutes a multifunctional complex, whose subunits moonlight in cascade: a fatty and amino acid degradation enzyme in tRNA methylation and the methyltransferase, in turn, in tRNA 5′ end processing.
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Affiliation(s)
- Elisa Vilardo
- Center for Anatomy and Cell Biology, Medical University of Vienna, 1090 Vienna, Austria
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Benítez-Páez A, Villarroya M, Armengod ME. The Escherichia coli RlmN methyltransferase is a dual-specificity enzyme that modifies both rRNA and tRNA and controls translational accuracy. RNA (NEW YORK, N.Y.) 2012; 18:1783-1795. [PMID: 22891362 PMCID: PMC3446703 DOI: 10.1261/rna.033266.112] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 06/26/2012] [Indexed: 05/28/2023]
Abstract
Modifying RNA enzymes are highly specific for substrate-rRNA or tRNA-and the target position. In Escherichia coli, there are very few multisite acting enzymes, and only one rRNA/tRNA dual-specificity enzyme, pseudouridine synthase RluA, has been identified to date. Among the tRNA-modifying enzymes, the methyltransferase responsible for the m(2)A synthesis at purine 37 in a tRNA set still remains unknown. m(2)A is also present at position 2503 in the peptidyl transferase center of 23S RNA, where it is introduced by RlmN, a radical S-adenosyl-L-methionine (SAM) enzyme. Here, we show that E. coli RlmN is a dual-specificity enzyme that catalyzes methylation of both rRNA and tRNA. The ΔrlmN mutant lacks m(2)A in both RNA types, whereas the expression of recombinant RlmN from a plasmid introduced into this mutant restores tRNA modification. Moreover, RlmN performs m(2)A(37) synthesis in vitro using a tRNA chimera as a substrate. This chimera has also proved useful to characterize some tRNA identity determinants for RlmN and other tRNA modification enzymes. Our data suggest that RlmN works in a late step during tRNA maturation by recognizing a precise 3D structure of tRNA. RlmN inactivation increases the misreading of a UAG stop codon. Since loss of m(2)A(37) from tRNA is expected to produce a hyperaccurate phenotype, we believe that the error-prone phenotype exhibited by the ΔrlmN mutant is due to loss of m(2)A from 23S rRNA and, accordingly, that the m(2)A2503 modification plays a crucial role in the proofreading step occurring at the peptidyl transferase center.
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Affiliation(s)
- Alfonso Benítez-Páez
- Laboratorio de Genética Molecular, Centro de Investigación Príncipe Felipe, 46012 Valencia, Spain
- Bioinformatic Analysis Group—GABi, Centro de Investigación y Desarrollo en Biotecnología, Bogotá D.C., 111221 Colombia
| | - Magda Villarroya
- Laboratorio de Genética Molecular, Centro de Investigación Príncipe Felipe, 46012 Valencia, Spain
| | - M.-Eugenia Armengod
- Laboratorio de Genética Molecular, Centro de Investigación Príncipe Felipe, 46012 Valencia, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Unidad 721, Centro de Investigación Príncipe Felipe, 46012 Valencia, Spain
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