1
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Romero Romero ML, Poehls J, Kirilenko A, Richter D, Jumel T, Shevchenko A, Toth-Petroczy A. Environment modulates protein heterogeneity through transcriptional and translational stop codon readthrough. Nat Commun 2024; 15:4446. [PMID: 38789441 PMCID: PMC11126739 DOI: 10.1038/s41467-024-48387-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 04/25/2024] [Indexed: 05/26/2024] Open
Abstract
Stop codon readthrough events give rise to longer proteins, which may alter the protein's function, thereby generating short-lasting phenotypic variability from a single gene. In order to systematically assess the frequency and origin of stop codon readthrough events, we designed a library of reporters. We introduced premature stop codons into mScarlet, which enabled high-throughput quantification of protein synthesis termination errors in E. coli using fluorescent microscopy. We found that under stress conditions, stop codon readthrough may occur at rates as high as 80%, depending on the nucleotide context, suggesting that evolution frequently samples stop codon readthrough events. The analysis of selected reporters by mass spectrometry and RNA-seq showed that not only translation but also transcription errors contribute to stop codon readthrough. The RNA polymerase was more likely to misincorporate a nucleotide at premature stop codons. Proteome-wide detection of stop codon readthrough by mass spectrometry revealed that temperature regulated the expression of cryptic sequences generated by stop codon readthrough in E. coli. Overall, our findings suggest that the environment affects the accuracy of protein production, which increases protein heterogeneity when the organisms need to adapt to new conditions.
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Affiliation(s)
- Maria Luisa Romero Romero
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307, Dresden, Germany.
- Center for Systems Biology Dresden, 01307, Dresden, Germany.
| | - Jonas Poehls
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307, Dresden, Germany
- Center for Systems Biology Dresden, 01307, Dresden, Germany
| | - Anastasiia Kirilenko
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307, Dresden, Germany
- Center for Systems Biology Dresden, 01307, Dresden, Germany
| | - Doris Richter
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307, Dresden, Germany
- Center for Systems Biology Dresden, 01307, Dresden, Germany
| | - Tobias Jumel
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307, Dresden, Germany
| | - Anna Shevchenko
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307, Dresden, Germany
| | - Agnes Toth-Petroczy
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307, Dresden, Germany.
- Center for Systems Biology Dresden, 01307, Dresden, Germany.
- Cluster of Excellence Physics of Life, TU Dresden, 01062, Dresden, Germany.
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2
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Bai Y, Xie C, Zhang Y, Zhang Z, Liu J, Cheng G, Li Y, Wang D, Cui B, Liu Y, Qin X. sRNA expression profile of KPC-2-producing carbapenem-resistant Klebsiella pneumoniae: Functional role of sRNA51. PLoS Pathog 2024; 20:e1012187. [PMID: 38718038 PMCID: PMC11078416 DOI: 10.1371/journal.ppat.1012187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 04/11/2024] [Indexed: 05/12/2024] Open
Abstract
The emergence of carbapenem-resistant Klebsiella pneumoniae (CRKP) has significant challenges to human health and clinical treatment, with KPC-2-producing CRKP being the predominant epidemic strain. Therefore, there is an urgent need to identify new therapeutic targets and strategies. Non-coding small RNA (sRNA) is a post-transcriptional regulator of genes involved in important biological processes in bacteria and represents an emerging therapeutic strategy for antibiotic-resistant bacteria. In this study, we analyzed the transcription profile of KPC-2-producing CRKP using RNA-seq. Of the 4693 known genes detected, the expression of 307 genes was significantly different from that of carbapenem-sensitive Klebsiella pneumoniae (CSKP), including 133 up-regulated and 174 down-regulated genes. Both the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment and Gene Ontology (GO) analysis showed that these differentially expressed genes (DEGs) were mainly related to metabolism. In addition, we identified the sRNA expression profile of KPC-2-producing CRKP for the first time and detected 115 sRNAs, including 112 newly discovered sRNAs. Compared to CSKP, 43 sRNAs were differentially expressed in KPC-2-producing CRKP, including 39 up-regulated and 4 down-regulated sRNAs. We chose sRNA51, the most significantly differentially expressed sRNA in KPC-2-producing CRKP, as our research subject. By constructing sRNA51-overexpressing KPC-2-producing CRKP strains, we found that sRNA51 overexpression down-regulated the expression of acrA and alleviated resistance to meropenem and ertapenem in KPC-2-producing CRKP, while overexpression of acrA in sRNA51-overexpressing strains restored the reduction of resistance. Therefore, we speculated that sRNA51 could affect the resistance of KPC-2-producing CRKP by inhibiting acrA expression and affecting the formation of efflux pumps. This provides a new approach for developing antibiotic adjuvants to restore the sensitivity of CRKP.
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Affiliation(s)
- Yibo Bai
- Department of Laboratory Medicine, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, China
- Liaoning Clinical Research Center for Laboratory Medicine, Shenyang, Liaoning Province, China
| | - Chonghong Xie
- Department of Laboratory Medicine, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, China
- Liaoning Clinical Research Center for Laboratory Medicine, Shenyang, Liaoning Province, China
| | - Yue Zhang
- Department of Laboratory Medicine, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, China
- Liaoning Clinical Research Center for Laboratory Medicine, Shenyang, Liaoning Province, China
| | - Zhijie Zhang
- Department of Laboratory Medicine, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, China
- Liaoning Clinical Research Center for Laboratory Medicine, Shenyang, Liaoning Province, China
| | - Jianhua Liu
- Department of Laboratory Medicine, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, China
- Liaoning Clinical Research Center for Laboratory Medicine, Shenyang, Liaoning Province, China
| | - Guixue Cheng
- Department of Laboratory Medicine, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, China
- Liaoning Clinical Research Center for Laboratory Medicine, Shenyang, Liaoning Province, China
| | - Yan Li
- Department of Laboratory Medicine, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, China
- Liaoning Clinical Research Center for Laboratory Medicine, Shenyang, Liaoning Province, China
| | - Di Wang
- Department of Laboratory Medicine, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, China
- Liaoning Clinical Research Center for Laboratory Medicine, Shenyang, Liaoning Province, China
| | - Bing Cui
- Department of Laboratory Medicine, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, China
- Liaoning Clinical Research Center for Laboratory Medicine, Shenyang, Liaoning Province, China
| | - Yong Liu
- Department of Laboratory Medicine, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, China
- Liaoning Clinical Research Center for Laboratory Medicine, Shenyang, Liaoning Province, China
| | - Xiaosong Qin
- Department of Laboratory Medicine, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, China
- Liaoning Clinical Research Center for Laboratory Medicine, Shenyang, Liaoning Province, China
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3
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Banerjee T, Rothenberg E, Belasco JG. RNase E searches for cleavage sites in RNA by linear diffusion: direct evidence from single-molecule FRET. Nucleic Acids Res 2024:gkae279. [PMID: 38647084 DOI: 10.1093/nar/gkae279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2024] [Revised: 03/24/2024] [Accepted: 04/06/2024] [Indexed: 04/25/2024] Open
Abstract
The ability of obstacles in cellular transcripts to protect downstream but not upstream sites en masse from attack by RNase E has prompted the hypothesis that this mRNA-degrading endonuclease may scan 5'-monophosphorylated RNA linearly for cleavage sites, starting at the 5' end. However, despite its proposed regulatory importance, the migration of RNase E on RNA has never been directly observed. We have now used single-molecule FRET to monitor the dynamics of this homotetrameric enzyme on RNA. Our findings reveal that RNase E slides along unpaired regions of RNA without consuming a molecular source of energy such as ATP and that its forward progress can be impeded when it encounters a large structural discontinuity. This movement, which is bidirectional, occurs in discrete steps of variable length and requires an RNA ligand much longer than needed to occupy a single RNase E subunit. These results indicate that RNase E scans for cleavage sites by one-dimensional diffusion and suggest a possible molecular mechanism.
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Affiliation(s)
- Tithi Banerjee
- Department of Microbiology, New York University School of Medicine, 550 First Avenue, New York, NY 10016, USA
| | - Eli Rothenberg
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, 450 E. 29th Street, New York, NY 10016, USA
| | - Joel G Belasco
- Department of Microbiology, New York University School of Medicine, 550 First Avenue, New York, NY 10016, USA
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4
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Jenniches L, Michaux C, Popella L, Reichardt S, Vogel J, Westermann AJ, Barquist L. Improved RNA stability estimation through Bayesian modeling reveals most Salmonella transcripts have subminute half-lives. Proc Natl Acad Sci U S A 2024; 121:e2308814121. [PMID: 38527194 PMCID: PMC10998600 DOI: 10.1073/pnas.2308814121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 02/16/2024] [Indexed: 03/27/2024] Open
Abstract
RNA decay is a crucial mechanism for regulating gene expression in response to environmental stresses. In bacteria, RNA-binding proteins (RBPs) are known to be involved in posttranscriptional regulation, but their global impact on RNA half-lives has not been extensively studied. To shed light on the role of the major RBPs ProQ and CspC/E in maintaining RNA stability, we performed RNA sequencing of Salmonella enterica over a time course following treatment with the transcription initiation inhibitor rifampicin (RIF-seq) in the presence and absence of these RBPs. We developed a hierarchical Bayesian model that corrects for confounding factors in rifampicin RNA stability assays and enables us to identify differentially decaying transcripts transcriptome-wide. Our analysis revealed that the median RNA half-life in Salmonella in early stationary phase is less than 1 min, a third of previous estimates. We found that over half of the 500 most long-lived transcripts are bound by at least one major RBP, suggesting a general role for RBPs in shaping the transcriptome. Integrating differential stability estimates with cross-linking and immunoprecipitation followed by RNA sequencing (CLIP-seq) revealed that approximately 30% of transcripts with ProQ binding sites and more than 40% with CspC/E binding sites in coding or 3' untranslated regions decay differentially in the absence of the respective RBP. Analysis of differentially destabilized transcripts identified a role for ProQ in the oxidative stress response. Our findings provide insights into posttranscriptional regulation by ProQ and CspC/E, and the importance of RBPs in regulating gene expression.
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Affiliation(s)
- Laura Jenniches
- Helmholtz Institute for RNA-based Infection Research, Helmholtz Centre for Infection Research, Würzburg97080, Germany
| | - Charlotte Michaux
- Institute of Molecular Infection Biology, University of Würzburg, Würzburg97080, Germany
| | - Linda Popella
- Institute of Molecular Infection Biology, University of Würzburg, Würzburg97080, Germany
| | - Sarah Reichardt
- Helmholtz Institute for RNA-based Infection Research, Helmholtz Centre for Infection Research, Würzburg97080, Germany
| | - Jörg Vogel
- Helmholtz Institute for RNA-based Infection Research, Helmholtz Centre for Infection Research, Würzburg97080, Germany
- Institute of Molecular Infection Biology, University of Würzburg, Würzburg97080, Germany
- Faculty of Medicine, University of Würzburg, Würzburg97080, Germany
| | - Alexander J. Westermann
- Helmholtz Institute for RNA-based Infection Research, Helmholtz Centre for Infection Research, Würzburg97080, Germany
- Institute of Molecular Infection Biology, University of Würzburg, Würzburg97080, Germany
| | - Lars Barquist
- Helmholtz Institute for RNA-based Infection Research, Helmholtz Centre for Infection Research, Würzburg97080, Germany
- Faculty of Medicine, University of Würzburg, Würzburg97080, Germany
- Department of Biology, University of Toronto Mississauga, Mississauga, ONL5L 1C6Canada
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5
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Ghosh T, Jahangirnejad S, Chauvier A, Stringer AM, Korepanov AP, Côté JP, Wade JT, Lafontaine DA. Direct and indirect control of Rho-dependent transcription termination by the Escherichia coli lysC riboswitch. RNA (NEW YORK, N.Y.) 2024; 30:381-391. [PMID: 38253429 PMCID: PMC10946432 DOI: 10.1261/rna.079779.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 12/21/2023] [Indexed: 01/24/2024]
Abstract
Bacterial riboswitches are molecular structures that play a crucial role in controlling gene expression to maintain cellular balance. The Escherichia coli lysC riboswitch has been previously shown to regulate gene expression through translation initiation and mRNA decay. Recent research suggests that lysC gene expression is also influenced by Rho-dependent transcription termination. Through a series of in silico, in vitro, and in vivo experiments, we provide experimental evidence that the lysC riboswitch directly and indirectly modulates Rho transcription termination. Our study demonstrates that Rho-dependent transcription termination plays a significant role in the cotranscriptional regulation of lysC expression. Together with previous studies, our work suggests that lysC expression is governed by a lysine-sensing riboswitch that regulates translation initiation, transcription termination, and mRNA degradation. Notably, both Rho and RNase E target the same region of the RNA molecule, implying that RNase E may degrade Rho-terminated transcripts, providing a means to selectively eliminate these incomplete messenger RNAs. Overall, this study sheds light on the complex regulatory mechanisms used by bacterial riboswitches, emphasizing the role of transcription termination in the control of gene expression and mRNA stability.
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Affiliation(s)
- Tithi Ghosh
- Department of Biology, Faculty of Science, RNA Group, Université de Sherbrooke, Sherbrooke, Quebec, Canada J1K 2R1
| | - Shirin Jahangirnejad
- Department of Biology, Faculty of Science, RNA Group, Université de Sherbrooke, Sherbrooke, Quebec, Canada J1K 2R1
| | - Adrien Chauvier
- Department of Biology, Faculty of Science, RNA Group, Université de Sherbrooke, Sherbrooke, Quebec, Canada J1K 2R1
| | - Anne M Stringer
- Wadsworth Center, New York State Department of Health, Albany, New York 12208, USA
| | - Alexey P Korepanov
- Expression Génétique Microbienne, UMR8261 CNRS, Université Paris Cité, Institut de Biologie Physico-Chimique, 75005 Paris, France
| | - Jean Phillippe Côté
- Department of Biology, Faculty of Science, RNA Group, Université de Sherbrooke, Sherbrooke, Quebec, Canada J1K 2R1
| | - Joseph T Wade
- Wadsworth Center, New York State Department of Health, Albany, New York 12208, USA
- Department of Biomedical Sciences, University at Albany, Albany, New York 12201, USA
| | - Daniel A Lafontaine
- Department of Biology, Faculty of Science, RNA Group, Université de Sherbrooke, Sherbrooke, Quebec, Canada J1K 2R1
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6
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Gioacchino E, Vandelannoote K, Ruberto AA, Popovici J, Cantaert T. Unraveling the intricacies of host-pathogen interaction through single-cell genomics. Microbes Infect 2024:105313. [PMID: 38369008 DOI: 10.1016/j.micinf.2024.105313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 11/23/2023] [Accepted: 02/13/2024] [Indexed: 02/20/2024]
Abstract
Single-cell genomics provide researchers with tools to assess host-pathogen interactions at a resolution previously inaccessible. Transcriptome analysis, epigenome analysis, and immune profiling techniques allow for a better comprehension of the heterogeneity underlying both the host response and infectious agents. Here, we highlight technological advancements and data analysis workflows that increase our understanding of host-pathogen interactions at the single-cell level. We review various studies that have used these tools to better understand host-pathogen dynamics in a variety of infectious disease contexts, including viral, bacterial, and parasitic diseases. We conclude by discussing how single-cell genomics can advance our understanding of host-pathogen interactions.
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Affiliation(s)
- Emanuele Gioacchino
- Immunology Unit, Institut Pasteur du Cambodge, The Pasteur Network, Phnom Penh, Cambodia
| | - Koen Vandelannoote
- Bacterial Phylogenomics Group, Institut Pasteur du Cambodge, The Pasteur Network, Phnom Penh, Cambodia
| | - Anthony A Ruberto
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA; Institute of Bioinformatics, University of Georgia, Athens, GA, USA
| | - Jean Popovici
- Malaria Research Unit, Institut Pasteur du Cambodge, The Pasteur Network, Phnom Penh, Cambodia; Infectious Disease Epidemiology and Analytics, Institut Pasteur, Paris, France
| | - Tineke Cantaert
- Immunology Unit, Institut Pasteur du Cambodge, The Pasteur Network, Phnom Penh, Cambodia.
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7
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Contreras X, Depierre D, Akkawi C, Srbic M, Helsmoortel M, Nogaret M, LeHars M, Salifou K, Heurteau A, Cuvier O, Kiernan R. PAPγ associates with PAXT nuclear exosome to control the abundance of PROMPT ncRNAs. Nat Commun 2023; 14:6745. [PMID: 37875486 PMCID: PMC10598014 DOI: 10.1038/s41467-023-42620-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 10/17/2023] [Indexed: 10/26/2023] Open
Abstract
Pervasive transcription of the human genome generates an abundance of RNAs that must be processed and degraded. The nuclear RNA exosome is the main RNA degradation machinery in the nucleus. However, nuclear exosome must be recruited to its substrates by targeting complexes, such as NEXT or PAXT. By proteomic analysis, we identify additional subunits of PAXT, including many orthologs of MTREC found in S. pombe. In particular, we show that polyA polymerase gamma (PAPγ) associates with PAXT. Genome-wide mapping of the binding sites of ZFC3H1, RBM27 and PAPγ shows that PAXT is recruited to the TSS of hundreds of genes. Loss of ZFC3H1 abolishes recruitment of PAXT subunits including PAPγ to TSSs and concomitantly increases the abundance of PROMPTs at the same sites. Moreover, PAPγ, as well as MTR4 and ZFC3H1, is implicated in the polyadenylation of PROMPTs. Our results thus provide key insights into the direct targeting of PROMPT ncRNAs by PAXT at their genomic sites.
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Affiliation(s)
- Xavier Contreras
- CNRS-UMR 9002, Institute of Human Genetics (IGH)/University of Montpellier, Gene Regulation Lab, 34396, Montpellier, France
| | - David Depierre
- Center of Integrative Biology (CBI-CNRS), Molecular, Cellular and Developmental Biology (MCD Unit), University of Toulouse, 31000, Toulouse, France
| | - Charbel Akkawi
- CNRS-UMR 9002, Institute of Human Genetics (IGH)/University of Montpellier, Gene Regulation Lab, 34396, Montpellier, France
| | - Marina Srbic
- CNRS-UMR 9002, Institute of Human Genetics (IGH)/University of Montpellier, Gene Regulation Lab, 34396, Montpellier, France
| | - Marion Helsmoortel
- CNRS-UMR 9002, Institute of Human Genetics (IGH)/University of Montpellier, Gene Regulation Lab, 34396, Montpellier, France
| | - Maguelone Nogaret
- CNRS-UMR 9002, Institute of Human Genetics (IGH)/University of Montpellier, Gene Regulation Lab, 34396, Montpellier, France
| | - Matthieu LeHars
- CNRS-UMR 9002, Institute of Human Genetics (IGH)/University of Montpellier, Gene Regulation Lab, 34396, Montpellier, France
| | - Kader Salifou
- CNRS-UMR 9002, Institute of Human Genetics (IGH)/University of Montpellier, Gene Regulation Lab, 34396, Montpellier, France
| | - Alexandre Heurteau
- Center of Integrative Biology (CBI-CNRS), Molecular, Cellular and Developmental Biology (MCD Unit), University of Toulouse, 31000, Toulouse, France
| | - Olivier Cuvier
- Center of Integrative Biology (CBI-CNRS), Molecular, Cellular and Developmental Biology (MCD Unit), University of Toulouse, 31000, Toulouse, France
| | - Rosemary Kiernan
- CNRS-UMR 9002, Institute of Human Genetics (IGH)/University of Montpellier, Gene Regulation Lab, 34396, Montpellier, France.
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8
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Moretti J, Jia B, Hutchins Z, Roy S, Yip H, Wu J, Shan M, Jaffrey SR, Coers J, Blander JM. Caspase-11 interaction with NLRP3 potentiates the noncanonical activation of the NLRP3 inflammasome. Nat Immunol 2022; 23:705-717. [PMID: 35487985 PMCID: PMC9106893 DOI: 10.1038/s41590-022-01192-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 03/18/2022] [Indexed: 11/08/2022]
Abstract
Caspase-11 detection of intracellular lipopolysaccharide (LPS) from invasive Gram-negative bacteria mediates noncanonical activation of the NLRP3 inflammasome. While avirulent bacteria do not invade the cytosol, their presence in tissues necessitates clearance and immune system mobilization. Despite sharing LPS, only live avirulent Gram-negative bacteria activate the NLRP3 inflammasome. Here, we found that bacterial mRNA, which signals bacterial viability, was required alongside LPS for noncanonical activation of the NLRP3 inflammasome in macrophages. Concurrent detection of bacterial RNA by NLRP3 and binding of LPS by pro-caspase-11 mediated a pro-caspase-11-NLRP3 interaction before caspase-11 activation and inflammasome assembly. LPS binding to pro-caspase-11 augmented bacterial mRNA-dependent assembly of the NLRP3 inflammasome, while bacterial viability and an assembled NLRP3 inflammasome were necessary for activation of LPS-bound pro-caspase-11. Thus, the pro-caspase-11-NLRP3 interaction nucleated a scaffold for their interdependent activation explaining their functional reciprocal exclusivity. Our findings inform new vaccine adjuvant combinations and sepsis therapy.
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Affiliation(s)
- Julien Moretti
- Jill Roberts Institute for Research in Inflammatory Bowel Disease, Weill Cornell Medicine, Cornell University, New York, NY, USA
- Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Baosen Jia
- Jill Roberts Institute for Research in Inflammatory Bowel Disease, Weill Cornell Medicine, Cornell University, New York, NY, USA
- Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Zachary Hutchins
- Jill Roberts Institute for Research in Inflammatory Bowel Disease, Weill Cornell Medicine, Cornell University, New York, NY, USA
- Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medicine, Cornell University, New York, NY, USA
- Department of Microbiology and Immunology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Soumit Roy
- Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- 182 E 95th St., New York, NY, USA
| | - Hilary Yip
- Jill Roberts Institute for Research in Inflammatory Bowel Disease, Weill Cornell Medicine, Cornell University, New York, NY, USA
- Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Jiahui Wu
- Department of Pharmacology, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Meimei Shan
- Jill Roberts Institute for Research in Inflammatory Bowel Disease, Weill Cornell Medicine, Cornell University, New York, NY, USA
- Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medicine, Cornell University, New York, NY, USA
- Patch Biosciences, New York, NY, USA
| | - Samie R Jaffrey
- Department of Pharmacology, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Jörn Coers
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC, USA
- Department of Immunology, Duke University Medical Center, Durham, NC, USA
| | - J Magarian Blander
- Jill Roberts Institute for Research in Inflammatory Bowel Disease, Weill Cornell Medicine, Cornell University, New York, NY, USA.
- Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medicine, Cornell University, New York, NY, USA.
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, New York, NY, USA.
- Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, Cornell University, New York, NY, USA.
- Immunology and Microbial Pathogenesis Program, Weill Cornell Medicine Graduate School of Medical Sciences, New York, NY, USA.
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9
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Kiparaki M, Khan C, Folgado-Marco V, Chuen J, Moulos P, Baker NE. The transcription factor Xrp1 orchestrates both reduced translation and cell competition upon defective ribosome assembly or function. eLife 2022; 11:e71705. [PMID: 35179490 PMCID: PMC8933008 DOI: 10.7554/elife.71705] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Accepted: 02/09/2022] [Indexed: 11/26/2022] Open
Abstract
Ribosomal Protein (Rp) gene haploinsufficiency affects translation rate, can lead to protein aggregation, and causes cell elimination by competition with wild type cells in mosaic tissues. We find that the modest changes in ribosomal subunit levels observed were insufficient for these effects, which all depended on the AT-hook, bZip domain protein Xrp1. Xrp1 reduced global translation through PERK-dependent phosphorylation of eIF2α. eIF2α phosphorylation was itself sufficient to enable cell competition of otherwise wild type cells, but through Xrp1 expression, not as the downstream effector of Xrp1. Unexpectedly, many other defects reducing ribosome biogenesis or function (depletion of TAF1B, eIF2, eIF4G, eIF6, eEF2, eEF1α1, or eIF5A), also increased eIF2α phosphorylation and enabled cell competition. This was also through the Xrp1 expression that was induced in these depletions. In the absence of Xrp1, translation differences between cells were not themselves sufficient to trigger cell competition. Xrp1 is shown here to be a sequence-specific transcription factor that regulates transposable elements as well as single-copy genes. Thus, Xrp1 is the master regulator that triggers multiple consequences of ribosomal stresses and is the key instigator of cell competition.
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Affiliation(s)
- Marianthi Kiparaki
- Department of Genetics, Albert Einstein College of MedicineThe BronxUnited States
- Institute for Fundamental Biomedical Research, Biomedical Sciences Research Center "Alexander Fleming”VariGreece
| | - Chaitali Khan
- Department of Genetics, Albert Einstein College of MedicineThe BronxUnited States
| | | | - Jacky Chuen
- Department of Genetics, Albert Einstein College of MedicineThe BronxUnited States
| | - Panagiotis Moulos
- Institute for Fundamental Biomedical Research, Biomedical Sciences Research Center "Alexander Fleming”VariGreece
| | - Nicholas E Baker
- Department of Genetics, Albert Einstein College of MedicineThe BronxUnited States
- Department of Developmental and Molecular Biology, Albert Einstein College of MedicineThe BronxUnited States
- Department of Opthalmology and Visual Sciences, Albert Einstein College of MedicineThe BronxUnited States
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10
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NUDT2 initiates viral RNA degradation by removal of 5'-phosphates. Nat Commun 2021; 12:6918. [PMID: 34824277 PMCID: PMC8616924 DOI: 10.1038/s41467-021-27239-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Accepted: 11/08/2021] [Indexed: 12/22/2022] Open
Abstract
While viral replication processes are largely understood, comparably little is known on cellular mechanisms degrading viral RNA. Some viral RNAs bear a 5′-triphosphate (PPP-) group that impairs degradation by the canonical 5′-3′ degradation pathway. Here we show that the Nudix hydrolase 2 (NUDT2) trims viral PPP-RNA into monophosphorylated (P)-RNA, which serves as a substrate for the 5′-3′ exonuclease XRN1. NUDT2 removes 5′-phosphates from PPP-RNA in an RNA sequence- and overhang-independent manner and its ablation in cells increases growth of PPP-RNA viruses, suggesting an involvement in antiviral immunity. NUDT2 is highly homologous to bacterial RNA pyrophosphatase H (RppH), a protein involved in the metabolism of bacterial mRNA, which is 5′-tri- or diphosphorylated. Our results show a conserved function between bacterial RppH and mammalian NUDT2, indicating that the function may have adapted from a protein responsible for RNA turnover in bacteria into a protein involved in the immune defense in mammals. RNA of some viruses is protected from degradation by a 5′ triphosphate group. Here the authors identify nudix hydrolase 2 (NUDT2) as novel antiviral defense protein that dephosphorylates viral RNA and thereby enables its degradation.
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11
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Sauder AB, Kendall MM. A pathogen-specific sRNA influences enterohemorrhagic Escherichia coli fitness and virulence in part by direct interaction with the transcript encoding the ethanolamine utilization regulatory factor EutR. Nucleic Acids Res 2021; 49:10988-11004. [PMID: 34591974 PMCID: PMC8565329 DOI: 10.1093/nar/gkab863] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 09/09/2021] [Accepted: 09/14/2021] [Indexed: 01/07/2023] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) O157:H7 relies on sRNAs to coordinate expression of metabolic and virulence factors to colonize the host. Here, we focus on the sRNA, named MavR (metabolism and virulence regulator), that is conserved among pathogenic Enterobacteriaceae. MavR is constitutively expressed under in vitro conditions that promote EHEC virulence gene expression. Using MS2-affinity purification coupled with RNA sequencing, the eutR transcript was identified as a putative target of MavR. EutR is a transcription factor that promotes expression of genes required for ethanolamine metabolism as well as virulence factors important for host colonization. MavR binds to the eutR coding sequence to protect the eutR transcript from RNase E-mediated degradation. Ultimately, MavR promotes EutR expression and in turn ethanolamine utilization and ethanolamine-dependent growth. RNAseq analyses revealed that MavR also affected expression of genes important for other metabolic pathways, motility, oxidative stress and attaching and effacing lesion formation, which contribute to EHEC colonization of the gastrointestinal tract. In support of the idea that MavR-dependent gene expression affects fitness during infection, deletion of mavR resulted in significant (∼10- to 100-fold) attenuation in colonization of the mammalian intestine. Altogether, these studies reveal an important, extensive, and robust phenotype for a bacterial sRNA in host-pathogen interactions.
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Affiliation(s)
- Amber B Sauder
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Melissa M Kendall
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
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12
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Hui MP, Belasco JG. Multifaceted impact of a nucleoside monophosphate kinase on 5'-end-dependent mRNA degradation in bacteria. Nucleic Acids Res 2021; 49:11038-11049. [PMID: 34643703 PMCID: PMC8565310 DOI: 10.1093/nar/gkab884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 09/14/2021] [Accepted: 10/06/2021] [Indexed: 11/13/2022] Open
Abstract
A key pathway for mRNA degradation in bacterial cells begins with conversion of the initial 5'-terminal triphosphate to a monophosphate, a modification that renders transcripts more vulnerable to attack by ribonucleases whose affinity for monophosphorylated 5' ends potentiates their catalytic efficacy. In Escherichia coli, the only proteins known to be important for controlling degradation via this pathway are the RNA pyrophosphohydrolase RppH, its heteromeric partner DapF, and the 5'-monophosphate-assisted endonucleases RNase E and RNase G. We have now identified the metabolic enzyme cytidylate kinase as another protein that affects rates of 5'-end-dependent mRNA degradation in E. coli. It does so by utilizing two distinct mechanisms to influence the 5'-terminal phosphorylation state of RNA, each dependent on the catalytic activity of cytidylate kinase and not its mere presence in cells. First, this enzyme acts in conjunction with DapF to stimulate the conversion of 5' triphosphates to monophosphates by RppH. In addition, it suppresses the direct synthesis of monophosphorylated transcripts that begin with cytidine by reducing the cellular concentration of cytidine monophosphate, thereby disfavoring the 5'-terminal incorporation of this nucleotide by RNA polymerase during transcription initiation. Together, these findings suggest dual signaling pathways by which nucleotide metabolism can impact mRNA degradation in bacteria.
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Affiliation(s)
- Monica P Hui
- Skirball Institute of Biomolecular Medicine, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA.,Department of Microbiology, New York University School of Medicine, 430 E. 29th Street, New York, NY 10016, USA
| | - Joel G Belasco
- Skirball Institute of Biomolecular Medicine, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA.,Department of Microbiology, New York University School of Medicine, 430 E. 29th Street, New York, NY 10016, USA
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13
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Francis N, Laishram RS. Transgenesis of mammalian PABP reveals mRNA polyadenylation as a general stress response mechanism in bacteria. iScience 2021; 24:103119. [PMID: 34646982 PMCID: PMC8496165 DOI: 10.1016/j.isci.2021.103119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 04/23/2021] [Accepted: 09/09/2021] [Indexed: 12/01/2022] Open
Abstract
In eukaryotes, mRNA 3′-polyadenylation triggers poly(A) binding protein (PABP) recruitment and stabilization. In a stark contrast, polyadenylation marks mRNAs for degradation in bacteria. To study this difference, we trans-express the mammalian nuclear PABPN1 chromosomally and extra-chromosomally in Escherichia coli. Expression of PABPN1 but not the mutant PABPN1 stabilizes polyadenylated mRNAs and improves their half-lives. In the presence of PABPN1, 3′-exonuclease PNPase is not detected on PA-tailed mRNAs compromising the degradation. We show that PABPN1 trans-expression phenocopies pcnB (that encodes poly(A) polymerase, PAPI) mutation and regulates plasmid copy number. Genome-wide RNA-seq analysis shows a general up-regulation of polyadenylated mRNAs on PABPN1 expression, the largest subset of which are those involved in general stress response. However, major global stress regulators are unaffected on PABPN1 expression. Concomitantly, PABPN1 expression or pcnB mutation imparts cellular tolerance to multiple stresses. This study establishes mRNA 3′-polyadenylation as a general stress response mechanism in E. coli. Trans expression of mammalian PABPN1 stabilizes polyadenyated mRNAs in E. coli PABPN1 expression phenocopies pcnB mutation and regulates plasmid copy number 3′-polyadenylation acts as a general stress response mechanism in bacteria This study indicates an evolutionary significance of PABP in mRNA metabolism
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Affiliation(s)
- Nimmy Francis
- Cardiovascular and Diabetes Biology Group, Rajiv Gandhi Centre for Biotechnology, Thycaud Post, Poojappura, Trivandrum 695014, India.,Manipal Academy of Higher Education, Manipal 576104, India
| | - Rakesh S Laishram
- Cardiovascular and Diabetes Biology Group, Rajiv Gandhi Centre for Biotechnology, Thycaud Post, Poojappura, Trivandrum 695014, India
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14
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Hirayama T. PARN-like Proteins Regulate Gene Expression in Land Plant Mitochondria by Modulating mRNA Polyadenylation. Int J Mol Sci 2021; 22:ijms221910776. [PMID: 34639116 PMCID: PMC8509313 DOI: 10.3390/ijms221910776] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 09/21/2021] [Accepted: 10/02/2021] [Indexed: 11/20/2022] Open
Abstract
Mitochondria have their own double-stranded DNA genomes and systems to regulate transcription, mRNA processing, and translation. These systems differ from those operating in the host cell, and among eukaryotes. In recent decades, studies have revealed several plant-specific features of mitochondrial gene regulation. The polyadenylation status of mRNA is critical for its stability and translation in mitochondria. In this short review, I focus on recent advances in understanding the mechanisms regulating mRNA polyadenylation in plant mitochondria, including the role of poly(A)-specific ribonuclease-like proteins (PARNs). Accumulating evidence suggests that plant mitochondria have unique regulatory systems for mRNA poly(A) status and that PARNs play pivotal roles in these systems.
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Affiliation(s)
- Takashi Hirayama
- Institute of Plant Science and Resources, Okayama University, 2-20-1 Chuo, Kurahiki 710-0046, Okayama, Japan
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15
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Zhang Y, Kuster D, Schmidt T, Kirrmaier D, Nübel G, Ibberson D, Benes V, Hombauer H, Knop M, Jäschke A. Extensive 5'-surveillance guards against non-canonical NAD-caps of nuclear mRNAs in yeast. Nat Commun 2020; 11:5508. [PMID: 33139726 PMCID: PMC7606564 DOI: 10.1038/s41467-020-19326-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 09/24/2020] [Indexed: 12/16/2022] Open
Abstract
The ubiquitous redox coenzyme nicotinamide adenine dinucleotide (NAD) acts as a non-canonical cap structure on prokaryotic and eukaryotic ribonucleic acids. Here we find that in budding yeast, NAD-RNAs are abundant (>1400 species), short (<170 nt), and mostly correspond to mRNA 5′-ends. The modification percentage of transcripts is low (<5%). NAD incorporation occurs mainly during transcription initiation by RNA polymerase II, which uses distinct promoters with a YAAG core motif for this purpose. Most NAD-RNAs are 3′-truncated. At least three decapping enzymes, Rai1, Dxo1, and Npy1, guard against NAD-RNA at different cellular locations, targeting overlapping transcript populations. NAD-mRNAs are not translatable in vitro. Our work indicates that in budding yeast, most of the NAD incorporation into RNA seems to be disadvantageous to the cell, which has evolved a diverse surveillance machinery to prematurely terminate, decap and reject NAD-RNAs. NAD (nicotinamide adenine dinucleotide) acts as a non-canonical RNA cap structure in bacteria and eukaryotes. Here the authors demonstrate the whole landscape of budding yeast NAD-RNAs which are subject to diverse surveillance pathways, suggesting that NAD caps in budding yeast are mostly dysfunctional.
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Affiliation(s)
- Yaqing Zhang
- Institute of Pharmacy and Molecular Biotechnology (IPMB), Heidelberg University, 69120, Heidelberg, Germany
| | - David Kuster
- Institute of Pharmacy and Molecular Biotechnology (IPMB), Heidelberg University, 69120, Heidelberg, Germany
| | - Tobias Schmidt
- DNA Repair Mechanisms and Cancer, German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany
| | - Daniel Kirrmaier
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg University, 69120, Heidelberg, Germany.,Cell Morphogenesis and Signal Transduction, German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, 69120, Heidelberg, Germany
| | - Gabriele Nübel
- Institute of Pharmacy and Molecular Biotechnology (IPMB), Heidelberg University, 69120, Heidelberg, Germany
| | - David Ibberson
- Deep Sequencing Core Facility, CellNetworks, Heidelberg University, 69120, Heidelberg, Germany
| | - Vladimir Benes
- Genomics Core Facility, European Molecular Biology Laboratory (EMBL), 69117, Heidelberg, Germany
| | - Hans Hombauer
- DNA Repair Mechanisms and Cancer, German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany.,Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg University, 69120, Heidelberg, Germany
| | - Michael Knop
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg University, 69120, Heidelberg, Germany.,Cell Morphogenesis and Signal Transduction, German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, 69120, Heidelberg, Germany
| | - Andres Jäschke
- Institute of Pharmacy and Molecular Biotechnology (IPMB), Heidelberg University, 69120, Heidelberg, Germany.
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16
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Li J, Hou Y, Gu X, Yue L, Guo L, Li D, Dong X. A newly identified duplex RNA unwinding activity of archaeal RNase J depends on processive exoribonucleolysis coupled steric occlusion by its structural archaeal loops. RNA Biol 2020; 17:1480-1491. [PMID: 32552320 DOI: 10.1080/15476286.2020.1777379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
RNase J is a prokaryotic 5'-3' exo/endoribonuclease that functions in mRNA decay and rRNA maturation. Here, we report a novel duplex unwinding activity of mpy-RNase J, an archaeal RNase J from Methanolobus psychrophilus, which enables it to degrade duplex RNAs with hairpins up to 40 bp when linking a 5' single-stranded overhangs of ≥ 7 nt, corresponding to the RNA channel length. A 6-nt RNA-mpy-RNase J-S247A structure reveals the RNA-interacting residues and a steric barrier at the RNA channel entrance comprising two archaeal loops and two helices. Mutagenesis of the residues key to either exoribonucleolysis or RNA translocation diminished the duplex unwinding activity. Substitution of the residues in the steric barrier yielded stalled degradation intermediates at the duplex RNA regions. Thus, an exoribonucleolysis-driven and steric occlusion-based duplex unwinding mechanism was identified. The duplex unwinding activity confers mpy-RNase J the capability of degrading highly structured RNAs, including the bacterial REP RNA, and archaeal mRNAs, rRNAs, tRNAs, SRPs, RNase P and CD-box RNAs, providing an indicative of the potential key roles of mpy-RNase J in pleiotropic RNA metabolisms. Hydrolysis-coupled duplex unwinding activity was also detected in a bacterial RNase J, which may use a shared but slightly different unwinding mechanism from archaeal RNase Js, indicating that duplex unwinding is a common property of the prokaryotic RNase Js.
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Affiliation(s)
- Jie Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences , Beijing, PR China.,Colleges of Life Sciences, University of Chinese Academy of Sciences , Beijing, China
| | - Yanjie Hou
- Institute of Biophysics, Chinese Academy of Sciences , Beijing, PR China
| | - Xien Gu
- School of Basic Medical Sciences, Hubei University of Medicine , Shiyan, China
| | - Lei Yue
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences , Beijing, PR China.,Colleges of Life Sciences, University of Chinese Academy of Sciences , Beijing, China
| | - Lu Guo
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences , Beijing, PR China
| | - Defeng Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences , Beijing, PR China.,Colleges of Life Sciences, University of Chinese Academy of Sciences , Beijing, China
| | - Xiuzhu Dong
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences , Beijing, PR China.,Colleges of Life Sciences, University of Chinese Academy of Sciences , Beijing, China
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17
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Trinquier A, Durand S, Braun F, Condon C. Regulation of RNA processing and degradation in bacteria. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2020; 1863:194505. [PMID: 32061882 DOI: 10.1016/j.bbagrm.2020.194505] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 01/13/2020] [Accepted: 02/11/2020] [Indexed: 12/22/2022]
Abstract
Messenger RNA processing and decay is a key mechanism to control gene expression at the post-transcriptional level in response to ever-changing environmental conditions. In this review chapter, we discuss the main ribonucleases involved in these processes in bacteria, with a particular but non-exclusive emphasis on the two best-studied paradigms of Gram-negative and Gram-positive bacteria, E. coli and B. subtilis, respectively. We provide examples of how the activity and specificity of these enzymes can be modulated at the protein level, by co-factor binding and by post-translational modifications, and how they can be influenced by specific properties of their mRNA substrates, such as 5' protective 'caps', nucleotide modifications, secondary structures and translation. This article is part of a Special Issue entitled: RNA and gene control in bacteria edited by Dr. M. Guillier and F. Repoila.
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Affiliation(s)
- Aude Trinquier
- UMR8261 (CNRS, Université de Paris), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Sylvain Durand
- UMR8261 (CNRS, Université de Paris), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France.
| | - Frédérique Braun
- UMR8261 (CNRS, Université de Paris), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France.
| | - Ciarán Condon
- UMR8261 (CNRS, Université de Paris), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France.
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18
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Melior H, Li S, Madhugiri R, Stötzel M, Azarderakhsh S, Barth-Weber S, Baumgardt K, Ziebuhr J, Evguenieva-Hackenberg E. Transcription attenuation-derived small RNA rnTrpL regulates tryptophan biosynthesis gene expression in trans. Nucleic Acids Res 2020; 47:6396-6410. [PMID: 30993322 PMCID: PMC6614838 DOI: 10.1093/nar/gkz274] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 03/01/2019] [Accepted: 04/12/2019] [Indexed: 01/06/2023] Open
Abstract
Ribosome-mediated transcription attenuation is a basic posttranscriptional regulation mechanism in bacteria. Liberated attenuator RNAs arising in this process are generally considered nonfunctional. In Sinorhizobium meliloti, the tryptophan (Trp) biosynthesis genes are organized into three operons, trpE(G), ppiD-trpDC-moaC-moeA, and trpFBA-accD-folC, of which only the first one, trpE(G), contains a short ORF (trpL) in the 5′-UTR and is regulated by transcription attenuation. Under conditions of Trp sufficiency, transcription is terminated between trpL and trpE(G), and a small attenuator RNA, rnTrpL, is produced. Here, we show that rnTrpL base-pairs with trpD and destabilizes the polycistronic trpDC mRNA, indicating rnTrpL-mediated downregulation of the trpDC operon in trans. Although all three trp operons are regulated in response to Trp availability, only in the two operons trpE(G) and trpDC the Trp-mediated regulation is controlled by rnTrpL. Together, our data show that the trp attenuator coordinates trpE(G) and trpDC expression posttranscriptionally by two fundamentally different mechanisms: ribosome-mediated transcription attenuation in cis and base-pairing in trans. Also, we present evidence that rnTrpL-mediated regulation of trpDC genes expression in trans is conserved in Agrobacterium and Bradyrhizobium, suggesting that the small attenuator RNAs may have additional conserved functions in the control of bacterial gene expression.
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Affiliation(s)
- Hendrik Melior
- Institute of Microbiology and Molecular Biology, Justus Liebig University, Giessen, 35392, Germany
| | - Siqi Li
- Institute of Microbiology and Molecular Biology, Justus Liebig University, Giessen, 35392, Germany
| | - Ramakanth Madhugiri
- Institute of Medical Virology, Justus Liebig University, Giessen, 35392, Germany
| | - Maximilian Stötzel
- Institute of Microbiology and Molecular Biology, Justus Liebig University, Giessen, 35392, Germany
| | - Saina Azarderakhsh
- Institute of Microbiology and Molecular Biology, Justus Liebig University, Giessen, 35392, Germany
| | - Susanne Barth-Weber
- Institute of Microbiology and Molecular Biology, Justus Liebig University, Giessen, 35392, Germany
| | - Kathrin Baumgardt
- Institute of Microbiology and Molecular Biology, Justus Liebig University, Giessen, 35392, Germany
| | - John Ziebuhr
- Institute of Medical Virology, Justus Liebig University, Giessen, 35392, Germany
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19
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Zhang C, Too HP. Strategies for the Biosynthesis of Pharmaceuticals and Nutraceuticals in Microbes from Renewable Feedstock. Curr Med Chem 2020; 27:4613-4621. [PMID: 32048953 DOI: 10.2174/0929867327666200212121047] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 09/06/2018] [Accepted: 10/18/2018] [Indexed: 01/03/2023]
Abstract
BACKGROUNDS Abundant and renewable biomaterials serve as ideal substrates for the sustainable production of various chemicals, including natural products (e.g., pharmaceuticals and nutraceuticals). For decades, researchers have been focusing on how to engineer microorganisms and developing effective fermentation processes to overproduce these molecules from biomaterials. Despite many laboratory achievements, it remains a challenge to transform some of these into successful industrial applications. RESULTS Here, we review recent progress in strategies and applications in metabolic engineering for the production of natural products. Modular engineering methods, such as a multidimensional heuristic process markedly improve efficiencies in the optimization of long and complex biosynthetic pathways. Dynamic pathway regulation realizes autonomous adjustment and can redirect metabolic carbon fluxes to avoid the accumulation of toxic intermediate metabolites. Microbial co-cultivation bolsters the identification and overproduction of natural products by introducing competition or cooperation of different species. Efflux engineering is applied to reduce product toxicity or to overcome storage limitation and thus improves product titers and productivities. CONCLUSION Without dispute, many of the innovative methods and strategies developed are gradually catalyzing this transformation from the laboratory into the industry in the biosynthesis of natural products. Sometimes, it is necessary to combine two or more strategies to acquire additive or synergistic benefits. As such, we foresee a bright future of the biosynthesis of pharmaceuticals and nutraceuticals in microbes from renewable biomaterials.
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Affiliation(s)
- Congqiang Zhang
- Biotransformation Innovation Platform (BioTrans), Agency for Science, Technology and Research (A*STAR), Singapore
| | - Heng-Phon Too
- Biotransformation Innovation Platform (BioTrans), Agency for Science, Technology and Research (A*STAR), Singapore
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20
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Abstract
Bacteria participate in a wide diversity of symbiotic associations with eukaryotic hosts that require precise interactions for bacterial recognition and persistence. Most commonly, host-associated bacteria interfere with host gene expression to modulate the immune response to the infection. However, many of these bacteria also interfere with host cellular differentiation pathways to create a hospitable niche, resulting in the formation of novel cell types, tissues, and organs. In both of these situations, bacterial symbionts must interact with eukaryotic regulatory pathways. Here, we detail what is known about how bacterial symbionts, from pathogens to mutualists, control host cellular differentiation across the central dogma, from epigenetic chromatin modifications, to transcription and mRNA processing, to translation and protein modifications. We identify four main trends from this survey. First, mechanisms for controlling host gene expression appear to evolve from symbionts co-opting cross-talk between host signaling pathways. Second, symbiont regulatory capacity is constrained by the processes that drive reductive genome evolution in host-associated bacteria. Third, the regulatory mechanisms symbionts exhibit correlate with the cost/benefit nature of the association. And, fourth, symbiont mechanisms for interacting with host genetic regulatory elements are not bound by native bacterial capabilities. Using this knowledge, we explore how the ubiquitous intracellular Wolbachia symbiont of arthropods and nematodes may modulate host cellular differentiation to manipulate host reproduction. Our survey of the literature on how infection alters gene expression in Wolbachia and its hosts revealed that, despite their intermediate-sized genomes, different strains appear capable of a wide diversity of regulatory manipulations. Given this and Wolbachia's diversity of phenotypes and eukaryotic-like proteins, we expect that many symbiont-induced host differentiation mechanisms will be discovered in this system.
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Affiliation(s)
- Shelbi L Russell
- Department of Molecular Cell and Developmental Biology, University of California, Santa Cruz, CA, USA.
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21
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Chiaruttini C, Guillier M. On the role of mRNA secondary structure in bacterial translation. WILEY INTERDISCIPLINARY REVIEWS-RNA 2019; 11:e1579. [PMID: 31760691 DOI: 10.1002/wrna.1579] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 10/17/2019] [Accepted: 10/18/2019] [Indexed: 11/07/2022]
Abstract
Messenger RNA (mRNA) is no longer considered as a mere informational molecule whose sole function is to convey the genetic information specified by DNA to the ribosome. Beyond this primary function, mRNA also contains additional instructions that influence the way and the extent to which this message is translated by the ribosome into protein(s). Indeed, owing to its intrinsic propensity to quickly and dynamically fold and form higher order structures, mRNA exhibits a second layer of structural information specified by the sequence itself. Besides influencing transcription and mRNA stability, this additional information also affects translation, and more precisely the frequency of translation initiation, the choice of open reading frame by recoding, the elongation speed, and the folding of the nascent protein. Many studies in bacteria have shown that mRNA secondary structure participates to the rapid adaptation of these versatile organisms to changing environmental conditions by efficiently tuning translation in response to diverse signals, such as the presence of ligands, regulatory proteins, or small RNAs. This article is categorized under: Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs RNA Structure and Dynamics > Influence of RNA Structure in Biological Systems Translation > Translation Regulation.
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22
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Gao A, Vasilyev N, Luciano DJ, Levenson-Palmer R, Richards J, Marsiglia WM, Traaseth NJ, Belasco JG, Serganov A. Structural and kinetic insights into stimulation of RppH-dependent RNA degradation by the metabolic enzyme DapF. Nucleic Acids Res 2019; 46:6841-6856. [PMID: 29733359 PMCID: PMC6061855 DOI: 10.1093/nar/gky327] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 04/17/2018] [Indexed: 01/07/2023] Open
Abstract
Vitally important for controlling gene expression in eukaryotes and prokaryotes, the deprotection of mRNA 5′ termini is governed by enzymes whose activity is modulated by interactions with ancillary factors. In Escherichia coli, 5′-end-dependent mRNA degradation begins with the generation of monophosphorylated 5′ termini by the RNA pyrophosphohydrolase RppH, which can be stimulated by DapF, a diaminopimelate epimerase involved in amino acid and cell wall biosynthesis. We have determined crystal structures of RppH–DapF complexes and measured rates of RNA deprotection. These studies show that DapF potentiates RppH activity in two ways, depending on the nature of the substrate. Its stimulatory effect on the reactivity of diphosphorylated RNAs, the predominant natural substrates of RppH, requires a substrate long enough to reach DapF in the complex, while the enhanced reactivity of triphosphorylated RNAs appears to involve DapF-induced changes in RppH itself and likewise increases with substrate length. This study provides a basis for understanding the intricate relationship between cellular metabolism and mRNA decay and reveals striking parallels with the stimulation of decapping activity in eukaryotes.
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Affiliation(s)
- Ang Gao
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, 550 First Avenue, New York, NY 10016, USA
| | - Nikita Vasilyev
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, 550 First Avenue, New York, NY 10016, USA
| | - Daniel J Luciano
- Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA.,Department of Microbiology, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA
| | - Rose Levenson-Palmer
- Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA.,Department of Microbiology, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA
| | - Jamie Richards
- Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA.,Department of Microbiology, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA
| | - William M Marsiglia
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY 10003, USA
| | - Nathaniel J Traaseth
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY 10003, USA
| | - Joel G Belasco
- Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA.,Department of Microbiology, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA
| | - Alexander Serganov
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, 550 First Avenue, New York, NY 10016, USA
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23
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Weihmann R, Domröse A, Drepper T, Jaeger KE, Loeschcke A. Protocols for yTREX/Tn5-based gene cluster expression in Pseudomonas putida. Microb Biotechnol 2019; 13:250-262. [PMID: 31162833 PMCID: PMC6922528 DOI: 10.1111/1751-7915.13402] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 02/25/2019] [Accepted: 03/08/2019] [Indexed: 11/30/2022] Open
Abstract
Bacterial gene clusters, which represent a genetic treasure trove for secondary metabolite pathways, often need to be activated in a heterologous host to access the valuable biosynthetic products. We provide here a detailed protocol for the application of the yTREX ‘gene cluster transplantation tool’: Via yeast recombinational cloning, a gene cluster of interest can be cloned in the yTREX vector, which enables the robust conjugational transfer of the gene cluster to bacteria like Pseudomonas putida, and their subsequent transposon Tn5‐based insertion into the host chromosome. Depending on the gene cluster architecture and chromosomal insertion site, the respective pathway genes can be transcribed effectively from a chromosomal promoter, thereby enabling the biosynthesis of a natural product. We describe workflows for the design of a gene cluster expression cassette, cloning of the cassette in the yTREX vector by yeast recombineering, and subsequent transfer and expression in P. putida. As an example for yTREX‐based transplantation of a natural product biosynthesis, we provide details on the cloning and activation of the phenazine‐1‐carboxylic acid biosynthetic genes from Pseudomonas aeruginosa in P. putidaKT2440 as well as the use of β‐galactosidase‐encoding lacZ as a reporter of production levels.
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Affiliation(s)
- Robin Weihmann
- Institute of Molecular Enzyme Technology, Heinrich-Heine-University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
| | - Andreas Domröse
- Institute of Medical Microbiology and Hospital Hygiene, Heinrich-Heine-University, Düsseldorf, Germany
| | - Thomas Drepper
- Institute of Molecular Enzyme Technology, Heinrich-Heine-University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
| | - Karl-Erich Jaeger
- Institute of Molecular Enzyme Technology, Heinrich-Heine-University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
| | - Anita Loeschcke
- Institute of Molecular Enzyme Technology, Heinrich-Heine-University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
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24
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Pseudomonas putida rDNA is a favored site for the expression of biosynthetic genes. Sci Rep 2019; 9:7028. [PMID: 31065014 PMCID: PMC6505042 DOI: 10.1038/s41598-019-43405-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 04/24/2019] [Indexed: 11/23/2022] Open
Abstract
Since high-value bacterial secondary metabolites, including antibiotics, are often naturally produced in only low amounts, their efficient biosynthesis typically requires the transfer of entire metabolic pathways into suitable bacterial hosts like Pseudomonas putida. Stable maintenance and sufficient expression of heterologous pathway-encoding genes in host microbes, however, still remain key challenges. In this study, the 21 kb prodigiosin gene cluster from Serratia marcescens was used as a reporter to identify genomic sites in P. putida KT2440 especially suitable for maintenance and expression of pathway genes. After generation of a strain library by random Tn5 transposon-based chromosomal integration of the cluster, 50 strains exhibited strong prodigiosin production. Remarkably, chromosomal integration sites were exclusively identified in the seven rRNA-encoding rrn operons of P. putida. We could further demonstrate that prodigiosin production was mainly dependent on (i) the individual rrn operon where the gene cluster was inserted as well as (ii) the distance between the rrn promoter and the inserted prodigiosin biosynthetic genes. In addition, the recombinant strains showed high stability upon subculturing for many generations. Consequently, our findings demonstrate the general applicability of rDNA loci as chromosomal integration sites for gene cluster expression and recombinant pathway implementation in P. putida KT2440.
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25
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Richards J, Belasco JG. Obstacles to Scanning by RNase E Govern Bacterial mRNA Lifetimes by Hindering Access to Distal Cleavage Sites. Mol Cell 2019; 74:284-295.e5. [PMID: 30852060 DOI: 10.1016/j.molcel.2019.01.044] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 12/11/2018] [Accepted: 01/29/2019] [Indexed: 12/27/2022]
Abstract
The diversity of mRNA lifetimes in bacterial cells is difficult to reconcile with the relaxed cleavage site specificity of RNase E, the endonuclease most important for governing mRNA degradation. This enzyme has generally been thought to locate cleavage sites by searching freely in three dimensions. However, our results now show that its access to such sites in 5'-monophosphorylated RNA is hindered by obstacles-such as bound proteins or ribosomes or coaxial small RNA (sRNA) base pairing-that disrupt the path from the 5' end to those sites and prolong mRNA lifetimes. These findings suggest that RNase E searches for cleavage sites by scanning linearly from the 5'-terminal monophosphate along single-stranded regions of RNA and that its progress is impeded by structural discontinuities encountered along the way. This discovery has major implications for gene regulation in bacteria and suggests a general mechanism by which other prokaryotic and eukaryotic regulatory proteins can be controlled.
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Affiliation(s)
- Jamie Richards
- Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA; Department of Microbiology, New York University School of Medicine, 430 E. 29th Street, New York, NY 10016, USA
| | - Joel G Belasco
- Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA; Department of Microbiology, New York University School of Medicine, 430 E. 29th Street, New York, NY 10016, USA.
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26
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Vasilyev N, Gao A, Serganov A. Noncanonical features and modifications on the 5'-end of bacterial sRNAs and mRNAs. WILEY INTERDISCIPLINARY REVIEWS. RNA 2019; 10:e1509. [PMID: 30276982 PMCID: PMC6657780 DOI: 10.1002/wrna.1509] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 09/05/2018] [Accepted: 09/17/2018] [Indexed: 12/20/2022]
Abstract
Although many eukaryotic transcripts contain cap structures, it has been long thought that bacterial RNAs do not carry any special modifications on their 5'-ends. In bacteria, primary transcripts are produced by transcription initiated with a nucleoside triphosphate and are therefore triphosphorylated on 5'-ends. Some transcripts are then processed by nucleases that yield monophosphorylated RNAs for specific cellular activities. Many primary transcripts are also converted to monophosphorylated species by removal of the terminal pyrophosphate for 5'-end-dependent degradation. Recent studies surprisingly revealed an expanded repertoire of chemical groups on 5'-ends of bacterial RNAs. In addition to mono- and triphosphorylated moieties, some mRNAs and sRNAs contain cap-like structures and diphosphates on their 5'-ends. Although incorporation and removal of these groups have become better understood in recent years, the physiological significance of these modifications remain obscure. This review highlights recent studies aimed at identification and elucidation of novel modifications on the 5'-ends of bacterial RNAs and discusses possible physiological applications of the modified RNAs. This article is categorized under: RNA Turnover and Surveillance > Regulation of RNA Stability RNA Structure and Dynamics > RNA Structure, Dynamics, and Chemistry RNA Processing > Capping and 5' End Modifications.
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Affiliation(s)
- Nikita Vasilyev
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, 550 First Avenue, New York, NY 10016, USA
| | - Ang Gao
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, 550 First Avenue, New York, NY 10016, USA
| | - Alexander Serganov
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, 550 First Avenue, New York, NY 10016, USA
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27
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Cholet F, Ijaz UZ, Smith CJ. Differential ratio amplicons (R amp ) for the evaluation of RNA integrity extracted from complex environmental samples. Environ Microbiol 2019; 21:827-844. [PMID: 30585386 PMCID: PMC6392129 DOI: 10.1111/1462-2920.14516] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 12/07/2018] [Accepted: 12/20/2018] [Indexed: 12/31/2022]
Abstract
Reliability and reproducibility of transcriptomics‐based studies are dependent on RNA integrity. In microbial ecology, microfluidics‐based techniques, such as the Ribosomal Integrity Number (RIN), targeting rRNA are currently the only approaches to evaluate RNA integrity. However, the relationship between rRNA and mRNA integrity is unknown. Here, we present an integrity index, the Ratio Amplicon, Ramp, adapted from human clinical studies, to directly monitor mRNA integrity from complex environmental samples. We show, in a suite of experimental degradations of RNA extracted from sediment, that while the RIN generally reflected the degradation status of RNA the Ramp mapped mRNA degradation better. Furthermore, we examined the effect of degradation on transcript community structure by amplicon sequencing of 16S rRNA, amoA and glnA transcripts. We successfully sequenced transcripts for all three targets even from highly‐degraded RNA samples. While RNA degradation changed the community structure of the mRNA profiles, no changes were observed for the 16S rRNA transcript profiles. Since both RT‐Q‐PCR and sequencing results were obtained, even from highly degraded samples, we strongly recommend evaluating RNA integrity prior to downstream processing to ensure meaningful results. For this, both the RIN and Ramp are useful, with the Ramp better evaluating mRNA integrity in this study.
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Affiliation(s)
- Fabien Cholet
- Infrastructure and Environment Research Division, School of Engineering, University of Glasgow, Glasgow, G12 8LT, UK
| | - Umer Z Ijaz
- Infrastructure and Environment Research Division, School of Engineering, University of Glasgow, Glasgow, G12 8LT, UK
| | - Cindy J Smith
- Infrastructure and Environment Research Division, School of Engineering, University of Glasgow, Glasgow, G12 8LT, UK
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28
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Green CA, Kamble NS, Court EK, Bryant OJ, Hicks MG, Lennon C, Fraser GM, Wright PC, Stafford GP. Engineering the flagellar type III secretion system: improving capacity for secretion of recombinant protein. Microb Cell Fact 2019; 18:10. [PMID: 30657054 PMCID: PMC6337784 DOI: 10.1186/s12934-019-1058-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 01/08/2019] [Indexed: 08/26/2023] Open
Abstract
BACKGROUND Many valuable biopharmaceutical and biotechnological proteins have been produced in Escherichia coli, however these proteins are almost exclusively localised in the cytoplasm or periplasm. This presents challenges for purification, i.e. the removal of contaminating cellular constituents. One solution is secretion directly into the surrounding media, which we achieved via the 'hijack' of the flagellar type III secretion system (FT3SS). Ordinarily flagellar subunits are exported through the centre of the growing flagellum, before assembly at the tip. However, we exploit the fact that in the absence of certain flagellar components (e.g. cap proteins), monomeric flagellar proteins are secreted into the supernatant. RESULTS We report the creation and iterative improvement of an E. coli strain, by means of a modified FT3SS and a modular plasmid system, for secretion of exemplar proteins. We show that removal of the flagellin and HAP proteins (FliC and FlgKL) resulted in an optimal prototype. We next developed a high-throughput enzymatic secretion assay based on cutinase. This indicated that removal of the flagellar motor proteins, motAB (to reduce metabolic burden) and protein degradation machinery, clpX (to boost FT3SS levels intracellularly), result in high capacity secretion. We also show that a secretion construct comprising the 5'UTR and first 47 amino acidsof FliC from E. coli (but no 3'UTR) achieved the highest levels of secretion. Upon combination, we show a 24-fold improvement in secretion of a heterologous (cutinase) enzyme over the original strain. This improved strain could export a range of pharmaceutically relevant heterologous proteins [hGH, TrxA, ScFv (CH2)], achieving secreted yields of up to 0.29 mg L-1, in low cell density culture. CONCLUSIONS We have engineered an E. coli which secretes a range of recombinant proteins, through the FT3SS, to the extracellular media. With further developments, including cell culture process strategies, we envision further improvement to the secreted titre of recombinant protein, with the potential application for protein production for biotechnological purposes.
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Affiliation(s)
- Charlotte A Green
- Integrated BioSciences, School of Clinical Dentistry, University of Sheffield, Sheffield, S10 2TA, UK.,Sustainable Process Technologies, Chemical and Environmental Engineering, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Nitin S Kamble
- Integrated BioSciences, School of Clinical Dentistry, University of Sheffield, Sheffield, S10 2TA, UK
| | - Elizabeth K Court
- Integrated BioSciences, School of Clinical Dentistry, University of Sheffield, Sheffield, S10 2TA, UK
| | - Owain J Bryant
- Department of Pathology, University of Cambridge, Cambridge, CB2 1QP, UK
| | - Matthew G Hicks
- Integrated BioSciences, School of Clinical Dentistry, University of Sheffield, Sheffield, S10 2TA, UK
| | - Christopher Lennon
- FUJIFILM Diosynth Biotechnologies, Belasis Avenue, Stockton-on-Tees, Billingham, TS23 1LH, UK
| | - Gillian M Fraser
- Department of Pathology, University of Cambridge, Cambridge, CB2 1QP, UK
| | - Phillip C Wright
- School of Engineering, The Faculty of Science, Agriculture and Engineering, Newcastle University, Newcastle, NE1 7RU, UK
| | - Graham P Stafford
- Integrated BioSciences, School of Clinical Dentistry, University of Sheffield, Sheffield, S10 2TA, UK.
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29
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Gill EE, Chan LS, Winsor GL, Dobson N, Lo R, Ho Sui SJ, Dhillon BK, Taylor PK, Shrestha R, Spencer C, Hancock REW, Unrau PJ, Brinkman FSL. High-throughput detection of RNA processing in bacteria. BMC Genomics 2018; 19:223. [PMID: 29587634 PMCID: PMC5870498 DOI: 10.1186/s12864-018-4538-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 02/12/2018] [Indexed: 01/19/2023] Open
Abstract
Background Understanding the RNA processing of an organism’s transcriptome is an essential but challenging step in understanding its biology. Here we investigate with unprecedented detail the transcriptome of Pseudomonas aeruginosa PAO1, a medically important and innately multi-drug resistant bacterium. We systematically mapped RNA cleavage and dephosphorylation sites that result in 5′-monophosphate terminated RNA (pRNA) using monophosphate RNA-Seq (pRNA-Seq). Transcriptional start sites (TSS) were also mapped using differential RNA-Seq (dRNA-Seq) and both datasets were compared to conventional RNA-Seq performed in a variety of growth conditions. Results The pRNA-Seq library revealed known tRNA, rRNA and transfer-messenger RNA (tmRNA) processing sites, together with previously uncharacterized RNA cleavage events that were found disproportionately near the 5′ ends of transcripts associated with basic bacterial functions such as oxidative phosphorylation and purine metabolism. The majority (97%) of the processed mRNAs were cleaved at precise codon positions within defined sequence motifs indicative of distinct endonucleolytic activities. The most abundant of these motifs corresponded closely to an E. coli RNase E site previously established in vitro. Using the dRNA-Seq library, we performed an operon analysis and predicted 3159 potential TSS. A correlation analysis uncovered 105 antiparallel pairs of TSS that were separated by 18 bp from each other and were centered on single palindromic TAT(A/T)ATA motifs (likely − 10 promoter elements), suggesting that, consistent with previous in vitro experimentation, these sites can initiate transcription bi-directionally and may thus provide a novel form of transcriptional regulation. TSS and RNA-Seq analysis allowed us to confirm expression of small non-coding RNAs (ncRNAs), many of which are differentially expressed in swarming and biofilm formation conditions. Conclusions This study uses pRNA-Seq, a method that provides a genome-wide survey of RNA processing, to study the bacterium Pseudomonas aeruginosa and discover extensive transcript processing not previously appreciated. We have also gained novel insight into RNA maturation and turnover as well as a potential novel form of transcription regulation. NOTE: All sequence data has been submitted to the NCBI sequence read archive. Accession numbers are as follows: [NCBI sequence read archive: SRX156386, SRX157659, SRX157660, SRX157661, SRX157683 and SRX158075]. The sequence data is viewable using Jbrowse on www.pseudomonas.com. Electronic supplementary material The online version of this article (10.1186/s12864-018-4538-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Erin E Gill
- Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Luisa S Chan
- Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Geoffrey L Winsor
- Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Neil Dobson
- Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Raymond Lo
- Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Shannan J Ho Sui
- Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Bhavjinder K Dhillon
- Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Patrick K Taylor
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Raunak Shrestha
- Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Cory Spencer
- Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Robert E W Hancock
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, BC, Canada
| | - Peter J Unrau
- Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada.
| | - Fiona S L Brinkman
- Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada.
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30
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Rath EC, Pitman S, Cho KH, Bai Y. Identification of streptococcal small RNAs that are putative targets of RNase III through bioinformatics analysis of RNA sequencing data. BMC Bioinformatics 2017; 18:540. [PMID: 29297355 PMCID: PMC5751559 DOI: 10.1186/s12859-017-1897-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Background Small noncoding regulatory RNAs (sRNAs) are post-transcriptional regulators, regulating mRNAs, proteins, and DNA in bacteria. One class of sRNAs, trans-acting sRNAs, are the most abundant sRNAs transcribed from the intergenic regions (IGRs) of the bacterial genome. In Streptococcus pyogenes, a common and potentially deadly pathogen, many sRNAs have been identified, but only a few have been studied. The goal of this study is to identify trans-acting sRNAs that can be substrates of RNase III. The endoribonuclease RNase III cleaves double stranded RNAs, which can be formed during the interaction between an sRNA and target mRNAs. Results For this study, we created an RNase III null mutant of Streptococcus pyogenes and its RNA sequencing (RNA-Seq) data were analyzed and compared to that of the wild-type. First, we developed a custom script that can detect intergenic regions of the S. pyogenes genome. A differential expression analysis with Cufflinks and Stringtie was then performed to identify the intergenic regions whose expression was influenced by the RNase III gene deletion. Conclusion This analysis yielded 12 differentially expressed regions with >|2| fold change and p ≤ 0.05. Using Artemis and Bamview genome viewers, these regions were visually verified leaving 6 putative sRNAs. This study not only expanded our knowledge on novel sRNAs but would also give us new insight into sRNA degradation.
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Affiliation(s)
- Ethan C Rath
- Department of Biology, Indiana State University, Terre Haute, IN, 47809, USA
| | - Stephanie Pitman
- Department of Biology, Indiana State University, Terre Haute, IN, 47809, USA
| | - Kyu Hong Cho
- Department of Biology, Indiana State University, Terre Haute, IN, 47809, USA.
| | - Yongsheng Bai
- Department of Biology, Indiana State University, Terre Haute, IN, 47809, USA. .,The Center for Genomic Advocacy, Indiana State University, Terre Haute, IN, 47809, USA.
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31
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Gauernack AS, Lassek C, Hou L, Dzieciolowski J, Evguenieva-Hackenberg E, Klug G. Nop5 interacts with the archaeal RNA exosome. FEBS Lett 2017; 591:4039-4048. [PMID: 29159940 DOI: 10.1002/1873-3468.12915] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 11/01/2017] [Accepted: 11/08/2017] [Indexed: 01/02/2023]
Abstract
The archaeal exosome, a protein complex responsible for phosphorolytic degradation and tailing of RNA, has an RNA-binding platform containing Rrp4, Csl4, and DnaG. Aiming to detect novel interaction partners of the exosome, we copurified Nop5, which is a part of an rRNA methylating ribonucleoprotein complex, with the exosome of Sulfolobus solfataricus grown to a late stationary phase. We demonstrated the capability of Nop5 to bind to the exosome with a homotrimeric Rrp4-cap and to increase the proportion of polyadenylated RNAin vitro, suggesting that Nop5 is a dual-function protein. Since tailing of RNA probably serves to enhance RNA degradation, association of Nop5 with the archaeal exosome in the stationary phase may enhance tailing and degradation of RNA as survival strategy.
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Affiliation(s)
- A Susann Gauernack
- Institute for Microbiology and Molecular Biology, Justus-Liebig-University Giessen, Germany
| | - Christian Lassek
- Institute for Microbiology and Molecular Biology, Justus-Liebig-University Giessen, Germany
| | - Linlin Hou
- Institute for Microbiology and Molecular Biology, Justus-Liebig-University Giessen, Germany
| | - Julia Dzieciolowski
- Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University Giessen, Germany
| | | | - Gabriele Klug
- Institute for Microbiology and Molecular Biology, Justus-Liebig-University Giessen, Germany
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32
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Chao Y, Li L, Girodat D, Förstner KU, Said N, Corcoran C, Śmiga M, Papenfort K, Reinhardt R, Wieden HJ, Luisi BF, Vogel J. In Vivo Cleavage Map Illuminates the Central Role of RNase E in Coding and Non-coding RNA Pathways. Mol Cell 2017; 65:39-51. [PMID: 28061332 PMCID: PMC5222698 DOI: 10.1016/j.molcel.2016.11.002] [Citation(s) in RCA: 180] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 09/26/2016] [Accepted: 10/31/2016] [Indexed: 01/21/2023]
Abstract
Understanding RNA processing and turnover requires knowledge of cleavages by major endoribonucleases within a living cell. We have employed TIER-seq (transiently inactivating an endoribonuclease followed by RNA-seq) to profile cleavage products of the essential endoribonuclease RNase E in Salmonella enterica. A dominating cleavage signature is the location of a uridine two nucleotides downstream in a single-stranded segment, which we rationalize structurally as a key recognition determinant that may favor RNase E catalysis. Our results suggest a prominent biogenesis pathway for bacterial regulatory small RNAs whereby RNase E acts together with the RNA chaperone Hfq to liberate stable 3' fragments from various precursor RNAs. Recapitulating this process in vitro, Hfq guides RNase E cleavage of a representative small-RNA precursor for interaction with a mRNA target. In vivo, the processing is required for target regulation. Our findings reveal a general maturation mechanism for a major class of post-transcriptional regulators.
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Affiliation(s)
- Yanjie Chao
- Institute of Molecular Infection Biology, University of Würzburg, 97080 Würzburg, Germany
| | - Lei Li
- Institute of Molecular Infection Biology, University of Würzburg, 97080 Würzburg, Germany; Core Unit Systems Medicine, University of Würzburg, 97080 Würzburg, Germany
| | - Dylan Girodat
- Alberta RNA Research and Training Institute, Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, Alberta T1K 3M4, Canada
| | - Konrad U Förstner
- Institute of Molecular Infection Biology, University of Würzburg, 97080 Würzburg, Germany; Core Unit Systems Medicine, University of Würzburg, 97080 Würzburg, Germany
| | - Nelly Said
- Laboratory of Structural Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
| | - Colin Corcoran
- Institute of Molecular Infection Biology, University of Würzburg, 97080 Würzburg, Germany
| | - Michał Śmiga
- Institute of Molecular Infection Biology, University of Würzburg, 97080 Würzburg, Germany
| | - Kai Papenfort
- Institute of Molecular Infection Biology, University of Würzburg, 97080 Würzburg, Germany; Department of Biology I, Microbiology, Ludwig-Maximilians-Universität Munich, 82152 Martinsried, Germany
| | - Richard Reinhardt
- Max Planck Genome Centre Cologne, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany
| | - Hans-Joachim Wieden
- Alberta RNA Research and Training Institute, Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, Alberta T1K 3M4, Canada
| | - Ben F Luisi
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, UK
| | - Jörg Vogel
- Institute of Molecular Infection Biology, University of Würzburg, 97080 Würzburg, Germany; Helmholtz Institute for RNA-based Infection Research (HIRI), 97080 Würzburg, Germany.
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33
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Zheng X, Feng N, Li D, Dong X, Li J. New molecular insights into an archaeal RNase J reveal a conserved processive exoribonucleolysis mechanism of the RNase J family. Mol Microbiol 2017; 106:351-366. [PMID: 28795788 DOI: 10.1111/mmi.13769] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2017] [Revised: 08/02/2017] [Accepted: 08/07/2017] [Indexed: 11/26/2022]
Abstract
RNase J, a prokaryotic 5'-3' exo/endoribonuclease, contributes to mRNA decay, rRNA maturation and post-transcriptional regulation. Yet the processive-exoribonucleolysis mechanism remains obscure. Here, we solved the first RNA-free and RNA-bound structures of an archaeal RNase J, and through intensive biochemical studies provided detailed mechanistic insights into the catalysis and processivity. Distinct dimerization/tetramerization patterns were observed for archaeal and bacterial RNase Js, and unique archaeal Loops I and II were found involved in RNA interaction. A hydrogen-bond-network was identified for the first time that assists catalysis by facilitating efficient proton transfer in the catalytic center. A conserved 5'-monophosphate-binding pocket that coordinates the RNA 5'-end ensures the 5'-monophosphate preferential exoribonucleolysis. To achieve exoribonucleolytic processivity, the 5'-monophosphate-binding pocket and nucleotide +4 binding site anchor RNA within the catalytic track; the 5'-capping residue Leu37 of the sandwich pocket coupled with the 5'-monophosphate-binding pocket are dedicated to translocating and controlling the RNA orientation for each exoribonucleolytic cycle. The processive-exoribonucleolysis mechanism was verified as conserved in bacterial RNase J and also exposes striking parallels with the non-homologous eukaryotic 5'-3' exoribonuclease, Xrn1. The findings in this work shed light on not only the molecular mechanism of the RNase J family, but also the evolutionary convergence of divergent exoribonucleases.
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Affiliation(s)
- Xin Zheng
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No.1 Beichen West Road, Chaoyang District, Beijing 100101, China.,University of Chinese Academy of Sciences, No.19A Yuquan Road, Shijingshan District, Beijing 100049, China.,Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, 19B YuquanLu, Shijingshan District, Beijing 100049, China
| | - Na Feng
- University of Chinese Academy of Sciences, No.19A Yuquan Road, Shijingshan District, Beijing 100049, China.,National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China
| | - Defeng Li
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China
| | - Xiuzhu Dong
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No.1 Beichen West Road, Chaoyang District, Beijing 100101, China
| | - Jie Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No.1 Beichen West Road, Chaoyang District, Beijing 100101, China
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Prasse D, Förstner KU, Jäger D, Backofen R, Schmitz RA. sRNA 154 a newly identified regulator of nitrogen fixation in Methanosarcina mazei strain Gö1. RNA Biol 2017; 14:1544-1558. [PMID: 28296572 DOI: 10.1080/15476286.2017.1306170] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Trans-encoded sRNA154 is exclusively expressed under nitrogen (N)-deficiency in Methanosarcina mazei strain Gö1. The sRNA154 deletion strain showed a significant decrease in growth under N-limitation, pointing toward a regulatory role of sRNA154 in N-metabolism. Aiming to elucidate its regulatory function we characterized sRNA154 by means of biochemical and genetic approaches. 24 homologs of sRNA154 were identified in recently reported draft genomes of Methanosarcina strains, demonstrating high conservation in sequence and predicted secondary structure with two highly conserved single stranded loops. Transcriptome studies of sRNA154 deletion mutants by an RNA-seq approach uncovered nifH- and nrpA-mRNA, encoding the α-subunit of nitrogenase and the transcriptional activator of the nitrogen fixation (nif)-operon, as potential targets besides other components of the N-metabolism. Furthermore, results obtained from stability, complementation and western blot analysis, as well as in silico target predictions combined with electrophoretic mobility shift-assays, argue for a stabilizing effect of sRNA154 on the polycistronic nif-mRNA and nrpA-mRNA by binding with both loops. Further identified N-related targets were studied, which demonstrates that translation initiation of glnA2-mRNA, encoding glutamine synthetase2, appears to be affected by sRNA154 masking the ribosome binding site, whereas glnA1-mRNA appears to be stabilized by sRNA154. Overall, we propose that sRNA154 has a crucial regulatory role in N-metabolism in M. mazei by stabilizing the polycistronic mRNA encoding nitrogenase and glnA1-mRNA, as well as allowing a feed forward regulation of nif-gene expression by stabilizing nrpA-mRNA. Consequently, sRNA154 represents the first archaeal sRNA, for which a positive posttranscriptional regulation is demonstrated as well as inhibition of translation initiation.
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Affiliation(s)
- Daniela Prasse
- a Institut für Allgemeine Mikrobiologie, Christian-Albrechts-Universität zu Kiel , Am Botanischen Garten 1-9, Kiel , Germany
| | - Konrad U Förstner
- b Zentrum für Infektionsforschung , Universität Würzburg , Josef Schneider-Str. 2/ Bau D15, Würzburg
| | - Dominik Jäger
- a Institut für Allgemeine Mikrobiologie, Christian-Albrechts-Universität zu Kiel , Am Botanischen Garten 1-9, Kiel , Germany
| | - Rolf Backofen
- c Institut für Informatik, Albert-Ludwigs-Universität zu Freiburg , Georges-Koehler-Allee, Freiburg , Germany
| | - Ruth A Schmitz
- a Institut für Allgemeine Mikrobiologie, Christian-Albrechts-Universität zu Kiel , Am Botanischen Garten 1-9, Kiel , Germany
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Baumgardt K, Melior H, Madhugiri R, Thalmann S, Schikora A, McIntosh M, Becker A, Evguenieva-Hackenberg E. RNase E and RNase J are needed for S-adenosylmethionine homeostasis in Sinorhizobium meliloti. MICROBIOLOGY-SGM 2017; 163:570-583. [PMID: 28141492 DOI: 10.1099/mic.0.000442] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The ribonucleases (RNases) E and J play major roles in E. coli and Bacillus subtilis, respectively, and co-exist in Sinorhizobium meliloti. We analysed S. meliloti 2011 mutants with mini-Tn5 insertions in the corresponding genes rne and rnj and found many overlapping effects. We observed similar changes in mRNA levels, including lower mRNA levels of the motility and chemotaxis related genes flaA, flgB and cheR and higher levels of ndvA (important for glucan export). The acyl-homoserine lactone (AHL) levels were also higher during exponential growth in both RNase mutants, despite no increase in the expression of the sinI AHL synthase gene. Furthermore, several RNAs from both mutants migrated aberrantly in denaturing gels at 300 V but not under stronger denaturing conditions at 1300 V. The similarities between the two mutants could be explained by increased levels of the key methyl donor S-adenosylmethionine (SAM), since this may result in faster AHL synthesis leading to higher AHL accumulation as well as in uncontrolled methylation of macromolecules including RNA, which may strengthen RNA secondary structures. Indeed, we found that in both mutants the N6-methyladenosine content was increased almost threefold and the SAM level was increased at least sevenfold. Complementation by induced ectopic expression of the respective RNase restored the AHL and SAM levels in each of the mutants. In summary, our data show that both RNase E and RNase J are needed for SAM homeostasis in S. meliloti.
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Affiliation(s)
- Kathrin Baumgardt
- Institute of Microbiology and Molecular Biology, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany.,Present address: CNRS, Institut de Biologie Physico-Chimique, 13 Rue Pierre et Marie Curie, 75005 Paris, France
| | - Hendrik Melior
- Institute of Microbiology and Molecular Biology, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany
| | - Ramakanth Madhugiri
- Institute of Microbiology and Molecular Biology, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany.,Present address: Institute of Medical Virology, Biomedical Research Center, Justus Liebig University, Schubertstr. 81, D 35392 Giessen, Germany
| | - Sebastian Thalmann
- Institute of Microbiology and Molecular Biology, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany
| | - Adam Schikora
- Institute of Phytopathology and Applied Zoology, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany.,Present address: Julius Kühn-Institut, Federal Research Centre for Cultivated Plants (JKI), Institute for Epidemiology and Pathogen Diagnostics, Messeweg 11/12, 38104, Brunswick, Germany
| | - Matthew McIntosh
- Centre of Synthetic Microbiology, Hans-Meerwein-Straße 6, D-35043 Marburg, Germany
| | - Anke Becker
- Centre of Synthetic Microbiology, Hans-Meerwein-Straße 6, D-35043 Marburg, Germany
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Bischler T, Hsieh PK, Resch M, Liu Q, Tan HS, Foley PL, Hartleib A, Sharma CM, Belasco JG. Identification of the RNA Pyrophosphohydrolase RppH of Helicobacter pylori and Global Analysis of Its RNA Targets. J Biol Chem 2016; 292:1934-1950. [PMID: 27974459 DOI: 10.1074/jbc.m116.761171] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 12/02/2016] [Indexed: 12/20/2022] Open
Abstract
RNA degradation is crucial for regulating gene expression in all organisms. Like the decapping of eukaryotic mRNAs, the conversion of the 5'-terminal triphosphate of bacterial transcripts to a monophosphate can trigger RNA decay by exposing the transcript to attack by 5'-monophosphate-dependent ribonucleases. In both biological realms, this deprotection step is catalyzed by members of the Nudix hydrolase family. The genome of the gastric pathogen Helicobacter pylori, a Gram-negative epsilonproteobacterium, encodes two proteins resembling Nudix enzymes. Here we present evidence that one of them, HP1228 (renamed HpRppH), is an RNA pyrophosphohydrolase that triggers RNA degradation in H. pylori, whereas the other, HP0507, lacks such activity. In vitro, HpRppH converts RNA 5'-triphosphates and diphosphates to monophosphates. It requires at least two unpaired nucleotides at the 5' end of its substrates and prefers three or more but has only modest sequence preferences. The influence of HpRppH on RNA degradation in vivo was examined by using RNA-seq to search the H. pylori transcriptome for RNAs whose 5'-phosphorylation state and cellular concentration are governed by this enzyme. Analysis of cDNA libraries specific for transcripts bearing a 5'-triphosphate and/or monophosphate revealed at least 63 potential HpRppH targets. These included mRNAs and sRNAs, several of which were validated individually by half-life measurements and quantification of their 5'-terminal phosphorylation state in wild-type and mutant cells. These findings demonstrate an important role for RppH in post-transcriptional gene regulation in pathogenic Epsilonproteobacteria and suggest a possible basis for the phenotypes of H. pylori mutants lacking this enzyme.
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Affiliation(s)
- Thorsten Bischler
- From the Research Center for Infectious Diseases, University of Würzburg, Josef-Schneider-Strasse 2/D15, 97080 Würzburg, Germany; the Institute of Molecular Infection Biology, University of Würzburg, Josef-Schneider-Strasse 2/D15, 97080 Würzburg, Germany and
| | - Ping-Kun Hsieh
- the Kimmel Center for Biology and Medicine at the Skirball Institute and the Department of Microbiology, New York University School of Medicine, New York, New York 10016
| | - Marcus Resch
- From the Research Center for Infectious Diseases, University of Würzburg, Josef-Schneider-Strasse 2/D15, 97080 Würzburg, Germany; the Institute of Molecular Infection Biology, University of Würzburg, Josef-Schneider-Strasse 2/D15, 97080 Würzburg, Germany and
| | - Quansheng Liu
- the Kimmel Center for Biology and Medicine at the Skirball Institute and the Department of Microbiology, New York University School of Medicine, New York, New York 10016
| | - Hock Siew Tan
- the Institute of Molecular Infection Biology, University of Würzburg, Josef-Schneider-Strasse 2/D15, 97080 Würzburg, Germany and
| | - Patricia L Foley
- the Kimmel Center for Biology and Medicine at the Skirball Institute and the Department of Microbiology, New York University School of Medicine, New York, New York 10016
| | - Anika Hartleib
- From the Research Center for Infectious Diseases, University of Würzburg, Josef-Schneider-Strasse 2/D15, 97080 Würzburg, Germany; the Institute of Molecular Infection Biology, University of Würzburg, Josef-Schneider-Strasse 2/D15, 97080 Würzburg, Germany and
| | - Cynthia M Sharma
- From the Research Center for Infectious Diseases, University of Würzburg, Josef-Schneider-Strasse 2/D15, 97080 Würzburg, Germany; the Institute of Molecular Infection Biology, University of Würzburg, Josef-Schneider-Strasse 2/D15, 97080 Würzburg, Germany and.
| | - Joel G Belasco
- the Kimmel Center for Biology and Medicine at the Skirball Institute and the Department of Microbiology, New York University School of Medicine, New York, New York 10016.
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37
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Cao D, Xu H, Zhao Y, Deng X, Liu Y, Soppe WJJ, Lin J. Transcriptome and Degradome Sequencing Reveals Dormancy Mechanisms of Cunninghamia lanceolata Seeds. PLANT PHYSIOLOGY 2016; 172:2347-2362. [PMID: 27760880 PMCID: PMC5129703 DOI: 10.1104/pp.16.00384] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 10/14/2016] [Indexed: 05/05/2023]
Abstract
Seeds with physiological dormancy usually experience primary and secondary dormancy in the nature; however, little is known about the differential regulation of primary and secondary dormancy. We combined multiple approaches to investigate cytological changes, hormonal levels, and gene expression dynamics in Cunninghamia lanceolata seeds during primary dormancy release and secondary dormancy induction. Light microscopy and transmission electron microscopy revealed that protein bodies in the embryo cells coalesced during primary dormancy release and then separated during secondary dormancy induction. Transcriptomic profiling demonstrated that expression of genes negatively regulating gibberellic acid (GA) sensitivity reduced specifically during primary dormancy release, whereas the expression of genes positively regulating abscisic acid (ABA) biosynthesis increased during secondary dormancy induction. Parallel analysis of RNA ends revealed uncapped transcripts for ∼55% of all unigenes. A negative correlation between fold changes in expression levels of uncapped versus capped mRNAs was observed during primary dormancy release. However, this correlation was loose during secondary dormancy induction. Our analyses suggest that the reversible changes in cytology and gene expression during dormancy release and induction are related to ABA/GA balance. Moreover, mRNA degradation functions as a critical posttranscriptional regulator during primary dormancy release. These findings provide a mechanistic framework for understanding physiological dormancy in seeds.
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Affiliation(s)
- Dechang Cao
- Key Laboratory for Genetics and Breeding of Forest Trees and Ornamental Plants of Ministry of Education, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China (D.C., H.X., Y.Z., J.L.)
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China (X.D., Y.L., J.L.)
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Jena 07745, Germany (D.C.); and
- Department of Plant Breeding and Genetics, Max Planck Institute for Plant Breeding Research, Cologne 50829, Germany (W.J.J.S.)
| | - Huimin Xu
- Key Laboratory for Genetics and Breeding of Forest Trees and Ornamental Plants of Ministry of Education, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China (D.C., H.X., Y.Z., J.L.)
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China (X.D., Y.L., J.L.)
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Jena 07745, Germany (D.C.); and
- Department of Plant Breeding and Genetics, Max Planck Institute for Plant Breeding Research, Cologne 50829, Germany (W.J.J.S.)
| | - Yuanyuan Zhao
- Key Laboratory for Genetics and Breeding of Forest Trees and Ornamental Plants of Ministry of Education, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China (D.C., H.X., Y.Z., J.L.)
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China (X.D., Y.L., J.L.)
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Jena 07745, Germany (D.C.); and
- Department of Plant Breeding and Genetics, Max Planck Institute for Plant Breeding Research, Cologne 50829, Germany (W.J.J.S.)
| | - Xin Deng
- Key Laboratory for Genetics and Breeding of Forest Trees and Ornamental Plants of Ministry of Education, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China (D.C., H.X., Y.Z., J.L.)
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China (X.D., Y.L., J.L.)
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Jena 07745, Germany (D.C.); and
- Department of Plant Breeding and Genetics, Max Planck Institute for Plant Breeding Research, Cologne 50829, Germany (W.J.J.S.)
| | - Yongxiu Liu
- Key Laboratory for Genetics and Breeding of Forest Trees and Ornamental Plants of Ministry of Education, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China (D.C., H.X., Y.Z., J.L.)
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China (X.D., Y.L., J.L.)
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Jena 07745, Germany (D.C.); and
- Department of Plant Breeding and Genetics, Max Planck Institute for Plant Breeding Research, Cologne 50829, Germany (W.J.J.S.)
| | - Wim J J Soppe
- Key Laboratory for Genetics and Breeding of Forest Trees and Ornamental Plants of Ministry of Education, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China (D.C., H.X., Y.Z., J.L.)
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China (X.D., Y.L., J.L.)
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Jena 07745, Germany (D.C.); and
- Department of Plant Breeding and Genetics, Max Planck Institute for Plant Breeding Research, Cologne 50829, Germany (W.J.J.S.)
| | - Jinxing Lin
- Key Laboratory for Genetics and Breeding of Forest Trees and Ornamental Plants of Ministry of Education, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China (D.C., H.X., Y.Z., J.L.);
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China (X.D., Y.L., J.L.);
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Jena 07745, Germany (D.C.); and
- Department of Plant Breeding and Genetics, Max Planck Institute for Plant Breeding Research, Cologne 50829, Germany (W.J.J.S.)
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38
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Weber L, Thoelken C, Volk M, Remes B, Lechner M, Klug G. The Conserved Dcw Gene Cluster of R. sphaeroides Is Preceded by an Uncommonly Extended 5' Leader Featuring the sRNA UpsM. PLoS One 2016; 11:e0165694. [PMID: 27802301 PMCID: PMC5089854 DOI: 10.1371/journal.pone.0165694] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 10/17/2016] [Indexed: 11/18/2022] Open
Abstract
Cell division and cell wall synthesis mechanisms are similarly conserved among bacteria. Consequently some bacterial species have comparable sets of genes organized in the dcw (division andcellwall) gene cluster. Dcw genes, their regulation and their relative order within the cluster are outstandingly conserved among rod shaped and gram negative bacteria to ensure an efficient coordination of growth and division. A well studied representative is the dcw gene cluster of E. coli. The first promoter of the gene cluster (mraZ1p) gives rise to polycistronic transcripts containing a 38 nt long 5’ UTR followed by the first gene mraZ. Despite reported conservation we present evidence for a much longer 5’ UTR in the gram negative and rod shaped bacterium Rhodobacter sphaeroides and in the family of Rhodobacteraceae. This extended 268 nt long 5’ UTR comprises a Rho independent terminator, which in case of termination gives rise to a non-coding RNA (UpsM). This sRNA is conditionally cleaved by RNase E under stress conditions in an Hfq- and very likely target mRNA-dependent manner, implying its function in trans. These results raise the question for the regulatory function of this extended 5’ UTR. It might represent the rarely described case of a trans acting sRNA derived from a riboswitch with exclusive presence in the family of Rhodobacteraceae.
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Affiliation(s)
- Lennart Weber
- Institute of Microbiology and Molecular Biology, IFZ, Justus-Liebig-University Giessen, Giessen, Germany
| | - Clemens Thoelken
- Institute of Pharmaceutical Chemistry, Philipps-University Marburg, Marburg, Germany
| | - Marcel Volk
- Institute of Microbiology and Molecular Biology, IFZ, Justus-Liebig-University Giessen, Giessen, Germany
| | - Bernhard Remes
- Institute of Microbiology and Molecular Biology, IFZ, Justus-Liebig-University Giessen, Giessen, Germany
| | - Marcus Lechner
- Institute of Pharmaceutical Chemistry, Philipps-University Marburg, Marburg, Germany
| | - Gabriele Klug
- Institute of Microbiology and Molecular Biology, IFZ, Justus-Liebig-University Giessen, Giessen, Germany
- * E-mail:
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Regulatory RNAs in Bacillus subtilis: a Gram-Positive Perspective on Bacterial RNA-Mediated Regulation of Gene Expression. Microbiol Mol Biol Rev 2016; 80:1029-1057. [PMID: 27784798 DOI: 10.1128/mmbr.00026-16] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Bacteria can employ widely diverse RNA molecules to regulate their gene expression. Such molecules include trans-acting small regulatory RNAs, antisense RNAs, and a variety of transcriptional attenuation mechanisms in the 5' untranslated region. Thus far, most regulatory RNA research has focused on Gram-negative bacteria, such as Escherichia coli and Salmonella. Hence, there is uncertainty about whether the resulting insights can be extrapolated directly to other bacteria, such as the Gram-positive soil bacterium Bacillus subtilis. A recent study identified 1,583 putative regulatory RNAs in B. subtilis, whose expression was assessed across 104 conditions. Here, we review the current understanding of RNA-based regulation in B. subtilis, and we categorize the newly identified putative regulatory RNAs on the basis of their conservation in other bacilli and the stability of their predicted secondary structures. Our present evaluation of the publicly available data indicates that RNA-mediated gene regulation in B. subtilis mostly involves elements at the 5' ends of mRNA molecules. These can include 5' secondary structure elements and metabolite-, tRNA-, or protein-binding sites. Importantly, sense-independent segments are identified as the most conserved and structured potential regulatory RNAs in B. subtilis. Altogether, the present survey provides many leads for the identification of new regulatory RNA functions in B. subtilis.
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Lukoszek R, Feist P, Ignatova Z. Insights into the adaptive response of Arabidopsis thaliana to prolonged thermal stress by ribosomal profiling and RNA-Seq. BMC PLANT BIOLOGY 2016; 16:221. [PMID: 27724872 PMCID: PMC5057212 DOI: 10.1186/s12870-016-0915-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 10/05/2016] [Indexed: 05/19/2023]
Abstract
BACKGROUND Environmental stress puts organisms at risk and requires specific stress-tailored responses to maximize survival. Long-term exposure to stress necessitates a global reprogramming of the cellular activities at different levels of gene expression. RESULTS Here, we use ribosome profiling and RNA sequencing to globally profile the adaptive response of Arabidopsis thaliana to prolonged heat stress. To adapt to long heat exposure, the expression of many genes is modulated in a coordinated manner at a transcriptional and translational level. However, a significant group of genes opposes this trend and shows mainly translational regulation. Different secondary structure elements are likely candidates to play a role in regulating translation of those genes. CONCLUSIONS Our data also uncover on how the subunit stoichiometry of multimeric protein complexes in plastids is maintained upon heat exposure.
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Affiliation(s)
- Radoslaw Lukoszek
- Biochemistry, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany
- Present Address: Division of Plant Sciences/Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH UK
| | - Peter Feist
- Biochemistry, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany
| | - Zoya Ignatova
- Biochemistry, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany
- Biochemistry and Molecular Biology, Department of Chemistry, University of Hamburg, Hamburg, Germany
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Distinct Residues Contribute to Motility Repression and Autoregulation in the Proteus mirabilis Fimbria-Associated Transcriptional Regulator AtfJ. J Bacteriol 2016; 198:2100-12. [PMID: 27246571 DOI: 10.1128/jb.00193-16] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 05/22/2016] [Indexed: 12/19/2022] Open
Abstract
UNLABELLED Proteus mirabilis contributes to a significant number of catheter-associated urinary tract infections, where coordinated regulation of adherence and motility is critical for ascending disease progression. Previously, the mannose-resistant Proteus-like (MR/P) fimbria-associated transcriptional regulator MrpJ has been shown to both repress motility and directly induce the transcription of its own operon; in addition, it affects the expression of a wide range of cellular processes. Interestingly, 14 additional mrpJ paralogs are included in the P. mirabilis genome. Looking at a selection of MrpJ paralogs, we discovered that these proteins, which consistently repress motility, also have nonidentical functions that include cross-regulation of fimbrial operons. A subset of paralogs, including AtfJ (encoded by the ambient temperature fimbrial operon), Fim8J, and MrpJ, are capable of autoinduction. We identified an element of the atf promoter extending from 487 to 655 nucleotides upstream of the transcriptional start site that is responsive to AtfJ, and we found that AtfJ directly binds this fragment. Mutational analysis of AtfJ revealed that its two identified functions, autoregulation and motility repression, are not invariably linked. Residues within the DNA-binding helix-turn-helix domain are required for motility repression but not necessarily autoregulation. Likewise, the C-terminal domain is dispensable for motility repression but is essential for autoregulation. Supported by a three-dimensional (3D) structural model, we hypothesize that the C-terminal domain confers unique regulatory capacities on the AtfJ family of regulators. IMPORTANCE Balancing adherence with motility is essential for uropathogens to successfully establish a foothold in their host. Proteus mirabilis uses a fimbria-associated transcriptional regulator to switch between these antagonistic processes by increasing fimbrial adherence while simultaneously downregulating flagella. The discovery of multiple related proteins, many of which also function as motility repressors, encoded in the P. mirabilis genome has raised considerable interest as to their functionality and potential redundancy in this organism. This study provides an important advance in this field by elucidating the nonidentical effects of these paralogs on a molecular level. Our mechanistic studies of one member of this group, AtfJ, shed light on how these differing functions may be conferred despite the limited sequence variety exhibited by the paralogous proteins.
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Brogna S, McLeod T, Petric M. The Meaning of NMD: Translate or Perish. Trends Genet 2016; 32:395-407. [PMID: 27185236 DOI: 10.1016/j.tig.2016.04.007] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Revised: 04/02/2016] [Accepted: 04/25/2016] [Indexed: 02/08/2023]
Abstract
Premature translation termination leads to a reduced mRNA level in all types of organisms. In eukaryotes, the phenomenon is known as nonsense-mediated mRNA decay (NMD). This is commonly regarded as the output of a specific surveillance and destruction mechanism that is activated by the presence of a premature translation termination codon (PTC) in an atypical sequence context. Despite two decades of research, it is still unclear how NMD discriminates between PTCs and normal stop codons. We suggest that cells do not possess any such mechanism and instead propose a new model in which this mRNA depletion is a consequence of the appearance of long tracts of mRNA that are unprotected by scanning ribosomes.
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Affiliation(s)
- Saverio Brogna
- University of Birmingham, School of Biosciences, Edgbaston, Birmingham, B15 2TT, UK.
| | - Tina McLeod
- University of Birmingham, School of Biosciences, Edgbaston, Birmingham, B15 2TT, UK
| | - Marija Petric
- University of Birmingham, School of Biosciences, Edgbaston, Birmingham, B15 2TT, UK
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Abstract
Over the last decade, small (often noncoding) RNA molecules have been discovered as important regulators influencing myriad aspects of bacterial physiology and virulence. In particular, small RNAs (sRNAs) have been implicated in control of both primary and secondary metabolic pathways in many bacterial species. This chapter describes characteristics of the major classes of sRNA regulators, and highlights what is known regarding their mechanisms of action. Specific examples of sRNAs that regulate metabolism in gram-negative bacteria are discussed, with a focus on those that regulate gene expression by base pairing with mRNA targets to control their translation and stability.
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44
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Bartholomäus A, Fedyunin I, Feist P, Sin C, Zhang G, Valleriani A, Ignatova Z. Bacteria differently regulate mRNA abundance to specifically respond to various stresses. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2016; 374:rsta.2015.0069. [PMID: 26857681 DOI: 10.1098/rsta.2015.0069] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/29/2015] [Indexed: 06/05/2023]
Abstract
Environmental stress is detrimental to cell viability and requires an adequate reprogramming of cellular activities to maximize cell survival. We present a global analysis of the response of Escherichia coli to acute heat and osmotic stress. We combine deep sequencing of total mRNA and ribosome-protected fragments to provide a genome-wide map of the stress response at transcriptional and translational levels. For each type of stress, we observe a unique subset of genes that shape the stress-specific response. Upon temperature upshift, mRNAs with reduced folding stability up- and downstream of the start codon, and thus with more accessible initiation regions, are translationally favoured. Conversely, osmotic upshift causes a global reduction of highly translated transcripts with high copy numbers, allowing reallocation of translation resources to not degraded and newly synthesized mRNAs.
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Affiliation(s)
- Alexander Bartholomäus
- Department of Biochemsitry, University of Potsdam, Karl-Liebknecht-Straße 24-25, Potsdam 14476, Germany Institute for Biochemsitry and Molecular Biology, Department of Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, Hamburg 20146, Germany
| | - Ivan Fedyunin
- Department of Biochemsitry, University of Potsdam, Karl-Liebknecht-Straße 24-25, Potsdam 14476, Germany
| | - Peter Feist
- Department of Biochemsitry, University of Potsdam, Karl-Liebknecht-Straße 24-25, Potsdam 14476, Germany
| | - Celine Sin
- Department of Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, Potsdam 14476, Germany
| | - Gong Zhang
- Department of Biochemsitry, University of Potsdam, Karl-Liebknecht-Straße 24-25, Potsdam 14476, Germany
| | - Angelo Valleriani
- Department of Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, Potsdam 14476, Germany
| | - Zoya Ignatova
- Department of Biochemsitry, University of Potsdam, Karl-Liebknecht-Straße 24-25, Potsdam 14476, Germany Institute for Biochemsitry and Molecular Biology, Department of Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, Hamburg 20146, Germany
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45
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Zhu H, Mao XJ, Guo XP, Sun YC. The hmsT 3' untranslated region mediates c-di-GMP metabolism and biofilm formation in Yersinia pestis. Mol Microbiol 2016; 99:1167-78. [PMID: 26711808 DOI: 10.1111/mmi.13301] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/01/2015] [Indexed: 02/04/2023]
Abstract
Yersinia pestis, the cause of plague, forms a biofilm in the proventriculus of its flea vector to enhance transmission. Biofilm formation in Y. pestis is regulated by the intracellular levels of cyclic diguanylate (c-di-GMP). In this study, we investigated the role of the 3' untranslated region (3'UTR) in hmsT mRNA, a transcript that encodes a diguanylate cyclase that stimulates biofilm formation in Y. pestis by synthesizing the second messenger c-di-GMP. Deletion of the 3'UTR increased the half-life of hmsT mRNA, thereby upregulating c-di-GMP levels and biofilm formation. Our findings indicate that multiple regulatory sequences might be present in the hmsT 3'UTR that function together to mediate mRNA turnover. We also found that polynucleotide phosphorylase is partially responsible for hmsT 3'UTR-mediated mRNA decay. In addition, the hmsT 3'UTR strongly repressed gene expression at 37°C and 26°C, but affected gene expression only slightly at 21°C. Our findings suggest that the 3'UTR might be involved in precise and rapid regulation of hmsT expression, allowing Y. pestis to fine-tune c-di-GMP synthesis and consequently regulate biofilm production to adapt to the changing host environment.
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Affiliation(s)
- Hui Zhu
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, 9, Dongdan Santiao, Dongcheng District, Beijing, 100730, China
| | - Xu-Jian Mao
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, 9, Dongdan Santiao, Dongcheng District, Beijing, 100730, 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, 9, Dongdan Santiao, Dongcheng District, Beijing, 100730, 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, 9, Dongdan Santiao, Dongcheng District, Beijing, 100730, China
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46
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Marbaniang CN, Vogel J. Emerging roles of RNA modifications in bacteria. Curr Opin Microbiol 2016; 30:50-57. [PMID: 26803287 DOI: 10.1016/j.mib.2016.01.001] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 12/24/2015] [Accepted: 01/06/2016] [Indexed: 01/28/2023]
Abstract
RNA modifications are known to abound in stable tRNA and rRNA, where they cluster around functionally important regions. However, RNA-seq based techniques profiling entire transcriptomes are now uncovering an abundance of modified ribonucleotides in mRNAs and noncoding RNAs, too. While most of the recent progress in understanding the regulatory influence of these new RNA modifications stems from eukaryotes, there is growing evidence in bacteria for modified nucleotides beyond the stable RNA species, including modifications of small regulatory RNAs. Given their small genome size, good genetic tractability, and ample knowledge of modification enzymes, bacteria offer excellent model systems to decipher cellular functions of RNA modifications in many diverse physiological contexts. This review highlights how new global approaches combining classic analysis with new sequencing techniques may usher in an era of bacterial epitranscriptomics.
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Affiliation(s)
- Carmelita Nora Marbaniang
- RNA Biology Group, Institute for Molecular Infection Biology, University of Würzburg, Josef-Schneider-Straße 2, D-97080 Würzburg, Germany
| | - Jörg Vogel
- RNA Biology Group, Institute for Molecular Infection Biology, University of Würzburg, Josef-Schneider-Straße 2, D-97080 Würzburg, Germany.
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Jäschke A, Höfer K, Nübel G, Frindert J. Cap-like structures in bacterial RNA and epitranscriptomic modification. Curr Opin Microbiol 2016; 30:44-49. [PMID: 26779928 DOI: 10.1016/j.mib.2015.12.009] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 12/22/2015] [Accepted: 12/24/2015] [Indexed: 12/25/2022]
Abstract
The absence of capped RNA is considered as a hallmark of prokaryotic gene expression. Recent developments combine next-generation sequencing with a chemo-enzymatic capture step that allows the enrichment of rare 5'-modified RNA from bacteria. This approach identified covalent cap-like linkage of a specific set of small RNAs to the ubiquitous redox cofactor NAD, and a profound influence of this modification on RNA turnover. The modification revealed an unexpected connection between redox biology and RNA processing. We discuss possible roles of the NAD modification as well as broader implications for structurally related cofactors and metabolites which may also be linked to RNAs, leading to a new epitranscriptomic layer of information encoded in the chemical structure of the attached cofactors.
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Affiliation(s)
- Andres Jäschke
- Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Im Neuenheimer Feld 364, D-69120 Heidelberg, Germany.
| | - Katharina Höfer
- Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Im Neuenheimer Feld 364, D-69120 Heidelberg, Germany
| | - Gabriele Nübel
- Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Im Neuenheimer Feld 364, D-69120 Heidelberg, Germany
| | - Jens Frindert
- Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Im Neuenheimer Feld 364, D-69120 Heidelberg, Germany
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48
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Thattai M. Universal Poisson Statistics of mRNAs with Complex Decay Pathways. Biophys J 2015; 110:301-305. [PMID: 26743048 PMCID: PMC4724633 DOI: 10.1016/j.bpj.2015.12.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 10/30/2015] [Accepted: 12/02/2015] [Indexed: 01/04/2023] Open
Abstract
Messenger RNA (mRNA) dynamics in single cells are often modeled as a memoryless birth-death process with a constant probability per unit time that an mRNA molecule is synthesized or degraded. This predicts a Poisson steady-state distribution of mRNA number, in close agreement with experiments. This is surprising, since mRNA decay is known to be a complex process. The paradox is resolved by realizing that the Poisson steady state generalizes to arbitrary mRNA lifetime distributions. A mapping between mRNA dynamics and queueing theory highlights an identifiability problem: a measured Poisson steady state is consistent with a large variety of microscopic models. Here, I provide a rigorous and intuitive explanation for the universality of the Poisson steady state. I show that the mRNA birth-death process and its complex decay variants all take the form of the familiar Poisson law of rare events, under a nonlinear rescaling of time. As a corollary, not only steady-states but also transients are Poisson distributed. Deviations from the Poisson form occur only under two conditions, promoter fluctuations leading to transcriptional bursts or nonindependent degradation of mRNA molecules. These results place severe limits on the power of single-cell experiments to probe microscopic mechanisms, and they highlight the need for single-molecule measurements.
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Affiliation(s)
- Mukund Thattai
- Simons Centre for the Study of Living Machines, National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India.
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Cheung BB, Tan O, Koach J, Liu B, Shum MSY, Carter DR, Sutton S, Po'uha ST, Chesler L, Haber M, Norris MD, Kavallaris M, Liu T, O'Neill GM, Marshall GM. Thymosin-β4 is a determinant of drug sensitivity for Fenretinide and Vorinostat combination therapy in neuroblastoma. Mol Oncol 2015; 9:1484-500. [PMID: 25963741 PMCID: PMC5528804 DOI: 10.1016/j.molonc.2015.04.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Revised: 04/17/2015] [Accepted: 04/17/2015] [Indexed: 10/23/2022] Open
Abstract
Retinoids are an important component of neuroblastoma therapy at the stage of minimal residual disease, yet 40-50% of patients treated with 13-cis-retinoic acid (13-cis-RA) still relapse, indicating the need for more effective retinoid therapy. Vorinostat, or Suberoylanilide hydroxamic acid (SAHA), is a potent inhibitor of histone deacetylase (HDAC) classes I & II and has antitumor activity in vitro and in vivo. Fenretinide (4-HPR) is a synthetic retinoid which acts on cancer cells through both nuclear retinoid receptor and non-receptor mechanisms. In this study, we found that the combination of 4-HPR + SAHA exhibited potent cytotoxic effects on neuroblastoma cells, much more effective than 13-cis-RA + SAHA. The 4-HPR + SAHA combination induced caspase-dependent apoptosis through activation of caspase 3, reduced colony formation and cell migration in vitro, and tumorigenicity in vivo. The 4-HPR and SAHA combination significantly increased mRNA expression of thymosin-beta-4 (Tβ4) and decreased mRNA expression of retinoic acid receptor α (RARα). Importantly, the up-regulation of Tβ4 and down-regulation of RARα were both necessary for the 4-HPR + SAHA cytotoxic effect on neuroblastoma cells. Moreover, Tβ4 knockdown in neuroblastoma cells increased cell migration and blocked the effect of 4-HPR + SAHA on cell migration and focal adhesion formation. In primary human neuroblastoma tumor tissues, low expression of Tβ4 was associated with metastatic disease and predicted poor patient prognosis. Our findings demonstrate that Tβ4 is a novel therapeutic target in neuroblastoma, and that 4-HPR + SAHA is a potential therapy for the disease.
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Affiliation(s)
- Belamy B Cheung
- Children's Cancer Institute Australia, University of New South Wales, Sydney, Australia.
| | - Owen Tan
- Children's Cancer Institute Australia, University of New South Wales, Sydney, Australia
| | - Jessica Koach
- Children's Cancer Institute Australia, University of New South Wales, Sydney, Australia
| | - Bing Liu
- Children's Cancer Institute Australia, University of New South Wales, Sydney, Australia
| | - Michael S Y Shum
- Kids Research Institute, Children's Hospital at Westmead, Sydney, Australia
| | - Daniel R Carter
- Children's Cancer Institute Australia, University of New South Wales, Sydney, Australia
| | - Selina Sutton
- Children's Cancer Institute Australia, University of New South Wales, Sydney, Australia
| | - Sela T Po'uha
- Children's Cancer Institute Australia, University of New South Wales, Sydney, Australia
| | - Louis Chesler
- Division of Clinical Studies, Institute of Cancer Research, Sutton, Surrey, UK
| | - Michelle Haber
- Children's Cancer Institute Australia, University of New South Wales, Sydney, Australia
| | - Murray D Norris
- Children's Cancer Institute Australia, University of New South Wales, Sydney, Australia
| | - Maria Kavallaris
- Children's Cancer Institute Australia, University of New South Wales, Sydney, Australia
| | - Tao Liu
- Children's Cancer Institute Australia, University of New South Wales, Sydney, Australia
| | - Geraldine M O'Neill
- Kids Research Institute, Children's Hospital at Westmead, Sydney, Australia; Discipline of Paediatrics and Child Health, University of Sydney, Australia
| | - Glenn M Marshall
- Children's Cancer Institute Australia, University of New South Wales, Sydney, Australia; Kids Cancer Centre, Sydney Children's Hospital, Sydney, Australia.
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50
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Sin C, Chiarugi D, Valleriani A. Single-molecule modeling of mRNA degradation by miRNA: Lessons from data. BMC SYSTEMS BIOLOGY 2015; 9 Suppl 3:S2. [PMID: 26050661 PMCID: PMC4464216 DOI: 10.1186/1752-0509-9-s3-s2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Recent experimental results on the effect of miRNA on the decay of its target mRNA have been analyzed against a previously hypothesized single molecule degradation pathway. According to that hypothesis, the silencing complex (miRISC) first interacts with its target mRNA and then recruits the protein complexes associated with NOT1 and PAN3 to trigger deadenylation (and subsequent degradation) of the target mRNA. Our analysis of the experimental decay patterns allowed us to refine the structure of the degradation pathways at the single molecule level. Surprisingly, we found that if the previously hypothesized network was correct, only about 7% of the target mRNA would be regulated by the miRNA mechanism, which is inconsistent with the available knowledge. Based on systematic data analysis, we propose the alternative hypothesis that NOT1 interacts with miRISC before binding to the target mRNA. Moreover, we show that when miRISC binds alone to the target mRNA, the mRNA is degraded more slowly, probably through a deadenylation-independent pathway. The new biochemical pathway proposed here both fits the data and paves the way for new experimental work to identify new interactions.
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