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Venero ECS, Giambartolomei L, Sosa E, Fernández do Porto D, López NI, Tribelli PM. Nitrosative stress under microaerobic conditions triggers inositol metabolism in Pseudomonas extremaustralis. PLoS One 2024; 19:e0301252. [PMID: 38696454 PMCID: PMC11065229 DOI: 10.1371/journal.pone.0301252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Accepted: 03/13/2024] [Indexed: 05/04/2024] Open
Abstract
Bacteria are exposed to reactive oxygen and nitrogen species that provoke oxidative and nitrosative stress which can lead to macromolecule damage. Coping with stress conditions involves the adjustment of cellular responses, which helps to address metabolic challenges. In this study, we performed a global transcriptomic analysis of the response of Pseudomonas extremaustralis to nitrosative stress, induced by S-nitrosoglutathione (GSNO), a nitric oxide donor, under microaerobic conditions. The analysis revealed the upregulation of genes associated with inositol catabolism; a compound widely distributed in nature whose metabolism in bacteria has aroused interest. The RNAseq data also showed heightened expression of genes involved in essential cellular processes like transcription, translation, amino acid transport and biosynthesis, as well as in stress resistance including iron-dependent superoxide dismutase, alkyl hydroperoxide reductase, thioredoxin, and glutathione S-transferase in response to GSNO. Furthermore, GSNO exposure differentially affected the expression of genes encoding nitrosylation target proteins, encompassing metalloproteins and proteins with free cysteine and /or tyrosine residues. Notably, genes associated with iron metabolism, such as pyoverdine synthesis and iron transporter genes, showed activation in the presence of GSNO, likely as response to enhanced protein turnover. Physiological assays demonstrated that P. extremaustralis can utilize inositol proficiently under both aerobic and microaerobic conditions, achieving growth comparable to glucose-supplemented cultures. Moreover, supplementing the culture medium with inositol enhances the stress tolerance of P. extremaustralis against combined oxidative-nitrosative stress. Concordant with the heightened expression of pyoverdine genes under nitrosative stress, elevated pyoverdine production was observed when myo-inositol was added to the culture medium. These findings highlight the influence of nitrosative stress on proteins susceptible to nitrosylation and iron metabolism. Furthermore, the activation of myo-inositol catabolism emerges as a protective mechanism against nitrosative stress, shedding light on this pathway in bacterial systems, and holding significance in the adaptation to unfavorable conditions.
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Affiliation(s)
| | - Lucia Giambartolomei
- Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Ezequiel Sosa
- Instituto de Cálculo, Facultad de Ciencias Exactas y Naturales, UBA, Buenos Aires, Argentina
| | - Darío Fernández do Porto
- Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Cálculo, Facultad de Ciencias Exactas y Naturales, UBA, Buenos Aires, Argentina
| | - Nancy I. López
- IQUIBICEN-CONICET, Buenos Aires, Argentina
- Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Paula M. Tribelli
- IQUIBICEN-CONICET, Buenos Aires, Argentina
- Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Universidad de Buenos Aires, Buenos Aires, Argentina
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2
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Zhou Y, Sun H, Rapiejko AR, Vargas-Blanco DA, Martini MC, Chase MR, Joubran SR, Davis AB, Dainis JP, Kelly JM, Ioerger TR, Roberts LA, Fortune SM, Shell SS. Mycobacterial RNase E cleaves with a distinct sequence preference and controls the degradation rates of most Mycolicibacterium smegmatis mRNAs. J Biol Chem 2023; 299:105312. [PMID: 37802316 PMCID: PMC10641625 DOI: 10.1016/j.jbc.2023.105312] [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: 03/16/2023] [Revised: 08/29/2023] [Accepted: 09/29/2023] [Indexed: 10/08/2023] Open
Abstract
The mechanisms and regulation of RNA degradation in mycobacteria have been subject to increased interest following the identification of interplay between RNA metabolism and drug resistance. Mycobacteria encode multiple ribonucleases predicted to participate in mRNA degradation and/or processing of stable RNAs. RNase E is hypothesized to play a major role in mRNA degradation because of its essentiality in mycobacteria and its role in mRNA degradation in gram-negative bacteria. Here, we defined the impact of RNase E on mRNA degradation rates transcriptome-wide in the nonpathogenic model Mycolicibacterium smegmatis. RNase E played a rate-limiting role in degradation of the transcripts encoded by at least 89% of protein-coding genes, with leadered transcripts often being more affected by RNase E repression than leaderless transcripts. There was an apparent global slowing of transcription in response to knockdown of RNase E, suggesting that M. smegmatis regulates transcription in responses to changes in mRNA degradation. This compensation was incomplete, as the abundance of most transcripts increased upon RNase E knockdown. We assessed the sequence preferences for cleavage by RNase E transcriptome-wide in M. smegmatis and Mycobacterium tuberculosis and found a consistent bias for cleavage in C-rich regions. Purified RNase E had a clear preference for cleavage immediately upstream of cytidines, distinct from the sequence preferences of RNase E in gram-negative bacteria. We furthermore report a high-resolution map of mRNA cleavage sites in M. tuberculosis, which occur primarily within the RNase E-preferred sequence context, confirming that RNase E has a broad impact on the M. tuberculosis transcriptome.
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Affiliation(s)
- Ying Zhou
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, Massachusetts, USA
| | - Huaming Sun
- Program in Bioinformatics and Computational Biology, Worcester Polytechnic Institute, Worcester, Massachusetts, USA
| | - Abigail R Rapiejko
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, Massachusetts, USA
| | - Diego A Vargas-Blanco
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, Massachusetts, USA
| | - Maria Carla Martini
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, Massachusetts, USA
| | - Michael R Chase
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Samantha R Joubran
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, Massachusetts, USA
| | - Alexa B Davis
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, Massachusetts, USA
| | - Joseph P Dainis
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, Massachusetts, USA
| | - Jessica M Kelly
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, Massachusetts, USA
| | - Thomas R Ioerger
- Department of Computer Science & Engineering, Texas A&M University, College Station, Texas, USA
| | - Louis A Roberts
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, Massachusetts, USA
| | - Sarah M Fortune
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Scarlet S Shell
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, Massachusetts, USA.
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3
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Small I, Melonek J, Bohne AV, Nickelsen J, Schmitz-Linneweber C. Plant organellar RNA maturation. THE PLANT CELL 2023; 35:1727-1751. [PMID: 36807982 PMCID: PMC10226603 DOI: 10.1093/plcell/koad049] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 01/05/2023] [Accepted: 01/17/2023] [Indexed: 05/30/2023]
Abstract
Plant organellar RNA metabolism is run by a multitude of nucleus-encoded RNA-binding proteins (RBPs) that control RNA stability, processing, and degradation. In chloroplasts and mitochondria, these post-transcriptional processes are vital for the production of a small number of essential components of the photosynthetic and respiratory machinery-and consequently for organellar biogenesis and plant survival. Many organellar RBPs have been functionally assigned to individual steps in RNA maturation, often specific to selected transcripts. While the catalog of factors identified is ever-growing, our knowledge of how they achieve their functions mechanistically is far from complete. This review summarizes the current knowledge of plant organellar RNA metabolism taking an RBP-centric approach and focusing on mechanistic aspects of RBP functions and the kinetics of the processes they are involved in.
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Affiliation(s)
- Ian Small
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Crawley 6009, Australia
| | - Joanna Melonek
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Crawley 6009, Australia
| | | | - Jörg Nickelsen
- Department of Molecular Plant Sciences, LMU Munich, 82152 Martinsried, Germany
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4
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Yu Z, Dai Y, Li T, Gu W, Yang Y, Li X, Peng P, Yang L, Li X, Wang J, Su Z, Li X, Xu M, Zhang H. A Novel Pathway of Chlorimuron-Ethyl Biodegradation by Chenggangzhangella methanolivorans Strain CHL1 and Its Molecular Mechanisms. Int J Mol Sci 2022; 23:ijms23179890. [PMID: 36077288 PMCID: PMC9456165 DOI: 10.3390/ijms23179890] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 08/21/2022] [Accepted: 08/29/2022] [Indexed: 11/16/2022] Open
Abstract
Chlorimuron-ethyl is a widely used herbicide in agriculture. However, uncontrolled chlorimuron-ethyl application causes serious environmental problems. Chlorimuron-ethyl can be effectively degraded by microbes, but the underlying molecular mechanisms are not fully understood. In this study, we identified the possible pathways and key genes involved in chlorimuron-ethyl degradation by the Chenggangzhangella methanolivorans strain CHL1, a Methylocystaceae strain with the ability to degrade sulfonylurea herbicides. Using a metabolomics method, eight intermediate degradation products were identified, and three pathways, including a novel pyrimidine-ring-opening pathway, were found to be involved in chlorimuron-ethyl degradation by strain CHL1. Transcriptome sequencing indicated that three genes (atzF, atzD, and cysJ) are involved in chlorimuron-ethyl degradation by strain CHL1. The gene knock-out and complementation techniques allowed for the functions of the three genes to be identified, and the enzymes involved in the different steps of chlorimuron-ethyl degradation pathways were preliminary predicted. The results reveal a previously unreported pathway and the key genes of chlorimuron-ethyl degradation by strain CHL1, which have implications for attempts to enrich the biodegradation mechanism of sulfonylurea herbicides and to construct engineered bacteria in order to remove sulfonylurea herbicide residues from environmental media.
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Affiliation(s)
- Zhixiong Yu
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
- Basic Medical College, Shenyang Medical College, Shenyang 100034, China
| | - Yumeng Dai
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tingting Li
- Shenyang Research Institute of Chemical Industry, Shenyang 110021, China
| | - Wu Gu
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yi Yang
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
| | - Xiang Li
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
| | - Pai Peng
- Shenyang Research Institute of Chemical Industry, Shenyang 110021, China
| | - Lijie Yang
- Shenyang Research Institute of Chemical Industry, Shenyang 110021, China
| | - Xinyu Li
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
| | - Jian Wang
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
| | - Zhencheng Su
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
| | - Xu Li
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
| | - Mingkai Xu
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
- Correspondence: (M.X.); (H.Z.)
| | - Huiwen Zhang
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
- Correspondence: (M.X.); (H.Z.)
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5
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Dynamic Mechanism of Phase Variations in Bacteria Based on Multistable Gene Regulatory Networks. J Theor Biol 2022; 549:111212. [DOI: 10.1016/j.jtbi.2022.111212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 06/23/2022] [Accepted: 06/28/2022] [Indexed: 11/20/2022]
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6
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Baliarda A, Winkler M, Tournier L, Tinsley CR, Aymerich S. Dynamic interspecies interactions and robustness in a four-species model biofilm. Microbiologyopen 2021; 10:e1254. [PMID: 34964290 PMCID: PMC8650569 DOI: 10.1002/mbo3.1254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/16/2021] [Accepted: 11/17/2021] [Indexed: 11/18/2022] Open
Abstract
Interspecific interactions within biofilms determine relative species abundance, growth dynamics, community resilience, and success or failure of invasion by an extraneous organism. However, deciphering interspecific interactions and assessing their contribution to biofilm properties and function remain a challenge. Here, we describe the constitution of a model biofilm composed of four bacterial species belonging to four different genera (Rhodocyclus sp., Pseudomonas fluorescens, Kocuria varians, and Bacillus cereus), derived from a biofilm isolated from an industrial milk pasteurization unit. We demonstrate that the growth dynamics and equilibrium composition of this biofilm are highly reproducible. Based on its equilibrium composition, we show that the establishment of this four-species biofilm is highly robust against initial, transient perturbations but less so towards continuous perturbations. By comparing biofilms formed from different numbers and combinations of the constituent species and by fitting a growth model to the experimental data, we reveal a network of dynamic, positive, and negative interactions that determine the final composition of the biofilm. Furthermore, we reveal that the molecular determinant of one negative interaction is the thiocillin I synthesized by the B. cereus strain, and demonstrate its importance for species distribution and its impact on robustness by mutational analysis of the biofilm ecosystem.
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Affiliation(s)
- Aurélie Baliarda
- INRAE, AgroParisTech, Micalis InstituteUniversité Paris‐SaclayJouy‐en‐JosasFrance
| | - Michèle Winkler
- INRAE, AgroParisTech, Micalis InstituteUniversité Paris‐SaclayJouy‐en‐JosasFrance
| | | | - Colin R. Tinsley
- INRAE, AgroParisTech, Micalis InstituteUniversité Paris‐SaclayJouy‐en‐JosasFrance
| | - Stéphane Aymerich
- INRAE, AgroParisTech, Micalis InstituteUniversité Paris‐SaclayJouy‐en‐JosasFrance
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7
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Français M, Bott R, Dargaignaratz C, Giniès C, Carlin F, Broussolle V, Nguyen-Thé C. Short-Chain and Unsaturated Fatty Acids Increase Sequentially From the Lag Phase During Cold Growth of Bacillus cereus. Front Microbiol 2021; 12:694757. [PMID: 34367095 PMCID: PMC8339379 DOI: 10.3389/fmicb.2021.694757] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 06/28/2021] [Indexed: 11/20/2022] Open
Abstract
Fatty acids of two mesophilic and one psychrotrophic strains of the foodborne pathogen Bacillus cereus were analyzed by gas chromatography coupled to mass spectrometry during growth at cold (10 and 12°C) vs. optimal (30°C) temperatures and during the whole growth process (6–7 sampling times) from lag to stationary phase. In all these strains, a sequential change of fatty acids during cold growth was observed. Fatty acids were modified as soon as the end of lag, with an increase of the short-chain fatty acids (less than 15 carbons), particularly i13. These short-chain fatty acids then reached a maximum at the beginning of growth and eventually decreased to their initial level, suggesting their importance as a rapid cold adaptation mechanism for B. cereus. In a second step, an increase in Δ5,10 di-saturated fatty acids and in monounsaturated fatty acids in Δ5 position, at the expense of unsaturation in Δ10, started during exponential phase and continued until the end of stationary phase, suggesting a role in growth consolidation and survival at cold temperatures. Among these unsaturated fatty acids, those produced by unsaturation of n16 increased in the three strains, whereas other unsaturated fatty acids increased in some strains only. This study highlights the importance of kinetic analysis of fatty acids during cold adaptation.
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Affiliation(s)
| | - Romain Bott
- INRAE, Avignon Université, UMR SQPOV, Avignon, France
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8
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Ma F, Zhou H, Yang Z, Wang C, An Y, Ni L, Liu M, Wang Y, Yu L. Gene expression profile analysis and target gene discovery of Mycobacterium tuberculosis biofilm. Appl Microbiol Biotechnol 2021; 105:5123-5134. [PMID: 34125278 DOI: 10.1007/s00253-021-11361-4] [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: 11/04/2020] [Revised: 04/27/2021] [Accepted: 05/20/2021] [Indexed: 10/21/2022]
Abstract
Tuberculosis (TB) caused by Mycobacterium tuberculosis (M. tuberculosis) is a fatal infectious disease to human health, and the drug tolerance and immune evasion of M. tuberculosis were reported to be related to its biofilm formation; however, the difficulty of M. tuberculosis biofilm culture and its unknown global mechanism impede its further research. Here, we developed a modified in vitro M. tuberculosis biofilm model with shorter culture time. Then we used Illumina RNA-seq technology to determine the global gene expression profile of M. tuberculosis H37Rv biofilms. Over 437 genes are expressed at significantly different levels in biofilm cells than in planktonic cells; among them, 153 were downregulated and 284 were upregulated. Go enrichment analysis and KEGG pathway analysis showed that genes involved in biosynthesis and metabolism of sulfur metabolism, steroid degradation, atrazine degradation, mammalian cell entry protein complex, etc. are involved in M. tuberculosis biofilm cells. Especially, ATP-binding cassette (ABC) transporters Rv1217c and Rv1218c were significantly upregulated in biofilm, whereas efflux pump inhibitors (EPIs) piperine and 1-(1-naphthylmethyl)-piperazine (NMP) inhibited biofilm formation and the expression of the Rv1217c and Rv1218c genes in a concentration-dependent manner, respectively, indicating Rv1217c and Rv1218c are potential target genes of M. tuberculosis biofilm. This study is the first RNA-Seq-based transcriptome profiling of M. tuberculosis biofilms and provides insights into a potential strategy for M. tuberculosis biofilm inhibition. KEY POINTS: • Characterize M. tuberculosis transcriptomes in biofilm cells by RNA-seq. • Inhibit the expression of Rv1217c and Rv1218c repressed biofilm formation.
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Affiliation(s)
- Fangxue Ma
- Key Laboratory for Zoonoses Research, Ministry of Education, Institute of Zoonosis, Department of Infectious Diseases, First Hospital of Jilin University, College of Veterinary Medicine, Jilin University, Changchun, 130062, China
| | - Hong Zhou
- Key Laboratory for Zoonoses Research, Ministry of Education, Institute of Zoonosis, Department of Infectious Diseases, First Hospital of Jilin University, College of Veterinary Medicine, Jilin University, Changchun, 130062, China
| | - Zhiqiang Yang
- Institute of Biomedical Sciences, School of Life Science, Shanxi University, Taiyuan, 030006, China
| | - Chao Wang
- Department of Immunology, Binzhou Medical University, Yantai, 264000, China
| | - Yanan An
- Department of Physiology, Binzhou Medical University, Yantai, 264000, China
| | - Lihui Ni
- Key Laboratory for Zoonoses Research, Ministry of Education, Institute of Zoonosis, Department of Infectious Diseases, First Hospital of Jilin University, College of Veterinary Medicine, Jilin University, Changchun, 130062, China
| | - Mingyuan Liu
- Key Laboratory for Zoonoses Research, Ministry of Education, Institute of Zoonosis, Department of Infectious Diseases, First Hospital of Jilin University, College of Veterinary Medicine, Jilin University, Changchun, 130062, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China
| | - Yang Wang
- Key Laboratory for Zoonoses Research, Ministry of Education, Institute of Zoonosis, Department of Infectious Diseases, First Hospital of Jilin University, College of Veterinary Medicine, Jilin University, Changchun, 130062, China.
| | - Lu Yu
- Key Laboratory for Zoonoses Research, Ministry of Education, Institute of Zoonosis, Department of Infectious Diseases, First Hospital of Jilin University, College of Veterinary Medicine, Jilin University, Changchun, 130062, China.
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9
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CdgL is a degenerate nucleotide cyclase domain protein affecting flagellin synthesis and motility in Bacillus thuringiensis. Res Microbiol 2021; 172:103850. [PMID: 34082027 DOI: 10.1016/j.resmic.2021.103850] [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: 10/02/2020] [Revised: 02/28/2021] [Accepted: 05/27/2021] [Indexed: 11/23/2022]
Abstract
In Bacillus subtilis, motility genes are expressed in a hierarchical pattern - governed by the σD transcription factor and other proteins such as the EpsE molecular clutch and SlrA/SlrR regulator proteins. In contrast, motile species in the Bacillus cereus group seem to express their motility genes in a non-hierarchical pattern, and less is known about their regulation, also given that no orthologs to σD, EpsE, SlrA or SlrR are found in B. cereus group genomes. Here we show that deletion of cdgL (BTB_RS26690/BTB_c54300) in Bacillus thuringiensis 407 (cry-) resulted in a six-to ten-fold downregulation of the entire motility locus, and loss of flagellar structures and swimming motility. cdgL is unique to the B. cereus group and is found in all phylogenetic clusters in the population except for group I, which comprises isolates of non-motile Bacillus pseudomycoides. Analysis of RNA-Seq data revealed cdgL to be expressed in a three-gene operon with a NupC like nucleoside transporter, and a putative glycosyl transferase for which transposon-based gene inactivation was previously shown to produce a similar phenotype to cdgL deletion. Interestingly, all three proteins were predicted to be membrane-bound and may provide a concerted function in the regulation of B. cereus group motility.
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10
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Vargas-Blanco DA, Shell SS. Regulation of mRNA Stability During Bacterial Stress Responses. Front Microbiol 2020; 11:2111. [PMID: 33013770 PMCID: PMC7509114 DOI: 10.3389/fmicb.2020.02111] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 08/11/2020] [Indexed: 12/12/2022] Open
Abstract
Bacteria have a remarkable ability to sense environmental changes, swiftly regulating their transcriptional and posttranscriptional machinery as a response. Under conditions that cause growth to slow or stop, bacteria typically stabilize their transcriptomes in what has been shown to be a conserved stress response. In recent years, diverse studies have elucidated many of the mechanisms underlying mRNA degradation, yet an understanding of the regulation of mRNA degradation under stress conditions remains elusive. In this review we discuss the diverse mechanisms that have been shown to affect mRNA stability in bacteria. While many of these mechanisms are transcript-specific, they provide insight into possible mechanisms of global mRNA stabilization. To that end, we have compiled information on how mRNA fate is affected by RNA secondary structures; interaction with ribosomes, RNA binding proteins, and small RNAs; RNA base modifications; the chemical nature of 5' ends; activity and concentration of RNases and other degradation proteins; mRNA and RNase localization; and the stringent response. We also provide an analysis of reported relationships between mRNA abundance and mRNA stability, and discuss the importance of stress-associated mRNA stabilization as a potential target for therapeutic development.
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Affiliation(s)
- Diego A Vargas-Blanco
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA, United States
| | - Scarlet S Shell
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA, United States.,Program in Bioinformatics and Computational Biology, Worcester Polytechnic Institute, Worcester, MA, United States
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11
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Abstract
RNA degradation is an important process that affects the final concentration of individual mRNAs, affecting protein expression and cellular physiology. Studies of how RNA is degraded increase our knowledge of this fundamental process as well as enable the creation of genetic tools to manipulate RNA stability. By studying global transcript turnover, we searched for sequence elements that correlated with transcript (in)stability and used these sequences to guide tool design. This study probes global RNA turnover in a cyanobacterium, Synechococcus sp. strain PCC 7002, that both has a unique array of RNases that facilitate RNA degradation and is an industrially relevant strain that could be used to convert CO2 and sunlight into useful products. RNA degradation is an important process that influences the ultimate concentration of individual proteins inside cells. While the main enzymes that facilitate this process have been identified, global maps of RNA turnover are available for only a few species. Even in these cases, there are few sequence elements that are known to enhance or destabilize a native transcript; even fewer confer the same effect when added to a heterologous transcript. To address this knowledge gap, we assayed genome-wide RNA degradation in the cyanobacterium Synechococcus sp. strain PCC 7002 by collecting total RNA samples after stopping nascent transcription with rifampin. We quantified the abundance of each position in the transcriptome as a function of time using RNA-sequencing data and later analyzed the global mRNA decay map using machine learning principles. Half-lives, calculated on a per-ORF (open reading frame) basis, were extremely short, with a median half-life of only 0.97 min. Despite extremely rapid turnover of most mRNA, transcripts encoding proteins involved in photosynthesis were both highly expressed and highly stable. Upon inspection of these stable transcripts, we identified an enriched motif in the 3′ untranslated region (UTR) that had similarity to Rho-independent terminators. We built statistical models for half-life prediction and used them to systematically identify sequence motifs in both 5′ and 3′ UTRs that correlate with stabilized transcripts. We found that transcripts linked to a terminator containing a poly(U) tract had a longer half-life than both those without a poly(U) tract and those without a terminator. IMPORTANCE RNA degradation is an important process that affects the final concentration of individual mRNAs, affecting protein expression and cellular physiology. Studies of how RNA is degraded increase our knowledge of this fundamental process as well as enable the creation of genetic tools to manipulate RNA stability. By studying global transcript turnover, we searched for sequence elements that correlated with transcript (in)stability and used these sequences to guide tool design. This study probes global RNA turnover in a cyanobacterium, Synechococcus sp. strain PCC 7002, that both has a unique array of RNases that facilitate RNA degradation and is an industrially relevant strain that could be used to convert CO2 and sunlight into useful products.
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12
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Xu Z, Asakawa S. Physiological RNA dynamics in RNA-Seq analysis. Brief Bioinform 2020; 20:1725-1733. [PMID: 30010714 DOI: 10.1093/bib/bby045] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 04/24/2018] [Indexed: 02/06/2023] Open
Abstract
Physiological RNA dynamics cause problems in transcriptome analysis. Physiological RNA accumulation affects the analysis of RNA quantification, and physiological RNA degradation affects the analysis of the RNA sequence length, feature site and quantification. In the present article, we review the effects of physiological degradation and accumulation of RNA on analysing RNA sequencing data. Physiological RNA accumulation and degradation probably led to such phenomena as incorrect estimations of transcription quantification, differential expressions, co-expressions, RNA decay rates, alternative splicing, boundaries of transcription, novel genes, new single-nucleotide polymorphisms, small RNAs and gene fusion. Thus, the transcriptomic data obtained up to date warrant further scrutiny. New and improved techniques and bioinformatics software are needed to produce accurate data in transcriptome research.
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Affiliation(s)
- Zhongneng Xu
- Department of Ecology, Jinan University, Guangzhou 510632, China
| | - Shuichi Asakawa
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Science, The University of Tokyo, Tokyo 113-8657, Japan
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13
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Yan H, Cheng Y, Wang L, Chen W. Function analysis of RNase E in the filamentous cyanobacterium Anabaena sp. PCC 7120. Res Microbiol 2020; 171:194-202. [PMID: 32590060 DOI: 10.1016/j.resmic.2020.06.001] [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: 01/04/2020] [Revised: 05/30/2020] [Accepted: 06/03/2020] [Indexed: 10/24/2022]
Abstract
RNase E is an endoribonuclease and plays a central role in RNA metabolism. Cyanobacteria, as ancient oxygen-producing photosynthetic bacteria, also contain RNase E homologues. Here, we introduced mutations into the S1 subdomain (F53A), the 5'-sensor subdomain (R160A), and the DNase I subdomain (D296A) according to the key activity sites of Escherichia coli RNase E. The results of degradation assays demonstrated that Asp296 is important to RNase E activity in Anabaena sp. PCC 7120 (hereafter PCC 7120). The docking model of RNase E in PCC 7120 (AnaRne) and RNA suggested a possible recognition mechanism of AnaRne to RNA. Moreover, overexpression of AnaRne and its N-terminal catalytic domain (AnaRneN) in vivo led to the abnormal cell division and inhibited the growth of PCC 7120. The quantitative analysis showed a significant decrease of ftsZ transcription in the case of overexpression of AnaRne or AnaRneN and ftsZ mRNA could be directly degraded by AnaRne through degradation assays in vitro, indicating that AnaRne was related to the expression of ftsZ and eventually affected cell division. In essence, our studies expand the understanding of the structural and functional evolutionary basis of RNase E and lay a foundation for further analysis of RNA metabolism in cyanobacteria.
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Affiliation(s)
- Huaduo Yan
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Yarui Cheng
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Li Wang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Wenli Chen
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
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14
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Lacoux C, Fouquier d'Hérouël A, Wessner-Le Bohec F, Innocenti N, Bohn C, Kennedy SP, Rochat T, Bonnin RA, Serror P, Aurell E, Bouloc P, Repoila F. Dynamic insights on transcription initiation and RNA processing during bacterial adaptation. RNA (NEW YORK, N.Y.) 2020; 26:382-395. [PMID: 31992590 PMCID: PMC7075262 DOI: 10.1261/rna.073288.119] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 01/20/2020] [Indexed: 05/04/2023]
Abstract
Transcription initiation and RNA processing govern gene expression and enable bacterial adaptation by reshaping the RNA landscape. The aim of this study was to simultaneously observe these two fundamental processes in a transcriptome responding to an environmental signal. A controlled σE system in E. coli was coupled to our previously described tagRNA-seq method to yield process kinetics information. Changes in transcription initiation frequencies (TIF) and RNA processing frequencies (PF) were followed using 5' RNA tags. Changes in TIF showed a binary increased/decreased pattern that alternated between transcriptionally activated and repressed promoters, providing the bacterial population with transcriptional oscillation. PF variation fell into three categories of cleavage activity: (i) constant and independent of RNA levels, (ii) increased once RNA has accumulated, and (iii) positively correlated to changes in TIF. This work provides a comprehensive and dynamic view of major events leading to transcriptomic reshaping during bacterial adaptation. It unveils an interplay between transcription initiation and the activity of specific RNA cleavage sites. This study utilized a well-known genetic system to analyze fundamental processes and can serve as a blueprint for comprehensive studies that exploit the RNA metabolism to decipher and understand bacterial gene expression control.
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Affiliation(s)
- Caroline Lacoux
- Université Paris-Saclay, INRAE, AgroParisTech, MIcalis Institute, 78350, Jouy-en-Josas, France
| | | | | | - Nicolas Innocenti
- Université Paris-Saclay, INRAE, AgroParisTech, MIcalis Institute, 78350, Jouy-en-Josas, France
- Department of Computational Biology, Royal Institute of Technology, AlbaNova University Center, SE-10691 Stockholm, Sweden
| | - Chantal Bohn
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Sean P Kennedy
- Department of Computational Biology, USR3756 CNRS, Institut Pasteur, 75 015 Paris, France
| | - Tatiana Rochat
- VIM, INRA, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Rémy A Bonnin
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Pascale Serror
- Université Paris-Saclay, INRAE, AgroParisTech, MIcalis Institute, 78350, Jouy-en-Josas, France
| | - Erik Aurell
- Department of Computational Biology, Royal Institute of Technology, AlbaNova University Center, SE-10691 Stockholm, Sweden
| | - Philippe Bouloc
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Francis Repoila
- Université Paris-Saclay, INRAE, AgroParisTech, MIcalis Institute, 78350, Jouy-en-Josas, France
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15
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Gray WT, Govers SK, Xiang Y, Parry BR, Campos M, Kim S, Jacobs-Wagner C. Nucleoid Size Scaling and Intracellular Organization of Translation across Bacteria. Cell 2020; 177:1632-1648.e20. [PMID: 31150626 DOI: 10.1016/j.cell.2019.05.017] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 04/01/2019] [Accepted: 05/08/2019] [Indexed: 01/10/2023]
Abstract
The scaling of organelles with cell size is thought to be exclusive to eukaryotes. Here, we demonstrate that similar scaling relationships hold for the bacterial nucleoid. Despite the absence of a nuclear membrane, nucleoid size strongly correlates with cell size, independent of changes in DNA amount and across various nutrient conditions. This correlation is observed in diverse bacteria, revealing a near-constant ratio between nucleoid and cell size for a given species. As in eukaryotes, the nucleocytoplasmic ratio in bacteria varies greatly among species. This spectrum of nucleocytoplasmic ratios is independent of genome size, and instead it appears linked to the average population cell size. Bacteria with different nucleocytoplasmic ratios have a cytoplasm with different biophysical properties, impacting ribosome mobility and localization. Together, our findings identify new organizational principles and biophysical features of bacterial cells, implicating the nucleocytoplasmic ratio and cell size as determinants of the intracellular organization of translation.
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Affiliation(s)
- William T Gray
- Microbial Sciences Institute, Yale University, West Haven, CT, USA; Department of Pharmacology, Yale University, New Haven, CT, USA
| | - Sander K Govers
- Microbial Sciences Institute, Yale University, West Haven, CT, USA; Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Yingjie Xiang
- Microbial Sciences Institute, Yale University, West Haven, CT, USA; Department of Mechanical Engineering and Materials Science, Yale University, New Haven, CT, USA
| | - Bradley R Parry
- Microbial Sciences Institute, Yale University, West Haven, CT, USA; Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Manuel Campos
- Microbial Sciences Institute, Yale University, West Haven, CT, USA; Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Sangjin Kim
- Microbial Sciences Institute, Yale University, West Haven, CT, USA; Department of Mechanical Engineering and Materials Science, Yale University, New Haven, CT, USA
| | - Christine Jacobs-Wagner
- Microbial Sciences Institute, Yale University, West Haven, CT, USA; Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA; Howard Hughes Medical Institute, Yale University, New Haven, CT, USA; Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, CT, USA.
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16
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Biofilm formation displays intrinsic offensive and defensive features of Bacillus cereus. NPJ Biofilms Microbiomes 2020; 6:3. [PMID: 31969984 PMCID: PMC6962202 DOI: 10.1038/s41522-019-0112-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 12/16/2019] [Indexed: 12/14/2022] Open
Abstract
Biofilm formation is a strategy of many bacterial species to adapt to a variety of stresses and has become a part of infections, contaminations, or beneficial interactions. In this study, we demonstrate that profound physiological changes permit Bacillus cereus to switch from a floating to a sessile lifestyle, to undergo further maturation of the biofilm and to differentiate into the offensive or defensive features. We report that floating and biofilm cells are populations that differentiate metabolically, with members of each subpopulation developing different branches of certain metabolic pathways. Secondly, biofilm populations rearrange nucleotides, sugars, amino acids, and energy metabolism. Thirdly, this metabolic rearrangement coexists with: the synthesis of the extracellular matrix, sporulation, reinforcement of the cell wall, activation of the ROS detoxification machinery and production of secondary metabolites. This strategy contributes to defend biofilm cells from competitors. However, floating cells maintain a fermentative metabolic status that ensures a higher aggressiveness against hosts, evidenced by the production of toxins. The maintenance of the two distinct subpopulations is an effective strategy to face different environmental conditions found in the life styles of B. cereus.
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17
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Steiner PA, De Corte D, Geijo J, Mena C, Yokokawa T, Rattei T, Herndl GJ, Sintes E. Highly variable mRNA half-life time within marine bacterial taxa and functional genes. Environ Microbiol 2019; 21:3873-3884. [PMID: 31298776 PMCID: PMC7379614 DOI: 10.1111/1462-2920.14737] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 07/08/2019] [Accepted: 07/09/2019] [Indexed: 02/04/2023]
Abstract
Messenger RNA can provide valuable insights into the variability of metabolic processes of microorganisms. However, due to uncertainties that include the stability of RNA, its application for activity profiling of environmental samples is questionable. We explored different factors affecting the decay rate of transcripts of three marine bacterial isolates using qPCR and determined mRNA half‐life time of specific bacterial taxa and of functional genes by metatranscriptomics of a coastal environmental prokaryotic community. The half‐life time of transcripts from 11 genes from bacterial isolates ranged from 1 to 46 min. About 80% of the analysed transcripts exhibited half‐live times shorter than 10 min. Significant differences were found in the half‐life time between mRNA and rRNA. The half‐life time of mRNA obtained from a coastal metatranscriptome ranged from 9 to 400 min. The shortest half‐life times of the metatranscriptome corresponded to transcripts from the same clusters of orthologous groups (COGs) in all bacterial classes. The prevalence of short mRNA half‐life time in genes related to defence mechanisms and motility indicate a tight connection of RNA decay rate to environmental stressors. The short half‐life time of RNA and its high variability needs to be considered when assessing metatranscriptomes especially in environmental samples.
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Affiliation(s)
- Paul A Steiner
- Limnology and Bio-Oceanography, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
| | - Daniele De Corte
- Marine Functional Biology Group, Research and Development Center for Marine Biosciences, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Natushima 2-15, Yokosuka, Kanagawa, Japan
| | - Javier Geijo
- Department of Microbiology and Ecosystem Science, Division of Computational Systems Biology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
| | - Catalina Mena
- Instituto Español de Oceanografia, Centre Oceanogràfic de les Balears, Moll de Ponent s/n, 07015, Palma, Spain
| | - Taichi Yokokawa
- Institute for Extra-cutting-edge Science and Technology Avant-garde Research (X-star), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Natushima 2-15, Yokosuka, Kanagawa, Japan
| | - Thomas Rattei
- Department of Microbiology and Ecosystem Science, Division of Computational Systems Biology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
| | - Gerhard J Herndl
- Limnology and Bio-Oceanography, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria.,Department of Marine Microbiology and Biogeochemistry, Royal Netherlands Institute for Sea Research, Utrecht University, PO Box 59, Alberta Den Burg, 1790, The Netherlands
| | - Eva Sintes
- Limnology and Bio-Oceanography, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria.,Instituto Español de Oceanografia, Centre Oceanogràfic de les Balears, Moll de Ponent s/n, 07015, Palma, Spain
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18
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Bacillus cereus cshA Is Expressed during the Lag Phase of Growth and Serves as a Potential Marker of Early Adaptation to Low Temperature and pH. Appl Environ Microbiol 2019; 85:AEM.00486-19. [PMID: 31076436 PMCID: PMC6606889 DOI: 10.1128/aem.00486-19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 05/01/2019] [Indexed: 12/14/2022] Open
Abstract
The spore-forming bacterium B. cereus is a major cause of foodborne outbreaks in Europe. Some B. cereus strains can grow at low temperatures and low pH in many processed foods. Modeling of the bacterial lag time is hampered by a lack of knowledge of the timing of events occurring during this phase. In this context, the identification of lag phase markers, not currently available, could be a real advance for the better prediction of lag time duration. Currently, no molecular markers of this phase are available. By determining that cshA was always expressed early during the lag phase, we provide a molecular marker of the early adaptation process of B. cereus cells when exposed to low temperature and pH. Bacterial adaptation is characterized by a lag phase during which cells do not multiply or modify their physiology to cope with the constraints of their environment. Our aim was to determine a sequence of events during the lag phase of growth at low temperature and pH for three Bacillus cereus strains. The onsets of expression of two genes, one of which is essential for stress adaptation (cshA, coding for a RNA helicase) and one of which is involved in the transition between lag phase and exponential phase (abrB, coding for a transition regulator), were determined using fluorescent transcriptional reporter systems. Regardless of the stressing conditions and the tested strains, the cshA promoter was active very early, while the biomass increased and always did so before the first cell division. At 12°C and pH 7.0, the onset of cshA promoter activity occurred at between 3 h and 7 h, while the bacterial counts started to increase at between 12 h and 13 h. At pH 5.0 and at 20°C or 30°C, the onset of cshA promoter activity occurred before 1 h and earlier than at pH 7.0. In contrast, the onset of abrB promoter activity depended on the strain and the stressing conditions. In the ATCC 14579 strain, the onset of abrB promoter activity always started at between 30 min and 3 h, before biomass increased and cell division occurred. For the other strains, it took place along with the first cell division at 12°C but did so much later during growth under the other tested conditions. IMPORTANCE The spore-forming bacterium B. cereus is a major cause of foodborne outbreaks in Europe. Some B. cereus strains can grow at low temperatures and low pH in many processed foods. Modeling of the bacterial lag time is hampered by a lack of knowledge of the timing of events occurring during this phase. In this context, the identification of lag phase markers, not currently available, could be a real advance for the better prediction of lag time duration. Currently, no molecular markers of this phase are available. By determining that cshA was always expressed early during the lag phase, we provide a molecular marker of the early adaptation process of B. cereus cells when exposed to low temperature and pH.
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19
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Gordon GC, Pfleger BF. Regulatory Tools for Controlling Gene Expression in Cyanobacteria. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1080:281-315. [PMID: 30091100 PMCID: PMC6662922 DOI: 10.1007/978-981-13-0854-3_12] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Cyanobacteria are attractive hosts for converting carbon dioxide and sunlight into desirable chemical products. To engineer these organisms and manipulate their metabolic pathways, the biotechnology community has developed genetic tools to control gene expression. Many native cyanobacterial promoters and related sequence elements have been used to regulate genes of interest, and heterologous tools that use non-native small molecules to induce gene expression have been demonstrated. Overall, IPTG-based induction systems seem to be leaky and initially demonstrate small dynamic ranges in cyanobacteria. Consequently, a variety of other induction systems have been optimized to enable tighter control of gene expression. Tools require significant optimization because they function quite differently in cyanobacteria when compared to analogous use in model heterotrophs. We hypothesize that these differences are due to fundamental differences in physiology between organisms. This review is not intended to summarize all known products made in cyanobacteria nor the performance (titer, rate, yield) of individual strains, but instead will focus on the genetic tools and the inherent aspects of cellular physiology that influence gene expression in cyanobacteria.
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Affiliation(s)
- Gina C Gordon
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI, USA
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, WI, USA
| | - Brian F Pfleger
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI, USA.
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, WI, USA.
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20
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Potts AH, Guo Y, Ahmer BMM, Romeo T. Role of CsrA in stress responses and metabolism important for Salmonella virulence revealed by integrated transcriptomics. PLoS One 2019; 14:e0211430. [PMID: 30682134 PMCID: PMC6347204 DOI: 10.1371/journal.pone.0211430] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 01/14/2019] [Indexed: 12/31/2022] Open
Abstract
To cause infection, Salmonella must survive and replicate in host niches that present dramatically different environmental conditions. This requires a flexible metabolism and physiology, responsive to conditions of the local milieu. The sequence specific RNA binding protein CsrA serves as a global regulator that governs gene expression required for pathogenicity, metabolism, biofilm formation, and motility in response to nutritional conditions. Its activity is determined by two noncoding small RNAs (sRNA), CsrB and CsrC, which sequester and antagonize this protein. Here, we used ribosome profiling and RNA-seq analysis to comprehensively examine the effects of CsrA on mRNA occupancy with ribosomes, a measure of translation, transcript stability, and the steady state levels of transcripts under in vitro SPI-1 inducing conditions, to simulate growth in the intestinal lumen, and under in vitro SPI-2-inducing conditions, to simulate growth in the Salmonella containing vacuole (SCV) of the macrophage. Our findings uncovered new roles for CsrA in controlling the expression of structural and regulatory genes involved in stress responses, metabolism, and virulence systems required for infection. We observed substantial variation in the CsrA regulon under the two growth conditions. In addition, CsrB/C sRNA levels were greatly reduced under the simulated intracellular conditions and were responsive to nutritional factors that distinguish the intracellular and luminal environments. Altogether, our results reveal CsrA to be a flexible regulator, which is inferred to be intimately involved in maintaining the distinct gene expression patterns associated with growth in the intestine and the macrophage.
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Affiliation(s)
- Anastasia H Potts
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States of America
| | - Yinping Guo
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States of America
| | - Brian M M Ahmer
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH, United States of America
| | - Tony Romeo
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States of America
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21
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Cheng Y, Zang H, Wang H, Li D, Li C. Global transcriptomic analysis of Rhodococcus erythropolis D310-1 in responding to chlorimuron-ethyl. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2018; 157:111-120. [PMID: 29614448 DOI: 10.1016/j.ecoenv.2018.03.074] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Revised: 03/24/2018] [Accepted: 03/27/2018] [Indexed: 06/08/2023]
Abstract
Chlorimuron-ethyl is a typical long-term residual sulfonylurea herbicide whose long period of residence poses a serious hazard to rotational crops. Microbial degradation is considered to be the most acceptable method for its removal, but the degradation mechanism is not clear. In this work, we investigated gene expression changes during the degradation of chlorimuron-ethyl by an effective chlorimuron-ethyl-degrading bacterium, Rhodococcus erythropolis D310-1. The genes that correspond to this degradation and their mode of action were identified using RNA-Seq and qRT-PCR. The RNA-Seq results revealed that 500 genes were up-regulated during chlorimuron-ethyl degradation by strain D310-1. KEGG annotation showed that the dominant metabolic pathways were "Toluene degradation" and "Aminobenzoate degradation". Combining GO and KEGG classification with the relevant literature, we predicted that cytochrome P-450, carboxylesterase, and monooxygenase were involved in metabolic chlorimuron-ethyl biodegradation and that the enzyme active site and mode of action coincided with the degradation pathway proposed in our previous study. qRT-PCR experiments suggested that the R. erythropolis D310-1 carboxylesterase, cytochrome P-450 and glycosyltransferase genes were the key genes expressed during chlorimuron-ethyl biodegradation. To the best of our knowledge, this report is the first to describe the transcriptome analysis of a Rhodococcus species during the degradation of chlorimuron-ethyl.
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Affiliation(s)
- Yi Cheng
- College of Science, China Agricultural University, Beijing 100083, PR China
| | - Hailian Zang
- College of Resources and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China
| | - Hailan Wang
- College of Resources and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China
| | - Dapeng Li
- College of Resources and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China
| | - Chunyan Li
- College of Resources and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China.
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22
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Stevens JT, Carothers JM. Programming Gene Expression by Engineering Transcript Stability Control and Processing in Bacteria. Synth Biol (Oxf) 2018. [DOI: 10.1002/9783527688104.ch10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Jason T. Stevens
- University of Washington; Center for Synthetic Biology, Molecular Engineering and Sciences Institute, Departments of Chemical Engineering and Bioengineering; 4000 15th Ave NE, Seattle WA 98195-1654 USA
| | - James M. Carothers
- University of Washington; Center for Synthetic Biology, Molecular Engineering and Sciences Institute, Departments of Chemical Engineering and Bioengineering; 4000 15th Ave NE, Seattle WA 98195-1654 USA
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23
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Hör J, Gorski SA, Vogel J. Bacterial RNA Biology on a Genome Scale. Mol Cell 2018; 70:785-799. [PMID: 29358079 DOI: 10.1016/j.molcel.2017.12.023] [Citation(s) in RCA: 125] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Revised: 12/11/2017] [Accepted: 12/22/2017] [Indexed: 12/16/2022]
Abstract
Bacteria are an exceedingly diverse group of organisms whose molecular exploration is experiencing a renaissance. While the classical view of bacterial gene expression was relatively simple, the emerging view is more complex, encompassing extensive post-transcriptional control involving riboswitches, RNA thermometers, and regulatory small RNAs (sRNAs) associated with the RNA-binding proteins CsrA, Hfq, and ProQ, as well as CRISPR/Cas systems that are programmed by RNAs. Moreover, increasing interest in members of the human microbiota and environmental microbial communities has highlighted the importance of understudied bacterial species with largely unknown transcriptome structures and RNA-based control mechanisms. Collectively, this creates a need for global RNA biology approaches that can rapidly and comprehensively analyze the RNA composition of a bacterium of interest. We review such approaches with a focus on RNA-seq as a versatile tool to investigate the different layers of gene expression in which RNA is made, processed, regulated, modified, translated, and turned over.
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Affiliation(s)
- Jens Hör
- Institute of Molecular Infection Biology, University of Würzburg, 97080 Würzburg, Germany
| | - Stanislaw A Gorski
- Institute of Molecular Infection Biology, University of Würzburg, 97080 Würzburg, Germany
| | - 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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24
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Bernardini A, Martínez JL. Genome-wide analysis shows that RNase G plays a global role in the stability of mRNAs in Stenotrophomonas maltophilia. Sci Rep 2017; 7:16016. [PMID: 29167539 PMCID: PMC5700063 DOI: 10.1038/s41598-017-16091-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 11/07/2017] [Indexed: 11/28/2022] Open
Abstract
Gene expression is determined by critical processes such as RNA synthesis and degradation. Ribonucleases participate in the coordinated and differential decay of messenger RNAs. We describe a suitable method of normalization and calculation of mRNAs half-life values quantified by RNA-Seq. We determined the mRNA half-lives of more than 2000 genes in Stenotrophomonas maltophilia D457 and in an isogenic RNase G deficient mutant. Median half-lives were 2,74 and 3 min in the wild-type and the rng-deficient strain, respectively. The absence of RNase G resulted in an overall enhancement of mRNA half-life times, showing that many RNAs are targets of RNase G in S. maltophilia. Around 40 genes are likely to be regulated directly by RNase G since their half-lives were more than two-fold higher in the rng-deficient mutant. Gene length, GC content or expression levels did not correlate with mRNAs lifetimes, although groups of genes with different functions showed different RNA half-lives. Further, we predicted 1542 gene pairs to be part of the same operons in S. maltophilia. In contrast to what was described for other bacteria, our data indicate that RNase G has a global role in mRNA stability and consequently in the regulation of S. maltophilia gene expression.
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Affiliation(s)
| | - José L Martínez
- Centro Nacional de Biotecnología, CSIC, Darwin 3, 28049, Madrid, Spain.
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25
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Ferreira R, Borges V, Borrego MJ, Gomes JP. Global survey of mRNA levels and decay rates of Chlamydia trachomatis trachoma and lymphogranuloma venereum biovars. Heliyon 2017; 3:e00364. [PMID: 28795162 PMCID: PMC5541142 DOI: 10.1016/j.heliyon.2017.e00364] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 07/18/2017] [Indexed: 12/15/2022] Open
Abstract
Interpreting the intricate bacterial transcriptomics implies understanding the dynamic relationship established between de novo transcription and the degradation of transcripts. Here, we performed a comparative overview of gene expression levels and mRNA decay rates for different-biovar (trachoma and lymphogranuloma venereum) strains of the obligate intracellular bacterium Chlamydia trachomatis. By using RNA-sequencing to measure gene expression levels at mid developmental stage and mRNA decay rates upon rifampicin-based transcription blockage, we observed that: i) 60-70% of the top-50 expressed genes encode proteins with unknown function and proteins involved in "Translation, ribosomal structure and biogenesis" for all strains; ii) the expression ranking by genes' functional categories was in general concordant among different-biovar strains; iii) the median of the half-life time (t1/2) values of transcripts were 15-17 min, indicating that the degree of transcripts' stability seems to correlate with the bacterial intracellular life-style, as these values are considerably higher than the ones observed in other studies for facultative intracellular and free-living bacteria; iv) transcript decay rates were highly heterogeneous within each C. trachomatis strain and did not correlate with steady-state expression levels; v) only at very few instances (essentially at gene functional category level) was possible to unveil dissimilarities potentially underlying phenotypic differences between biovars. In summary, the unveiled transcriptomic scenario, marked by a general lack of correlation between transcript production and degradation and a huge inter-transcript heterogeneity in decay rates, likely reflects the challenges underlying the unique biphasic developmental cycle of C. trachomatis and its intricate interactions with the human host, which probably exacerbate the complexity of the bacterial transcription regulation.
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Affiliation(s)
- Rita Ferreira
- Reference Laboratory of Bacterial Sexually Transmitted Infections, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal
| | - Vítor Borges
- Reference Laboratory of Bacterial Sexually Transmitted Infections, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal.,Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal
| | - Maria José Borrego
- Reference Laboratory of Bacterial Sexually Transmitted Infections, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal
| | - João Paulo Gomes
- Reference Laboratory of Bacterial Sexually Transmitted Infections, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal.,Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal
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26
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Hassan KA, Fagerlund A, Elbourne LDH, Vörös A, Kroeger JK, Simm R, Tourasse NJ, Finke S, Henderson PJF, Økstad OA, Paulsen IT, Kolstø AB. The putative drug efflux systems of the Bacillus cereus group. PLoS One 2017; 12:e0176188. [PMID: 28472044 PMCID: PMC5417439 DOI: 10.1371/journal.pone.0176188] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 04/06/2017] [Indexed: 12/19/2022] Open
Abstract
The Bacillus cereus group of bacteria includes seven closely related species, three of which, B. anthracis, B. cereus and B. thuringiensis, are pathogens of humans, animals and/or insects. Preliminary investigations into the transport capabilities of different bacterial lineages suggested that genes encoding putative efflux systems were unusually abundant in the B. cereus group compared to other bacteria. To explore the drug efflux potential of the B. cereus group all putative efflux systems were identified in the genomes of prototypical strains of B. cereus, B. anthracis and B. thuringiensis using our Transporter Automated Annotation Pipeline. More than 90 putative drug efflux systems were found within each of these strains, accounting for up to 2.7% of their protein coding potential. Comparative analyses demonstrated that the efflux systems are highly conserved between these species; 70-80% of the putative efflux pumps were shared between all three strains studied. Furthermore, 82% of the putative efflux system proteins encoded by the prototypical B. cereus strain ATCC 14579 (type strain) were found to be conserved in at least 80% of 169 B. cereus group strains that have high quality genome sequences available. However, only a handful of these efflux pumps have been functionally characterized. Deletion of individual efflux pump genes from B. cereus typically had little impact to drug resistance phenotypes or the general fitness of the strains, possibly because of the large numbers of alternative efflux systems that may have overlapping substrate specificities. Therefore, to gain insight into the possible transport functions of efflux systems in B. cereus, we undertook large-scale qRT-PCR analyses of efflux pump gene expression following drug shocks and other stress treatments. Clustering of gene expression changes identified several groups of similarly regulated systems that may have overlapping drug resistance functions. In this article we review current knowledge of the small molecule efflux pumps encoded by the B. cereus group and suggest the likely functions of numerous uncharacterised pumps.
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Affiliation(s)
- Karl A. Hassan
- Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW, Australia
- School of BioMedical Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom
| | - Annette Fagerlund
- Laboratory for Microbial Dynamics (LaMDa), Section for Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway
| | - Liam D. H. Elbourne
- Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW, Australia
| | - Aniko Vörös
- Laboratory for Microbial Dynamics (LaMDa), Section for Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway
| | - Jasmin K. Kroeger
- Laboratory for Microbial Dynamics (LaMDa), Section for Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway
- Institut für Pharmazeutische Biologie und Biotechnologie, Albert-Ludwigs Universität, Freiburg, Germany
| | - Roger Simm
- Laboratory for Microbial Dynamics (LaMDa), Section for Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway
| | - Nicolas J. Tourasse
- Laboratory for Microbial Dynamics (LaMDa), Section for Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway
| | - Sarah Finke
- Laboratory for Microbial Dynamics (LaMDa), Section for Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway
- Centre for Integrative Microbial Evolution (CIME), Faculty of Mathematics and Natural Sciences, University of Oslo, 0316 Oslo, Norway
| | - Peter J. F. Henderson
- School of BioMedical Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom
| | - Ole Andreas Økstad
- Laboratory for Microbial Dynamics (LaMDa), Section for Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway
- Centre for Integrative Microbial Evolution (CIME), Faculty of Mathematics and Natural Sciences, University of Oslo, 0316 Oslo, Norway
| | - Ian T. Paulsen
- Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW, Australia
- * E-mail: (ABK); (ITP)
| | - Anne-Brit Kolstø
- Laboratory for Microbial Dynamics (LaMDa), Section for Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway
- Centre for Integrative Microbial Evolution (CIME), Faculty of Mathematics and Natural Sciences, University of Oslo, 0316 Oslo, Norway
- * E-mail: (ABK); (ITP)
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27
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Jeong Y, Shin H, Seo SW, Kim D, Cho S, Cho BK. Elucidation of bacterial translation regulatory networks. ACTA ACUST UNITED AC 2017. [DOI: 10.1016/j.coisb.2017.01.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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28
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Cho KH. The Structure and Function of the Gram-Positive Bacterial RNA Degradosome. Front Microbiol 2017; 8:154. [PMID: 28217125 PMCID: PMC5289998 DOI: 10.3389/fmicb.2017.00154] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 01/20/2017] [Indexed: 11/24/2022] Open
Abstract
The RNA degradosome is a highly structured protein complex responsible for bulk RNA decay in bacteria. The main components of the complex, ribonucleases, an RNA helicase, and glycolytic enzymes are well-conserved in bacteria. Some components of the degradosome are essential for growth and the disruption of degradosome formation causes slower growth, indicating that this complex is required for proper cellular function. The study of the Escherichia coli degradosome has been performed extensively for the last several decades and has revealed detailed information on its structure and function. On the contrary, the Gram-positive bacterial degradosome, which contains ribonucleases different from the E. coli one, has been studied only recently. Studies on the Gram-positive degradosome revealed that its major component RNase Y was necessary for the full virulence of medically important Gram-positive bacterial pathogens, suggesting that it could be a target of antimicrobial therapy. This review describes the structures and function of Gram-positive bacterial RNA degradosomes, especially those of a Gram-positive model organism Bacillus subtilis, and two important Gram-positive pathogens, Staphylococcus aureus and Streptococcus pyogenes.
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Affiliation(s)
- Kyu Hong Cho
- Department of Biology, Indiana State University Terre Haute, IN, USA
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29
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Peterson JR, Thor S, Kohler L, Kohler PR, Metcalf WW, Luthey-Schulten Z. Genome-wide gene expression and RNA half-life measurements allow predictions of regulation and metabolic behavior in Methanosarcina acetivorans. BMC Genomics 2016; 17:924. [PMID: 27852217 PMCID: PMC5112694 DOI: 10.1186/s12864-016-3219-8] [Citation(s) in RCA: 16] [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: 07/15/2016] [Accepted: 10/26/2016] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND While a few studies on the variations in mRNA expression and half-lives measured under different growth conditions have been used to predict patterns of regulation in bacterial organisms, the extent to which this information can also play a role in defining metabolic phenotypes has yet to be examined systematically. Here we present the first comprehensive study for a model methanogen. RESULTS We use expression and half-life data for the methanogen Methanosarcina acetivorans growing on fast- and slow-growth substrates to examine the regulation of its genes. Unlike Escherichia coli where only small shifts in half-lives were observed, we found that most mRNA have significantly longer half-lives for slow growth on acetate compared to fast growth on methanol or trimethylamine. Interestingly, half-life shifts are not uniform across functional classes of enzymes, suggesting the existence of a selective stabilization mechanism for mRNAs. Using the transcriptomics data we determined whether transcription or degradation rate controls the change in transcript abundance. Degradation was found to control abundance for about half of the metabolic genes underscoring its role in regulating metabolism. Genes involved in half of the metabolic reactions were found to be differentially expressed among the substrates suggesting the existence of drastically different metabolic phenotypes that extend beyond just the methanogenesis pathways. By integrating expression data with an updated metabolic model of the organism (iST807) significant differences in pathway flux and production of metabolites were predicted for the three growth substrates. CONCLUSIONS This study provides the first global picture of differential expression and half-lives for a class II methanogen, as well as provides the first evidence in a single organism that drastic genome-wide shifts in RNA half-lives can be modulated by growth substrate. We determined which genes in each metabolic pathway control the flux and classified them as regulated by transcription (e.g. transcription factor) or degradation (e.g. post-transcriptional modification). We found that more than half of genes in metabolism were controlled by degradation. Our results suggest that M. acetivorans employs extensive post-transcriptional regulation to optimize key metabolic steps, and more generally that degradation could play a much greater role in optimizing an organism's metabolism than previously thought.
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Affiliation(s)
- Joseph R. Peterson
- Department of Chemistry, University of Illinois at Urbana-Champaign, 505 S Mathews Ave, Urbana, 60801 IL USA
| | - ShengShee Thor
- Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, 1110 W Green St, Urbana, 60801 IL USA
| | - Lars Kohler
- Department of Chemistry, University of Illinois at Urbana-Champaign, 505 S Mathews Ave, Urbana, 60801 IL USA
| | - Petra R.A. Kohler
- Department of Microbiology, University of Illinois at Urbana-Champaign, 601 S Goodwin AveIL, Urbana, 60801 USA
| | - William W. Metcalf
- Department of Microbiology, University of Illinois at Urbana-Champaign, 601 S Goodwin AveIL, Urbana, 60801 USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W Gregory DrIL, Urbana, 60801 USA
| | - Zaida Luthey-Schulten
- Department of Chemistry, University of Illinois at Urbana-Champaign, 505 S Mathews Ave, Urbana, 60801 IL USA
- Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, 1110 W Green St, Urbana, 60801 IL USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W Gregory DrIL, Urbana, 60801 USA
- Beckman Institute, University of Illinois at Urbana-Champaign, 405 N Mathews Ave, Urbana, 60801 IL USA
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30
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Alqarni B, Colley B, Klebensberger J, McDougald D, Rice SA. Expression stability of 13 housekeeping genes during carbon starvation of Pseudomonas aeruginosa. J Microbiol Methods 2016; 127:182-187. [PMID: 27297333 DOI: 10.1016/j.mimet.2016.06.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2016] [Revised: 06/09/2016] [Accepted: 06/09/2016] [Indexed: 11/29/2022]
Abstract
Quantitative real-time polymerase chain reaction (qRT-PCR) is a reliable technique for quantifying mRNA levels when normalised by a stable reference gene/s. Many putative reference genes are known to be affected by physiological stresses, such as nutrient limitation and hence may not be suitable for normalisation. In this study of Pseudomonas aeruginosa, the expression of 13 commonly used reference genes, rpoS, proC, recA, rpsL, rho, oprL, anr, tipA, nadB, fabD, ampC, algD and gyrA, were analysed for changes in expression under carbon starvation and nutrient replete conditions. The results showed that rpoS was the only stably expressed housekeeping gene during carbon starvation. In contrast, other commonly used housekeeping genes were shown to vary by as much as 10-100 fold under starvation conditions. This study has identified a suitable reference gene for qRT-PCR in P. aeruginosa during carbon starvation. The results presented here highlight the need to validate housekeeping genes under the chosen experimental conditions.
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Affiliation(s)
- Budoor Alqarni
- Centre for Marine Bio-Innovation, Earth and Environmental Sciences, The University of New South Wales, Sydney, New South Wales, Australia; The School of Biotechnology and Biomolecular Sciences, Earth and Environmental Sciences, The University of New South Wales, Sydney, New South Wales, Australia
| | - Brendan Colley
- Centre for Marine Bio-Innovation, Earth and Environmental Sciences, The University of New South Wales, Sydney, New South Wales, Australia; The School of Biotechnology and Biomolecular Sciences, Earth and Environmental Sciences, The University of New South Wales, Sydney, New South Wales, Australia
| | - Janosch Klebensberger
- University of Stuttgart, Institute of Technical Biochemistry, Allmandring 31, D-70569 Stuttgart, Germany
| | - Diane McDougald
- The ithree Institute, The University of Technology Sydney, Australia; Singapore Centre for Environmental Life Sciences Engineering and the School of Biological Sciences, Nanyang Technological University, Singapore
| | - Scott A Rice
- Centre for Marine Bio-Innovation, Earth and Environmental Sciences, The University of New South Wales, Sydney, New South Wales, Australia; The School of Biological, Earth and Environmental Sciences, The University of New South Wales, Sydney, New South Wales, Australia; Singapore Centre for Environmental Life Sciences Engineering and the School of Biological Sciences, Nanyang Technological University, Singapore.
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31
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Moffitt JR, Pandey S, Boettiger AN, Wang S, Zhuang X. Spatial organization shapes the turnover of a bacterial transcriptome. eLife 2016; 5. [PMID: 27198188 PMCID: PMC4874777 DOI: 10.7554/elife.13065] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Accepted: 03/20/2016] [Indexed: 12/21/2022] Open
Abstract
Spatial organization of the transcriptome has emerged as a powerful means for regulating the post-transcriptional fate of RNA in eukaryotes; however, whether prokaryotes use RNA spatial organization as a mechanism for post-transcriptional regulation remains unclear. Here we used super-resolution microscopy to image the E. coli transcriptome and observed a genome-wide spatial organization of RNA: mRNAs encoding inner-membrane proteins are enriched at the membrane, whereas mRNAs encoding outer-membrane, cytoplasmic and periplasmic proteins are distributed throughout the cytoplasm. Membrane enrichment is caused by co-translational insertion of signal peptides recognized by the signal-recognition particle. Time-resolved RNA-sequencing revealed that degradation rates of inner-membrane-protein mRNAs are on average greater that those of the other mRNAs and that this selective destabilization of inner-membrane-protein mRNAs is abolished by dissociating the RNA degradosome from the membrane. Together, these results demonstrate that the bacterial transcriptome is spatially organized and suggest that this organization shapes the post-transcriptional dynamics of mRNAs. DOI:http://dx.doi.org/10.7554/eLife.13065.001 Within a cell, molecules of messenger RNA (mRNA) encode the proteins that the cell needs to survive and thrive. The amount of mRNA within a cell therefore plays an important role in determining both the amount and types of proteins that a cell contains and, thus, the behavior of the cell. In eukaryotic organisms, like humans, it has been established that it is not just the amount of mRNA that influences cell behavior, but also where the mRNA molecules are found within the cell. However, in bacteria, which are much smaller than human cells, it has long been believed that the location of an mRNA within the cell does not affect its behavior. Despite this, recent studies that have looked at small numbers of bacterial mRNAs have shown that some of these molecules are found in larger numbers than usual at certain sites inside cells. This suggests that location may actually affect the activity of some bacterial mRNAs. But do similar localization patterns occur for all of the thousands of different mRNAs that bacteria can make? To address this question, Moffitt et al. developed an approach that allows large, defined sets of mRNAs to be imaged in bacteria. Using this approach to study E. coli revealed that a considerable fraction of all the mRNAs that these bacteria can make locate themselves at specific sites within a cell. For example, mRNAs that encode proteins that reside inside the cell’s inner membrane are found enriched at this membrane. This localization also plays an important role in the life of these mRNAs, as they are degraded more quickly than those found elsewhere in the cell. This enhanced degradation rate arises partly because the enzymes that break down mRNA molecules are also found at the membrane. Thus, bacteria can shape the process by which an mRNA is made into protein by controlling where in a cell the mRNA is located. The next steps are to understand why bacteria use cell location to influence the rate of mRNA degradation. DOI:http://dx.doi.org/10.7554/eLife.13065.002
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Affiliation(s)
- Jeffrey R Moffitt
- Howard Hughes Medical Institute, Harvard University, Cambridge, United States.,Department of Chemistry and Chemical Biology, Harvard University, Cambridge, United States
| | - Shristi Pandey
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, United States
| | - Alistair N Boettiger
- Howard Hughes Medical Institute, Harvard University, Cambridge, United States.,Department of Chemistry and Chemical Biology, Harvard University, Cambridge, United States
| | - Siyuan Wang
- Howard Hughes Medical Institute, Harvard University, Cambridge, United States.,Department of Chemistry and Chemical Biology, Harvard University, Cambridge, United States
| | - Xiaowei Zhuang
- Howard Hughes Medical Institute, Harvard University, Cambridge, United States.,Department of Chemistry and Chemical Biology, Harvard University, Cambridge, United States.,Department of Physics, Harvard University, Cambridge, United States
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32
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Heu CC, Kurtti TJ, Nelson CM, Munderloh UG. Transcriptional Analysis of the Conjugal Transfer Genes of Rickettsia bellii RML 369-C. PLoS One 2015; 10:e0137214. [PMID: 26352829 PMCID: PMC4564193 DOI: 10.1371/journal.pone.0137214] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 08/13/2015] [Indexed: 11/19/2022] Open
Abstract
Rickettsia bellii is an obligate intracellular bacterium that is one of the few rickettsiae that encode a complete set of conjugative transfer (tra) genes involved in bacterial conjugation and has been shown to exhibit pili-like structures. The reductive genomes of rickettsiae beg the question whether the tra genes are nonfunctional or functioning to enhance the genetic plasticity and biology of rickettsiae. We characterized the transcriptional dynamics of R. bellii tra genes in comparison to genes transcribed stably and above the background level to understand when and at what levels the tra genes are active or whether the tra genes are degenerative. We determined that the best reference genes, out of 10 tested, were methionyl tRNA ligase (metG) or a combination of metG and ribonucleoside diphosphate reductase 2 subunit beta (nrdF), using statistical algorithms from two different programs: Normfinder and BestKeeper. To validate the use of metG with other rickettsial genes exhibiting variable transcriptional patterns we examined its use with sca2 and rickA, genes involved in actin based motility. Both were shown to be up-regulated at different times of replication in Vero cells, showing variable and stable transcription levels of rickA and sca2, respectively. traATi was up-regulated at 72 hours post inoculation in the tick cell line ISE6, but showed no apparent changes in the monkey cell line Vero and mouse cell line L929. The transcription of tra genes was positively correlated with one another and up-regulated from 12 to 72 hours post inoculation (HPI) when compared to RBE_0422 (an inactivated transposase-derivative found within the tra cluster). Thus, the up-regulation of the tra genes indicated that the integrity and activity of each gene were intact and may facilitate the search for the optimal conditions necessary to demonstrate conjugation in rickettsiae.
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Affiliation(s)
- Chan C. Heu
- Department of Entomology, University of Minnesota, 219 Hodson Hall, 1980 Folwell Ave, St. Paul, Minnesota, United States of America
- * E-mail:
| | - Timothy J. Kurtti
- Department of Entomology, University of Minnesota, 219 Hodson Hall, 1980 Folwell Ave, St. Paul, Minnesota, United States of America
| | - Curtis M. Nelson
- Department of Entomology, University of Minnesota, 219 Hodson Hall, 1980 Folwell Ave, St. Paul, Minnesota, United States of America
| | - Ulrike G. Munderloh
- Department of Entomology, University of Minnesota, 219 Hodson Hall, 1980 Folwell Ave, St. Paul, Minnesota, United States of America
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Góis F, González Ruiz LR, Scillato-Yané GJ, Soibelzon E. A Peculiar New Pampatheriidae (Mammalia: Xenarthra: Cingulata) from the Pleistocene of Argentina and Comments on Pampatheriidae Diversity. PLoS One 2015; 10:e0128296. [PMID: 26083486 PMCID: PMC4470999 DOI: 10.1371/journal.pone.0128296] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 03/04/2015] [Indexed: 11/19/2022] Open
Abstract
Pampatheriidae are a group of cingulates native to South American that are known from the middle Miocene to the lower Holocene. Two genera have been recognized between the lower Pleistocene and the lower Holocene: Pampatherium Gervais and Ameghino (Ensenadan, Bonaerian and Lujanian, lower Pleistocene-lower Holocene) and Holmesina Simpson (Blancan, Irvingtonian, upper Pliocene-lower Holocene). They have been mainly differentiated by their osteoderm morphology and cranio-dental characters. These taxa had a wide latitudinal distribution, extending from the southern part of South America (Península Valdés, Argentina) to North America (Florida, USA). In this contribution, we describe a new genus and species of Pampatheriidae for the lower and middle Pleistocene of Buenos Aires Province and for the upper Pleistocene of Santa Fe Province (Argentina).The new taxon is represented by disarticulated osteoderms, one skull element, two thoracic vertebrae and a right femur and patella. It has extremely complex osteoderm ornamentations and particular morphological characters of the cranial element and femur that are not found in any other species of the family. This new taxon, recorded in the lower-middle Pleistocene (Ensenadan Stage/Age) and in the upper Pleistocene-early Holocene (Lujanian Stage/Age), is incorporated to the Pleistocene mammal assemblage of South America. Finally, the Pampatheriidae diversity is greater during the Lujanian Stage/Age than the Ensenadan Stage/Age.
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Affiliation(s)
- Flávio Góis
- Laboratorio de Paleontología de Vertebrados, Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción (CICYTTP–CONICET), Materi y España, 3105 Diamante, Entre Ríos, Argentina
- CONICET, Consejo Nacional de Investigaciones Científicas y Técnicas, Rivadavia, 1917, Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina
| | - Laureano Raúl González Ruiz
- Laboratorio de Investigaciones en Evolución y Biodiversidad (LIEB), Universidad Nacional de la Patagonia ‘San Juan Bosco’ sede Esquel (UNPSJB), Ruta Nacional 259, km 16.5, 9200, Esquel, Chubut, Argentina
- CONICET, Consejo Nacional de Investigaciones Científicas y Técnicas, Rivadavia, 1917, Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina
| | - Gustavo Juan Scillato-Yané
- División Paleontología Vertebrados, Museo de La Plata, Paseo del Bosque, s/n, 1900, La Plata, Buenos Aires, Argentina
- CONICET, Consejo Nacional de Investigaciones Científicas y Técnicas, Rivadavia, 1917, Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina
| | - Esteban Soibelzon
- División Paleontología Vertebrados, Museo de La Plata, Paseo del Bosque, s/n, 1900, La Plata, Buenos Aires, Argentina
- CONICET, Consejo Nacional de Investigaciones Científicas y Técnicas, Rivadavia, 1917, Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina
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34
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Innocenti N, Golumbeanu M, Fouquier d'Hérouël A, Lacoux C, Bonnin RA, Kennedy SP, Wessner F, Serror P, Bouloc P, Repoila F, Aurell E. Whole-genome mapping of 5' RNA ends in bacteria by tagged sequencing: a comprehensive view in Enterococcus faecalis. RNA (NEW YORK, N.Y.) 2015; 21:1018-30. [PMID: 25737579 PMCID: PMC4408782 DOI: 10.1261/rna.048470.114] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 12/22/2014] [Indexed: 05/21/2023]
Abstract
Enterococcus faecalis is the third cause of nosocomial infections. To obtain the first snapshot of transcriptional organizations in this bacterium, we used a modified RNA-seq approach enabling to discriminate primary from processed 5' RNA ends. We also validated our approach by confirming known features in Escherichia coli. We mapped 559 transcription start sites (TSSs) and 352 processing sites (PSSs) in E. faecalis. A blind motif search retrieved canonical features of SigA- and SigN-dependent promoters preceding transcription start sites mapped. We discovered 85 novel putative regulatory RNAs, small- and antisense RNAs, and 72 transcriptional antisense organizations. Presented data constitute a significant insight into bacterial RNA landscapes and a step toward the inference of regulatory processes at transcriptional and post-transcriptional levels in a comprehensive manner.
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Affiliation(s)
- Nicolas Innocenti
- Department of Computational Biology, KTH Royal Institute of Technology, AlbaNova University Center, SE-10691 Stockholm, Sweden INRA, UMR1319 Micalis, Domaine de Vilvert, F-78352, Jouy-en-Josas, France AgroParisTech, UMR Micalis, Domaine de Vilvert, F-78350, Jouy-en-Josas, France
| | - Monica Golumbeanu
- Department of Biosystems Science and Engineering, ETH Zürich, CH-4058, Basel, Switzerland SIB Swiss Institute of Bioinformatics, University of Basel, CH-4056, Basel, Switzerland
| | - Aymeric Fouquier d'Hérouël
- Department of Computational Biology, KTH Royal Institute of Technology, AlbaNova University Center, SE-10691 Stockholm, Sweden Luxembourg Centre for Systems Biomedicine, University of Luxembourg, L-4362, Esch-sur-Alzette, Luxembourg
| | - Caroline Lacoux
- INRA, UMR1319 Micalis, Domaine de Vilvert, F-78352, Jouy-en-Josas, France AgroParisTech, UMR Micalis, Domaine de Vilvert, F-78350, Jouy-en-Josas, France
| | - Rémy A Bonnin
- Institut de Génétique et Microbiologie, Université Paris-Sud, CNRS, UMR8621, F-91405, Orsay, France
| | - Sean P Kennedy
- INRA, MetaGenoPolis US1367, Domaine de Vilvert, F-78350, Jouy-en-Josas, France
| | - Françoise Wessner
- INRA, UMR1319 Micalis, Domaine de Vilvert, F-78352, Jouy-en-Josas, France AgroParisTech, UMR Micalis, Domaine de Vilvert, F-78350, Jouy-en-Josas, France
| | - Pascale Serror
- INRA, UMR1319 Micalis, Domaine de Vilvert, F-78352, Jouy-en-Josas, France AgroParisTech, UMR Micalis, Domaine de Vilvert, F-78350, Jouy-en-Josas, France
| | - Philippe Bouloc
- Institut de Génétique et Microbiologie, Université Paris-Sud, CNRS, UMR8621, F-91405, Orsay, France
| | - Francis Repoila
- INRA, UMR1319 Micalis, Domaine de Vilvert, F-78352, Jouy-en-Josas, France AgroParisTech, UMR Micalis, Domaine de Vilvert, F-78350, Jouy-en-Josas, France
| | - Erik Aurell
- Department of Computational Biology, KTH Royal Institute of Technology, AlbaNova University Center, SE-10691 Stockholm, Sweden Department of Information and Computer Science, Aalto University, FI-02150 Espoo, Finland
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Esquerré T, Moisan A, Chiapello H, Arike L, Vilu R, Gaspin C, Cocaign-Bousquet M, Girbal L. Genome-wide investigation of mRNA lifetime determinants in Escherichia coli cells cultured at different growth rates. BMC Genomics 2015; 16:275. [PMID: 25887031 PMCID: PMC4421995 DOI: 10.1186/s12864-015-1482-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 03/24/2015] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND Changes to mRNA lifetime adjust mRNA concentration, facilitating the adaptation of growth rate to changes in growth conditions. However, the mechanisms regulating mRNA lifetime are poorly understood at the genome-wide scale and have not been investigated in bacteria growing at different rates. RESULTS We used linear covariance models and the best model selected according to the Akaike information criterion to identify and rank intrinsic and extrinsic general transcript parameters correlated with mRNA lifetime, using mRNA half-life datasets for E. coli, obtained at four growth rates. The principal parameter correlated with mRNA stability was mRNA concentration, the mRNAs most concentrated in the cells being the least stable. However, sequence-related features (codon adaptation index (CAI), ORF length, GC content, polycistronic mRNA), gene function and essentiality also affected mRNA lifetime at all growth rates. We also identified sequence motifs within the 5'UTRs potentially related to mRNA stability. Growth rate-dependent effects were confined to particular functional categories (e.g. carbohydrate and nucleotide metabolism). Finally, mRNA stability was less strongly correlated with the amount of protein produced than mRNA concentration and CAI. CONCLUSIONS This study provides the most complete genome-wide analysis to date of the general factors correlated with mRNA lifetime in E. coli. We have generalized for the entire population of transcripts or excluded determinants previously defined as regulators of stability for some particular mRNAs and identified new, unexpected general indicators. These results will pave the way for discussions of the underlying mechanisms and their interaction with the growth physiology of bacteria.
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Affiliation(s)
- Thomas Esquerré
- Université de Toulouse; ISBP, INSA, UPS, INP; LISBP, 135, avenue de Rangueil, 31077, Toulouse cedex 4, France. .,INRA, UMR792 Ingénierie des systèmes biologiques et des procédés, 31400, Toulouse, France. .,CNRS, UMR5504, 31400, Toulouse, France. .,Laboratoire de Microbiologie et Génétique Moléculaires, UMR5100, Centre National de la Recherche Scientifique et Université Paul Sabatier, 118 Route de Narbonne, 31062, Toulouse, France.
| | | | | | - Liisa Arike
- Competence Center of Food and Fermentation Technologies, Akadeemia tee 15A, 12618, Tallinn, Estonia.
| | - Raivo Vilu
- Competence Center of Food and Fermentation Technologies, Akadeemia tee 15A, 12618, Tallinn, Estonia. .,Department of Chemistry, Tallinn University of Technology, Akadeemia tee 15, 12618, Tallinn, Estonia.
| | | | - Muriel Cocaign-Bousquet
- Université de Toulouse; ISBP, INSA, UPS, INP; LISBP, 135, avenue de Rangueil, 31077, Toulouse cedex 4, France. .,INRA, UMR792 Ingénierie des systèmes biologiques et des procédés, 31400, Toulouse, France. .,CNRS, UMR5504, 31400, Toulouse, France.
| | - Laurence Girbal
- Université de Toulouse; ISBP, INSA, UPS, INP; LISBP, 135, avenue de Rangueil, 31077, Toulouse cedex 4, France. .,INRA, UMR792 Ingénierie des systèmes biologiques et des procédés, 31400, Toulouse, France. .,CNRS, UMR5504, 31400, Toulouse, France.
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Li R, Xu L, Shi H. Strategy of tuning gene expression ratio in prokaryotic cell from perspective of noise and correlation. J Theor Biol 2015; 365:377-89. [PMID: 25446713 DOI: 10.1016/j.jtbi.2014.11.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 10/31/2014] [Accepted: 11/03/2014] [Indexed: 10/24/2022]
Abstract
Genes are organized into operons in procaryote, and these genes in one operon generally have related functions. However, genes in the same operon are usually not equally expressed, and the ratio needs to be fine-tuned for specific functions. We examine the difference of gene expression noise and correlation when tuning the expression level at the transcriptional or translational level in a bicistronic operon driven by a constitutive or a two-state promoter. We get analytic results for the noise and correlation of gene expression levels, which is confirmed by our stochastic simulations. Both the noise and the correlation of gene expressions in an operon with a two-state promoter are higher than in an operon with a constitutive promoter. Premature termination of mRNA induced by transcription terminator in the intergenic region or changing translation rates can tune the protein ratio at the transcriptional level or at the translational level. We find that gene expression correlation between promoter-proximal and promoter-distal genes at the protein level decreases as termination increases. In contrast, changing translation rates in the normal range almost does not alter the correlation. This explains why the translation rate is a key factor of modulating gene expressions in an operon. Our results can be useful to understand the relationship between the operon structure and the biological function of a gene network, and also may help in synthetic biology design.
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Affiliation(s)
- Rui Li
- State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Liufang Xu
- Department of Physics and Biophysics & Complex System Center, Jilin University, Changchun 130012, China
| | - Hualin Shi
- State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190, China.
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Chen H, Shiroguchi K, Ge H, Xie XS. Genome-wide study of mRNA degradation and transcript elongation in Escherichia coli. Mol Syst Biol 2015; 11:781. [PMID: 25583150 PMCID: PMC4332155 DOI: 10.15252/msb.20145794] [Citation(s) in RCA: 130] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
An essential part of gene expression is the coordination of RNA synthesis and degradation, which occurs in the same cellular compartment in bacteria. Here, we report a genome-wide RNA degradation study in Escherichia coli using RNA-seq, and present evidence that the stereotypical exponential RNA decay curve obtained using initiation inhibitor, rifampicin, consists of two phases: residual RNA synthesis, a delay in the interruption of steady state that is dependent on distance relative to the mRNA's 5′ end, and the exponential decay. This gives a more accurate RNA lifetime and RNA polymerase elongation rate simultaneously genome-wide. Transcripts typically have a single RNA decay constant along all positions, which is distinct between different operons, indicating that RNA stability is unlikely determined by local sequences. These measurements allowed us to establish a model for RNA processing involving co-transcriptional degradation, providing quantitative description of the macromolecular coordination in gene expression in bacteria on a system-wide level.
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Affiliation(s)
- Huiyi Chen
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Katsuyuki Shiroguchi
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Hao Ge
- Biodynamic Optical Imaging Center (BIOPIC), School of Life Science Peking University, Beijing, China Beijing International Center for Mathematical Research (BICMR) Peking University, Beijing, China
| | - Xiaoliang Sunney Xie
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA Biodynamic Optical Imaging Center (BIOPIC), School of Life Science Peking University, Beijing, China
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Gerwig J, Stülke J. Caught in the act: RNA-Seq provides novel insights into mRNA degradation. Mol Microbiol 2014; 94:5-8. [PMID: 25155548 DOI: 10.1111/mmi.12769] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/21/2014] [Indexed: 11/27/2022]
Abstract
RNA degradation is a major mechanism of post-transcriptional control of gene expression. Moreover, the rapid turnover of bacterial mRNAs is central to the fast adaptation of these organisms to changing environmental conditions by the regulation of transcription initiation. In most bacteria, RNA processing and degradation require the concerted action of endo- and exoribonucleases. In Molecular Microbiology, Liu et al. (2014) have analysed RNA processing by polynucleotide phosphorylase, the major 3'-5' exonuclease in Bacillus subtilis. For the first time, they were able to study RNA degradation by this enzyme at single nucleotide resolution. The work provides novel insights into the mechanism by which RNA degradation acts in B. subtilis. Moreover, Liu et al. demonstrate that the post-transcriptional control of central regulators affects the expression of whole regulons.
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Affiliation(s)
- Jan Gerwig
- Department of General Microbiology, Georg-August-University Göttingen, Göttingen, Germany
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Liu B, Deikus G, Bree A, Durand S, Kearns DB, Bechhofer DH. Global analysis of mRNA decay intermediates in Bacillus subtilis wild-type and polynucleotide phosphorylase-deletion strains. Mol Microbiol 2014; 94:41-55. [PMID: 25099370 DOI: 10.1111/mmi.12748] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/05/2014] [Indexed: 11/30/2022]
Abstract
Messenger RNA decay in Bacillus subtilis is accomplished by a combination of exoribonucleases and endoribonucleases. Intermediates in the decay process have not been readily detectable, and previous studies on mRNA decay have used a handful of highly expressed transcripts as models. Here, we use RNA-Seq analysis to probe mRNA turnover globally. A significant fraction of messages showed differential accumulation of RNA fragments that mapped near the 5' or 3' end of the coding sequence, consistent with initiation of decay from either the 5' end or from an internal cleavage site. Patterns of mRNA decay in the wild type were compared with patterns in a mutant strain lacking polynucleotide phosphorylase (PNPase), which is considered the major 3' exonuclease activity in mRNA decay and which is one of four known 3' exonucleases in B. subtilis. The results showed a striking dependence on PNPase for mRNA turnover in many cases, suggesting specificity in the ability of 3' exonucleases to degrade from 3'-hydroxyl termini. RNA-Seq data demonstrated a sharp decrease in expression of Sigma D in the PNPase-deletion strain. Reduction in sigD regulon expression explained the chain growth phenotype of the PNPase mutant and also predicted a defect in swarming motility.
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Affiliation(s)
- Bo Liu
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, Box 1603, New York, NY, 10029, USA
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Wiegand S, Dietrich S, Hertel R, Bongaerts J, Evers S, Volland S, Daniel R, Liesegang H. RNA-Seq of Bacillus licheniformis: active regulatory RNA features expressed within a productive fermentation. BMC Genomics 2013; 14:667. [PMID: 24079885 PMCID: PMC3871023 DOI: 10.1186/1471-2164-14-667] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Accepted: 09/25/2013] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND The production of enzymes by an industrial strain requires a complex adaption of the bacterial metabolism to the conditions within the fermenter. Regulatory events within the process result in a dynamic change of the transcriptional activity of the genome. This complex network of genes is orchestrated by proteins as well as regulatory RNA elements. Here we present an RNA-Seq based study considering selected phases of an industry-oriented fermentation of Bacillus licheniformis. RESULTS A detailed analysis of 20 strand-specific RNA-Seq datasets revealed a multitude of transcriptionally active genomic regions. 3314 RNA features encoded by such active loci have been identified and sorted into ten functional classes. The identified sequences include the expected RNA features like housekeeping sRNAs, metabolic riboswitches and RNA switches well known from studies on Bacillus subtilis as well as a multitude of completely new candidates for regulatory RNAs. An unexpectedly high number of 855 RNA features are encoded antisense to annotated protein and RNA genes, in addition to 461 independently transcribed small RNAs. These antisense transcripts contain molecules with a remarkable size range variation from 38 to 6348 base pairs in length. The genome of the type strain B. licheniformis DSM13 was completely reannotated using data obtained from RNA-Seq analyses and from public databases. CONCLUSION The hereby generated data-sets represent a solid amount of knowledge on the dynamic transcriptional activities during the investigated fermentation stages. The identified regulatory elements enable research on the understanding and the optimization of crucial metabolic activities during a productive fermentation of Bacillus licheniformis strains.
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Affiliation(s)
- Sandra Wiegand
- Department of Genomic and Applied Microbiology & Göttingen Genomics Laboratory, Institut für Mikrobiologie und Genetik, Norddeutsches Zentrum für Mikrobielle Genomforschung, Georg-August-Universität Göttingen, Grisebachstr, 8, D-37077 Göttingen, Germany.
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Abstract
The importance of gene regulation in the enzootic cycle of Borrelia burgdorferi, the spirochete that causes Lyme disease, is well established. B. burgdorferi regulates gene expression in response to changes in environmental stimuli associated with changing hosts. In this study, we monitored mRNA decay in B. burgdorferi following transcriptional arrest with actinomycin D. The time-dependent decay of transcripts encoding RNA polymerase subunits (rpoA and rpoS), ribosomal proteins (rpsD, rpsK, rpsM, rplQ, and rpsO), a nuclease (pnp), outer surface lipoproteins (ospA and ospC), and a flagellar protein (flaB) have different profiles and indicate half-lives ranging from approximately 1 min to more than 45 min in cells cultured at 35°C. Our results provide a first step in characterizing mRNA decay in B. burgdorferi and in investigating its role in gene expression and regulation.
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Multiple roles of RNase Y in Streptococcus pyogenes mRNA processing and degradation. J Bacteriol 2013; 195:2585-94. [PMID: 23543715 DOI: 10.1128/jb.00097-13] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Control over mRNA stability is an essential part of gene regulation that involves both endo- and exoribonucleases. RNase Y is a recently identified endoribonuclease in Gram-positive bacteria, and an RNase Y ortholog has been identified in Streptococcus pyogenes (group A streptococcus [GAS]). In this study, we used microarray and Northern blot analyses to determine the S. pyogenes mRNA half-life of the transcriptome and to understand the role of RNase Y in global mRNA degradation and processing. We demonstrated that S. pyogenes has an unusually high mRNA turnover rate, with median and mean half-lives of 0.88 min and 1.26 min, respectively. A mutation of the RNase Y-encoding gene (rny) led to a 2-fold increase in overall mRNA stability. RNase Y was also found to play a significant role in the mRNA processing of virulence-associated genes as well as in the rapid degradation of rnpB read-through transcripts. From these results, we conclude that RNase Y is a pleiotropic regulator required for mRNA stability, mRNA processing, and removal of read-through transcripts in S. pyogenes.
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Stewart FJ. Preparation of Microbial Community cDNA for Metatranscriptomic Analysis in Marine Plankton. Methods Enzymol 2013; 531:187-218. [DOI: 10.1016/b978-0-12-407863-5.00010-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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