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Martínez Tolibia SE, Díaz Pacheco A, Villalobos López MÁ, Pacheco Cabañas RK, Cabrera R, Rocha J, López Y López VE. The role of AbrB from plate to bioreactor: implications of induced expression on physiological and metabolic responses in Bacillus thuringiensis. World J Microbiol Biotechnol 2025; 41:120. [PMID: 40164926 DOI: 10.1007/s11274-025-04334-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2024] [Accepted: 03/19/2025] [Indexed: 04/02/2025]
Abstract
Transition state regulators from Bacillus can control diverse physiological responses such as growth, metabolism, motility, virulence, and sporulation. The AbrB protein is a transcriptional regulator involved in multiple functions during exponential phase and intricated regulatory pathways that control adaptive states differentially. Despite its importance, the AbrB role has not been well characterized during the growth cycle, and its implication in metabolic functions remains elusive, especially in the Bacillus cereus group. In this work, we characterized the role of AbrB on phenotypes such as spreading motility, growth profiles, sporulation, and on activity of core metabolic pathways of Bacillus thuringiensis. For this, a strain with inducible abrB expression was generated in the wild type Bt HD73 background. In vitro evaluations of phenotypic traits demonstrated differences in sporulation and motility, where induction of abrB presumably affected these functions under nutrient-limited media. In addition, AbrB induction during bioreactor fermentations led to higher biomass production and changes dissolved oxygen (DO) profile, which was also accompanied with a delay in sporulation. Based on these results, metabolic pathways such as glycolysis and the Krebs cycle were explored to address the effect of AbrB overproduction on transcription of genes coding for pyruvate dehydrogenase (pdHA), lactate dehydrogenase (ldH), citrate synthase (citZ) and aconitase (citB). Our findings suggest variations in the carbon-flux in the central carbon metabolism due to abrB overexpression. This work contributes to the elucidation of AbrB involvement in regulatory networks of B. thuringiensis, to develop engineering-based strategies to use these bacteria in other biotechnological applications besides as biological control agent.
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Affiliation(s)
- Shirlley Elizabeth Martínez Tolibia
- Centro de Investigación en Biotecnología Aplicada del Instituto Politécnico Nacional, Carretera Estatal Santa Inés Tecuexcomac-Tepetitla, Km 1.5. Tepetitla de Lardizábal, Tlaxcala, C.P. 90700, México
| | - Adrián Díaz Pacheco
- Unidad Profesional Interdisciplinaria de Ingeniería Campus Tlaxcala, Instituto Politécnico Nacional, Guillermo Valle, Tlaxcala, 90000, Mexico
| | - Miguel Ángel Villalobos López
- Centro de Investigación en Biotecnología Aplicada del Instituto Politécnico Nacional, Carretera Estatal Santa Inés Tecuexcomac-Tepetitla, Km 1.5. Tepetitla de Lardizábal, Tlaxcala, C.P. 90700, México
| | - Rita Karen Pacheco Cabañas
- Unidad Profesional Interdisciplinaria de Ingeniería Campus Palenque del Instituto Politécnico Nacional, Carretera Palenque-Pakal-Na S/N, Centro, Palenque, Chiapas, 29960, Mexico
| | - Rosina Cabrera
- Centro de Investigación en Alimentación y Desarrollo, CONAHCYT- Unidad Regional Hidalgo, A.C, Pachuca Ciudad del Conocimiento y la Cultura. Blvd. Santa Catarina, San Agustín Tlaxiaca, Hidalgo, C.P. 42163, SN, México
| | - Jorge Rocha
- Programa de Agricultura en Zonas Áridas, Centro de Investigaciones Biológicas del Noroeste, Instituto Politécnico Nacional 195, Playa Palo de Santa Rita Sur, La Paz, B.C.S., C.P. 23096, México
| | - Víctor Eric López Y López
- Centro de Investigación en Biotecnología Aplicada del Instituto Politécnico Nacional, Carretera Estatal Santa Inés Tecuexcomac-Tepetitla, Km 1.5. Tepetitla de Lardizábal, Tlaxcala, C.P. 90700, México.
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Li Y, Cao X, Chai Y, Chen R, Zhao Y, Borriss R, Ding X, Wu X, Ye J, Hao D, He J, Wang G, Cao M, Jiang C, Han Z, Fan B. A phosphate starvation induced small RNA promotes Bacillus biofilm formation. NPJ Biofilms Microbiomes 2024; 10:115. [PMID: 39472585 PMCID: PMC11522486 DOI: 10.1038/s41522-024-00586-6] [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: 11/16/2023] [Accepted: 10/13/2024] [Indexed: 11/02/2024] Open
Abstract
Currently, almost all known regulators involved in bacterial phosphorus metabolism are proteins. In this study, we identified a conserved new small regulatory RNA (sRNA), named PhoS, encoded in the 3' untranslated region (UTR) of the phoPR genes in Bacillus velezensis and B. subtilis. Expression of phoS is strongly induced upon phosphorus scarcity and stimulated by the transcription factor PhoP. Conversely, PhoS positively regulates PhoP translation by binding to the ribosome binding site (RBS) of phoP mRNA. PhoS can promote Bacillus biofilm formation through, at least in part, enhancing the expression of the matrix-related genes, such as the eps genes and the tapA-sipW-tasA operon. The positive regulation of phoP expression by PhoS contributes to the promoting effect of PhoS on biofilm formation. sRNAs regulating biofilm formation have rarely been reported in gram-positive Bacillus species. Here we highlight the significance of sRNAs involved in two important biological processes: phosphate metabolism and biofilm formation.
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Affiliation(s)
- Yulong Li
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry and Grassland, Nanjing Forestry University, Nanjing, China
- School of Agriculture, Ningxia University, Ningxia, China
| | - Xianming Cao
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry and Grassland, Nanjing Forestry University, Nanjing, China
| | - Yunrong Chai
- Department of Biology, Northeastern University, Boston, USA
| | - Ruofu Chen
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry and Grassland, Nanjing Forestry University, Nanjing, China
| | - Yinjuan Zhao
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry and Grassland, Nanjing Forestry University, Nanjing, China
| | - Rainer Borriss
- Institut für Biologie, Humboldt Universität Berlin, Berlin, Germany
| | - Xiaolei Ding
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry and Grassland, Nanjing Forestry University, Nanjing, China
| | - Xiaoqin Wu
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry and Grassland, Nanjing Forestry University, Nanjing, China
| | - Jianren Ye
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry and Grassland, Nanjing Forestry University, Nanjing, China
| | - Dejun Hao
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry and Grassland, Nanjing Forestry University, Nanjing, China.
| | - Jian He
- College of Life Science, Nanjing Agricultural University, Nanjing, China
| | - Guibin Wang
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry and Grassland, Nanjing Forestry University, Nanjing, China
| | - Mingmin Cao
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry and Grassland, Nanjing Forestry University, Nanjing, China
| | - Chunliang Jiang
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry and Grassland, Nanjing Forestry University, Nanjing, China
| | - Zhengmin Han
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry and Grassland, Nanjing Forestry University, Nanjing, China
| | - Ben Fan
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry and Grassland, Nanjing Forestry University, Nanjing, China.
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Termination factor Rho mediates transcriptional reprogramming of Bacillus subtilis stationary phase. PLoS Genet 2023; 19:e1010618. [PMID: 36735730 PMCID: PMC9931155 DOI: 10.1371/journal.pgen.1010618] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 02/15/2023] [Accepted: 01/14/2023] [Indexed: 02/04/2023] Open
Abstract
Transcription termination factor Rho is known for its ubiquitous role in suppression of pervasive, mostly antisense, transcription. In the model Gram-positive bacterium Bacillus subtilis, de-repression of pervasive transcription by inactivation of rho revealed the role of Rho in the regulation of post-exponential differentiation programs. To identify other aspects of the regulatory role of Rho during adaptation to starvation, we have constructed a B. subtilis strain (Rho+) that expresses rho at a relatively stable high level in order to compensate for its decrease in the wild-type cells entering stationary phase. The RNAseq analysis of Rho+, WT and Δrho strains (expression profiles can be visualized at http://genoscapist.migale.inrae.fr/seb_rho/) shows that Rho over-production enhances the termination efficiency of Rho-sensitive terminators, thus reducing transcriptional read-through and antisense transcription genome-wide. Moreover, the Rho+ strain exhibits global alterations of sense transcription with the most significant changes observed for the AbrB, CodY, and stringent response regulons, forming the pathways governing the transition to stationary phase. Subsequent physiological analyses demonstrated that maintaining rho expression at a stable elevated level modifies stationary phase-specific physiology of B. subtilis cells, weakens stringent response, and thereby negatively affects the cellular adaptation to nutrient limitations and other stresses, and blocks the development of genetic competence and sporulation. These results highlight the Rho-specific termination of transcription as a novel element controlling stationary phase. The release of this control by decreasing Rho levels during the transition to stationary phase appears crucial for the functionality of complex gene networks ensuring B. subtilis survival in stationary phase.
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Tolibia SEM, Pacheco AD, Balbuena SYG, Rocha J, López Y López VE. Engineering of global transcription factors in Bacillus, a genetic tool for increasing product yields: a bioprocess overview. World J Microbiol Biotechnol 2022; 39:12. [PMID: 36372802 DOI: 10.1007/s11274-022-03460-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 11/06/2022] [Indexed: 11/15/2022]
Abstract
Transcriptional factors are well studied in bacteria for their global interactions and the effects they produce at the phenotypic level. Particularly, Bacillus subtilis has been widely employed as a model Gram-positive microorganism used to characterize these network interactions. Bacillus species are currently used as efficient commercial microbial platforms to produce diverse metabolites such as extracellular enzymes, antibiotics, surfactants, industrial chemicals, heterologous proteins, among others. However, the pleiotropic effects caused by the genetic modification of specific genes that codify for global regulators (transcription factors) have not been implicated commonly from a bioprocess point of view. Recently, these strategies have attracted the attention in Bacillus species because they can have an application to increase production efficiency of certain commercial interest metabolites. In this review, we update the recent advances that involve this trend in the use of genetic engineering (mutations, deletion, or overexpression) performed to global regulators such as Spo0A, CcpA, CodY and AbrB, which can provide an advantage for the development or improvement of bioprocesses that involve Bacillus species as production platforms. Genetic networks, regulation pathways and their relationship to the development of growth stages are also discussed to correlate the interactions that occur between these regulators, which are important to consider for application in the improvement of commercial-interest metabolites. Reported yields from these products currently produced mostly under laboratory conditions and, in a lesser extent at bioreactor level, are also discussed to give valuable perspectives about their potential use and developmental level directed to process optimization at large-scale.
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Affiliation(s)
- Shirlley Elizabeth Martínez Tolibia
- Centro de Investigación en Biotecnología Aplicada del Instituto Politécnico Nacional, Carretera Estatal Santa Inés Tecuexcomac-Tepetitla, Km 1.5, C.P. 90700, Tepetitla de Lardizábal, Tlaxcala, Mexico
| | - Adrián Díaz Pacheco
- Unidad Profesional Interdisciplinaria de Ingeniería Campus Tlaxcala del Instituto Politécnico Nacional, CP 90000, Guillermo Valle, Tlaxcala, Mexico
| | - Sulem Yali Granados Balbuena
- Centro de Investigación en Biotecnología Aplicada del Instituto Politécnico Nacional, Carretera Estatal Santa Inés Tecuexcomac-Tepetitla, Km 1.5, C.P. 90700, Tepetitla de Lardizábal, Tlaxcala, Mexico
| | - Jorge Rocha
- CONACyT - Unidad Regional Hidalgo, Centro de Investigación en Alimentación y Desarrollo, A.C. Blvd. Santa Catarina, SN, C.P. 42163, San Agustín Tlaxiaca, Hidalgo, Mexico
| | - Víctor Eric López Y López
- Centro de Investigación en Biotecnología Aplicada del Instituto Politécnico Nacional, Carretera Estatal Santa Inés Tecuexcomac-Tepetitla, Km 1.5, C.P. 90700, Tepetitla de Lardizábal, Tlaxcala, Mexico.
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Liu J, Wang X, Dai G, Zhang Y, Bian X. Microbial chassis engineering drives heterologous production of complex secondary metabolites. Biotechnol Adv 2022; 59:107966. [PMID: 35487394 DOI: 10.1016/j.biotechadv.2022.107966] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 04/20/2022] [Accepted: 04/21/2022] [Indexed: 12/27/2022]
Abstract
The cryptic secondary metabolite biosynthetic gene clusters (BGCs) far outnumber currently known secondary metabolites. Heterologous production of secondary metabolite BGCs in suitable chassis facilitates yield improvement and discovery of new-to-nature compounds. The two juxtaposed conventional model microorganisms, Escherichia coli, Saccharomyces cerevisiae, have been harnessed as microbial chassis to produce a bounty of secondary metabolites with the help of certain host engineering. In last decade, engineering non-model microbes to efficiently biosynthesize secondary metabolites has received increasing attention due to their peculiar advantages in metabolic networks and/or biosynthesis. The state-of-the-art synthetic biology tools lead the way in operating genetic manipulation in non-model microorganisms for phenotypic optimization or yields improvement of desired secondary metabolites. In this review, we firstly discuss the pros and cons of several model and non-model microbial chassis, as well as the importance of developing broader non-model microorganisms as alternative programmable heterologous hosts to satisfy the desperate needs of biosynthesis study and industrial production. Then we highlight the lately advances in the synthetic biology tools and engineering strategies for optimization of non-model microbial chassis, in particular, the successful applications for efficient heterologous production of multifarious complex secondary metabolites, e.g., polyketides, nonribosomal peptides, as well as ribosomally synthesized and post-translationally modified peptides. Lastly, emphasis is on the perspectives of chassis cells development to access the ideal cell factory in the artificial intelligence-driven genome era.
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Affiliation(s)
- Jiaqi Liu
- Helmholtz International Lab for Anti-Infectives, Shandong University-Helmholtz Institute of Biotechnology, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, Shandong 266237, PR China; Present address: Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Saarland University, Campus E8 1, 66123 Saarbrücken, Germany
| | - Xue Wang
- Helmholtz International Lab for Anti-Infectives, Shandong University-Helmholtz Institute of Biotechnology, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, Shandong 266237, PR China
| | - Guangzhi Dai
- Helmholtz International Lab for Anti-Infectives, Shandong University-Helmholtz Institute of Biotechnology, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, Shandong 266237, PR China
| | - Youming Zhang
- Helmholtz International Lab for Anti-Infectives, Shandong University-Helmholtz Institute of Biotechnology, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, Shandong 266237, PR China
| | - Xiaoying Bian
- Helmholtz International Lab for Anti-Infectives, Shandong University-Helmholtz Institute of Biotechnology, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, Shandong 266237, PR China.
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High-Throughput Time-Lapse Fluorescence Microscopy Screening for Heterogeneously Expressed Genes in Bacillus subtilis. Microbiol Spectr 2022; 10:e0204521. [PMID: 35171018 PMCID: PMC8849057 DOI: 10.1128/spectrum.02045-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Elucidating phenotypic heterogeneity in clonal bacterial populations is important for both the fundamental understanding of bacterial behavior and the synthetic engineering of bacteria in biotechnology. In this study, we present and validate a high-throughput and high-resolution time-lapse fluorescence microscopy-based strategy to easily and systematically screen for heterogeneously expressed genes in the Bacillus subtilis model bacterium. This screen allows detection of expression patterns at high spatial and temporal resolution, which often escape detection by other approaches, and can readily be extrapolated to other bacteria. A proof-of-concept screening in B. subtilis revealed both recognized and yet unrecognized heterogeneously expressed genes, thereby validating the approach. IMPORTANCE Differential gene expression among isogenic siblings often leads to phenotypic heterogeneity and the emergence of complex social behavior and functional capacities within clonal bacterial populations. Despite the importance of such features for both the fundamental understanding and synthetic engineering of bacterial behavior, approaches to systematically map such population heterogeneity are scarce. In this context, we have elaborated a new time-lapse fluorescence microscopy-based strategy to easily and systematically screen for such heterogeneously expressed genes in bacteria with high resolution and throughput. A proof-of-concept screening in the Bacillus subtilis model bacterium revealed both recognized and yet unrecognized heterogeneously expressed genes, thereby validating our approach.
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Brantl S, Müller P. Cis- and Trans-Encoded Small Regulatory RNAs in Bacillus subtilis. Microorganisms 2021; 9:microorganisms9091865. [PMID: 34576762 PMCID: PMC8464778 DOI: 10.3390/microorganisms9091865] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 08/23/2021] [Accepted: 08/24/2021] [Indexed: 12/12/2022] Open
Abstract
Small regulatory RNAs (sRNAs) that act by base-pairing are the most abundant posttranscriptional regulators in all three kingdoms of life. Over the past 20 years, a variety of approaches have been employed to discover chromosome-encoded sRNAs in a multitude of bacterial species. However, although largely improved bioinformatics tools are available to predict potential targets of base-pairing sRNAs, it is still challenging to confirm these targets experimentally and to elucidate the mechanisms as well as the physiological role of their sRNA-mediated regulation. Here, we provide an overview of currently known cis- and trans-encoded sRNAs from B. subtilis with known targets and defined regulatory mechanisms and on the potential role of RNA chaperones that are or might be required to facilitate sRNA regulation in this important Gram-positive model organism.
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Liao C, Ayansola H, Ma Y, Ito K, Guo Y, Zhang B. Advances in Enhanced Menaquinone-7 Production From Bacillus subtilis. Front Bioeng Biotechnol 2021; 9:695526. [PMID: 34354987 PMCID: PMC8330505 DOI: 10.3389/fbioe.2021.695526] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 07/01/2021] [Indexed: 12/02/2022] Open
Abstract
The production of nutraceutical compounds through biosynthetic approaches has received considerable attention in recent years. For example, Menaquinone-7 (MK-7), a sub-type of Vitamin K2, biosynthesized from Bacillus subtilis (B. subtilis), proved to be more efficiently produced than the conventional chemical synthesis techniques. This is possible due to the development of B. subtilis as a chassis cell during the biosynthesis stages. Hence, it is imperative to provide insights on the B. subtilis membrane permeability modifications, biofilm reactors, and fermentation optimization as advanced techniques relevant to MK-7 production. Although the traditional gene-editing method of homologous recombination improves the biosynthetic pathway, CRISPR-Cas9 could potentially resolve the drawbacks of traditional genome editing techniques. For these reasons, future studies should explore the applications of CRISPRi (CRISPR interference) and CRISPRa (CRISPR activation) system gene-editing tools in the MK-7 anabolism pathway.
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Affiliation(s)
- Chaoyong Liao
- State Key Laboratory of Animal Nutrition, Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Hammed Ayansola
- State Key Laboratory of Animal Nutrition, Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Yanbo Ma
- Henan International Joint Laboratory of Animal Welfare and Health Breeding, Department of Animal Physiology, College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, China
| | - Koichi Ito
- Department of Food and Physiological Models, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Ibaraki, Japan
| | - Yuming Guo
- State Key Laboratory of Animal Nutrition, Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Bingkun Zhang
- State Key Laboratory of Animal Nutrition, Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, China Agricultural University, Beijing, China
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Durand S, Callan-Sidat A, McKeown J, Li S, Kostova G, Hernandez-Fernaud JR, Alam MT, Millard A, Allouche D, Constantinidou C, Condon C, Denham EL. Identification of an RNA sponge that controls the RoxS riboregulator of central metabolism in Bacillus subtilis. Nucleic Acids Res 2021; 49:6399-6419. [PMID: 34096591 PMCID: PMC8216469 DOI: 10.1093/nar/gkab444] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 04/23/2021] [Accepted: 05/06/2021] [Indexed: 02/05/2023] Open
Abstract
sRNAs are a taxonomically-restricted but transcriptomically-abundant class of post-transcriptional regulators. While of major importance for adaption to the environment, we currently lack global-scale methodology enabling target identification, especially in species without known RNA hub proteins (e.g. Hfq). Using psoralen RNA cross-linking and Illumina-sequencing we identify RNA-RNA interacting pairs in vivo in Bacillus subtilis, resolving previously well-described interactants. Although sRNA-sRNA pairings are rare (compared with sRNA-mRNA), we identify a robust example involving the conserved sRNA RoxS and an unstudied sRNA RosA (Regulator of sRNA A). We show RosA to be the first confirmed RNA sponge described in a Gram-positive bacterium. RosA interacts with at least two sRNAs, RoxS and FsrA. The RosA/RoxS interaction not only affects the levels of RoxS but also its processing and regulatory activity. We also found that the transcription of RosA is repressed by CcpA, the key regulator of carbon-metabolism in B. subtilis. Since RoxS is already known to be transcriptionally controlled by malate via the transcriptional repressor Rex, its post-transcriptional regulation by CcpA via RosA places RoxS in a key position to control central metabolism in response to varying carbon sources.
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Affiliation(s)
- Sylvain Durand
- UMR8261, CNRS, Université de Paris, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Adam Callan-Sidat
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Gibbet Hill Road, Coventry, UK
| | - Josie McKeown
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Gibbet Hill Road, Coventry, UK
| | - Stephen Li
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Gibbet Hill Road, Coventry, UK
| | - Gergana Kostova
- UMR8261, CNRS, Université de Paris, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Juan R Hernandez-Fernaud
- School of Life Sciences, Proteomics Research Technology Platform, University of Warwick, Gibbet Hill Road, Coventry, UK
| | - Mohammad Tauqeer Alam
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Gibbet Hill Road, Coventry, UK
| | - Andrew Millard
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Gibbet Hill Road, Coventry, UK
| | - Delphine Allouche
- UMR8261, CNRS, Université de Paris, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Chrystala Constantinidou
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Gibbet Hill Road, Coventry, UK
| | - Ciarán Condon
- UMR8261, CNRS, Université de Paris, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Emma L Denham
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Gibbet Hill Road, Coventry, UK
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Identification of a non-coding RNA and its putative involvement in the regulation of tetanus toxin synthesis in Clostridium tetani. Sci Rep 2021; 11:4157. [PMID: 33603121 PMCID: PMC7892561 DOI: 10.1038/s41598-021-83623-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 01/29/2021] [Indexed: 11/17/2022] Open
Abstract
Clostridium tetani produces the tetanus toxin (TeNT), one of the most powerful bacterial toxins known to humankind and responsible for tetanus. The regulation of toxin expression is complex and involves the alternative sigma factor TetR as well as other regulators. Here, a transcriptional analysis of the TeNT-encoding large plasmid of C. tetani identified a putative non-coding small RNA (sRNA), located in close vicinity of the 3′ untranslated region of the tent gene. A northern blot experiment could identify a respective sRNA with a size of approx. 140 nucleotides. Sequence analysis showed that the sRNA contains a 14-nucleotide region that is complementary to a 5′ located region of tent. In order to investigate the function of the sRNA, we applied a RNA interference approach targeting the sRNA in two C. tetani wild-type strains; the constructed antisense C. tetani strains showed an approx. threefold increase in both extracellular and total TeNT production compared to the respective wild-type strains. In addition, recombinant C. tetani strains were constructed that contained tent-locus harboring plasmids with and without the sRNA. However, the introduction of the tent-locus without the sRNA in a C. tetani strain lacking the wild-type TeNT-encoding large plasmid resulted in a lower TeNT production compared to the same strain with recombinant tent-locus with the sRNA. This suggests that the expression or the effect of the sRNA is modulated by the C. tetani genetic background, notably that of the wild-type TeNT-encoding large plasmid. In addition, some recombinant strains exhibited modulated growth patterns, characterized by premature bacterial cell lysis. Taken together, our data indicate that the sRNA acts as a negative regulator of TeNT synthesis, with a possible impact on the growth of C. tetani. We hypothesize that the role of this sRNA is to limit toxin levels in the exponential growth phase in order to prevent premature bacterial lysis.
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Chromosome segregation in B. subtilis is highly heterogeneous. BMC Res Notes 2020; 13:477. [PMID: 33036658 PMCID: PMC7547420 DOI: 10.1186/s13104-020-05322-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 09/30/2020] [Indexed: 01/19/2023] Open
Abstract
Objective The bacterial cell cycle comprises initiation of replication and ensuing elongation, concomitant chromosome segregation (in some organisms with a delay termed cohesion), and finally cell division. By quantifying the number of origin and terminus regions in exponentially growing Bacillus subtilis cells, and after induction of DNA damage, we aimed at determining cell cycle parameters at different growth rates at a single cell level. Results B. subtilis cells are mostly mero-oligoploid during fast growth and diploid during slow growth. However, we found that the number of replication origins and of termini is highly heterogeneous within the cell population at two different growth rates, and that even at slow growth, a majority of cells attempts to maintain more than a single chromosome at all times of the cell cycle. Heterogeneity of chromosome copy numbers may reflect different subpopulations having diverging growth rates even during exponential growth conditions. Cells continued to initiate replication and segregate chromosomes after induction of DNA damage, as judged by an increase in origin numbers per cell, showing that replication and segregation are relatively robust against cell cycle perturbation.
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Tian R, Wang M, Shi J, Qin X, Guo H, Jia X, Li J, Liu L, Du G, Chen J, Liu Y. Cell-free synthesis system-assisted pathway bottleneck diagnosis and engineering in Bacillus subtilis. Synth Syst Biotechnol 2020; 5:131-136. [PMID: 32637666 PMCID: PMC7320236 DOI: 10.1016/j.synbio.2020.06.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 06/12/2020] [Accepted: 06/15/2020] [Indexed: 11/29/2022] Open
Abstract
Metabolic engineering is a key technology for cell factories construction by rewiring cellular resources to achieve efficient production of target chemicals. However, the existence of bottlenecks in synthetic pathway can seriously affect production efficiency, which is also one of the core issues for metabolic engineers to solve. Therefore, developing an approach for diagnosing potential metabolic bottlenecks in a faster and simpler manner is of great significance to accelerate cell factories construction. The cell-free reaction system based on cell lysates can transfer metabolic reactions from in vivo to in vitro, providing a flexible access to directly change protein and metabolite variables, thus provides a potential solution for rapid identification of bottlenecks. Here, bottleneck diagnosis of the N-acetylneuraminic acid (NeuAc) biosynthesis pathway in industrially important chassis microorganism Bacillus subtilis was performed using cell-free synthesis system. Specifically, a highly efficient B. subtilis cell-free system for NeuAc de novo synthesis was firstly constructed, which had a 305-fold NeuAc synthesis rate than that in vivo and enabled fast pathway dynamics analysis. Next, through the addition of all potential key intermediates in combination with substrate glucose respectively, it was found that insufficient phosphoenolpyruvate supply was one of the NeuAc pathway bottlenecks. Rational in vivo metabolic engineering of NeuAc-producing B. subtilis was further performed to eliminate the bottleneck. By down-regulating the expression level of pyruvate kinase throughout the growth phase or only in the stationary phase using inhibitory N-terminal coding sequences (NCSs) and growth-dependent regulatory NCSs respectively, the maximal NeuAc titer increased 2.0-fold. Our study provides a rapid method for bottleneck diagnosis, which may help to accelerate the cycle of design, build, test and learn cycle for metabolic engineering.
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Affiliation(s)
- Rongzhen Tian
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Minghu Wang
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Jintian Shi
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Xiaolong Qin
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Haoyu Guo
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Xuanjie Jia
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Jianghua Li
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
| | - Long Liu
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Guocheng Du
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Jian Chen
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, 214122, China
| | - Yanfeng Liu
- Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
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13
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Ul Haq I, Müller P, Brantl S. Intermolecular Communication in Bacillus subtilis: RNA-RNA, RNA-Protein and Small Protein-Protein Interactions. Front Mol Biosci 2020; 7:178. [PMID: 32850966 PMCID: PMC7430163 DOI: 10.3389/fmolb.2020.00178] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 07/09/2020] [Indexed: 11/29/2022] Open
Abstract
In bacterial cells we find a variety of interacting macromolecules, among them RNAs and proteins. Not only small regulatory RNAs (sRNAs), but also small proteins have been increasingly recognized as regulators of bacterial gene expression. An average bacterial genome encodes between 200 and 300 sRNAs, but an unknown number of small proteins. sRNAs can be cis- or trans-encoded. Whereas cis-encoded sRNAs interact only with their single completely complementary mRNA target transcribed from the opposite DNA strand, trans-encoded sRNAs are only partially complementary to their numerous mRNA targets, resulting in huge regulatory networks. In addition to sRNAs, uncharged tRNAs can interact with mRNAs in T-box attenuation mechanisms. For a number of sRNA-mRNA interactions, the stability of sRNAs or translatability of mRNAs, RNA chaperones are required. In Gram-negative bacteria, the well-studied abundant RNA-chaperone Hfq fulfils this role, and recently another chaperone, ProQ, has been discovered and analyzed in this respect. By contrast, evidence for RNA chaperones or their role in Gram-positive bacteria is still scarce, but CsrA might be such a candidate. Other RNA-protein interactions involve tmRNA/SmpB, 6S RNA/RNA polymerase, the dual-function aconitase and protein-bound transcriptional terminators and antiterminators. Furthermore, small proteins, often missed in genome annotations and long ignored as potential regulators, can interact with individual regulatory proteins, large protein complexes, RNA or the membrane. Here, we review recent advances on biological role and regulatory principles of the currently known sRNA-mRNA interactions, sRNA-protein interactions and small protein-protein interactions in the Gram-positive model organism Bacillus subtilis. We do not discuss RNases, ribosomal proteins, RNA helicases or riboswitches.
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Affiliation(s)
| | | | - Sabine Brantl
- Matthias-Schleiden-Institut, AG Bakteriengenetik, Friedrich-Schiller-Universität Jena, Jena, Germany
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14
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Denham EL. The Sponge RNAs of bacteria - How to find them and their role in regulating the post-transcriptional network. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2020; 1863:194565. [PMID: 32475775 DOI: 10.1016/j.bbagrm.2020.194565] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 04/15/2020] [Accepted: 04/20/2020] [Indexed: 02/06/2023]
Abstract
In bacteria small regulatory RNAs (sRNAs) interact with their mRNA targets through non-consecutive base-pairing. The loose base-pairing specificity allows sRNAs to regulate large numbers of genes, either affecting the stability and/or the translation of mRNAs. Mechanisms enabling post-transcriptional regulation of the sRNAs themselves have also been described involving so-called sponge RNAs. Sponge RNAs modulate free sRNA levels in the cell through RNA-RNA interactions that sequester ("soak up") the sRNA and/or promote degradation of the target sRNA or the sponge RNA-sRNA complex. The development of complex RNA sequencing strategies for the detection of RNA-RNA interactions has enabled identification of several sponge RNAs, as well as previously known regulatory RNAs able to act as both regulators and sponges. This review highlights techniques that have enabled the identification of these sponge RNAs, the origins of sponge RNAs and the mechanisms by which they function in the post-transcriptional network.
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Affiliation(s)
- Emma L Denham
- University of Bath, Department of Biology and Biochemistry, Claverton Down, Bath BA2 7AY, United Kingdom.
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15
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Metabolic Heterogeneity and Cross-Feeding in Bacterial Multicellular Systems. Trends Microbiol 2020; 28:732-743. [PMID: 32781027 DOI: 10.1016/j.tim.2020.03.008] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 03/25/2020] [Indexed: 01/19/2023]
Abstract
Cells in assemblages differentiate and perform distinct roles. Though many pathways of differentiation are understood at the molecular level in multicellular eukaryotes, the elucidation of similar processes in bacterial assemblages is recent and ongoing. Here, we discuss examples of bacterial differentiation, focusing on cases in which distinct metabolisms coexist and those that exhibit cross-feeding, with one subpopulation producing substrates that are metabolized by a second subpopulation. We describe several studies of single-species systems, then segue to studies of multispecies metabolic heterogeneity and cross-feeding in the clinical setting. Many of the studies described exemplify the application of new techniques and modeling approaches that provide insights into metabolic interactions relevant for bacterial growth outside the laboratory.
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16
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Planson AG, Sauveplane V, Dervyn E, Jules M. Bacterial growth physiology and RNA metabolism. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2020; 1863:194502. [PMID: 32044462 DOI: 10.1016/j.bbagrm.2020.194502] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 01/17/2020] [Accepted: 02/06/2020] [Indexed: 12/31/2022]
Abstract
Bacteria are sophisticated systems with high capacity and flexibility to adapt to various environmental conditions. Each prokaryote however possesses a defined metabolic network, which sets its overall metabolic capacity, and therefore the maximal growth rate that can be reached. To achieve optimal growth, bacteria adopt various molecular strategies to optimally adjust gene expression and optimize resource allocation according to the nutrient availability. The resulting physiological changes are often accompanied by changes in the growth rate, and by global regulation of gene expression. The growth-rate-dependent variation of the abundances in the cellular machineries, together with condition-specific regulatory mechanisms, affect RNA metabolism and fate and pose a challenge for rational gene expression reengineering of synthetic circuits. This article is part of a Special Issue entitled: RNA and gene control in bacteria, edited by Dr. M. Guillier and F. Repoila.
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Affiliation(s)
- Anne-Gaëlle Planson
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350 Jouy-en-Josas, France.
| | - Vincent Sauveplane
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350 Jouy-en-Josas, France.
| | - Etienne Dervyn
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350 Jouy-en-Josas, France.
| | - Matthieu Jules
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350 Jouy-en-Josas, France.
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17
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Haning K, Engels SM, Williams P, Arnold M, Contreras LM. Applying a New REFINE Approach in Zymomonas mobilis Identifies Novel sRNAs That Confer Improved Stress Tolerance Phenotypes. Front Microbiol 2020; 10:2987. [PMID: 31998271 PMCID: PMC6970203 DOI: 10.3389/fmicb.2019.02987] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 12/10/2019] [Indexed: 12/19/2022] Open
Abstract
As global controllers of gene expression, small RNAs represent powerful tools for engineering complex phenotypes. However, a general challenge prevents the more widespread use of sRNA engineering strategies: mechanistic analysis of these regulators in bacteria lags far behind their high-throughput search and discovery. This makes it difficult to understand how to efficiently identify useful sRNAs to engineer a phenotype of interest. To help address this, we developed a forward systems approach to identify naturally occurring sRNAs relevant to a desired phenotype: RNA-seq Examiner for Phenotype-Informed Network Engineering (REFINE). This pipeline uses existing RNA-seq datasets under different growth conditions. It filters the total transcriptome to locate and rank regulatory-RNA-containing regions that can influence a metabolic phenotype of interest, without the need for previous mechanistic characterization. Application of this approach led to the uncovering of six novel sRNAs related to ethanol tolerance in non-model ethanol-producing bacterium Zymomonas mobilis. Furthermore, upon overexpressing multiple sRNA candidates predicted by REFINE, we demonstrate improved ethanol tolerance reflected by up to an approximately twofold increase in relative growth rate compared to controls not expressing these sRNAs in 7% ethanol (v/v) RMG-supplemented media. In this way, the REFINE approach informs strain-engineering strategies that we expect are applicable for general strain engineering.
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Affiliation(s)
- Katie Haning
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, United States
| | - Sean M. Engels
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, United States
| | - Paige Williams
- Department of Aerospace Engineering & Engineering Mechanics, The University of Texas at Austin, Austin, TX, United States
| | - Margaret Arnold
- Department of Computer Science and Engineering, School of Engineering and Applied Sciences, University at Buffalo, Buffalo, NY, United States
| | - Lydia M. Contreras
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, United States
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, United States
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18
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RNA sequencing reveals small RNAs in Bacillus pumilus under different growth phases of the protease fermentation process. Appl Microbiol Biotechnol 2019; 104:833-852. [PMID: 31848654 DOI: 10.1007/s00253-019-10276-5] [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: 09/10/2019] [Revised: 11/06/2019] [Accepted: 11/23/2019] [Indexed: 10/25/2022]
Abstract
Bacillus pumilus, an endospore-forming soil bacterium, produces a wide array of extracellular proteins, such as proteases, which are already applied in the chemical, detergent and leather industries. Small noncoding regulatory RNAs (sRNAs) in bacteria are important RNA regulators that act in response to various environmental signals. Here, an RNA-seq-based transcriptome analysis was applied to B. pumilus SCU11, a strain that produces extracellular alkaline protease, across various growth phases of the protease fermentation process. Through bioinformatics screening of the sequencing data and visual inspection, 84 putative regulatory sRNAs were identified in B. pumilus, including 21 antisense sRNAs and 63 sRNAs in intergenic regions. We experimentally validated the expression of 48 intergenic sRNAs by quantitative RT-PCR (qRT-PCR). Meanwhile, the expression of 6 novel sRNAs was confirmed by northern blotting, and the expression profiles of 5 sRNAs showed close correlation with the growth phase. We revealed that the sRNA Bpsr137 was involved in flagellum and biofilm formation in B. pumilus. The identification of a global set of sRNAs increases the inventory of regulatory sRNAs in Bacillus and implies the important regulatory roles of sRNA in B. pumilus. These findings will contribute another dimension to the optimization of crucial metabolic activities of B. pumilus during a productive fermentation process.
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19
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Peng D, Luo X, Zhang N, Guo S, Zheng J, Chen L, Sun M. Small RNA-mediated Cry toxin silencing allows Bacillus thuringiensis to evade Caenorhabditis elegans avoidance behavioral defenses. Nucleic Acids Res 2019; 46:159-173. [PMID: 29069426 PMCID: PMC5758910 DOI: 10.1093/nar/gkx959] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 10/09/2017] [Indexed: 11/14/2022] Open
Abstract
Pathogen avoidance behavior protects animal hosts against microbial pathogens. Pathogens have evolved specific strategies during coevolution in response to such host defenses. However, these strategies for combatting host avoidance behavioral defenses remain poorly understood. Here, we used Caenorhabditis elegans and its bacterial pathogen Bacillus thuringiensis as a model and determined that small RNA (sRNA)-mediated Cry toxin silencing allowed pathogens to evade host avoidance behavioral defenses. The B. thuringiensis strain YBT-1518, which encodes three nematicidal cry genes, is highly toxic to C. elegans. However, the expression of the most potent toxin, Cry5Ba, was silenced in this strain when YBT-1518 was outside the host. Cry5Ba silencing was due to the sRNA BtsR1, which bound to the RBS site of the cry5Ba transcript via direct base pairing and inhibited Cry5Ba expression. Upon ingestion by C. elegans, Cry5Ba was expressed in vivo by strain YBT-1518. Cry5Ba silencing may allow B. thuringiensis to avoid nematode behavioral defenses and then express toxins once ingested to kill the host and gain a survival advantage. Our work describes a novel model of sRNA-mediated regulation to aid pathogens in combating host avoidance behavioral defenses.
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Affiliation(s)
- Donghai Peng
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Xiaoxia Luo
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Ni Zhang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Suxia Guo
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Jinshui Zheng
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Ling Chen
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Ming Sun
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
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20
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Kumar N, Zarringhalam K, Kulkarni RV. Stochastic Modeling of Gene Regulation by Noncoding Small RNAs in the Strong Interaction Limit. Biophys J 2019; 114:2530-2539. [PMID: 29874604 DOI: 10.1016/j.bpj.2018.04.044] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 04/11/2018] [Accepted: 04/24/2018] [Indexed: 12/18/2022] Open
Abstract
Noncoding small RNAs (sRNAs) are known to play a key role in regulating diverse cellular processes, and their dysregulation is linked to various diseases such as cancer. Such diseases are also marked by phenotypic heterogeneity, which is often driven by the intrinsic stochasticity of gene expression. Correspondingly, there is significant interest in developing quantitative models focusing on the interplay between stochastic gene expression and regulation by sRNAs. We consider the canonical model of regulation of stochastic gene expression by sRNAs, wherein interaction between constitutively expressed sRNAs and mRNAs leads to stoichiometric mutual degradation. The exact solution of this model is analytically intractable given the nonlinear interaction term between sRNAs and mRNAs, and theoretical approaches typically invoke the mean-field approximation. However, mean-field results are inaccurate in the limit of strong interactions and low abundances; thus, alternative theoretical approaches are needed. In this work, we obtain analytical results for the canonical model of regulation of stochastic gene expression by sRNAs in the strong interaction limit. We derive analytical results for the steady-state generating function of the joint distribution of mRNAs and sRNAs in the limit of strong interactions and use the results derived to obtain analytical expressions characterizing the corresponding protein steady-state distribution. The results obtained can serve as building blocks for the analysis of genetic circuits involving sRNAs and provide new insights into the role of sRNAs in regulating stochastic gene expression in the limit of strong interactions.
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Affiliation(s)
- Niraj Kumar
- Department of Physics, University of Massachusetts Boston, Boston, Massachusetts.
| | - Kourosh Zarringhalam
- Department of Mathematics, University of Massachusetts Boston, Boston, Massachusetts
| | - Rahul V Kulkarni
- Department of Physics, University of Massachusetts Boston, Boston, Massachusetts
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21
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Synthetic Biology Toolbox and Chassis Development in Bacillus subtilis. Trends Biotechnol 2019; 37:548-562. [DOI: 10.1016/j.tibtech.2018.10.005] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 10/15/2018] [Accepted: 10/17/2018] [Indexed: 12/24/2022]
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22
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Müller P, Gimpel M, Wildenhain T, Brantl S. A new role for CsrA: promotion of complex formation between an sRNA and its mRNA target in Bacillus subtilis. RNA Biol 2019; 16:972-987. [PMID: 31043113 PMCID: PMC6546359 DOI: 10.1080/15476286.2019.1605811] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
CsrA is a widely conserved, abundant small RNA binding protein that has been found in E. coli and other Gram-negative bacteria where it is involved in the regulation of carbon metabolism, biofilm formation and virulence. CsrA binds to single-stranded GGA motifs around the SD sequence of target mRNAs where it inhibits or activates translation or influences RNA processing. Small RNAs like CsrB or CsrC containing 13–22 GGA motifs can sequester CsrA, thereby abrogating the effect of CsrA on its target mRNAs. In B. subtilis, CsrA has so far only been found to regulate one target, hag mRNA and to be sequestered by a protein (FliW) and not by an sRNA. Here, we employ a combination of in vitro and in vivo methods to investigate the effect of CsrA on the small regulatory RNA SR1 from B. subtilis, its primary target ahrC mRNA and its downstream targets, the rocABC and rocDEF operons. We demonstrate that CsrA can promote the base-pairing interactions between SR1 and ahrC mRNA, a function that has so far only been found for Hfq or ProQ. Abbreviations: aa, amino acid; bp, basepair; nt, nucleotide; PAA, polyacrylamide; SD, Shine Dalgarno.
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Affiliation(s)
- Peter Müller
- a Matthias-Schleiden-Institut für Genetik, Bioinformatik und Molekulare Botanik, AG Bakteriengenetik , Friedrich-Schiller-Universität Jena , Jena , Germany
| | - Matthias Gimpel
- a Matthias-Schleiden-Institut für Genetik, Bioinformatik und Molekulare Botanik, AG Bakteriengenetik , Friedrich-Schiller-Universität Jena , Jena , Germany.,b Institut für Biotechnologie , Fachgebiet Bioverfahrenstechnik , Berlin , Germany
| | - Theresa Wildenhain
- a Matthias-Schleiden-Institut für Genetik, Bioinformatik und Molekulare Botanik, AG Bakteriengenetik , Friedrich-Schiller-Universität Jena , Jena , Germany
| | - Sabine Brantl
- a Matthias-Schleiden-Institut für Genetik, Bioinformatik und Molekulare Botanik, AG Bakteriengenetik , Friedrich-Schiller-Universität Jena , Jena , Germany
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23
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Cao H, Kuipers OP. Influence of global gene regulatory networks on single cell heterogeneity of green fluorescent protein production in Bacillus subtilis. Microb Cell Fact 2018; 17:134. [PMID: 30165856 PMCID: PMC6117926 DOI: 10.1186/s12934-018-0985-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Accepted: 08/24/2018] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Gram-positive bacterium Bacillus subtilis has been extensively studied as a microbial cell factory for high-level producing a wide range of interesting products. Green fluorescent protein (GFP) is commonly used as a marker for determining the strength of a given promoter or for the subcellular localization of a fusion protein. However, the inherent heterogeneity of GFP expression among individual cells that can arise from global regulation differences in the expression host, has not yet been systematically assessed. B. subtilis strains with single mutation(s) in the two major transcriptional regulators CcpA and/or CodY were earlier found to improve overall heterologous protein production levels. Here, we investigate the dynamic production performance of GFP in the reporter strains with chromosomally integrated Physpank-sfGFP(Sp). RESULTS The mutation R214C in the DNA-binding domain of CodY effectively enhances GFP production at the population level relative to two other strains, i.e. wildtype (WT) and CcpAT19S. During the late stationary phase, the high- and low-level GFP-producing cells coexist in the WT population, while the CodYR214C population at the single-cell level shows higher phenotypic homogeneity of fluorescence signals. CONCLUSION Expression of GFP is prominently heterogeneous in the WT B. subtilis cells, and this phenotypic heterogeneity can be significantly reduced by CodYR214C mutation. The rates of production heterogeneity show a high correlation to the overall GFP yields. Moreover, the toolkit of flow cytometry and fluorescence microscopy that can achieve real-time profiles of GFP production performance in various strains may facilitate the further use of B. subtilis as a cell factory.
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Affiliation(s)
- Haojie Cao
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands
| | - Oscar P. Kuipers
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands
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24
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Westermann AJ. Regulatory RNAs in Virulence and Host-Microbe Interactions. Microbiol Spectr 2018; 6:10.1128/microbiolspec.rwr-0002-2017. [PMID: 30003867 PMCID: PMC11633609 DOI: 10.1128/microbiolspec.rwr-0002-2017] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Indexed: 02/06/2023] Open
Abstract
Bacterial regulatory RNAs are key players in adaptation to changing environmental conditions and response to diverse cellular stresses. However, while regulatory RNAs of bacterial pathogens have been intensely studied under defined conditions in vitro, characterization of their role during the infection of eukaryotic host organisms is lagging behind. This review summarizes our current understanding of the contribution of the different classes of regulatory RNAs and RNA-binding proteins to bacterial virulence and illustrates their role in infection by reviewing the mechanisms of some prominent representatives of each class. Emerging technologies are described that bear great potential for global, unbiased studies of virulence-related RNAs in bacterial model and nonmodel pathogens in the future. The review concludes by deducing common principles of RNA-mediated gene expression control of virulence programs in different pathogens, and by defining important open questions for upcoming research in the field.
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Affiliation(s)
- Alexander J Westermann
- Institute of Molecular Infection Biology, University of Würzburg
- Helmholtz Institute for RNA-Based Infection Research, D-97080 Würzburg, Germany
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25
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Brosse A, Guillier M. Bacterial Small RNAs in Mixed Regulatory Networks. Microbiol Spectr 2018; 6:10.1128/microbiolspec.rwr-0014-2017. [PMID: 29916348 PMCID: PMC11633589 DOI: 10.1128/microbiolspec.rwr-0014-2017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2017] [Indexed: 12/16/2022] Open
Abstract
Small regulatory RNAs are now recognized as key regulators of gene expression in bacteria. They accumulate under specific conditions, most often because their synthesis is directly controlled by transcriptional regulators, including but not limited to alternative sigma factors and response regulators of two-component systems. In turn, small RNAs regulate, mostly at the posttranscriptional level, expression of multiple genes, among which are genes encoding transcriptional regulators. Small RNAs are thus embedded in mixed regulatory circuits combining transcriptional and posttranscriptional controls, and whose properties are discussed here.
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Affiliation(s)
- Anaïs Brosse
- CNRS UMR8261, Associated with University Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, 75005 Paris, France
| | - Maude Guillier
- CNRS UMR8261, Associated with University Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, 75005 Paris, France
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26
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The Small RNA ncS35 Regulates Growth in Burkholderia cenocepacia J2315. mSphere 2018; 3:mSphere00579-17. [PMID: 29359187 PMCID: PMC5760752 DOI: 10.1128/msphere.00579-17] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 12/13/2017] [Indexed: 12/16/2022] Open
Abstract
Small RNAs play an important role in the survival of bacteria in diverse environments. We explored the physiological role of ncS35, a small RNA expressed in B. cenocepacia J2315, an opportunistic pathogen in cystic fibrosis patients. In cystic fibrosis patients, infections can lead to “cepacia syndrome,” a rapidly progressing and often fatal pneumonia. Infections with Burkholderia spp. are difficult to threat with antibiotics because of their high intrinsic resistance and ability to form biofilms. We show that ncS35 attenuates the growth and reduces the metabolic rate of B. cenocepacia and influences biofilm structure. This demonstrates that as-yet-uncharacterized small RNAs with regulatory function can influence physiological traits of B. cenocepacia that are relevant for infection. Burkholderia cenocepacia J2315 is a member of the B. cepacia complex. It has a large genome with three replicons and one plasmid; 7,261 genes code for annotated proteins, while 113 code for functional RNAs. Small regulatory RNAs of B. cenocepacia have not yet been functionally characterized. We investigated a small regulatory RNA, designated ncS35, that was discovered by differential RNA sequencing. Its expression under various conditions was quantified, and a deletion mutant, ΔncS35, was constructed. Compared to planktonic growth in a rich medium, the expression of ncS35 was elevated when B. cenocepacia J2315 was grown in biofilms and in minimal medium. Cells of the deletion mutant showed increased aggregation, higher metabolic activity, a higher growth rate, and an increased susceptibility to tobramycin. A transcriptomic analysis revealed upregulation of the phenylacetic acid and tryptophan degradation pathways in ΔncS35. Computational target prediction indicated that ncS35 likely interacts with the first gene of the tryptophan degradation pathway. Overall, we demonstrated that small RNA ncS35 is a noncoding RNA with an attenuating effect on the metabolic rate and growth. It is possible that slower growth protects B. cenocepacia J2315 against stressors acting on fast-dividing cells and enhances survival under unfavorable conditions. IMPORTANCE Small RNAs play an important role in the survival of bacteria in diverse environments. We explored the physiological role of ncS35, a small RNA expressed in B. cenocepacia J2315, an opportunistic pathogen in cystic fibrosis patients. In cystic fibrosis patients, infections can lead to “cepacia syndrome,” a rapidly progressing and often fatal pneumonia. Infections with Burkholderia spp. are difficult to threat with antibiotics because of their high intrinsic resistance and ability to form biofilms. We show that ncS35 attenuates the growth and reduces the metabolic rate of B. cenocepacia and influences biofilm structure. This demonstrates that as-yet-uncharacterized small RNAs with regulatory function can influence physiological traits of B. cenocepacia that are relevant for infection.
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Cerutti F, Mallet L, Painset A, Hoede C, Moisan A, Bécavin C, Duval M, Dussurget O, Cossart P, Gaspin C, Chiapello H. Unraveling the evolution and coevolution of small regulatory RNAs and coding genes in Listeria. BMC Genomics 2017; 18:882. [PMID: 29145803 PMCID: PMC5689173 DOI: 10.1186/s12864-017-4242-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 10/29/2017] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Small regulatory RNAs (sRNAs) are widely found in bacteria and play key roles in many important physiological and adaptation processes. Studying their evolution and screening for events of coevolution with other genomic features is a powerful way to better understand their origin and assess a common functional or adaptive relationship between them. However, evolution and coevolution of sRNAs with coding genes have been sparsely investigated in bacterial pathogens. RESULTS We designed a robust and generic phylogenomics approach that detects correlated evolution between sRNAs and protein-coding genes using their observed and inferred patterns of presence-absence in a set of annotated genomes. We applied this approach on 79 complete genomes of the Listeria genus and identified fifty-two accessory sRNAs, of which most were present in the Listeria common ancestor and lost during Listeria evolution. We detected significant coevolution between 23 sRNA and 52 coding genes and inferred the Listeria sRNA-coding genes coevolution network. We characterized a main hub of 12 sRNAs that coevolved with genes encoding cell wall proteins and virulence factors. Among them, an sRNA specific to L. monocytogenes species, rli133, coevolved with genes involved either in pathogenicity or in interaction with host cells, possibly acting as a direct negative post-transcriptional regulation. CONCLUSIONS Our approach allowed the identification of candidate sRNAs potentially involved in pathogenicity and host interaction, consistent with recent findings on known pathogenicity actors. We highlight four sRNAs coevolving with seven internalin genes, some of which being important virulence factors in Listeria.
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Affiliation(s)
- Franck Cerutti
- Université de Toulouse, INRA, UR 875 Unité Mathématiques et Informatique Appliquées de Toulouse, Auzeville, 31326, Castanet-Tolosan, France
| | - Ludovic Mallet
- Université de Toulouse, INRA, UR 875 Unité Mathématiques et Informatique Appliquées de Toulouse, Auzeville, 31326, Castanet-Tolosan, France
| | - Anaïs Painset
- Université de Toulouse, INRA, UR 875 Unité Mathématiques et Informatique Appliquées de Toulouse, Auzeville, 31326, Castanet-Tolosan, France.,Present address: Public Health England, 61 Colindale Avenue, London, NW9 5EQ, England
| | - Claire Hoede
- Université de Toulouse, INRA, UR 875 Unité Mathématiques et Informatique Appliquées de Toulouse, Auzeville, 31326, Castanet-Tolosan, France
| | - Annick Moisan
- Université de Toulouse, INRA, UR 875 Unité Mathématiques et Informatique Appliquées de Toulouse, Auzeville, 31326, Castanet-Tolosan, France
| | - Christophe Bécavin
- Département de Biologie Cellulaire et Infection, Institut Pasteur, Unité des Interactions Bactéries-Cellules, F-75015, Paris, France.,INSERM, U604,F-75015, Paris, France.,INRA, USC2020, F-75015, Paris, France.,Institut Pasteur - Bioinformatics and Biostatistics Hub - C3BI, USR 3756 IP CNRS, Paris, France
| | - Mélodie Duval
- Département de Biologie Cellulaire et Infection, Institut Pasteur, Unité des Interactions Bactéries-Cellules, F-75015, Paris, France.,INSERM, U604,F-75015, Paris, France.,INRA, USC2020, F-75015, Paris, France
| | - Olivier Dussurget
- Département de Biologie Cellulaire et Infection, Institut Pasteur, Unité des Interactions Bactéries-Cellules, F-75015, Paris, France.,INSERM, U604,F-75015, Paris, France.,INRA, USC2020, F-75015, Paris, France.,Université Paris Diderot, Sorbonne Paris Cité, F-75013, Paris, France
| | - Pascale Cossart
- Département de Biologie Cellulaire et Infection, Institut Pasteur, Unité des Interactions Bactéries-Cellules, F-75015, Paris, France.,INSERM, U604,F-75015, Paris, France.,INRA, USC2020, F-75015, Paris, France
| | - Christine Gaspin
- Université de Toulouse, INRA, UR 875 Unité Mathématiques et Informatique Appliquées de Toulouse, Auzeville, 31326, Castanet-Tolosan, France
| | - Hélène Chiapello
- Université de Toulouse, INRA, UR 875 Unité Mathématiques et Informatique Appliquées de Toulouse, Auzeville, 31326, Castanet-Tolosan, France.
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28
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Bidnenko E, Bidnenko V. Transcription termination factor Rho and microbial phenotypic heterogeneity. Curr Genet 2017; 64:541-546. [PMID: 29094196 DOI: 10.1007/s00294-017-0775-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 10/27/2017] [Accepted: 10/28/2017] [Indexed: 12/21/2022]
Abstract
Populations of genetically identical microorganisms exhibit high degree of cell-to-cell phenotypic diversity even when grown in uniform environmental conditions. Heterogeneity is a genetically determined trait, which ensures bacterial adaptation and survival in the ever changing environmental conditions. Fluctuations in gene expression (noise) at the level of transcription initiation largely contribute to cell-to-cell variability within population. Not surprisingly, the analyses of the mechanisms driving phenotypic heterogeneity are mainly focused on the activity of promoters and transcriptional factors. Less attention is currently given to a role of intrinsic and factor-dependent transcription terminators. Here, we discuss recent advances in understanding the regulatory role of the multi-functional transcription termination factor Rho, the major inhibitor of pervasive transcription in bacteria and the emerging global regulator of gene expression. We propose that termination activity of Rho might be among the mechanisms by which cells manage the intensity of transcriptional noise, thus affecting population heterogeneity.
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Affiliation(s)
- Elena Bidnenko
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France.
| | - Vladimir Bidnenko
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
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29
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Liu Y, Li J, Du G, Chen J, Liu L. Metabolic engineering of Bacillus subtilis fueled by systems biology: Recent advances and future directions. Biotechnol Adv 2017; 35:20-30. [DOI: 10.1016/j.biotechadv.2016.11.003] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 10/21/2016] [Accepted: 11/16/2016] [Indexed: 12/25/2022]
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30
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Kirkpatrick CL, Lesouhaitier O, Malone JG, An SQ, Caly DL. Interaction and signalling networks: a report from the fourth 'Young Microbiologists Symposium on Microbe Signalling, Organisation and Pathogenesis'. MICROBIOLOGY-SGM 2016; 163:4-8. [PMID: 27902434 DOI: 10.1099/mic.0.000401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
At the end of June, over 120 microbiologists from 18 countries gathered in Dundee, Scotland for the fourth edition of the Young Microbiologists Symposium on 'Microbe Signalling, Organisation and Pathogenesis'. The aim of the symposium was to give early career microbiologists the opportunity to present their work in a convivial environment and to interact with senior world-renowned scientists in exciting fields of microbiology research. The meeting was supported by the Microbiology Society, the Society of Applied Microbiology and the American Society for Microbiology with further sponsorship from the European Molecular Biology Organisation and the Royal Society of Edinburgh. In this report, we highlight some themes that emerged from the many interesting talks and poster presentations, as well as some of the other activities that were on offer at this energetic meeting.
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Affiliation(s)
- Clare L Kirkpatrick
- Department of Microbiology & Molecular Medicine, Institute of Genetics & Genomics in Geneva (iGE3), Faculty of Medicine/University Medical Centre, University of Geneva, Geneva, Switzerland
| | - Olivier Lesouhaitier
- Laboratory of Microbiology Signals and Microenvironment, Normandy University, Université de Rouen, Évreux, France
| | - Jacob G Malone
- University of East Anglia, Norwich, UK.,John Innes Centre, Norwich Research Park, Norwich, UK
| | - Shi-Qi An
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, UK
| | - Delphine L Caly
- Institut Charles Viollette - ICV, Univ Lille, EA 7394, Lille, France
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31
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Regulatory RNAs in Bacillus subtilis: a Gram-Positive Perspective on Bacterial RNA-Mediated Regulation of Gene Expression. Microbiol Mol Biol Rev 2016; 80:1029-1057. [PMID: 27784798 DOI: 10.1128/mmbr.00026-16] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Bacteria can employ widely diverse RNA molecules to regulate their gene expression. Such molecules include trans-acting small regulatory RNAs, antisense RNAs, and a variety of transcriptional attenuation mechanisms in the 5' untranslated region. Thus far, most regulatory RNA research has focused on Gram-negative bacteria, such as Escherichia coli and Salmonella. Hence, there is uncertainty about whether the resulting insights can be extrapolated directly to other bacteria, such as the Gram-positive soil bacterium Bacillus subtilis. A recent study identified 1,583 putative regulatory RNAs in B. subtilis, whose expression was assessed across 104 conditions. Here, we review the current understanding of RNA-based regulation in B. subtilis, and we categorize the newly identified putative regulatory RNAs on the basis of their conservation in other bacilli and the stability of their predicted secondary structures. Our present evaluation of the publicly available data indicates that RNA-mediated gene regulation in B. subtilis mostly involves elements at the 5' ends of mRNA molecules. These can include 5' secondary structure elements and metabolite-, tRNA-, or protein-binding sites. Importantly, sense-independent segments are identified as the most conserved and structured potential regulatory RNAs in B. subtilis. Altogether, the present survey provides many leads for the identification of new regulatory RNA functions in B. subtilis.
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32
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Kumar N, Jia T, Zarringhalam K, Kulkarni RV. Frequency modulation of stochastic gene expression bursts by strongly interacting small RNAs. Phys Rev E 2016; 94:042419. [PMID: 27841647 DOI: 10.1103/physreve.94.042419] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Indexed: 06/06/2023]
Abstract
The sporadic nature of gene expression at the single-cell level-long periods of inactivity punctuated by bursts of mRNA or protein production-plays a critical role in diverse cellular processes. To elucidate the cellular role of bursting in gene expression, synthetic biology approaches have been used to design simple genetic circuits with bursty mRNA or protein production. Understanding how such genetic circuits can be designed with the ability to control burst-related parameters requires the development of quantitative stochastic models of gene expression. In this work, we analyze stochastic models for the regulation of gene expression bursts by strongly interacting small RNAs. For the parameter range considered, results based on mean-field approaches are significantly inaccurate and alternative analytical approaches are needed. Using simplifying approximations, we obtain analytical results for the corresponding steady-state distributions that are in agreement with results from stochastic simulations. These results indicate that regulation by small RNAs, in the strong interaction limit, can be used to effectively modulate the frequency of bursting. We explore the consequences of such regulation for simple genetic circuits involving feedback effects and switching between promoter states.
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Affiliation(s)
- Niraj Kumar
- Department of Physics, University of Massachusetts, Boston, Massachusetts 02125, USA
| | - Tao Jia
- College of Computer and Information Science, Southwest University, Chongqing 400715, People's Republic of China
| | - Kourosh Zarringhalam
- Department of Mathematics, University of Massachusetts, Boston, Massachusetts 02125, USA
| | - Rahul V Kulkarni
- Department of Physics, University of Massachusetts, Boston, Massachusetts 02125, USA
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33
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Xia K, Zang N, Zhang J, Zhang H, Li Y, Liu Y, Feng W, Liang X. New insights into the mechanisms of acetic acid resistance in Acetobacter pasteurianus using iTRAQ-dependent quantitative proteomic analysis. Int J Food Microbiol 2016; 238:241-251. [PMID: 27681379 DOI: 10.1016/j.ijfoodmicro.2016.09.016] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 09/20/2016] [Accepted: 09/21/2016] [Indexed: 12/01/2022]
Abstract
Acetobacter pasteurianus is the main starter in rice vinegar manufacturing due to its remarkable abilities to resist and produce acetic acid. Although several mechanisms of acetic acid resistance have been proposed and only a few effector proteins have been identified, a comprehensive depiction of the biological processes involved in acetic acid resistance is needed. In this study, iTRAQ-based quantitative proteomic analysis was adopted to investigate the whole proteome of different acidic titers (3.6, 7.1 and 9.3%, w/v) of Acetobacter pasteurianus Ab3 during the vinegar fermentation process. Consequently, 1386 proteins, including 318 differentially expressed proteins (p<0.05), were identified. Compared to that in the low titer circumstance, cells conducted distinct biological processes under high acetic acid stress, where >150 proteins were differentially expressed. Specifically, proteins involved in amino acid metabolic processes and fatty acid biosynthesis were differentially expressed, which may contribute to the acetic acid resistance of Acetobacter. Transcription factors, two component systems and toxin-antitoxin systems were implicated in the modulatory network at multiple levels. In addition, the identification of proteins involved in redox homeostasis, protein metabolism, and the cell envelope suggested that the whole cellular system is mobilized in response to acid stress. These findings provide a differential proteomic profile of acetic acid resistance in Acetobacter pasteurianus and have potential application to highly acidic rice vinegar manufacturing.
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Affiliation(s)
- Kai Xia
- Department of Biochemical Engineering, School of Food Science and Biochemical Engineering, Zhejiang Gongshang University, Hangzhou 310025, China
| | - Ning Zang
- Medical Scientific Research Center, Guangxi Medical University, Nanning 530021, China
| | - Junmei Zhang
- Department of Biochemical Engineering, School of Food Science and Biochemical Engineering, Zhejiang Gongshang University, Hangzhou 310025, China
| | - Hong Zhang
- Department of Biochemical Engineering, School of Food Science and Biochemical Engineering, Zhejiang Gongshang University, Hangzhou 310025, China
| | - Yudong Li
- Department of Biochemical Engineering, School of Food Science and Biochemical Engineering, Zhejiang Gongshang University, Hangzhou 310025, China
| | - Ye Liu
- Zhejiang Wuweihe Food Co. Ltd., Huzhou 313213, China
| | - Wei Feng
- Zhejiang Wuweihe Food Co. Ltd., Huzhou 313213, China
| | - Xinle Liang
- Department of Biochemical Engineering, School of Food Science and Biochemical Engineering, Zhejiang Gongshang University, Hangzhou 310025, China.
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34
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Cerulus B, New AM, Pougach K, Verstrepen KJ. Noise and Epigenetic Inheritance of Single-Cell Division Times Influence Population Fitness. Curr Biol 2016; 26:1138-47. [PMID: 27068419 DOI: 10.1016/j.cub.2016.03.010] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 02/05/2016] [Accepted: 03/01/2016] [Indexed: 01/24/2023]
Abstract
The fitness effect of biological noise remains unclear. For example, even within clonal microbial populations, individual cells grow at different speeds. Although it is known that the individuals' mean growth speed can affect population-level fitness, it is unclear how or whether growth speed heterogeneity itself is subject to natural selection. Here, we show that noisy single-cell division times can significantly affect population-level growth rate. Using time-lapse microscopy to measure the division times of thousands of individual S. cerevisiae cells across different genetic and environmental backgrounds, we find that the length of individual cells' division times can vary substantially between clonal individuals and that sublineages often show epigenetic inheritance of division times. By combining these experimental measurements with mathematical modeling, we find that, for a given mean division time, increasing heterogeneity and epigenetic inheritance of division times increases the population growth rate. Furthermore, we demonstrate that the heterogeneity and epigenetic inheritance of single-cell division times can be linked with variation in the expression of catabolic genes. Taken together, our results reveal how a change in noisy single-cell behaviors can directly influence fitness through dynamics that operate independently of effects caused by changes to the mean. These results not only allow a better understanding of microbial fitness but also help to more accurately predict fitness in other clonal populations, such as tumors.
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Affiliation(s)
- Bram Cerulus
- KU Leuven Department Microbiële en Moleculaire Systemen, CMPG Laboratory of Genetics and Genomics, Gaston Geenslaan 1, 3001 Leuven, Belgium; VIB Laboratory of Systems Biology, Gaston Geenslaan 1, 3001 Leuven, Belgium
| | - Aaron M New
- KU Leuven Department Microbiële en Moleculaire Systemen, CMPG Laboratory of Genetics and Genomics, Gaston Geenslaan 1, 3001 Leuven, Belgium; VIB Laboratory of Systems Biology, Gaston Geenslaan 1, 3001 Leuven, Belgium; Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain; Universitat Pompeu Fabra (UPF), Barcelona 08002, Spain
| | - Ksenia Pougach
- KU Leuven Department Microbiële en Moleculaire Systemen, CMPG Laboratory of Genetics and Genomics, Gaston Geenslaan 1, 3001 Leuven, Belgium; VIB Laboratory of Systems Biology, Gaston Geenslaan 1, 3001 Leuven, Belgium
| | - Kevin J Verstrepen
- KU Leuven Department Microbiële en Moleculaire Systemen, CMPG Laboratory of Genetics and Genomics, Gaston Geenslaan 1, 3001 Leuven, Belgium; VIB Laboratory of Systems Biology, Gaston Geenslaan 1, 3001 Leuven, Belgium.
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35
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Mäder U, Nicolas P, Depke M, Pané-Farré J, Debarbouille M, van der Kooi-Pol MM, Guérin C, Dérozier S, Hiron A, Jarmer H, Leduc A, Michalik S, Reilman E, Schaffer M, Schmidt F, Bessières P, Noirot P, Hecker M, Msadek T, Völker U, van Dijl JM. Staphylococcus aureus Transcriptome Architecture: From Laboratory to Infection-Mimicking Conditions. PLoS Genet 2016; 12:e1005962. [PMID: 27035918 PMCID: PMC4818034 DOI: 10.1371/journal.pgen.1005962] [Citation(s) in RCA: 146] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 03/04/2016] [Indexed: 11/18/2022] Open
Abstract
Staphylococcus aureus is a major pathogen that colonizes about 20% of the human population. Intriguingly, this Gram-positive bacterium can survive and thrive under a wide range of different conditions, both inside and outside the human body. Here, we investigated the transcriptional adaptation of S. aureus HG001, a derivative of strain NCTC 8325, across experimental conditions ranging from optimal growth in vitro to intracellular growth in host cells. These data establish an extensive repertoire of transcription units and non-coding RNAs, a classification of 1412 promoters according to their dependence on the RNA polymerase sigma factors SigA or SigB, and allow identification of new potential targets for several known transcription factors. In particular, this study revealed a relatively low abundance of antisense RNAs in S. aureus, where they overlap only 6% of the coding genes, and only 19 antisense RNAs not co-transcribed with other genes were found. Promoter analysis and comparison with Bacillus subtilis links the small number of antisense RNAs to a less profound impact of alternative sigma factors in S. aureus. Furthermore, we revealed that Rho-dependent transcription termination suppresses pervasive antisense transcription, presumably originating from abundant spurious transcription initiation in this A+T-rich genome, which would otherwise affect expression of the overlapped genes. In summary, our study provides genome-wide information on transcriptional regulation and non-coding RNAs in S. aureus as well as new insights into the biological function of Rho and the implications of spurious transcription in bacteria. The major human pathogen Staphylococcus aureus can survive under a wide range of conditions, both inside and outside the human body. The goal of this study was to determine how S. aureus adapts to such different conditions and, additionally, we wanted to identify general factors governing the staphylococcal transcriptome architecture. Therefore, we performed a precise analysis of all RNA transcripts of S. aureus across experimental conditions ranging from in vitro growth in different media to internalization by eukaryotic host cells. We systematically mapped all transcription units, annotated non-coding RNAs, and assigned promoters controlled by particular RNA polymerase sigma factors and transcription factors. By a comparison with data available for the related Gram-positive bacterium Bacillus subtilis, we made key observations concerning the abundance and origin of antisense RNAs. Intriguingly, these findings support the view that many antisense RNAs in a bacterium like B. subtilis could be byproducts of spurious promoter recognition by condition-specific alternative sigma factors. We also report that the transcription termination factor Rho prevents widespread antisense transcription, presumably caused by pervasive transcription initiation in the A+T-rich genome of S. aureus. Altogether our study presents new perspectives on the biological significance of antisense and pervasive transcription in bacteria.
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Affiliation(s)
- Ulrike Mäder
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Pierre Nicolas
- MaIAGE, INRA, Université Paris-Saclay, Jouy-en-Josas, France
| | - Maren Depke
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Jan Pané-Farré
- Institute for Microbiology, Ernst-Moritz-Arndt-University Greifswald, Greifswald, Germany
| | - Michel Debarbouille
- Biology of Gram-Positive Pathogens, Department of Microbiology, Institut Pasteur and CNRS ERL 3526, Paris, France
| | - Magdalena M. van der Kooi-Pol
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Cyprien Guérin
- MaIAGE, INRA, Université Paris-Saclay, Jouy-en-Josas, France
| | - Sandra Dérozier
- MaIAGE, INRA, Université Paris-Saclay, Jouy-en-Josas, France
| | - Aurelia Hiron
- Biology of Gram-Positive Pathogens, Department of Microbiology, Institut Pasteur and CNRS ERL 3526, Paris, France
| | - Hanne Jarmer
- Center for Biological Sequence Analysis, Department of Systems Biology, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Aurélie Leduc
- MaIAGE, INRA, Université Paris-Saclay, Jouy-en-Josas, France
| | - Stephan Michalik
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Ewoud Reilman
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Marc Schaffer
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Frank Schmidt
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | | | - Philippe Noirot
- Institut Micalis, INRA and AgroParisTech, Jouy-en-Josas, France
| | - Michael Hecker
- Institute for Microbiology, Ernst-Moritz-Arndt-University Greifswald, Greifswald, Germany
| | - Tarek Msadek
- Biology of Gram-Positive Pathogens, Department of Microbiology, Institut Pasteur and CNRS ERL 3526, Paris, France
| | - Uwe Völker
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
- * E-mail: (UV); (JMvD)
| | - Jan Maarten van Dijl
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- * E-mail: (UV); (JMvD)
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36
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Ploss TN, Reilman E, Monteferrante CG, Denham EL, Piersma S, Lingner A, Vehmaanperä J, Lorenz P, van Dijl JM. Homogeneity and heterogeneity in amylase production by Bacillus subtilis under different growth conditions. Microb Cell Fact 2016; 15:57. [PMID: 27026185 PMCID: PMC4812647 DOI: 10.1186/s12934-016-0455-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 03/22/2016] [Indexed: 12/22/2022] Open
Abstract
Background Bacillus subtilis is an important cell factory for the biotechnological industry due to its ability to secrete commercially relevant proteins in large amounts directly into the growth medium. However, hyper-secretion of proteins, such as α-amylases, leads to induction of the secretion stress-responsive CssR-CssS regulatory system, resulting in up-regulation of the HtrA and HtrB proteases. These proteases degrade misfolded proteins secreted via the Sec pathway, resulting in a loss of product. The aim of this study was to investigate the secretion stress response in B. subtilis 168 cells overproducing the industrially relevant α-amylase AmyM from Geobacillus stearothermophilus, which was expressed from the strong promoter P(amyQ)-M. Results Here we show that activity of the htrB promoter as induced by overproduction of AmyM was “noisy”, which is indicative for heterogeneous activation of the secretion stress pathway. Plasmids were constructed to allow real-time analysis of P(amyQ)-M promoter activity and AmyM production by, respectively, transcriptional and out-of-frame translationally coupled fusions with gfpmut3. Our results show the emergence of distinct sub-populations of high- and low-level AmyM-producing cells, reflecting heterogeneity in the activity of P(amyQ)-M. This most likely explains the heterogeneous secretion stress response. Importantly, more homogenous cell populations with regard to P(amyQ)-M activity were observed for the B. subtilis mutant strain 168degUhy32, and the wild-type strain 168 under optimized growth conditions. Conclusion Expression heterogeneity of secretory proteins in B. subtilis can be suppressed by degU mutation and optimized growth conditions. Further, the out-of-frame translational fusion of a gene for a secreted target protein and gfp represents a versatile tool for real-time monitoring of protein production and opens novel avenues for Bacillus production strain improvement.
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Affiliation(s)
- Tina N Ploss
- AB Enzymes GmbH, Feldbergstrasse 78, 64293, Darmstadt, Germany
| | - Ewoud Reilman
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RD, Groningen, The Netherlands
| | - Carmine G Monteferrante
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RD, Groningen, The Netherlands.,Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Emma L Denham
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RD, Groningen, The Netherlands.,Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, CV4 7AL, UK
| | - Sjouke Piersma
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RD, Groningen, The Netherlands
| | - Anja Lingner
- AB Enzymes GmbH, Feldbergstrasse 78, 64293, Darmstadt, Germany.,c-LEcta GmbH, Perlickstraße 5, 04103, Leipzig, Germany
| | | | - Patrick Lorenz
- AB Enzymes GmbH, Feldbergstrasse 78, 64293, Darmstadt, Germany
| | - Jan Maarten van Dijl
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RD, Groningen, The Netherlands.
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Fan B, Li L, Chao Y, Förstner K, Vogel J, Borriss R, Wu XQ. dRNA-Seq Reveals Genomewide TSSs and Noncoding RNAs of Plant Beneficial Rhizobacterium Bacillus amyloliquefaciens FZB42. PLoS One 2015; 10:e0142002. [PMID: 26540162 PMCID: PMC4634765 DOI: 10.1371/journal.pone.0142002] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 10/15/2015] [Indexed: 12/13/2022] Open
Abstract
Bacillus amyloliquefaciens subsp. plantarum FZB42 is a representative of Gram-positive plant-growth-promoting rhizobacteria (PGPR) that inhabit plant root environments. In order to better understand the molecular mechanisms of bacteria-plant symbiosis, we have systematically analyzed the primary transcriptome of strain FZB42 grown under rhizosphere-mimicking conditions using differential RNA sequencing (dRNA-seq). Our analysis revealed 4,877 transcription start sites for protein-coding genes, identified genes differentially expressed under different growth conditions, and corrected many previously mis-annotated genes. We also identified a large number of riboswitches and cis-encoded antisense RNAs, as well as trans-encoded small noncoding RNAs that may play important roles in the gene regulation of Bacillus. Overall, our analyses provided a landscape of Bacillus primary transcriptome and improved the knowledge of rhizobacteria-host interactions.
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Affiliation(s)
- Ben Fan
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, 210037 Nanjing, China
- * E-mail: (BF); (XW)
| | - Lei Li
- RNA Biology Group, Institute for Molecular Infection Biology, University of Würzburg, 97080 Würzburg, Germany
| | - Yanjie Chao
- RNA Biology Group, Institute for Molecular Infection Biology, University of Würzburg, 97080 Würzburg, Germany
| | - Konrad Förstner
- RNA Biology Group, Institute for Molecular Infection Biology, University of Würzburg, 97080 Würzburg, Germany
| | - Jörg Vogel
- RNA Biology Group, Institute for Molecular Infection Biology, University of Würzburg, 97080 Würzburg, Germany
| | - Rainer Borriss
- Fachgebiet Phytomedizin, Albrecht Daniel Thaer Institut für Agrar- und Gartenbauwissenschaften, Lebenswissenschaftliche Fakultät, Humboldt Universität zu Berlin, 14195 Berlin, Germany
| | - Xiao-Qin Wu
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, 210037 Nanjing, China
- * E-mail: (BF); (XW)
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