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Dar D, Sorek R. High-resolution RNA 3'-ends mapping of bacterial Rho-dependent transcripts. Nucleic Acids Res 2019; 46:6797-6805. [PMID: 29669055 PMCID: PMC6061677 DOI: 10.1093/nar/gky274] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 04/04/2018] [Indexed: 01/20/2023] Open
Abstract
Transcription termination in bacteria can occur either via Rho-dependent or independent (intrinsic) mechanisms. Intrinsic terminators are composed of a stem-loop RNA structure followed by a uridine stretch and are known to terminate in a precise manner. In contrast, Rho-dependent terminators have more loosely defined characteristics and are thought to terminate in a diffuse manner. While transcripts ending in an intrinsic terminator are protected from 3′-5′ exonuclease digestion due to the stem-loop structure of the terminator, it remains unclear what protects Rho-dependent transcripts from being degraded. In this study, we mapped the exact steady-state RNA 3′ ends of hundreds of Escherichia coli genes terminated either by Rho-dependent or independent mechanisms. We found that transcripts generated from Rho-dependent termination have precise 3′-ends at steady state. These termini were localized immediately downstream of energetically stable stem-loop structures, which were not followed by uridine rich sequences. We provide evidence that these structures protect Rho-dependent transcripts from 3′-5′ exonucleases such as PNPase and RNase II, and present data localizing the Rho-utilization (rut) sites immediately downstream of these protective structures. This study represents the first extensive in-vivo map of exact RNA 3′-ends of Rho-dependent transcripts in E. coli.
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Affiliation(s)
- Daniel Dar
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Rotem Sorek
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
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102
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Nikolaev Y, Ripin N, Soste M, Picotti P, Iber D, Allain FHT. Systems NMR: single-sample quantification of RNA, proteins and metabolites for biomolecular network analysis. Nat Methods 2019; 16:743-749. [PMID: 31363225 PMCID: PMC6837886 DOI: 10.1038/s41592-019-0495-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 06/17/2019] [Indexed: 12/14/2022]
Abstract
Cellular behavior is controlled by the interplay of diverse biomolecules. Most experimental methods, however, can only monitor a single molecule class or reaction type at a time. We developed an in vitro nuclear magnetic resonance spectroscopy (NMR) approach, which permitted dynamic quantification of an entire 'heterotypic' network-simultaneously monitoring three distinct molecule classes (metabolites, proteins and RNA) and all elementary reaction types (bimolecular interactions, catalysis, unimolecular changes). Focusing on an eight-reaction co-transcriptional RNA folding network, in a single sample we recorded over 35 time points with over 170 observables each, and accurately determined five core reaction constants in multiplex. This reconstruction revealed unexpected cross-talk between the different reactions. We further observed dynamic phase-separation in a system of five distinct RNA-binding domains in the course of the RNA transcription reaction. Our Systems NMR approach provides a deeper understanding of biological network dynamics by combining the dynamic resolution of biochemical assays and the multiplexing ability of 'omics'.
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Affiliation(s)
- Yaroslav Nikolaev
- Department of Biology, Institute of Molecular Biology & Biophysics, ETH Zurich, Zurich, Switzerland.
| | - Nina Ripin
- Department of Biology, Institute of Molecular Biology & Biophysics, ETH Zurich, Zurich, Switzerland
| | - Martin Soste
- Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
| | - Paola Picotti
- Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
| | - Dagmar Iber
- Department of Biosystems Science and Engineering, ETH Zurich, Zurich, Switzerland
| | - Frédéric H-T Allain
- Department of Biology, Institute of Molecular Biology & Biophysics, ETH Zurich, Zurich, Switzerland.
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103
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Matsumoto S, Caliskan N, Rodnina MV, Murata A, Nakatani K. Small synthetic molecule-stabilized RNA pseudoknot as an activator for -1 ribosomal frameshifting. Nucleic Acids Res 2019; 46:8079-8089. [PMID: 30085309 PMCID: PMC6144811 DOI: 10.1093/nar/gky689] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 07/31/2018] [Indexed: 12/02/2022] Open
Abstract
Programmed –1 ribosomal frameshifting (−1PRF) is a recoding mechanism to make alternative proteins from a single mRNA transcript. −1PRF is stimulated by cis-acting signals in mRNA, a seven-nucleotide slippery sequence and a downstream secondary structure element, which is often a pseudoknot. In this study we engineered the frameshifting pseudoknot from the mouse mammary tumor virus to respond to a rationally designed small molecule naphthyridine carbamate tetramer (NCTn). We demonstrate that NCTn can stabilize the pseudoknot structure in mRNA and activate –1PRF both in vitro and in human cells. The results illustrate how NCTn-inducible –1PRF may serve as an important component of the synthetic biology toolbox for the precise control of gene expression using small synthetic molecules.
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Affiliation(s)
- Saki Matsumoto
- Department of Regulatory Bioorganic Chemistry, The Institute of Scientific and Industrial Research (ISIR), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Neva Caliskan
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research, Josef-Schneider-Str.2/D15, 97080, Würzburg, Germany
| | - Marina V Rodnina
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Asako Murata
- Department of Regulatory Bioorganic Chemistry, The Institute of Scientific and Industrial Research (ISIR), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Kazuhiko Nakatani
- Department of Regulatory Bioorganic Chemistry, The Institute of Scientific and Industrial Research (ISIR), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
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104
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Dwidar M, Seike Y, Kobori S, Whitaker C, Matsuura T, Yokobayashi Y. Programmable Artificial Cells Using Histamine-Responsive Synthetic Riboswitch. J Am Chem Soc 2019; 141:11103-11114. [PMID: 31241330 DOI: 10.1021/jacs.9b03300] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Artificial cells that encapsulate DNA-programmable protein expression machinery are emerging as an attractive platform for studying fundamental cellular properties and applications in synthetic biology. However, interfacing these artificial cells with the complex and dynamic chemical environment remains a major and urgent challenge. We demonstrate that the repertoire of molecules that artificial cells respond to can be expanded by synthetic RNA-based gene switches, or riboswitches. We isolated an RNA aptamer that binds histamine with high affinity and specificity and used it to design robust riboswitches that activate protein expression in the presence of histamine. Finally, the riboswitches were incorporated in artificial cells to achieve controlled release of an encapsulated small molecule and to implement a self-destructive kill-switch. Synthetic riboswitches should serve as modular and versatile interfaces to link artificial cell phenotypes with the complex chemical environment.
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Affiliation(s)
- Mohammed Dwidar
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University , Onna , Okinawa 904-0495 , Japan
| | - Yusuke Seike
- Department of Biotechnology, Graduate School of Engineering , Osaka University , 2-1 Yamadaoka , Suita , Osaka 565-0871 , Japan
| | - Shungo Kobori
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University , Onna , Okinawa 904-0495 , Japan
| | - Charles Whitaker
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University , Onna , Okinawa 904-0495 , Japan
| | - Tomoaki Matsuura
- Department of Biotechnology, Graduate School of Engineering , Osaka University , 2-1 Yamadaoka , Suita , Osaka 565-0871 , Japan
| | - Yohei Yokobayashi
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University , Onna , Okinawa 904-0495 , Japan
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105
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Pavlova N, Kaloudas D, Penchovsky R. Riboswitch distribution, structure, and function in bacteria. Gene 2019; 708:38-48. [PMID: 31128223 DOI: 10.1016/j.gene.2019.05.036] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 05/12/2019] [Accepted: 05/20/2019] [Indexed: 10/26/2022]
Abstract
Riboswitches are gene control elements that directly bind to specific ligands to regulate gene expression without the need for proteins. They are found in all three domains of life, including Bacteria, Archaea, and Eukaryota. Riboswitches are mostly spread in bacteria and archaea. In this paper, we discuss the general distribution, structure, and function of 28 different riboswitch classes as we focus our attention on riboswitches in bacteria. Bacterial riboswitches regulate gene expression by four distinct mechanisms. They regulate the expression of a limited number of genes. However, most of these genes are responsible for the synthesis of essential metabolites without which the cell cannot function. Therefore, riboswitch distribution is also important for antibacterial drug development.
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Affiliation(s)
- Nikolet Pavlova
- Department of Genetics, Faculty of Biology, Sofia University "Saint Kliment Ohridski", 8 Dragan Tzankov Blvd., 1164 Sofia, Bulgaria
| | - Dimitrios Kaloudas
- Department of Genetics, Faculty of Biology, Sofia University "Saint Kliment Ohridski", 8 Dragan Tzankov Blvd., 1164 Sofia, Bulgaria
| | - Robert Penchovsky
- Department of Genetics, Faculty of Biology, Sofia University "Saint Kliment Ohridski", 8 Dragan Tzankov Blvd., 1164 Sofia, Bulgaria.
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106
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Comparative Transcriptomic Profiling of Yersinia enterocolitica O:3 and O:8 Reveals Major Expression Differences of Fitness- and Virulence-Relevant Genes Indicating Ecological Separation. mSystems 2019; 4:mSystems00239-18. [PMID: 31020044 PMCID: PMC6478967 DOI: 10.1128/msystems.00239-18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 02/27/2019] [Indexed: 01/16/2023] Open
Abstract
Yersinia enterocolitica is a major diarrheal pathogen and is associated with a large range of gut-associated diseases. Members of this species have evolved into different phylogroups with genotypic variations. We performed the first characterization of the Y. enterocolitica transcriptional landscape and tracked the consequences of the genomic variations between two different pathogenic phylogroups by comparing their RNA repertoire, promoter usage, and expression profiles under four different virulence-relevant conditions. Our analysis revealed major differences in the transcriptional outputs of the closely related strains, pointing to an ecological separation in which one is more adapted to an environmental lifestyle and the other to a mostly mammal-associated lifestyle. Moreover, a variety of pathoadaptive alterations, including alterations in acid resistance genes, colonization factors, and toxins, were identified which affect virulence and host specificity. This illustrates that comparative transcriptomics is an excellent approach to discover differences in the functional output from closely related genomes affecting niche adaptation and virulence, which cannot be directly inferred from DNA sequences. Yersinia enterocolitica is a zoonotic pathogen and an important cause of bacterial gastrointestinal infections in humans. Large-scale population genomic analyses revealed genetic and phenotypic diversity of this bacterial species, but little is known about the differences in the transcriptome organization, small RNA (sRNA) repertoire, and transcriptional output. Here, we present the first comparative high-resolution transcriptome analysis of Y. enterocolitica strains representing highly pathogenic phylogroup 2 (serotype O:8) and moderately pathogenic phylogroup 3 (serotype O:3) grown under four infection-relevant conditions. Our transcriptome sequencing (RNA-seq) approach revealed 1,299 and 1,076 transcriptional start sites and identified strain-specific sRNAs that could contribute to differential regulation among the phylogroups. Comparative transcriptomics further uncovered major gene expression differences, in particular, in the temperature-responsive regulon. Multiple virulence-relevant genes are differentially regulated between the two strains, supporting an ecological separation of phylogroups with certain niche-adapted properties. Strong upregulation of the ystA enterotoxin gene in combination with constitutive high expression of cell invasion factor InvA further showed that the toxicity of recent outbreak O:3 strains has increased. Overall, our report provides new insights into the specific transcriptome organization of phylogroups 2 and 3 and reveals gene expression differences contributing to the substantial phenotypic differences that exist between the lineages. IMPORTANCEYersinia enterocolitica is a major diarrheal pathogen and is associated with a large range of gut-associated diseases. Members of this species have evolved into different phylogroups with genotypic variations. We performed the first characterization of the Y. enterocolitica transcriptional landscape and tracked the consequences of the genomic variations between two different pathogenic phylogroups by comparing their RNA repertoire, promoter usage, and expression profiles under four different virulence-relevant conditions. Our analysis revealed major differences in the transcriptional outputs of the closely related strains, pointing to an ecological separation in which one is more adapted to an environmental lifestyle and the other to a mostly mammal-associated lifestyle. Moreover, a variety of pathoadaptive alterations, including alterations in acid resistance genes, colonization factors, and toxins, were identified which affect virulence and host specificity. This illustrates that comparative transcriptomics is an excellent approach to discover differences in the functional output from closely related genomes affecting niche adaptation and virulence, which cannot be directly inferred from DNA sequences.
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107
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Atilho RM, Mirihana Arachchilage G, Greenlee EB, Knecht KM, Breaker RR. A bacterial riboswitch class for the thiamin precursor HMP-PP employs a terminator-embedded aptamer. eLife 2019; 8:45210. [PMID: 30950790 PMCID: PMC6478431 DOI: 10.7554/elife.45210] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 04/04/2019] [Indexed: 12/29/2022] Open
Abstract
We recently implemented a bioinformatics pipeline that can uncover novel, but rare, riboswitch candidates as well as other noncoding RNA structures in bacteria. A prominent candidate revealed by our initial search efforts was called the ‘thiS motif’ because of its frequent association with a gene coding for the ThiS protein, which delivers sulfur to form the thiazole moiety of the thiamin precursor HET-P. In the current report, we describe biochemical and genetic data demonstrating that thiS motif RNAs function as sensors of the thiamin precursor HMP-PP, which is fused with HET-P ultimately to form the final active coenzyme thiamin pyrophosphate (TPP). HMP-PP riboswitches exhibit a distinctive architecture wherein an unusually small ligand-sensing aptamer is almost entirely embedded within an otherwise classic intrinsic transcription terminator stem. This arrangement yields remarkably compact genetic switches that bacteria use to tune the levels of thiamin precursors during the biosynthesis of this universally distributed coenzyme. Many bacteria use small genetic devices called riboswitches to sense molecules that are essential for life and regulate the genes necessary to make, break or move these molecules. Riboswitches are made of molecules of RNA and appear to have ancient origins that predate the evolution of bacteria and other lifeforms made of cells. Inside modern bacteria, chunks of DNA in the genome provide the instructions to make riboswitches and around 40 different types of riboswitch have been identified so far. However, it has been proposed that the instructions for thousands more riboswitches may remain hidden in the DNA of bacteria. All of the currently known riboswitches contain a region called an aptamer that binds to a target molecule. This binding causes another structure in the riboswitch RNA to switch a specific gene on or off. For example, the aptamer binding might cause a hairpin-like structure called a terminator to form, which stops a gene being used to make new RNA molecules. In 2019 a team of researchers reported using a computational approach to identify new riboswitches in bacteria. This approach identified many different chunks of DNA that might code for a riboswitch, including one known as the thiS motif. This potential new riboswitch appeared to be associated with a gene that encodes a protein required to make a vitamin called thiamin (also known as vitamin B1). To test the new computational approach, Atilho et al. including several of the researchers involved in the earlier work used genetic and biochemical techniques to study the thiS motif. The experiments revealed that the motif binds to a molecule called HMP-PP, which bacteria use to make thiamin. Unexpectedly, the aptamer of the riboswitch was nested within a terminator, rather than being a separate entity. The findings of Atilho et al. reveal that riboswitches can be even more compact than previously thought. Furthermore, these findings reveal new insights into how bacteria use riboswitches to manage their vitamin levels. In the future it may be possible to develop drugs that target such riboswitches to starve bacteria of these essential molecules.
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Affiliation(s)
- Ruben M Atilho
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, United States
| | | | - Etienne B Greenlee
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, United States
| | - Kirsten M Knecht
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, United States
| | - Ronald R Breaker
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, United States.,Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, United States
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108
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Stav S, Atilho RM, Mirihana Arachchilage G, Nguyen G, Higgs G, Breaker RR. Genome-wide discovery of structured noncoding RNAs in bacteria. BMC Microbiol 2019; 19:66. [PMID: 30902049 PMCID: PMC6429828 DOI: 10.1186/s12866-019-1433-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 03/07/2019] [Indexed: 12/15/2022] Open
Abstract
Background Structured noncoding RNAs (ncRNAs) play essential roles in many biological processes such as gene regulation, signaling, RNA processing, and protein synthesis. Among the most common groups of ncRNAs in bacteria are riboswitches. These cis-regulatory, metabolite-binding RNAs are present in many species where they regulate various metabolic and signaling pathways. Collectively, there are likely to be hundreds of novel riboswitch classes that remain hidden in the bacterial genomes that have already been sequenced, and potentially thousands of classes distributed among various other species in the biosphere. The vast majority of these undiscovered classes are proposed to be exceedingly rare, and so current bioinformatics search techniques are reaching their limits for differentiating between true riboswitch candidates and false positives. Results Herein, we exploit a computational search pipeline that can efficiently identify intergenic regions most likely to encode structured ncRNAs. Application of this method to five bacterial genomes yielded nearly 70 novel genetic elements including 30 novel candidate ncRNA motifs. Among the riboswitch candidates identified is an RNA motif involved in the regulation of thiamin biosynthesis. Conclusions Analysis of other genomes will undoubtedly lead to the discovery of many additional novel structured ncRNAs, and provide insight into the range of riboswitches and other kinds of ncRNAs remaining to be discovered in bacteria and archaea. Electronic supplementary material The online version of this article (10.1186/s12866-019-1433-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Shira Stav
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, USA
| | - Ruben M Atilho
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, USA
| | | | - Giahoa Nguyen
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, USA
| | - Gadareth Higgs
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, USA
| | - Ronald R Breaker
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, USA. .,Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, USA. .,Howard Hughes Medical Institute, Yale University, New Haven, CT, 06520, USA.
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109
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Eubanks CS, Zhao B, Patwardhan NN, Thompson RD, Zhang Q, Hargrove AE. Visualizing RNA Conformational Changes via Pattern Recognition of RNA by Small Molecules. J Am Chem Soc 2019; 141:5692-5698. [DOI: 10.1021/jacs.8b09665] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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110
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Atilho RM, Perkins KR, Breaker RR. Rare variants of the FMN riboswitch class in Clostridium difficile and other bacteria exhibit altered ligand specificity. RNA (NEW YORK, N.Y.) 2019; 25:23-34. [PMID: 30287481 PMCID: PMC6298564 DOI: 10.1261/rna.067975.118] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 10/02/2018] [Indexed: 05/10/2023]
Abstract
Many bacteria use flavin mononucleotide (FMN) riboswitches to control the expression of genes responsible for the biosynthesis and transport of this enzyme cofactor or its precursor, riboflavin. Rare variants of FMN riboswitches found in strains of Clostridium difficile and some other bacteria typically control the expression of proteins annotated as transporters, including multidrug efflux pumps. These RNAs no longer recognize FMN, and differ from the original riboswitch consensus sequence at nucleotide positions normally involved in binding of the ribityl and phosphate moieties of the cofactor. Representatives of one of the two variant subtypes were found to bind the FMN precursor riboflavin and the FMN degradation products lumiflavin and lumichrome. Although the biologically relevant ligand sensed by these variant FMN riboswitches remains uncertain, our findings suggest that many strains of C. difficile might use rare riboswitches to sense flavin degradation products and activate transporters for their detoxification.
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Affiliation(s)
- Ruben M Atilho
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520-8103, USA
| | - Kevin R Perkins
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut 06520-8103, USA
| | - Ronald R Breaker
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520-8103, USA
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut 06520-8103, USA
- Howard Hughes Medical Institute, Yale University, New Haven, Connecticut 06520-8103, USA
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111
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Zhao JP, Zhu H, Guo XP, Sun YC. AU-Rich Long 3' Untranslated Region Regulates Gene Expression in Bacteria. Front Microbiol 2018; 9:3080. [PMID: 30619162 PMCID: PMC6299119 DOI: 10.3389/fmicb.2018.03080] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 11/29/2018] [Indexed: 12/02/2022] Open
Abstract
3′ untranslated regions (3′ UTRs) and particularly long 3′ UTRs have been shown to act as a new class of post-transcriptional regulatory element. We previously reported that hmsT mRNA stability is negatively regulated by the 3′ UTR of hmsT in Yersinia pestis. To investigate more general effects of 3′ UTRs in Y. pestis, we selected 15 genes potentially possessing long 3′ UTRs with different AU content and constructed their 3′ UTR deletion mutants. Deletion of AU-rich 3′ UTRs increased mRNA levels, whereas deletion of 3′ UTRs with normal AU content resulted in slight or no changes in the mRNA level. In addition, we found that PNPase was important for 3′ UTR-mediated mRNA decay when the transcriptional terminator was Rho-dependent. Finally, we showed that ribosomes promote mRNA stability when bound to a 3′ UTR. Our findings suggest that functional 3′ UTRs might be broadly distributed in bacteria and their novel regulatory mechanisms require further investigation.
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Affiliation(s)
- Ju-Ping Zhao
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Hui Zhu
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xiao-Peng Guo
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yi-Cheng Sun
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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112
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Li X, Chen F, Xiao J, Chou SH, Li X, He J. Genome-wide Analysis of the Distribution of Riboswitches and Function Analyses of the Corresponding Downstream Genes in Prokaryotes. Curr Bioinform 2018. [DOI: 10.2174/1574893613666180423145812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Background:
Riboswitches are structured elements that usually reside in the noncoding
regions of mRNAs, with which various ligands bind to control a wide variety of downstream gene
expressions. To date, more than twenty different classes of riboswitches have been characterized to
sense various metabolites, including purines and their derivatives, coenzymes, amino acids, and metal
ions, etc.
</P><P>
Objective: This study aims to study the genome-wide analysis of the distribution of riboswitches and
function analyses of the corresponding downstream genes in prokaryotes.
Results:
In this study, we have completed a genome context analysis of 27 riboswitches to elucidate
their metabolic capacities of riboswitch-mediated gene regulation from the completely-sequenced 3,079
prokaryotic genomes. Furthermore, Cluster of Orthologous Groups of proteins (COG) annotation was
applied to predict and classify the possible functions of corresponding downstream genes of these
riboswitches. We found that they could all be successfully annotated and grouped into 20 different COG
functional categories, in which the two main clusters "coenzyme metabolism [H]" and "amino acid
transport and metabolism [E]" were the most significantly enriched.
Conclusion:
Riboswitches are found to be widespread in bacteria, among which three main classes of
TPP-, cobalamin- and SAM-riboswitch were the most widely distributed. We found a wide variety of
functions were associated with the corresponding downstream genes, suggesting that a wide extend of
regulatory roles were mediated by these riboswitches in prokaryotes.
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Affiliation(s)
- Xinfeng Li
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Fang Chen
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Jinfeng Xiao
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Shan-Ho Chou
- Institute of Biochemistry and NCHU Agricultural Biotechnology Center, National Chung Hsing University, Taichung 40227, Taiwan
| | - Xuming Li
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Jin He
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
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Warrier I, Ram-Mohan N, Zhu Z, Hazery A, Echlin H, Rosch J, Meyer MM, van Opijnen T. The Transcriptional landscape of Streptococcus pneumoniae TIGR4 reveals a complex operon architecture and abundant riboregulation critical for growth and virulence. PLoS Pathog 2018; 14:e1007461. [PMID: 30517198 PMCID: PMC6296669 DOI: 10.1371/journal.ppat.1007461] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 12/17/2018] [Accepted: 11/07/2018] [Indexed: 11/21/2022] Open
Abstract
Efficient and highly organized regulation of transcription is fundamental to an organism’s ability to survive, proliferate, and quickly respond to its environment. Therefore, precise mapping of transcriptional units and understanding their regulation is crucial to determining how pathogenic bacteria cause disease and how they may be inhibited. In this study, we map the transcriptional landscape of the bacterial pathogen Streptococcus pneumoniae TIGR4 by applying a combination of high-throughput RNA-sequencing techniques. We successfully map 1864 high confidence transcription termination sites (TTSs), 790 high confidence transcription start sites (TSSs) (742 primary, and 48 secondary), and 1360 low confidence TSSs (74 secondary and 1286 primary) to yield a total of 2150 TSSs. Furthermore, our study reveals a complex transcriptome wherein environment-respondent alternate transcriptional units are observed within operons stemming from internal TSSs and TTSs. Additionally, we identify many putative cis-regulatory RNA elements and riboswitches within 5’-untranslated regions (5’-UTR). By integrating TSSs and TTSs with independently collected RNA-Seq datasets from a variety of conditions, we establish the response of these regulators to changes in growth conditions and validate several of them. Furthermore, to demonstrate the importance of ribo-regulation by 5’-UTR elements for in vivo virulence, we show that the pyrR regulatory element is essential for survival, successful colonization and infection in mice suggesting that such RNA elements are potential drug targets. Importantly, we show that our approach of combining high-throughput sequencing with in vivo experiments can reconstruct a global understanding of regulation, but also pave the way for discovery of compounds that target (ribo-)regulators to mitigate virulence and antibiotic resistance. The canonical relationship between a bacterial operon and the mRNA transcript produced from the operon has become significantly more complex as numerous regulatory mechanisms that impact the stability, translational efficiency, and early termination rates for mRNA transcripts have been described. With the rise of antibiotic resistance, these mechanisms offer new potential targets for antibiotic development. In this study we used a combination of high-throughput sequencing technologies to assess genome-wide transcription start and stop sites, as well as determine condition specific global transcription patterns in the human pathogen Streptococcus pneumoniae. We find that the majority of multi-gene operons have alternative start and stop sites enabling condition specific regulation of genes within the same operon. Furthermore, we identified many putative RNA regulators that are widespread in the S. pneumoniae pan-genome. Finally, we show that separately collected RNA-Seq data enables identification of conditional triggers for regulatory RNAs, and experimentally demonstrate that our approach may be used to identify drug-able RNA targets by establishing that pyrR RNA functionality is critical for successful S. pneumoniae mouse colonization and infection. Thus, our study not only uses genome-wide high-throughput approaches to identify putative RNA regulators, but also establishes the importance of such regulators in S. pneumoniae virulence.
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Affiliation(s)
- Indu Warrier
- Biology Department, Boston College, Chestnut Hill, Massachusetts, United States of America
| | - Nikhil Ram-Mohan
- Biology Department, Boston College, Chestnut Hill, Massachusetts, United States of America
| | - Zeyu Zhu
- Biology Department, Boston College, Chestnut Hill, Massachusetts, United States of America
| | - Ariana Hazery
- Biology Department, Boston College, Chestnut Hill, Massachusetts, United States of America
| | - Haley Echlin
- Department of Infectious Diseases, St Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Jason Rosch
- Department of Infectious Diseases, St Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Michelle M. Meyer
- Biology Department, Boston College, Chestnut Hill, Massachusetts, United States of America
- * E-mail: (MMM); (TvO)
| | - Tim van Opijnen
- Biology Department, Boston College, Chestnut Hill, Massachusetts, United States of America
- * E-mail: (MMM); (TvO)
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Abstract
Synthetic biology has undergone dramatic advancements for over a decade, during which it has expanded our understanding on the systems of life and opened new avenues for microbial engineering. Many biotechnological and computational methods have been developed for the construction of synthetic systems. Achievements in synthetic biology have been widely adopted in metabolic engineering, a field aimed at engineering micro-organisms to produce substances of interest. However, the engineering of metabolic systems requires dynamic redistribution of cellular resources, the creation of novel metabolic pathways, and optimal regulation of the pathways to achieve higher production titers. Thus, the design principles and tools developed in synthetic biology have been employed to create novel and flexible metabolic pathways and to optimize metabolic fluxes to increase the cells’ capability to act as production factories. In this review, we introduce synthetic biology tools and their applications to microbial cell factory constructions.
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115
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Abstract
A growing collection of bacterial riboswitch classes is being discovered that sense central metabolites, coenzymes, and signaling molecules. Included among the various mechanisms of gene regulation exploited by these RNA regulatory elements are several that modulate messenger RNA (mRNA) translation. In this review, the mechanisms of riboswitch-mediated translation control are summarized to highlight both their diversity and potential ancient origins. These mechanisms include ligand-gated presentation or occlusion of ribosome-binding sites, control of alternative splicing of mRNAs, and the regulation of mRNA stability. Moreover, speculation on the potential for novel riboswitch discoveries is presented, including a discussion on the potential for the discovery of a greater diversity of mechanisms for translation control.
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Affiliation(s)
- Ronald R Breaker
- Department of Molecular, Cellular and Developmental Biology, Department of Molecular Biophysics and Biochemistry, Howard Hughes Medical Institute, Yale University, New Haven, Connecticut 06520-8103
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116
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Knittel V, Vollmer I, Volk M, Dersch P. Discovering RNA-Based Regulatory Systems for Yersinia Virulence. Front Cell Infect Microbiol 2018; 8:378. [PMID: 30460205 PMCID: PMC6232918 DOI: 10.3389/fcimb.2018.00378] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 10/05/2018] [Indexed: 12/26/2022] Open
Abstract
The genus Yersinia includes three human pathogenic species, Yersinia pestis, the causative agent of the bubonic and pneumonic plague, and enteric pathogens Y. enterocolitica and Y. pseudotuberculosis that cause a number of gut-associated diseases. Over the past years a large repertoire of RNA-based regulatory systems has been discovered in these pathogens using different RNA-seq based approaches. Among them are several conserved or species-specific RNA-binding proteins, regulatory and sensory RNAs as well as various RNA-degrading enzymes. Many of them were shown to control the expression of important virulence-relevant factors and have a very strong impact on Yersinia virulence. The precise targets, the molecular mechanism and their role for Yersinia pathogenicity is only known for a small subset of identified genus- or species-specific RNA-based control elements. However, the ongoing development of new RNA-seq based methods and data analysis methods to investigate the synthesis, composition, translation, decay, and modification of RNAs in the bacterial cell will help us to generate a more comprehensive view of Yersinia RNA biology in the near future.
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Affiliation(s)
- Vanessa Knittel
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Ines Vollmer
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Marcel Volk
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Petra Dersch
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
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117
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Abstract
Transcription is a discontinuous process, where each nucleotide incorporation cycle offers a decision between elongation, pausing, halting, or termination. Many cis-acting regulatory RNAs, such as riboswitches, exert their influence over transcription elongation. Through such mechanisms, certain RNA elements can couple physiological or environmental signals to transcription attenuation, a process where cis-acting regulatory RNAs directly influence formation of transcription termination signals. However, through another regulatory mechanism called processive antitermination (PA), RNA polymerase can bypass termination sites over much greater distances than transcription attenuation. PA mechanisms are widespread in bacteria, although only a few classes have been discovered overall. Also, although traditional, signal-responsive riboswitches have not yet been discovered to promote PA, it is increasingly clear that small RNA elements are still oftentimes required. In some instances, small RNA elements serve as loading sites for cellular factors that promote PA. In other instances, larger, more complicated RNA elements participate in PA in unknown ways, perhaps even acting alone to trigger PA activity. These discoveries suggest that what is now needed is a systematic exploration of PA in bacteria, to determine how broadly these transcription elongation mechanisms are utilized, to reveal the diversity in their molecular mechanisms, and to understand the general logic behind their cellular applications. This review covers the known examples of PA regulatory mechanisms and speculates that they may be broadly important to bacteria.
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Affiliation(s)
- Jonathan R. Goodson
- The University of Maryland, Department of Cell Biology and Molecular Genetics, College Park, MD 20742
| | - Wade C. Winkler
- The University of Maryland, Department of Cell Biology and Molecular Genetics, College Park, MD 20742
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118
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Peselis A, Serganov A. ykkC riboswitches employ an add-on helix to adjust specificity for polyanionic ligands. Nat Chem Biol 2018; 14:887-894. [PMID: 30120360 PMCID: PMC6263941 DOI: 10.1038/s41589-018-0114-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 07/02/2018] [Indexed: 12/20/2022]
Abstract
The ykkC family of bacterial riboswitches combines several widespread classes that have similar secondary structures and consensus motifs but control different genes in response to different cellular metabolites. Here we report the crystal structures of two distinct ykkC riboswitches specifically bound to their cognate ligands ppGpp, a second messenger involved in stress response, or PRPP, a precursor in purine biosynthesis. Both RNAs adopt similar structures and contain a conserved core previously observed in the guanidine-specific ykkC riboswitch. However, ppGpp and PRPP riboswitches uniquely employ an additional helical element that joins the ends of the ligand-sensing domains and creates a tunnel for direct and Mg2+-mediated binding of ligands. Mutational and footprinting experiments highlight the importance of conserved nucleotides forming the tunnel and long-distance contacts for ligand binding and genetic response. Our work provides new insights into the specificity of riboswitches and gives a unique opportunity for future studies of RNA evolution.
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Affiliation(s)
- Alla Peselis
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Alexander Serganov
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA.
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119
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Synthetic Gene Regulation in Cyanobacteria. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1080:317-355. [DOI: 10.1007/978-981-13-0854-3_13] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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120
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Kesherwani M, N H V K, Velmurugan D. Conformational Dynamics of thiM Riboswitch To Understand the Gene Regulation Mechanism Using Markov State Modeling and the Residual Fluctuation Network Approach. J Chem Inf Model 2018; 58:1638-1651. [PMID: 29939019 DOI: 10.1021/acs.jcim.8b00155] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Thiamine pyrophosphate (TPP) riboswitch is a cis-regulatory element in the noncoding region of mRNA. The aptamer domain of TPP riboswitch detects the high abundance of coenzyme thiamine pyrophosphate (TPP) and modulates the gene expression for thiamine synthetic gene. The mechanistic understanding in recognition of TPP in aptamer domain and ligand-induced compactness for folding of expression platform are most important to designing novel modulators. To understand the dynamic behavior of TPP riboswitch upon TPP binding, molecular dynamics simulations were performed for 400 ns in both apo and TPP bound forms of thiM riboswitch from E. coli and analyzed in terms of eRMSD-based Markov state modeling and residual fluctuation network. Markov state models show good correlations in transition probability among metastable states from simulated trajectory and generated models. Structural compactness in TPP bound form is observed which is correlated with SAXS experiment. The importance of junction of P4 and P5 is evident during dynamics, which correlates with FRET analysis. The dynamic nature of two sensor forearms is due to the flexible P1 helix, which is its intrinsic property. The transient state in TPP-bound form was observed in the Markov state model, along with stable states. We believe that this transient state is responsible to assist the influx and outflux of ligand molecule by creating a solvent channel around the junction region of P4 and P5 and such a structure was anticipated in FRET analysis. The dynamic nature of riboswitch is dependent on the interaction between residues on distal loops L3 and L5/P3 and junction P4 and P5, J3/2 which stabilize the J2/4. It helps in the transfer of allosteric information between J2/4 and P3/L5 tertiary docking region through the active site residues. Understanding such information flow will benefit in highlighting crucial residues in highly dynamic and kinetic systems. Here, we report the residues and segments in riboswitch that play vital roles in providing stability and this can be exploited in designing inhibitors to regulate the functioning of riboswitches.
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Affiliation(s)
- Manish Kesherwani
- Centre for Advanced Study in Crystallography and Biophysics , University of Madras, Guindy Campus , Chennai - 600025 India
| | - Kutumbarao N H V
- Centre for Advanced Study in Crystallography and Biophysics , University of Madras, Guindy Campus , Chennai - 600025 India
| | - Devadasan Velmurugan
- Centre for Advanced Study in Crystallography and Biophysics , University of Madras, Guindy Campus , Chennai - 600025 India
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121
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Zhang JL, Wang D, Liang YW, Zhong WY, Ming ZH, Tang DJ, Tang JL. The Gram-negative phytopathogen Xanthomonas campestris pv. campestris employs a 5'UTR as a feedback controller to regulate methionine biosynthesis. MICROBIOLOGY-SGM 2018; 164:1146-1155. [PMID: 30024369 PMCID: PMC6230763 DOI: 10.1099/mic.0.000690] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The synthesis of methionine is critical for most bacteria. It is known that cellular methionine has a feedback effect on the expression of met genes involved in de novo methionine biosynthesis. Previous studies revealed that Gram-negative bacteria control met gene expression at the transcriptional level by regulator proteins, while most Gram-positive bacteria regulate met genes at post-transcriptional level by RNA regulators (riboregulators) located in the 5′UTR of met genes. However, despite its importance, the methionine biosynthesis pathway in the Gram-negative Xanthomonas genus that includes many important plant pathogens is completely uncharacterized. Here, we address this issue using the crucifer black rot pathogen Xanthomonas campestris pv. campestris (Xcc), a model bacterium in microbe–plant interaction studies. The work identified an operon (met) involved in de novo methionine biosynthesis in Xcc. Disruption of the operon resulted in defective growth in methionine-limited media and in planta. Western blot analysis revealed that the expression of the operon is dependent on methionine levels. Further molecular analyses demonstrated that the 5′UTR, but not the promoter of the operon, is involved in feedback regulation on operon expression in response to methionine availability, providing an example of a Gram-negative bacterium utilizing a 5′UTR region to control the expression of the genes involved in methionine biosynthesis.
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Affiliation(s)
- Jian-Ling Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, PR China
| | - Dan Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, PR China
| | - Yu-Wei Liang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, PR China
| | - Wan-Ying Zhong
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, PR China
| | - Zhen-Hua Ming
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, PR China
| | - Dong-Jie Tang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, PR China
- *Correspondence: Dong-Jie Tang,
| | - Ji-Liang Tang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, PR China
- Ji-Liang Tang,
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122
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Sun T, Li S, Song X, Diao J, Chen L, Zhang W. Toolboxes for cyanobacteria: Recent advances and future direction. Biotechnol Adv 2018; 36:1293-1307. [DOI: 10.1016/j.biotechadv.2018.04.007] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 04/09/2018] [Accepted: 04/26/2018] [Indexed: 12/20/2022]
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123
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Schwenk S, Moores A, Nobeli I, McHugh TD, Arnvig KB. Cell-wall synthesis and ribosome maturation are co-regulated by an RNA switch in Mycobacterium tuberculosis. Nucleic Acids Res 2018; 46:5837-5849. [PMID: 29618088 PMCID: PMC6009663 DOI: 10.1093/nar/gky226] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 03/11/2018] [Accepted: 03/15/2018] [Indexed: 01/16/2023] Open
Abstract
The success of Mycobacterium tuberculosis relies on the ability to switch between active growth and non-replicating persistence, associated with latent TB infection. Resuscitation promoting factors (Rpfs) are essential for the transition between these states. Rpf expression is tightly regulated as these enzymes are able to degrade the cell wall, and hence potentially lethal to the bacterium itself. We have identified a regulatory element in the 5' untranslated region (UTR) of rpfB. We demonstrate that this element is a transcriptionally regulated RNA switch/riboswitch candidate, which appears to be restricted to pathogenic mycobacteria, suggesting a role in virulence. We have used translation start site mapping to re-annotate the RpfB start codon and identified and validated a ribosome binding site that is likely to be targeted by an rpfB antisense RNA. Finally, we show that rpfB is co-transcribed with ksgA and ispE downstream. ksgA encodes a universally conserved methyltransferase involved in ribosome maturation and ispE encodes an essential kinase involved in cell wall synthesis. This arrangement implies co-regulation of resuscitation, cell wall synthesis and ribosome maturation via the RNA switch.
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Affiliation(s)
- Stefan Schwenk
- Institute for Structural and Molecular Biology, University College London, London WC1E 6BT, UK
| | - Alexandra Moores
- Institute for Structural and Molecular Biology, University College London, London WC1E 6BT, UK
| | - Irene Nobeli
- Institute for Structural and Molecular Biology, Birkbeck, London WC1E 7HX, UK
| | - Timothy D McHugh
- Centre for Clinical Microbiology, Royal Free Campus, University College London, London NW3 2QG, UK
| | - Kristine B Arnvig
- Institute for Structural and Molecular Biology, University College London, London WC1E 6BT, UK
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Nichols PJ, Henen MA, Born A, Strotz D, Güntert P, Vögeli B. High-resolution small RNA structures from exact nuclear Overhauser enhancement measurements without additional restraints. Commun Biol 2018; 1:61. [PMID: 30271943 PMCID: PMC6123705 DOI: 10.1038/s42003-018-0067-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 05/09/2018] [Indexed: 11/29/2022] Open
Abstract
RNA not only translates the genetic code into proteins, but also carries out important cellular functions. Understanding such functions requires knowledge of the structure and dynamics at atomic resolution. Almost half of the published RNA structures have been solved by nuclear magnetic resonance (NMR). However, as a result of severe resonance overlap and low proton density, high-resolution RNA structures are rarely obtained from nuclear Overhauser enhancement (NOE) data alone. Instead, additional semi-empirical restraints and labor-intensive techniques are required for structural averages, while there are only a few experimentally derived ensembles representing dynamics. Here we show that our exact NOE (eNOE) based structure determination protocol is able to define a 14-mer UUCG tetraloop structure at high resolution without other restraints. Additionally, we use eNOEs to calculate a two-state structure, which samples its conformational space. The protocol may open an avenue to obtain high-resolution structures of small RNA of unprecedented accuracy with moderate experimental efforts.
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Affiliation(s)
- Parker J Nichols
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver, Anschutz Medical Campus, 12801 East 17th Avenue, Aurora,, CO, 80045, USA
| | - Morkos A Henen
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver, Anschutz Medical Campus, 12801 East 17th Avenue, Aurora,, CO, 80045, USA
- Faculty of Pharmacy, Mansoura University, Mansoura, 35516, Egypt
| | - Alexandra Born
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver, Anschutz Medical Campus, 12801 East 17th Avenue, Aurora,, CO, 80045, USA
| | - Dean Strotz
- Laboratory of Physical Chemistry, ETH Zürich, ETH-Hönggerberg, Zürich, 8093, Switzerland
| | - Peter Güntert
- Laboratory of Physical Chemistry, ETH Zürich, ETH-Hönggerberg, Zürich, 8093, Switzerland
- Institute of Biophysical Chemistry, Center for Biomolecular Magnetic Resonance, Goethe University Frankfurt am Main, Frankfurt am Main, 60438, Germany
- Graduate School of Science, Tokyo Metropolitan University, Hachioji, Tokyo, 192-0397, Japan
| | - Beat Vögeli
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver, Anschutz Medical Campus, 12801 East 17th Avenue, Aurora,, CO, 80045, USA.
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125
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Abduljalil JM. Bacterial riboswitches and RNA thermometers: Nature and contributions to pathogenesis. Noncoding RNA Res 2018; 3:54-63. [PMID: 30159440 PMCID: PMC6096418 DOI: 10.1016/j.ncrna.2018.04.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 04/10/2018] [Accepted: 04/10/2018] [Indexed: 12/31/2022] Open
Abstract
Bacterial pathogens are always challenged by fluctuations of chemical and physical parameters that pose serious threats to cellular integrity and metabolic status. Sudden deprivation of nutrients or key metabolites, changes in surrounding pH, and temperature shifts are the most important examples of such parameters. To elicit a proper response to such fluctuations, bacterial cells coordinate the expression of parameter-relevant genes. Although protein-mediated control of gene expression is well appreciated since many decades, RNA-based regulation has been discovered in early 2000s as a parallel level of regulation. Small regulatory RNAs have emerged as one of the most widespread and important gene regulatory systems in bacteria with rare representatives found in Archaea and Eukarya. Riboswitches and thermosensors are cis-encoded RNA regulatory elements that employ different mechanisms to regulate the expression of related genes controlling key metabolic pathways and genes of temperature relevant proteins including virulence factors. The extent of RNA contributions to gene regulation is not completely known even in well-studied models such E. coli and B. subtilis. In depth understanding of riboswitches is promising for opportunity to discover a narrow spectrum antibacterial drugs that target riboswitches of essential metabolic pathways.
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Key Words
- 5ʹ-UTRs, 5ʹ-untranslated region
- AdoCbl, adenosylcobalamine
- Aptamer
- Bacterial pathogenicity
- CSPs, Cold Shock Proteins
- FMN, Flavin mononucleotide
- Gene expression
- ORFs, open reading frames
- RBS, Ribosomal Binding Site
- RNA thermometer
- RNAP, RNA polymerase
- RNAT, RNA thermometer
- Riboswitches
- SAH, S-adenosylhomocysteine
- SAM, S-adenosylmethionine
- SD, Shine-Dalgarno
- TPP, Thiamine pyrophosphate
- Transcription termination
- Virulence
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126
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Xie H, Zhan H, Gao Q, Li J, Zhou Q, Chen Z, Liu Y, Ding M, Xiao H, Liu Y, Huang W, Cai Z. Synthetic artificial "long non-coding RNAs" targeting oncogenic microRNAs and transcriptional factors inhibit malignant phenotypes of bladder cancer cells. Cancer Lett 2018; 422:94-106. [PMID: 29501702 DOI: 10.1016/j.canlet.2018.02.038] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 02/13/2018] [Accepted: 02/26/2018] [Indexed: 02/05/2023]
Abstract
Both oncogenic transcription factors (TFs) and microRNAs (miRNAs) play important roles in human cancers, acting as transcriptional and post-transcriptional regulators, respectively. These phenomena raise questions about the ability of an artificial device to simultaneously regulate miRNAs and TFs. In this study, we aimed to construct artificial long non-coding RNAs, "alncRNAs", and to investigate their therapeutic effects on bladder cancer cell lines. Based on engineering principles of synthetic biology, we combined tandem arrayed aptamer cDNA sequences for TFs with tandem arrayed cDNA copies of binding sites for the miRNAs to construct alncRNAs. In order to prove the utility of this platform, we chose β-catenin and the miR-183-182-96 cluster as the functional targets and used the bladder cancer cell lines 5637 and SW780 as the test models. Dual-luciferase reporter assay, real-time quantitative PCR (qRT-PCR) and related phenotypic experiments were used to test the expression of related genes and the therapeutic effects of our devices. The result of dual-luciferase reporter assay and qRT-PCR showed that alncRNAs could inhibit transcriptional activity of TFs and expression of corresponding microRNAs. Using functional experiments, we observed decreased cell proliferation, increased apoptosis, and motility inhibition in alncRNA-infected bladder cancer cells. What's more, follow-up mechanism experiments further confirmed the anti-tumor effect of our devices. In summary, our synthetic devices indeed function as anti-tumor regulators, which synchronously accomplish transcriptional and post-transcriptional regulation in bladder cancer cells. Most importantly, anti-cancer effects were induced by the synthetic alncRNAs in the bladder cancer lines. Our devices, all in all, provided a novel strategy and methodology for cancer studies, and might show a great potential for cancer therapy if the challenges of in vivo DNA delivery are overcome.
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Affiliation(s)
- Haibiao Xie
- Key Laboratory of Medical Reprogramming Technology, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, 518039, China; Shantou University Medical College, Shantou, 515041, Guangdong Province, China; Department of Urology, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, 518039, China
| | - Hengji Zhan
- Key Laboratory of Medical Reprogramming Technology, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, 518039, China; Department of Urology, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, 518039, China
| | - Qunjun Gao
- Key Laboratory of Medical Reprogramming Technology, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, 518039, China; Department of Urology, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, 518039, China; Guangzhou Medical University, Guangzhou, 511436, China
| | - Jianfa Li
- Key Laboratory of Medical Reprogramming Technology, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, 518039, China; Shantou University Medical College, Shantou, 515041, Guangdong Province, China; Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Peking University, Shenzhen, 518036, China
| | - Qun Zhou
- Key Laboratory of Medical Reprogramming Technology, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, 518039, China; Department of Urology, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, 518039, China; Shenzhen Second People's Hospital, Clinical Medicine College of Anhui Medical University, Shenzhen, 518039, Guangdong, China
| | - Zhicong Chen
- Key Laboratory of Medical Reprogramming Technology, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, 518039, China; Department of Urology, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, 518039, China
| | - Yuhan Liu
- Key Laboratory of Medical Reprogramming Technology, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, 518039, China; Department of Urology, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, 518039, China
| | - Mengting Ding
- Key Laboratory of Medical Reprogramming Technology, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, 518039, China; Department of Urology, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, 518039, China
| | - Huizhong Xiao
- Key Laboratory of Medical Reprogramming Technology, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, 518039, China; Department of Urology, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, 518039, China
| | - Yuchen Liu
- Key Laboratory of Medical Reprogramming Technology, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, 518039, China; Shantou University Medical College, Shantou, 515041, Guangdong Province, China.
| | - Weiren Huang
- Key Laboratory of Medical Reprogramming Technology, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, 518039, China.
| | - Zhiming Cai
- Key Laboratory of Medical Reprogramming Technology, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, 518039, China; Shantou University Medical College, Shantou, 515041, Guangdong Province, China; Department of Urology, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, 518039, China.
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127
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Cai Y, Xia M, Dong H, Qian Y, Zhang T, Zhu B, Wu J, Zhang D. Engineering a vitamin B 12 high-throughput screening system by riboswitch sensor in Sinorhizobium meliloti. BMC Biotechnol 2018; 18:27. [PMID: 29751749 PMCID: PMC5948670 DOI: 10.1186/s12896-018-0441-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 04/30/2018] [Indexed: 12/23/2022] Open
Abstract
Background As a very important coenzyme in the cell metabolism, Vitamin B12 (cobalamin, VB12) has been widely used in food and medicine fields. The complete biosynthesis of VB12 requires approximately 30 genes, but overexpression of these genes did not result in expected increase of VB12 production. High-yield VB12-producing strains are usually obtained by mutagenesis treatments, thus developing an efficient screening approach is urgently needed. Result By the help of engineered strains with varied capacities of VB12 production, a riboswitch library was constructed and screened, and the btuB element from Salmonella typhimurium was identified as the best regulatory device. A flow cytometry high-throughput screening system was developed based on the btuB riboswitch with high efficiency to identify positive mutants. Mutation of Sinorhizobium meliloti (S. meliloti) was optimized using the novel mutation technique of atmospheric and room temperature plasma (ARTP). Finally, the mutant S. meliloti MC5–2 was obtained and considered as a candidate for industrial applications. After 7 d’s cultivation on a rotary shaker at 30 °C, the VB12 titer of S. meliloti MC5–2 reached 156 ± 4.2 mg/L, which was 21.9% higher than that of the wild type strain S. meliloti 320 (128 ± 3.2 mg/L). The genome of S. meliloti MC5–2 was sequenced, and gene mutations were identified and analyzed. Conclusion To our knowledge, it is the first time that a riboswitch element was used in S. meliloti. The flow cytometry high-throughput screening system was successfully developed and a high-yield VB12 producing strain was obtained. The identified and analyzed gene mutations gave useful information for developing high-yield strains by metabolic engineering. Overall, this work provides a useful high-throughput screening method for developing high VB12-yield strains. Electronic supplementary material The online version of this article (10.1186/s12896-018-0441-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yingying Cai
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China.,College of Biotechnology, Tianjin University of Science & Technology, No. 29, thirteenth Avenue Binhai District, Tianjin, 300457, China
| | - Miaomiao Xia
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China
| | - Huina Dong
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China
| | - Yuan Qian
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China
| | - Tongcun Zhang
- College of Biotechnology, Tianjin University of Science & Technology, No. 29, thirteenth Avenue Binhai District, Tianjin, 300457, China
| | - Beiwei Zhu
- School of Food Science and Technology, Dalian Polytechnic University, National Engineering Research Center of Seafood, Dalian, 116034, People's Republic of China
| | - Jinchuan Wu
- Industrial Biotechnology Division, Institute of Chemical and Engineering Sciences, 1 Pesek Road, Jurong Island, 627833, Singapore
| | - Dawei Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China. .,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China. .,School of Food Science and Technology, Dalian Polytechnic University, National Engineering Research Center of Seafood, Dalian, 116034, People's Republic of China.
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128
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Inuzuka S, Kakizawa H, Nishimura KI, Naito T, Miyazaki K, Furuta H, Matsumura S, Ikawa Y. Recognition of cyclic-di-GMP by a riboswitch conducts translational repression through masking the ribosome-binding site distant from the aptamer domain. Genes Cells 2018; 23:435-447. [PMID: 29693296 DOI: 10.1111/gtc.12586] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 03/18/2018] [Indexed: 12/31/2022]
Abstract
The riboswitch is a class of RNA-based gene regulatory machinery that is dependent on recognition of its target ligand by RNA tertiary structures. Ligand recognition is achieved by the aptamer domain, and ligand-dependent structural changes of the expression platform then usually mediate termination of transcription or translational initiation. Ligand-dependent structural changes of the aptamer domain and expression platform have been reported for several riboswitches with short (<40 nucleotides) expression platforms. In this study, we characterized structural changes of the Vc2 c-di-GMP riboswitch that represses translation of downstream open reading frames in a ligand-dependent manner. The Vc2 riboswitch has a long (97 nucleotides) expression platform, but its structure and function are largely unknown. Through mutational analysis and chemical probing, we identified its secondary structures that are possibly responsible for switch-OFF and switch-ON states of translational initiation.
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Affiliation(s)
- Saki Inuzuka
- Department of Chemistry, Graduate School of Science and Engineering, University of Toyama, Toyama, Japan
| | - Hitoshi Kakizawa
- Department of Chemistry, Graduate School of Science and Engineering, University of Toyama, Toyama, Japan
| | - Kei-Ichiro Nishimura
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Fukuoka, Japan
| | - Takuto Naito
- Department of Chemistry, Graduate School of Science and Engineering, University of Toyama, Toyama, Japan
| | - Katsushi Miyazaki
- Department of Chemistry, Graduate School of Science and Engineering, University of Toyama, Toyama, Japan
| | - Hiroyuki Furuta
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Fukuoka, Japan
| | - Shigeyoshi Matsumura
- Department of Chemistry, Graduate School of Science and Engineering, University of Toyama, Toyama, Japan
| | - Yoshiya Ikawa
- Department of Chemistry, Graduate School of Science and Engineering, University of Toyama, Toyama, Japan
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129
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Findeiß S, Hammer S, Wolfinger MT, Kühnl F, Flamm C, Hofacker IL. In silico design of ligand triggered RNA switches. Methods 2018; 143:90-101. [PMID: 29660485 DOI: 10.1016/j.ymeth.2018.04.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 03/06/2018] [Accepted: 04/06/2018] [Indexed: 02/06/2023] Open
Abstract
This contribution sketches a work flow to design an RNA switch that is able to adapt two structural conformations in a ligand-dependent way. A well characterized RNA aptamer, i.e., knowing its Kd and adaptive structural features, is an essential ingredient of the described design process. We exemplify the principles using the well-known theophylline aptamer throughout this work. The aptamer in its ligand-binding competent structure represents one structural conformation of the switch while an alternative fold that disrupts the binding-competent structure forms the other conformation. To keep it simple we do not incorporate any regulatory mechanism to control transcription or translation. We elucidate a commonly used design process by explicitly dissecting and explaining the necessary steps in detail. We developed a novel objective function which specifies the mechanistics of this simple, ligand-triggered riboswitch and describe an extensive in silico analysis pipeline to evaluate important kinetic properties of the designed sequences. This protocol and the developed software can be easily extended or adapted to fit novel design scenarios and thus can serve as a template for future needs.
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Affiliation(s)
- Sven Findeiß
- Bioinformatics, Institute of Computer Science, and Interdisciplinary Center for Bioinformatics, Leipzig University, Härtelstraße 16-18, 04107 Leipzig, Germany; University of Vienna, Faculty of Computer Science, Research Group Bioinformatics and Computational Biology, Währingerstraße 29, 1090 Vienna, Austria; University of Vienna, Faculty of Chemistry, Department of Theoretical Chemistry, Währingerstraße 17, 1090 Vienna, Austria.
| | - Stefan Hammer
- Bioinformatics, Institute of Computer Science, and Interdisciplinary Center for Bioinformatics, Leipzig University, Härtelstraße 16-18, 04107 Leipzig, Germany; University of Vienna, Faculty of Computer Science, Research Group Bioinformatics and Computational Biology, Währingerstraße 29, 1090 Vienna, Austria; University of Vienna, Faculty of Chemistry, Department of Theoretical Chemistry, Währingerstraße 17, 1090 Vienna, Austria
| | - Michael T Wolfinger
- University of Vienna, Faculty of Chemistry, Department of Theoretical Chemistry, Währingerstraße 17, 1090 Vienna, Austria; Medical University of Vienna, Center for Anatomy and Cell Biology, Währingerstraße 13, 1090 Vienna, Austria
| | - Felix Kühnl
- Bioinformatics, Institute of Computer Science, and Interdisciplinary Center for Bioinformatics, Leipzig University, Härtelstraße 16-18, 04107 Leipzig, Germany
| | - Christoph Flamm
- University of Vienna, Faculty of Chemistry, Department of Theoretical Chemistry, Währingerstraße 17, 1090 Vienna, Austria
| | - Ivo L Hofacker
- University of Vienna, Faculty of Computer Science, Research Group Bioinformatics and Computational Biology, Währingerstraße 29, 1090 Vienna, Austria; University of Vienna, Faculty of Chemistry, Department of Theoretical Chemistry, Währingerstraße 17, 1090 Vienna, Austria
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130
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Kraft CE, Angert ER. Competition for vitamin B1 (thiamin) structures numerous ecological interactions. QUARTERLY REVIEW OF BIOLOGY 2018; 92:151-68. [PMID: 29562121 DOI: 10.1086/692168] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Thiamin (vitamin B1) is a cofactor required for essential biochemical reactions in all living organisms, yet free thiamin is scarce in the environment. The diversity of biochemical pathways involved in the acquisition, degradation, and synthesis of thiamin indicates that organisms have evolved numerous ecological strategies for meeting this nutritional requirement. In this review we synthesize information from multiple disciplines to show how the complex biochemistry of thiamin influences ecological outcomes of interactions between organisms in environments ranging from the open ocean and the Australian outback to the gastrointestinal tract of animals. We highlight population and ecosystem responses to the availability or absence of thiamin. These include widespread mortality of fishes, birds, and mammals, as well as the thiamin-dependent regulation of ocean productivity. Overall, we portray thiamin biochemistry as the foundation for molecularly mediated ecological interactions that influence survival and abundance of a vast array of organisms.
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131
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Phylogenomic and comparative analysis of the distribution and regulatory patterns of TPP riboswitches in fungi. Sci Rep 2018; 8:5563. [PMID: 29615754 PMCID: PMC5882874 DOI: 10.1038/s41598-018-23900-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 03/20/2018] [Indexed: 01/01/2023] Open
Abstract
Riboswitches are metabolite or ion sensing cis-regulatory elements that regulate the expression of the associated genes involved in biosynthesis or transport of the corresponding metabolite. Among the nearly 40 different classes of riboswitches discovered in bacteria so far, only the TPP riboswitch has also been found in algae, plants, and in fungi where their presence has been experimentally validated in a few instances. We analyzed all the available complete fungal and related genomes and identified TPP riboswitch-based regulation systems in 138 fungi and 15 oomycetes. We find that TPP riboswitches are most abundant in Ascomycota and Basidiomycota where they regulate TPP biosynthesis and/or transporter genes. Many of these transporter genes were found to contain conserved domains consistent with nucleoside, urea and amino acid transporter gene families. The genomic location of TPP riboswitches when correlated with the intron structure of the regulated genes enabled prediction of the precise regulation mechanism employed by each riboswitch. Our comprehensive analysis of TPP riboswitches in fungi provides insights about the phylogenomic distribution, regulatory patterns and functioning mechanisms of TPP riboswitches across diverse fungal species and provides a useful resource that will enhance the understanding of RNA-based gene regulation in eukaryotes.
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132
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Koirala D, Shelke SA, Dupont M, Ruiz S, DasGupta S, Bailey LJ, Benner SA, Piccirilli JA. Affinity maturation of a portable Fab-RNA module for chaperone-assisted RNA crystallography. Nucleic Acids Res 2018; 46:2624-2635. [PMID: 29309709 PMCID: PMC5861428 DOI: 10.1093/nar/gkx1292] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 12/13/2017] [Accepted: 12/28/2017] [Indexed: 12/13/2022] Open
Abstract
Antibody fragments such as Fabs possess properties that can enhance protein and RNA crystallization and therefore can facilitate macromolecular structure determination. In particular, Fab BL3-6 binds to an AAACA RNA pentaloop closed by a GC pair with ∼100 nM affinity. The Fab and hairpin have served as a portable module for RNA crystallization. The potential for general application make it desirable to adjust the properties of this crystallization module in a manner that facilitates its use for RNA structure determination, such as ease of purification, surface entropy or binding affinity. In this work, we used both in vitro RNA selection and phage display selection to alter the epitope and paratope sides of the binding interface, respectively, for improved binding affinity. We identified a 5'-GNGACCC-3' consensus motif in the RNA and S97N mutation in complimentarity determining region L3 of the Fab that independently impart about an order of magnitude improvement in affinity, resulting from new hydrogen bonding interactions. Using a model RNA, these modifications facilitated crystallization under a wider range of conditions and improved diffraction. The improved features of the Fab-RNA module may facilitate its use as an affinity tag for RNA purification and imaging and as a chaperone for RNA crystallography.
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Affiliation(s)
- Deepak Koirala
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA
| | - Sandip A Shelke
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA
| | - Marcel Dupont
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA
| | - Stormy Ruiz
- Department of Chemistry, The University of Chicago, Chicago, IL 60637, USA
| | - Saurja DasGupta
- Department of Chemistry, The University of Chicago, Chicago, IL 60637, USA
| | - Lucas J Bailey
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA
| | - Steven A Benner
- Foundation for Applied Molecular Evolution, Firebird Biomolecular Sciences LLC, 13709 Progress Boulevard, Alachua, FL 32615, USA
| | - Joseph A Piccirilli
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA
- Department of Chemistry, The University of Chicago, Chicago, IL 60637, USA
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133
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Rizvi NF, Howe JA, Nahvi A, Klein DJ, Fischmann TO, Kim HY, McCoy MA, Walker SS, Hruza A, Richards MP, Chamberlin C, Saradjian P, Butko MT, Mercado G, Burchard J, Strickland C, Dandliker PJ, Smith GF, Nickbarg EB. Discovery of Selective RNA-Binding Small Molecules by Affinity-Selection Mass Spectrometry. ACS Chem Biol 2018; 13:820-831. [PMID: 29412640 DOI: 10.1021/acschembio.7b01013] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Recent advances in understanding the relevance of noncoding RNA (ncRNA) to disease have increased interest in drugging ncRNA with small molecules. The recent discovery of ribocil, a structurally distinct synthetic mimic of the natural ligand of the flavin mononucleotide (FMN) riboswitch, has revealed the potential chemical diversity of small molecules that target ncRNA. Affinity-selection mass spectrometry (AS-MS) is theoretically applicable to high-throughput screening (HTS) of small molecules binding to ncRNA. Here, we report the first application of the Automated Ligand Detection System (ALIS), an indirect AS-MS technique, for the selective detection of small molecule-ncRNA interactions, high-throughput screening against large unbiased small-molecule libraries, and identification and characterization of novel compounds (structurally distinct from both FMN and ribocil) that target the FMN riboswitch. Crystal structures reveal that different compounds induce various conformations of the FMN riboswitch, leading to different activity profiles. Our findings validate the ALIS platform for HTS screening for RNA-binding small molecules and further demonstrate that ncRNA can be broadly targeted by chemically diverse yet selective small molecules as therapeutics.
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Affiliation(s)
- Noreen F. Rizvi
- Merck & Co., Inc., Boston, Massachusetts 02115, United States
| | - John A. Howe
- Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Ali Nahvi
- Merck & Co., Inc., West Point, Pennsylvania 19486, United States
| | - Daniel J. Klein
- Merck & Co., Inc., West Point, Pennsylvania 19486, United States
| | | | - Hai-Young Kim
- Merck & Co., Inc., Boston, Massachusetts 02115, United States
| | - Mark A. McCoy
- Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Scott S. Walker
- Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Alan Hruza
- Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | | | - Chad Chamberlin
- Merck & Co., Inc., Boston, Massachusetts 02115, United States
| | - Peter Saradjian
- Merck & Co., Inc., Boston, Massachusetts 02115, United States
| | | | - Gabriel Mercado
- Biodesy, Inc., South San Francisco, California 94080, United States
| | - Julja Burchard
- Merck & Co., Inc., Boston, Massachusetts 02115, United States
| | | | | | - Graham F. Smith
- Merck & Co., Inc., Boston, Massachusetts 02115, United States
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134
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Kan J, An L, Wu Y, Long J, Song L, Fang R, Jia Y. A dual role for proline iminopeptidase in the regulation of bacterial motility and host immunity. MOLECULAR PLANT PATHOLOGY 2018; 19:2011-2024. [PMID: 29517846 PMCID: PMC6638124 DOI: 10.1111/mpp.12677] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 03/06/2018] [Accepted: 03/06/2018] [Indexed: 05/07/2023]
Abstract
During plant-pathogen interactions, pathogenic bacteria have evolved multiple strategies to cope with the sophisticated defence systems of host plants. Proline iminopeptidase (PIP) is essential to Xanthomonas campestris pv. campestris (Xcc) virulence, and is conserved in many plant-associated bacteria, but its pathogenic mechanism remains unclear. In this study, we found that disruption of pip in Xcc enhanced its flagella-mediated bacterial motility by decreasing intracellular bis-(3',5')-cyclic dimeric guanosine monophosphate (c-di-GMP) levels, whereas overexpression of pip in Xcc restricted its bacterial motility by elevating c-di-GMP levels. We also found that PIP is a type III secretion system-dependent effector capable of eliciting a hypersensitive response in non-host, but not host plants. When we transformed pip into the host plant Arabidopsis, higher bacterial titres were observed in pip-overexpressing plants relative to wild-type plants after Xcc inoculation. The repressive function of PIP on plant immunity was dependent on PIP's enzymatic activity and acted through interference with the salicylic acid (SA) biosynthetic and regulatory genes. Thus, PIP simultaneously regulates two distinct regulatory networks during plant-microbe interactions, i.e. it affects intracellular c-di-GMP levels to coordinate bacterial behaviour, such as motility, and functions as a type III effector translocated into plant cells to suppress plant immunity. Both processes provide bacteria with the regulatory potential to rapidly adapt to complex environments, to utilize limited resources for growth and survival in a cost-efficient manner and to improve the chances of bacterial survival by helping pathogens to inhabit the internal tissues of host plants.
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Affiliation(s)
- Jinhong Kan
- State Key Laboratory of Plant Genomics, Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China
- National Plant Gene Research CenterBeijing 100101China
- College of Life Sciences, University of the Chinese Academy of SciencesBeijing 100049China
- Present address:
Center for Crop Germplasm Resources, Institute of Crop SciencesChinese Academy of Agricultural SciencesBeijing 100081China
| | - Lin An
- State Key Laboratory of Plant Genomics, Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China
- National Plant Gene Research CenterBeijing 100101China
- College of Life Sciences, University of the Chinese Academy of SciencesBeijing 100049China
| | - Yao Wu
- State Key Laboratory of Plant Genomics, Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China
- National Plant Gene Research CenterBeijing 100101China
| | - Jia Long
- College of Life Sciences, Capital Normal UniversityBeijing 100048China
| | - Liyang Song
- State Key Laboratory of Plant Genomics, Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China
- National Plant Gene Research CenterBeijing 100101China
- College of Life Sciences, University of the Chinese Academy of SciencesBeijing 100049China
| | - Rongxiang Fang
- State Key Laboratory of Plant Genomics, Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China
- National Plant Gene Research CenterBeijing 100101China
| | - Yantao Jia
- State Key Laboratory of Plant Genomics, Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China
- National Plant Gene Research CenterBeijing 100101China
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135
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Sherlock ME, Sudarsan N, Stav S, Breaker RR. Tandem riboswitches form a natural Boolean logic gate to control purine metabolism in bacteria. eLife 2018; 7:e33908. [PMID: 29504937 PMCID: PMC5912903 DOI: 10.7554/elife.33908] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 03/04/2018] [Indexed: 12/28/2022] Open
Abstract
Gene control systems sometimes interpret multiple signals to set the expression levels of the genes they regulate. In rare instances, ligand-binding riboswitch aptamers form tandem arrangements to approximate the function of specific two-input Boolean logic gates. Here, we report the discovery of riboswitch aptamers for phosphoribosyl pyrophosphate (PRPP) that naturally exist either in singlet arrangements, or occur in tandem with guanine aptamers. Tandem guanine-PRPP aptamers can bind the target ligands, either independently or in combination, to approximate the function expected for an IMPLY Boolean logic gate to regulate transcription of messenger RNAs for de novo purine biosynthesis in bacteria. The existence of sophisticated all-RNA regulatory systems that sense two ancient ribonucleotide derivatives to control synthesis of RNA molecules supports the hypothesis that RNA World organisms could have managed a complex metabolic state without the assistance of protein regulatory factors.
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Affiliation(s)
- Madeline E Sherlock
- Department of Molecular Biophysics and BiochemistryYale UniversityNew HavenUnited States
| | | | - Shira Stav
- Molecular, Cellular and Developmental BiologyYale UniversityNew HavenUnited States
| | - Ronald R Breaker
- Department of Molecular Biophysics and BiochemistryYale UniversityNew HavenUnited States
- Howard Hughes Medical InstituteNew HavenUnited States
- Molecular, Cellular and Developmental BiologyYale UniversityNew HavenUnited States
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136
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Greenlee EB, Stav S, Atilho RM, Brewer KI, Harris KA, Malkowski SN, Mirihana Arachchilage G, Perkins KR, Sherlock ME, Breaker RR. Challenges of ligand identification for the second wave of orphan riboswitch candidates. RNA Biol 2018; 15:377-390. [PMID: 29135333 PMCID: PMC5927730 DOI: 10.1080/15476286.2017.1403002] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 10/25/2017] [Accepted: 10/30/2017] [Indexed: 12/18/2022] Open
Abstract
Orphan riboswitch candidates are noncoding RNA motifs whose representatives are believed to function as genetic regulatory elements, but whose target ligands have yet to be identified. The study of certain orphans, particularly classes that have resisted experimental validation for many years, has led to the discovery of important biological pathways and processes once their ligands were identified. Previously, we highlighted details for four of the most common and intriguing orphan riboswitch candidates. This facilitated the validation of riboswitches for the signaling molecules c-di-AMP, ZTP, and ppGpp, the metal ion Mn2+, and the metabolites guanidine and PRPP. Such studies also yield useful linkages between the ligands sensed by the riboswitches and numerous biochemical pathways. In the current report, we describe the known characteristics of 30 distinct classes of orphan riboswitch candidates - some of which have remained unsolved for over a decade. We also discuss the prospects for uncovering novel biological insights via focused studies on these RNAs. Lastly, we make recommendations for experimental objectives along the path to finding ligands for these mysterious RNAs.
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Affiliation(s)
- Etienne B. Greenlee
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Shira Stav
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Ruben M. Atilho
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Kenneth I. Brewer
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Kimberly A. Harris
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | | | | | - Kevin R. Perkins
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Madeline E. Sherlock
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Ronald R. Breaker
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
- Howard Hughes Medical Institute, Yale University, New Haven, CT, USA
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137
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Singh P, Kumar N, Jethva M, Yadav S, Kumari P, Thakur A, Kushwaha HR. Riboswitch regulation in cyanobacteria is independent of their habitat adaptations. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2018; 24:315-324. [PMID: 29515325 PMCID: PMC5834989 DOI: 10.1007/s12298-018-0504-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 12/13/2017] [Accepted: 01/02/2018] [Indexed: 01/17/2024]
Abstract
Cyanobacteria are one of the ancient bacterial species occupying a variety of habitats with diverse metabolic preferences. RNA regulators like riboswitches play significant role in controlling the gene expression in prokaryotes. The taxonomic distribution of riboswitches suggests that they might be one of the oldest mechanisms of gene control system. In this paper, we analyzed the distribution of different riboswitch families in various cyanobacterial genomes. It was observed that only four riboswitch classes were abundant in cyanobacteria, B12-element (Cob)/AdoCbl/AdoCbl-variant riboswitch being the most abundant. The analysis suggests that riboswitch mode of regulation is present in cyanobacterial species irrespective of their habitat types. A large number of unidentified genes regulated by riboswitches listed in this analysis indicate the wide range of targets for these riboswitch families. The analysis revealed a large number of genes regulated by riboswitches which may assist in elaborating the diversity among the cyanobacterial species.
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Affiliation(s)
- Payal Singh
- Synthetic Biology and Biofuel, ternational Center for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India
| | - Nilesh Kumar
- Synthetic Biology and Biofuel, ternational Center for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India
| | - Minesh Jethva
- Synthetic Biology and Biofuel, ternational Center for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India
| | - Saurabh Yadav
- Department of Biotechnology, Hemwati Nandan Bahuguna Garhwal University, Srinagar Garhwal, Uttarakhand India
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138
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Churkin A, Retwitzer MD, Reinharz V, Ponty Y, Waldispühl J, Barash D. Design of RNAs: comparing programs for inverse RNA folding. Brief Bioinform 2018; 19:350-358. [PMID: 28049135 PMCID: PMC6018860 DOI: 10.1093/bib/bbw120] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Computational programs for predicting RNA sequences with desired folding properties have been extensively developed and expanded in the past several years. Given a secondary structure, these programs aim to predict sequences that fold into a target minimum free energy secondary structure, while considering various constraints. This procedure is called inverse RNA folding. Inverse RNA folding has been traditionally used to design optimized RNAs with favorable properties, an application that is expected to grow considerably in the future in light of advances in the expanding new fields of synthetic biology and RNA nanostructures. Moreover, it was recently demonstrated that inverse RNA folding can successfully be used as a valuable preprocessing step in computational detection of novel noncoding RNAs. This review describes the most popular freeware programs that have been developed for such purposes, starting from RNAinverse that was devised when formulating the inverse RNA folding problem. The most recently published ones that consider RNA secondary structure as input are antaRNA, RNAiFold and incaRNAfbinv, each having different features that could be beneficial to specific biological problems in practice. The various programs also use distinct approaches, ranging from ant colony optimization to constraint programming, in addition to adaptive walk, simulated annealing and Boltzmann sampling. This review compares between the various programs and provides a simple description of the various possibilities that would benefit practitioners in selecting the most suitable program. It is geared for specific tasks requiring RNA design based on input secondary structure, with an outlook toward the future of RNA design programs.
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Affiliation(s)
- Alexander Churkin
- Shamoon College of Engineering and Physics Department at Ben-Gurion University, Beer-Sheva, Israel
| | | | - Vladimir Reinharz
- Department of Computer Science, Ben-Gurion University, Beer-Sheva, Israel
- School of Computer Science, McGill University, Montréal QC, Canada
| | - Yann Ponty
- Laboratoire d’informatique, École Polytechnique, Palaiseau, France
| | | | - Danny Barash
- Department of Computer Science, Ben-Gurion University, Beer-Sheva, Israel
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139
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Abstract
Ethanolamine (EA) is a valuable source of carbon and/or nitrogen for bacteria capable of its catabolism. Because it is derived from the membrane phospholipid phosphatidylethanolamine, it is particularly prevalent in the gastrointestinal tract, which is membrane rich due to turnover of the intestinal epithelium and the resident microbiota. Intriguingly, many gut pathogens carry the eut (ethanolamine utilization) genes. EA utilization has been studied for about 50 years, with most of the early work occurring in just a couple of species of Enterobacteriaceae. Once the metabolic pathways and enzymes were characterized by biochemical approaches, genetic screens were used to map the various activities to the eut genes. With the rise of genomics, the diversity of bacteria containing the eut genes and surprising differences in eut gene content were recognized. Some species contain nearly 20 genes and encode many accessory proteins, while others contain only the core catabolic enzyme. Moreover, the eut genes are regulated by very different mechanisms, depending on the organism and the eut regulator encoded. In the last several years, exciting progress has been made in elucidating the complex regulatory mechanisms that govern eut gene expression. Furthermore, a new appreciation for how EA contributes to infection and colonization in the host is emerging. In addition to providing an overview of EA-related biology, this minireview will give special attention to these recent advances.
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140
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Mirihana Arachchilage G, Sherlock ME, Weinberg Z, Breaker RR. SAM-VI RNAs selectively bind S-adenosylmethionine and exhibit similarities to SAM-III riboswitches. RNA Biol 2018; 15:371-378. [PMID: 29106323 DOI: 10.1080/15476286.2017.1399232] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Five distinct riboswitch classes that regulate gene expression in response to the cofactor S-adenosylmethionine (SAM) or its metabolic breakdown product S-adenosylhomocysteine (SAH) have been reported previously. Collectively, these SAM- or SAH-sensing RNAs constitute the most abundant collection of riboswitches, and are found in nearly every major bacterial lineage. Here, we report a potential sixth member of this pervasive riboswitch family, called SAM-VI, which is predominantly found in Bifidobacterium species. SAM-VI aptamers selectively bind the cofactor SAM and strongly discriminate against SAH. The consensus sequence and structural model for SAM-VI share some features with the consensus model for the SAM-III riboswitch class, whose members are mainly found in lactic acid bacteria. However, there are sufficient differences between the two classes such that current bioinformatics methods separately cluster representatives of the two motifs. These findings highlight the abundance of RNA structures that can form to selectively recognize SAM, and showcase the ability of RNA to utilize diverse strategies to perform similar biological functions.
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Affiliation(s)
| | - Madeline E Sherlock
- b Department of Molecular Biophysics and Biochemistry , Yale University , New Haven , CT , USA
| | - Zasha Weinberg
- a Howard Hughes Medical Institute, Yale University , New Haven , CT , USA
| | - Ronald R Breaker
- a Howard Hughes Medical Institute, Yale University , New Haven , CT , USA.,b Department of Molecular Biophysics and Biochemistry , Yale University , New Haven , CT , USA.,c Department of Molecular , Cellular and Developmental Biology, Yale University , New Haven , CT , USA
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141
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Moon MH, Hilimire TA, Sanders AM, Schneekloth JS. Measuring RNA-Ligand Interactions with Microscale Thermophoresis. Biochemistry 2018; 57:4638-4643. [PMID: 29327580 DOI: 10.1021/acs.biochem.7b01141] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
In recent years, there has been dramatic growth in the study of RNA. RNA has gone from being known as an intermediate in the central dogma of molecular biology to a molecule with a large diversity of structure and function that is involved in all aspects of biology. As new functions are rapidly discovered, it has become clear that there is a need for RNA-targeting small molecule probes to investigate RNA biology and clarify the potential for therapeutics based on RNA-small molecule interactions. While a host of techniques exist to measure RNA-small molecule interactions, many of these have drawbacks that make them intractable for routine use and are often not broadly applicable. A newer technology called microscale thermophoresis (MST), which measures the directed migration of a molecule and/or molecule-ligand complex along a temperature gradient, can be used to measure binding affinities using very small amounts of sample. The high sensitivity of this technique enables measurement of affinity constants in the nanomolar and micromolar range. Here, we demonstrate how MST can be used to study a range of biologically relevant RNA interactions, including peptide-RNA interactions, RNA-small molecule interactions, and displacement of an RNA-bound peptide by a small molecule.
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Affiliation(s)
- Michelle H Moon
- Chemical Biology Laboratory , National Cancer Institute , Frederick , Maryland 21702 , United States
| | - Thomas A Hilimire
- Chemical Biology Laboratory , National Cancer Institute , Frederick , Maryland 21702 , United States
| | - Allix M Sanders
- Chemical Biology Laboratory , National Cancer Institute , Frederick , Maryland 21702 , United States
| | - John S Schneekloth
- Chemical Biology Laboratory , National Cancer Institute , Frederick , Maryland 21702 , United States
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142
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Gong S, Wang Y, Wang Z, Sun Y, Zhang W. Folding behaviors of purine riboswitch aptamers. ACTA ACUST UNITED AC 2018. [DOI: 10.1007/s11859-018-1292-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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143
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Studying Parasite Gene Function and Interaction Through Ribozymes and Riboswitches Design Mechanism. Synth Biol (Oxf) 2018. [DOI: 10.1007/978-981-10-8693-9_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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144
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Li X, Mei H, Chen F, Tang Q, Yu Z, Cao X, Andongma BT, Chou SH, He J. Transcriptome Landscape of Mycobacterium smegmatis. Front Microbiol 2017; 8:2505. [PMID: 29326668 PMCID: PMC5741613 DOI: 10.3389/fmicb.2017.02505] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 12/01/2017] [Indexed: 11/13/2022] Open
Abstract
The non-pathogenic bacterium Mycobacterium smegmatis mc2155 has been widely used as a model organism in mycobacterial research, yet a detailed study about its transcription landscape remains to be established. Here we report the transcriptome, expression profiles and transcriptional structures through growth-phase-dependent RNA sequencing (RNA-seq) as well as other related experiments. We found: (1) 2,139 transcriptional start sites (TSSs) in the genome-wide scale, of which eight samples were randomly selected and further verified by 5′-RACE; (2) 2,233 independent monocistronic or polycistronic mRNAs in the transcriptome within the operon/sub-operon structures which are classified into five groups; (3) 47.50% (1016/2139) genes were transcribed into leaderless mRNAs, with the TSSs of 41.3% (883/2139) mRNAs overlapping with the first base of the annotated start codon. Initial amino acids of MSMEG_4921 and MSMEG_6422 proteins were identified by Edman degradation, indicating the presence of distinctive widespread leaderless features in M. smegmatis mc2155. (4) 150 genes with potentially wrong structural annotation, of which 124 proposed genes have been corrected; (5) eight highly active promoters, with their activities further determined by β-galactosidase assays. These data integrated the transcriptional landscape to genome information of model organism mc2155 and lay a solid foundation for further works in Mycobacterium.
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Affiliation(s)
- Xinfeng Li
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Han Mei
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Fang Chen
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Qing Tang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Zhaoqing Yu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Xiaojian Cao
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Binda T Andongma
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Shan-Ho Chou
- Institute of Biochemistry and NCHU Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan
| | - Jin He
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
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145
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Genetic regulation mechanism of the yjdF riboswitch. J Theor Biol 2017; 439:152-159. [PMID: 29223402 DOI: 10.1016/j.jtbi.2017.12.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 12/05/2017] [Accepted: 12/06/2017] [Indexed: 01/08/2023]
Abstract
The yjdF riboswitch resides in potential 5' UTRs of homologues of protein-coding gene yjdF in Firmicutes. Unlike other 30 riboswitch classes previously validated, this riboswitch class, can sense and bind to a broad collection of azaaromatic ligands. Among these compounds, some do activate production of yjdF protein driven by the riboswitch, while others are out of riboswitch-mediated modulation possibly because of the toxicity at high ligand concentrations. By incorporating the structures with pseudoknots and ligand binding kinetics into the co-transcriptional folding theory, we theoretically studied the co-transcriptional folding behaviors of the yjdF riboswitch from Bacillus subtilis at different transcription conditions. Like most riboswitches, the yjdF riboswitch can quickly fold into the aptamer structure without any trapped states during the transcription process. After the aptamer structure is formed, the riboswitch shows two main co-transcriptional folding pathways: aptamer→ON state→OFF state and aptamer → the ligand bound aptamer → the ligand bound ON state. Our results suggested that this translational riboswitch is coupled with the transcription process to exert its biological function and it is kinetically controlled. The threshold concentration for the ligand to activate the riboswitch depends on the transcription rate and the association rate of the ligand binding.
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146
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Tandon P, Jin Q, Huang L. A promising approach to enhance microalgae productivity by exogenous supply of vitamins. Microb Cell Fact 2017; 16:219. [PMID: 29183381 PMCID: PMC5706373 DOI: 10.1186/s12934-017-0834-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 11/21/2017] [Indexed: 12/22/2022] Open
Abstract
In order to reduce the consumption of traditional fossil fuels and their impact on the environment, strategies to mitigate greenhouse gas emissions especially carbon dioxide needs exploration. Microalgae-based biofuels can be the best-fit plant based feed-stocks for diminishing a majority of the Universe’s energy problems. Interestingly, the eukaryotic microalgae aid in fixation of almost 50% of the global carbon in the environment. Thus, determination of parameters that will enhance microalgal growth and productivity is crucial, if they are to be used as future renewable energy sources. A large percentage of phytoplankton species are auxotroph for one or more vitamins. These species, in turn, are also dependent upon the vitamin biosynthetic pathways for processing of these vitamins. The present study serves as a base to discuss the prevalence of vitamin auxotrophy in microalgae and the methods of its acquirement from external sources such as heterotrophic bacteria. The next section of the paper sheds light on possible species-specific symbiotic interactions among microalgae and bacteria. Lastly is the discussion on how heterotrophic bacteria can act as a vitamin prototroph for an explicit microalgal vitamin auxotroph. The overall focus is placed upon harnessing these symbiotic interactions with intentions to obtain enhancements in microalgal biomass, lipid productivity, and flocculation rates. Moreover, the growth and distribution of a microalgal cell that thrives on a specific vitamin is perhaps met by growing it with the bacterial communities that nourish it. Thus, possibly by ecologically engineering a potential species-specific microalgal–bacterial consortium, it could tremendously contribute to the acceleration of photosynthetic activity, microalgal productivity, exchange of primary metabolites and other biogeochemical nutrients within the mini ecosystem. ![]()
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Affiliation(s)
- Puja Tandon
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China
| | - Qiang Jin
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China.
| | - Limin Huang
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China
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147
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Stamatopoulou V, Apostolidi M, Li S, Lamprinou K, Papakyriakou A, Zhang J, Stathopoulos C. Direct modulation of T-box riboswitch-controlled transcription by protein synthesis inhibitors. Nucleic Acids Res 2017; 45:10242-10258. [PMID: 28973457 PMCID: PMC5622331 DOI: 10.1093/nar/gkx663] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 07/18/2017] [Indexed: 11/14/2022] Open
Abstract
Recently, it was discovered that exposure to mainstream antibiotics activate numerous bacterial riboregulators that control antibiotic resistance genes including metabolite-binding riboswitches and other transcription attenuators. However, the effects of commonly used antibiotics, many of which exhibit RNA-binding properties, on the widespread T-box riboswitches, remain unknown. In Staphylococcus aureus, a species-specific glyS T-box controls the supply of glycine for both ribosomal translation and cell wall synthesis, making it a promising target for next-generation antimicrobials. Here, we report that specific protein synthesis inhibitors could either significantly increase T-box-mediated transcription antitermination, while other compounds could suppress it, both in vitro and in vivo. In-line probing of the full-length T-box combined with molecular modelling and docking analyses suggest that the antibiotics that promote transcription antitermination stabilize the T-box:tRNA complex through binding specific positions on stem I and the Staphylococcal-specific stem Sa. By contrast, the antibiotics that attenuate T-box transcription bind to other positions on stem I and do not interact with stem Sa. Taken together, our results reveal that the transcription of essential genes controlled by T-box riboswitches can be directly modulated by commonly used protein synthesis inhibitors. These findings accentuate the regulatory complexities of bacterial response to antimicrobials that involve multiple riboregulators.
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Affiliation(s)
| | - Maria Apostolidi
- Department of Biochemistry, School of Medicine, University of Patras, 26504 Patras, Greece
| | - Shuang Li
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, 50 South Drive, Bethesda, MD 20892, USA
| | - Katerina Lamprinou
- Department of Biochemistry, School of Medicine, University of Patras, 26504 Patras, Greece
| | - Athanasios Papakyriakou
- Institute of Biosciences and Applications, National Centre for Scientific Research 'Demokritos', Athens, Greece
| | - Jinwei Zhang
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, 50 South Drive, Bethesda, MD 20892, USA
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148
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Arif A, Yao P, Terenzi F, Jia J, Ray PS, Fox PL. The GAIT translational control system. WILEY INTERDISCIPLINARY REVIEWS-RNA 2017; 9. [PMID: 29152905 PMCID: PMC5815886 DOI: 10.1002/wrna.1441] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 07/12/2017] [Accepted: 07/31/2017] [Indexed: 01/19/2023]
Abstract
The interferon (IFN)‐γ‐activated inhibitor of translation (GAIT) system directs transcript‐selective translational control of functionally related genes. In myeloid cells, IFN‐γ induces formation of a multiprotein GAIT complex that binds structural GAIT elements in the 3′‐untranslated regions (UTRs) of multiple inflammation‐related mRNAs, including ceruloplasmin and VEGF‐A, and represses their translation. The human GAIT complex is a heterotetramer containing glutamyl‐prolyl tRNA synthetase (EPRS), NS1‐associated protein 1 (NSAP1), ribosomal protein L13a (L13a), and glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH). A network of IFN‐γ‐stimulated kinases regulates recruitment and assembly of GAIT complex constituents. Activation of cyclin‐dependent kinase 5 (Cdk5), mammalian target of rapamycin complex 1 (mTORC1), and S6K1 kinases induces EPRS release from its parental multiaminoacyl tRNA synthetase complex to join NSAP1 in a ‘pre‐GAIT’ complex. Subsequently, the DAPK‐ZIPK kinase axis phosphorylates L13a, inducing release from the 60S ribosomal subunit and binding to GAPDH. The subcomplexes join to form the functional GAIT complex. Each constituent has a distinct role in the GAIT system. EPRS binds the GAIT element in target mRNAs, NSAP1 negatively regulates mRNA binding, L13a binds eIF4G to block ribosome recruitment, and GAPDH shields L13a from proteasomal degradation. The GAIT system is susceptible to genetic and condition‐specific regulation. An N‐terminus EPRS truncate is a dominant‐negative inhibitor ensuring a ‘translational trickle’ of target transcripts. Also, hypoxia and oxidatively modified lipoproteins regulate GAIT activity. Mouse models exhibiting absent or genetically modified GAIT complex constituents are beginning to elucidate the physiological role of the GAIT system, particularly in the resolution of chronic inflammation. Finally, GAIT‐like systems in proto‐chordates suggests an evolutionarily conserved role of the pathway in innate immunity. WIREs RNA 2018, 9:e1441. doi: 10.1002/wrna.1441 This article is categorized under:
Translation > Translation Regulation RNA Interactions with Proteins and Other Molecules > RNA–Protein Complexes Regulatory RNAs/RNAi/Riboswitches > Riboswitches
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Affiliation(s)
- Abul Arif
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Peng Yao
- Aab Cardiovascular Research Institute, University of Rochester School of Medicine & Dentistry, Rochester, NY, USA
| | - Fulvia Terenzi
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Jie Jia
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Partho Sarothi Ray
- Department of Biological Sciences, Indian Institute of Science Education and Research, Kolkata, India
| | - Paul L Fox
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
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149
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Gong S, Wang Y, Wang Z, Zhang W. Computational Methods for Modeling Aptamers and Designing Riboswitches. Int J Mol Sci 2017; 18:E2442. [PMID: 29149090 PMCID: PMC5713409 DOI: 10.3390/ijms18112442] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 11/12/2017] [Accepted: 11/14/2017] [Indexed: 02/04/2023] Open
Abstract
Riboswitches, which are located within certain noncoding RNA region perform functions as genetic "switches", regulating when and where genes are expressed in response to certain ligands. Understanding the numerous functions of riboswitches requires computation models to predict structures and structural changes of the aptamer domains. Although aptamers often form a complex structure, computational approaches, such as RNAComposer and Rosetta, have already been applied to model the tertiary (three-dimensional (3D)) structure for several aptamers. As structural changes in aptamers must be achieved within the certain time window for effective regulation, kinetics is another key point for understanding aptamer function in riboswitch-mediated gene regulation. The coarse-grained self-organized polymer (SOP) model using Langevin dynamics simulation has been successfully developed to investigate folding kinetics of aptamers, while their co-transcriptional folding kinetics can be modeled by the helix-based computational method and BarMap approach. Based on the known aptamers, the web server Riboswitch Calculator and other theoretical methods provide a new tool to design synthetic riboswitches. This review will represent an overview of these computational methods for modeling structure and kinetics of riboswitch aptamers and for designing riboswitches.
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Affiliation(s)
- Sha Gong
- Hubei Key Laboratory of Economic Forest Germplasm Improvement and Resources Comprehensive Utilization, Hubei Collaborative Innovation Center for the Characteristic Resources Exploitation of Dabie Mountains, Huanggang Normal University, Huanggang 438000, China.
| | - Yanli Wang
- Department of Physics, Wuhan University, Wuhan 430072, China.
| | - Zhen Wang
- Department of Physics, Wuhan University, Wuhan 430072, China.
| | - Wenbing Zhang
- Department of Physics, Wuhan University, Wuhan 430072, China.
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150
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Abstract
In this issue, Nelson and colleagues (2017) determined that guanidine, the prevalent protein denaturant, is the long-lost ligand sensed by the ykkC class of riboswitches, and identified that members of its regulon are involved in guanidine detoxification and export.
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Affiliation(s)
- Wendy W K Mok
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Mark P Brynildsen
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA.
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