1
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Kok LC, Tsai CC, Liao YH, Lo YL, Cheng NW, Lin CT, Chang HY. Roles of transcriptional factor PsrA in the regulation of quorum sensing in Pseudomonas aeruginosa PAO1. Front Microbiol 2024; 15:1424330. [PMID: 38989021 PMCID: PMC11233452 DOI: 10.3389/fmicb.2024.1424330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2024] [Accepted: 06/14/2024] [Indexed: 07/12/2024] Open
Abstract
The transcription factor PsrA regulates fatty acid metabolism, the type III secretion system, and quinolone signaling quorum sensing system in Pseudomonas aeruginosa. To explore additional roles of PsrA in P. aeruginosa, this study engineered a P. aeruginosa PAO1 strain to carry a recombinant plasmid with the psrA gene (pMMBpsrA) and examined the impact of elevated psrA expression to the bacterium. Transcriptomic analysis revealed that PsrA significantly downregulated genes encoding the master quorum-sensing regulators, RhlR and LasR, and influenced many quorum-sensing-associated genes. The role of PsrA in quorum sensing was further corroborated by testing autoinducer synthesis in PAO1 [pMMBpsrA] using two reporter bacteria strains Chromobacterium violaceum CV026 and Escherichia coli [pSB1075], which respond to short- and long-chain acyl homoserine lactones, respectively. Phenotypic comparisons of isogenic ΔpsrA, ΔlasR, and ΔpsrAΔlasR mutants revealed that the reduced elastase, caseinase, and swarming activity in PAO1 [pMMBpsrA] were likely mediated through LasR. Additionally, electrophoretic mobility shift assays demonstrated that recombinant PsrA could bind to the lasR promoter at a 5'-AAACGTTTGCTT-3' sequence, which displays moderate similarity to the previously reported consensus PsrA binding motif. Furthermore, the PsrA effector molecule oleic acid inhibited PsrA binding to the lasR promoter and restored several quorum sensing-related phenotypes to wild-type levels. These findings suggest that PsrA regulates certain quorum-sensing phenotypes by negatively regulating lasR expression, with oleic acid acting as a crucial signaling molecule.
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Affiliation(s)
- Li-Ching Kok
- Institute of Molecular Medicine, National Tsing Hua University, Hsinchu City, Taiwan
| | - Chia-Chun Tsai
- Institute of Molecular Medicine, National Tsing Hua University, Hsinchu City, Taiwan
| | - Yu-Hsuan Liao
- Institute of Molecular Medicine, National Tsing Hua University, Hsinchu City, Taiwan
| | - Yi-Ling Lo
- Institute of Molecular Medicine, National Tsing Hua University, Hsinchu City, Taiwan
| | - Nai-Wei Cheng
- Institute of Molecular Medicine, National Tsing Hua University, Hsinchu City, Taiwan
| | - Ching-Ting Lin
- School of Chinese Medicine, China Medical University, Taichung City, Taiwan
| | - Hwan-You Chang
- Institute of Molecular Medicine, National Tsing Hua University, Hsinchu City, Taiwan
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2
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Schiaffi V, Barras F, Bouveret E. Matching the β-oxidation gene repertoire with the wide diversity of fatty acids. Curr Opin Microbiol 2024; 77:102402. [PMID: 37992547 DOI: 10.1016/j.mib.2023.102402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 10/23/2023] [Accepted: 10/28/2023] [Indexed: 11/24/2023]
Abstract
Bacteria can use fatty acids (FAs) from their environment as carbon and energy source. This catabolism is performed by the enzymes of the well-known β-oxidation machinery, producing reducing power and releasing acetyl-CoA that can feed the tricarboxylic acid cycle. FAs are extremely diverse: they can be saturated or (poly)unsaturated and are found in different sizes. The need to degrade such a wide variety of compounds may explain why so many seemingly homologous enzymes are found for each step of the β-oxidation cycle. In addition, the degradation of unsaturated fatty acids requires specific auxiliary enzymes for isomerase and reductase reactions. Furthermore, the β-oxidation cycle can be blocked by dead-end products, which are taken care of by acyl-CoA thioesterases. Yet, the functional characterization of the enzymes required for the degradation of the full diversity of FAs remains to be documented in most bacteria.
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Affiliation(s)
- Veronica Schiaffi
- Institut Pasteur, Department of Microbiology, Université Paris-Cité, UMR CNRS 6047, SAMe Unit, France
| | - Frédéric Barras
- Institut Pasteur, Department of Microbiology, Université Paris-Cité, UMR CNRS 6047, SAMe Unit, France
| | - Emmanuelle Bouveret
- Institut Pasteur, Department of Microbiology, Université Paris-Cité, UMR CNRS 6047, SAMe Unit, France.
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3
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Vinayavekhin N, Wattanophas T, Murphy MF, Vangnai AS, Hobbs G. Metabolomics responses and tolerance of Pseudomonas aeruginosa under acoustic vibration stress. PLoS One 2024; 19:e0297030. [PMID: 38285708 PMCID: PMC10824448 DOI: 10.1371/journal.pone.0297030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 12/25/2023] [Indexed: 01/31/2024] Open
Abstract
Sound has been shown to impact microbial behaviors. However, our understanding of the chemical and molecular mechanisms underlying these microbial responses to acoustic vibration is limited. In this study, we used untargeted metabolomics analysis to investigate the effects of 100-Hz acoustic vibration on the intra- and extracellular hydrophobic metabolites of P. aeruginosa PAO1. Our findings revealed increased levels of fatty acids and their derivatives, quinolones, and N-acylethanolamines upon sound exposure, while rhamnolipids (RLs) showed decreased levels. Further quantitative real-time polymerase chain reaction experiments showed slight downregulation of the rhlA gene (1.3-fold) and upregulation of fabY (1.5-fold), fadE (1.7-fold), and pqsA (1.4-fold) genes, which are associated with RL, fatty acid, and quinolone biosynthesis. However, no alterations in the genes related to the rpoS regulators or quorum-sensing networks were observed. Supplementing sodium oleate to P. aeruginosa cultures to simulate the effects of sound resulted in increased tolerance of P. aeruginosa in the presence of sound at 48 h, suggesting a potential novel response-tolerance correlation. In contrast, adding RL, which went against the response direction, did not affect its growth. Overall, these findings provide potential implications for the control and manipulation of virulence and bacterial characteristics for medical and industrial applications.
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Affiliation(s)
- Nawaporn Vinayavekhin
- Center of Excellence in Natural Products Chemistry, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
- Center of Excellence in Biocatalyst and Sustainable Biotechnology, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
| | - Thanyaporn Wattanophas
- Center of Excellence in Natural Products Chemistry, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
| | - Mark Francis Murphy
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool, United Kingdom
| | - Alisa S. Vangnai
- Center of Excellence in Biocatalyst and Sustainable Biotechnology, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
| | - Glyn Hobbs
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool, United Kingdom
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4
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Wang H, Wang X, Tang Q, Wang L, Mei C, Shao Y, Xu Y, Lu Z, Zhong W. Regulation Mechanism of Nicotine Catabolism in Sphingomonas melonis TY by a Dual Role Transcriptional Regulator NdpR. Appl Environ Microbiol 2023; 89:e0032423. [PMID: 37071026 PMCID: PMC10231238 DOI: 10.1128/aem.00324-23] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 03/25/2023] [Indexed: 04/19/2023] Open
Abstract
A gene cluster ndp, responsible for nicotine degradation via a variant of the pyridine and pyrrolidine pathways, was previously identified in Sphingomonas melonis TY, but the regulation mechanism remains unknown. The gene ndpR within the cluster was predicted to encode a TetR family transcriptional regulator. Deletion of ndpR resulted in a notably shorter lag phase, higher maximum turbidity, and faster substrate degradation when cultivated in the presence of nicotine. Real-time quantitative PCR and promoter activity analysis in wild-type TY and TYΔndpR strains revealed that genes in the ndp cluster were negatively regulated by NdpR. However, complementation of ndpR to TYΔndpR did not restore transcription repression, but, instead, the complemented strain showed better growth than TYΔndpR. Promoter activity analysis indicates that NdpR also functions as an activator in the transcription regulation of ndpHFEGD. Further analysis through electrophoretic mobility shift assay and DNase I footprinting assay revealed that NdpR binds five DNA sequences within ndp and that NdpR has no autoregulation. These binding motifs overlap with the -35 or -10 box or are located distal upstream of the corresponding transcriptional start site. Multiple sequence alignment of these five NdpR-binding DNA sequences found a conserved motif, with two of the binding sequences being partially palindromic. 2,5-Dihydroxypyridine acted as a ligand of NdpR, preventing NdpR from binding to the promoter region of ndpASAL, ndpTB, and ndpHFEGD. This study revealed that NdpR binds to three promoters in the ndp cluster and is a dual-role transcriptional regulator in nicotine metabolism. IMPORTANCE Gene regulation is critical for microorganisms in the environment in which they may encounter various kinds of organic pollutants. Our study revealed that transcription of ndpASAL, ndpTB, and ndpHFEGD is negatively regulated by NdpR, and NdpR also exhibits a positive regulatory effect on PndpHFEGD. Furthermore, 2,5-dihydroxypyridine was identified as the effector molecular for NdpR and can both prevent the binding of free NdpR to the promoter and release NdpR from the promoters, which is different from previously reported NicR2. Additionally, NdpR was found to have both negative and positive transcription regulatory effects on the same target, PndpHFEGD, while only one binding site was identified, which is notably different from the previously reported TetR family regulators. Moreover, NdpR was revealed to be a global transcriptional regulator. This study provides new insight into the complex gene expression regulation of the TetR family.
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Affiliation(s)
- Haixia Wang
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Xiaoyu Wang
- MOE Laboratory of Biosystem Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Qi Tang
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Lvjing Wang
- MOE Laboratory of Biosystem Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Chengyu Mei
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Yunhai Shao
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Ying Xu
- Department of Microbial Sciences, State Key Laboratory of Microbial Metabolism, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Zhenmei Lu
- MOE Laboratory of Biosystem Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Weihong Zhong
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
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5
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Zhang N, Wu J, Zhang S, Yuan M, Xu H, Li J, Zhang P, Wang M, Kempher ML, Tao X, Zhang LQ, Ge H, He YX. Molecular basis for coordinating secondary metabolite production by bacterial and plant signaling molecules. J Biol Chem 2022; 298:102027. [PMID: 35568198 PMCID: PMC9163588 DOI: 10.1016/j.jbc.2022.102027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 05/03/2022] [Accepted: 05/05/2022] [Indexed: 11/28/2022] Open
Abstract
The production of secondary metabolites is a major mechanism used by beneficial rhizobacteria to antagonize plant pathogens. These bacteria have evolved to coordinate the production of different secondary metabolites due to the heavy metabolic burden imposed by secondary metabolism. However, for most secondary metabolites produced by bacteria, it is not known how their biosynthesis is coordinated. Here, we showed that PhlH from the rhizobacterium Pseudomonas fluorescens is a TetR-family regulator coordinating the expression of enzymes related to the biosynthesis of several secondary metabolites, including 2,4-diacetylphloroglucinol (2,4-DAPG), mupirocin, and pyoverdine. We present structures of PhlH in both its apo form and 2,4-DAPG-bound form and elucidate its ligand-recognizing and allosteric switching mechanisms. Moreover, we found that dissociation of 2,4-DAPG from the ligand-binding domain of PhlH was sufficient to allosterically trigger a pendulum-like movement of the DNA-binding domains within the PhlH dimer, leading to a closed-to-open conformational transition. Finally, molecular dynamics simulations confirmed that two distinct conformational states were stabilized by specific hydrogen bonding interactions and that disruption of these hydrogen bonds had profound effects on the conformational transition. Our findings not only reveal a well-conserved route of allosteric signal transduction in TetR-family regulators but also provide novel mechanistic insights into bacterial metabolic coregulation.
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Affiliation(s)
- Nannan Zhang
- School of Life Sciences, Anhui University, Hefei 230601, P.R. China; Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, Hefei 230601, Anhui, China.
| | - Jin Wu
- School of Life Sciences, Anhui University, Hefei 230601, P.R. China; Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, P.R. China
| | - Siping Zhang
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, P.R. China
| | - Maoran Yuan
- School of Life Sciences, Anhui University, Hefei 230601, P.R. China; Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, P.R. China
| | - Hang Xu
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, P.R. China
| | - Jie Li
- School of Life Sciences, Anhui University, Hefei 230601, P.R. China; Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, P.R. China
| | - Pingping Zhang
- School of Life Sciences, Anhui University, Hefei 230601, P.R. China; Key Laboratory of Human Microenvironment and Precision Medicine of Anhui Higher Education Institutes, Anhui University, Hefei 230601, Anhui, China
| | - Mingzhu Wang
- School of Life Sciences, Anhui University, Hefei 230601, P.R. China; Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, P.R. China
| | - Megan L Kempher
- Institute for Environmental Genomics, Department of Microbiology and Plant Biology, and School of Civil Engineering and Environmental Sciences, University of Oklahoma, Norman, Ok, USA
| | - Xuanyu Tao
- Institute for Environmental Genomics, Department of Microbiology and Plant Biology, and School of Civil Engineering and Environmental Sciences, University of Oklahoma, Norman, Ok, USA
| | - Li-Qun Zhang
- College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Honghua Ge
- School of Life Sciences, Anhui University, Hefei 230601, P.R. China; Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, P.R. China.
| | - Yong-Xing He
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, P.R. China.
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6
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Brinkman FSL, Winsor GL, Done RE, Filloux A, Francis VI, Goldberg JB, Greenberg EP, Han K, Hancock REW, Haney CH, Häußler S, Klockgether J, Lamont IL, Levesque RC, Lory S, Nikel PI, Porter SL, Scurlock MW, Schweizer HP, Tümmler B, Wang M, Welch M. The Pseudomonas aeruginosa whole genome sequence: A 20th anniversary celebration. Adv Microb Physiol 2021; 79:25-88. [PMID: 34836612 DOI: 10.1016/bs.ampbs.2021.07.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Toward the end of August 2000, the 6.3 Mbp whole genome sequence of Pseudomonas aeruginosa strain PAO1 was published. With 5570 open reading frames (ORFs), PAO1 had the largest microbial genome sequenced up to that point in time-including a large proportion of metabolic, transport and antimicrobial resistance genes supporting its ability to colonize diverse environments. A remarkable 9% of its ORFs were predicted to encode proteins with regulatory functions, providing new insight into bacterial network complexity as a function of network size. In this celebratory article, we fast forward 20 years, and examine how access to this resource has transformed our understanding of P. aeruginosa. What follows is more than a simple review or commentary; we have specifically asked some of the leaders in the field to provide personal reflections on how the PAO1 genome sequence, along with the Pseudomonas Community Annotation Project (PseudoCAP) and Pseudomonas Genome Database (pseudomonas.com), have contributed to the many exciting discoveries in this field. In addition to bringing us all up to date with the latest developments, we also ask our contributors to speculate on how the next 20 years of Pseudomonas research might pan out.
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Affiliation(s)
- Fiona S L Brinkman
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Geoffrey L Winsor
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Rachel E Done
- Department of Pediatrics, Division of Pulmonary, Allergy and Immunology, Cystic Fibrosis, and Sleep, Emory Children's Center for Cystic Fibrosis and Airway Disease Research, Emory University School of Medicine, Atlanta, GA, United States
| | - Alain Filloux
- Department of Life Sciences, MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Vanessa I Francis
- Geoffrey Pope Building, University of Exeter, Exeter, United Kingdom
| | - Joanna B Goldberg
- Department of Pediatrics, Division of Pulmonary, Allergy and Immunology, Cystic Fibrosis, and Sleep, Emory Children's Center for Cystic Fibrosis and Airway Disease Research, Emory University School of Medicine, Atlanta, GA, United States
| | - E Peter Greenberg
- Department of Microbiology, University of Washington, Seattle, WA, United States
| | - Kook Han
- Department of Microbiology, Harvard Medical School, Boston, MA, United States
| | | | - Cara H Haney
- Department of Microbiology and Immunology, The University of British Columbia, Vancouver, BC, Canada
| | - Susanne Häußler
- Department of Molecular Bacteriology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Jens Klockgether
- Klinik für Pädiatrische Pneumologie, Allergologie und Neonatologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Iain L Lamont
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Roger C Levesque
- Institut de biologie intégrative et des systèmes (IBIS), Pavillon Charles-Eugène Marchand, Faculté of Médicine, Université Laval, Québec City, QC, Canada
| | - Stephen Lory
- Department of Microbiology, Harvard Medical School, Boston, MA, United States
| | - Pablo I Nikel
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Steven L Porter
- Geoffrey Pope Building, University of Exeter, Exeter, United Kingdom
| | | | - Herbert P Schweizer
- Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ, United States
| | - Burkhard Tümmler
- Klinik für Pädiatrische Pneumologie, Allergologie und Neonatologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Meng Wang
- Department of Biochemistry (Hopkins Building), University of Cambridge, Cambridge, United Kingdom
| | - Martin Welch
- Department of Biochemistry (Hopkins Building), University of Cambridge, Cambridge, United Kingdom.
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7
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Velázquez-Sánchez C, Vences-Guzmán MÁ, Moreno S, Tinoco-Valencia R, Espín G, Guzmán J, Sahonero-Canavesi DX, Sohlenkamp C, Segura D. PsrA positively regulates the unsaturated fatty acid synthesis operon fabAB in Azotobacter vinelandii. Microbiol Res 2021; 249:126775. [PMID: 33964629 DOI: 10.1016/j.micres.2021.126775] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 03/12/2021] [Accepted: 04/27/2021] [Indexed: 10/21/2022]
Abstract
In Pseudomonas spp. PsrA, a transcriptional activator of the rpoS gene, regulates fatty acid catabolism by repressing the fadBA5 β-oxidation operon. In Azotobacter vinelandii, a soil bacterium closely related to Pseudomonas species, PsrA is also an activator of rpoS expression, although its participation in the regulation of lipid metabolism has not been analyzed. In this work we found that inactivation of psrA had no effect on the expression of β-oxidation genes in this bacterium, but instead decreased expression of the unsaturated fatty acid biosynthetic operon fabAB (3-hydroxydecanoyl-ACP dehydratase/isomerase and 3-ketoacyl-ACP synthase I). This inactivation also reduced the unsaturated fatty acid content, as revealed by the thin-layer chromatographic analysis, and confirmed by gas chromatography; notably, there was also a lower content of cyclopropane fatty acids, which are synthesized from unsaturated fatty acids. The absence of PsrA has no effect on the growth rate, but showed loss of cell viability during long-term growth, in accordance with the role of these unsaturated and cyclopropane fatty acids in the protection of membranes. Finally, an electrophoretic mobility shift assay revealed specific binding of PsrA to the fabA promoter region, where a putative binding site for this regulator was located. Taken together, our data show that PsrA plays an important role in the regulation of unsaturated fatty acids metabolism in A. vinelandii by positively regulating fabAB.
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Affiliation(s)
- Claudia Velázquez-Sánchez
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | | | - Soledad Moreno
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Raunel Tinoco-Valencia
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Guadalupe Espín
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Josefina Guzmán
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | | | - Christian Sohlenkamp
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Daniel Segura
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México.
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8
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Wang T, Sun W, Fan L, Hua C, Wu N, Fan S, Zhang J, Deng X, Yan J. An atlas of the binding specificities of transcription factors in Pseudomonas aeruginosa directs prediction of novel regulators in virulence. eLife 2021; 10:61885. [PMID: 33779544 PMCID: PMC8041468 DOI: 10.7554/elife.61885] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 03/26/2021] [Indexed: 12/14/2022] Open
Abstract
A high-throughput systematic evolution of ligands by exponential enrichment assay was applied to 371 putative TFs in Pseudomonas aeruginosa, which resulted in the robust enrichment of 199 unique sequence motifs describing the binding specificities of 182 TFs. By scanning the genome, we predicted in total 33,709 significant interactions between TFs and their target loci, which were more than 11-fold enriched in the intergenic regions but depleted in the gene body regions. To further explore and delineate the physiological and pathogenic roles of TFs in P. aeruginosa, we constructed regulatory networks for nine major virulence-associated pathways and found that 51 TFs were potentially significantly associated with these virulence pathways, 32 of which had not been characterized before, and some were even involved in multiple pathways. These results will significantly facilitate future studies on transcriptional regulation in P. aeruginosa and other relevant pathogens, and accelerate to discover effective treatment and prevention strategies for the associated infectious diseases.
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Affiliation(s)
- Tingting Wang
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
| | - Wenju Sun
- School of Medicine, Northwest University, Xi'an, China
| | - Ligang Fan
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China.,School of Medicine, Northwest University, Xi'an, China
| | - Canfeng Hua
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
| | - Nan Wu
- School of Medicine, Northwest University, Xi'an, China
| | - Shaorong Fan
- School of Medicine, Northwest University, Xi'an, China
| | - Jilin Zhang
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Solna, Sweden
| | - Xin Deng
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
| | - Jian Yan
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China.,School of Medicine, Northwest University, Xi'an, China
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9
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Horna G, Ruiz J. Type 3 secretion system of Pseudomonas aeruginosa. Microbiol Res 2021; 246:126719. [PMID: 33582609 DOI: 10.1016/j.micres.2021.126719] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 01/19/2021] [Accepted: 01/26/2021] [Indexed: 12/27/2022]
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen, mainly affecting severe patients, such as those in intensive care units (ICUs). High levels of antibiotic resistance and a long battery of virulence factors characterise this pathogen. Among virulence factors, the T3SS (Type 3 Secretion Systems) are especially relevant, being one of the most important virulence factors in P. aeruginosa. T3SS are a complex "molecular syringe" able to inject different effectors in host cells, subverting cell machinery influencing immune responses, and increasing bacterial survival rates. While T3SS have been largely studied and the molecular structure and main effector functions have been established, a series of questions and further points remain to be clarified or established. The key role of T3SS in P. aeruginosa virulence has resulted in the search for T3SS-targeting molecules able to impair their functions and subsequently improve patient outcomes. This review aims to summarise the most relevant features of the P. aeruginosa T3SS.
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Affiliation(s)
- Gertrudis Horna
- Universidad Catolica Los Angeles de Chimbote, Instituto de Investigación, Chimbote, Peru.
| | - Joaquim Ruiz
- Laboratorio de Microbiología Molecular y Genómica Bacteriana, Universidad Científica del Sur, Panamericana Sur, Km 19, Lima, Peru.
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10
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Juárez-Rodríguez MM, Cortes-López H, García-Contreras R, González-Pedrajo B, Díaz-Guerrero M, Martínez-Vázquez M, Rivera-Chávez JA, Soto-Hernández RM, Castillo-Juárez I. Tetradecanoic Acids With Anti-Virulence Properties Increase the Pathogenicity of Pseudomonas aeruginosa in a Murine Cutaneous Infection Model. Front Cell Infect Microbiol 2021; 10:597517. [PMID: 33585272 PMCID: PMC7876447 DOI: 10.3389/fcimb.2020.597517] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 12/08/2020] [Indexed: 12/25/2022] Open
Abstract
Blocking virulence is a promising alternative to counteract Pseudomonas aeruginosa infections. In this regard, the phenomenon of cell-cell communication by quorum sensing (QS) is an important anti-virulence target. In this field, fatty acids (FA) have gained notoriety for their role as autoinducers, as well as anti-virulence molecules in vitro, like some saturated FA (SAFA). In this study, we analyzed the anti-virulence activity of SAFA with 12 to18 carbon atoms and compared their effect with the putative autoinducer cis-2-decenoic acid (CDA). The effect of SAFA on six QS-regulated virulence factors and on the secretion of the exoenzyme ExoU was evaluated. In addition, a murine cutaneous infection model was used to determine their influence on the establishment and damage caused by P. aeruginosa PA14. Dodecanoic (lauric, C12:0) and tetradecanoic (myristic, C14:0) acids (SAFA C12-14) reduced the production of pyocyanin by 35-58% at 40 and 1,000 µM, while CDA inhibited it 62% at a 3.1 µM concentration. Moreover, the SAFA C12-14 reduced swarming by 90% without affecting biofilm formation. In contrast, CDA reduced the biofilm by 57% at 3 µM but did not affect swarming. Furthermore, lauric and myristic acids abolished ExoU secretion at 100 and 50 µM respectively, while CDA reduced it by ≈ 92% at 100 µM. Remarkably, the coadministration of myristic acid (200 and 1,000 µM) with P. aeruginosa PA14 induced greater damage and reduced survival of the animals up to 50%, whereas CDA to 500 µM reduced the damage without affecting the viability of the PA14 strain. Hence, our results show that SAFA C12-14 and CDA have a role in regulation of P. aeruginosa virulence, although their inhibition/activation molecular mechanisms are different in complex environments such as in vivo systems.
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Affiliation(s)
| | - Humberto Cortes-López
- Laboratorio de Fitoquímica, Posgrado de Botánica, Colegio de Postgraduados, Texcoco, Mexico
| | - Rodolfo García-Contreras
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Bertha González-Pedrajo
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Miguel Díaz-Guerrero
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Mariano Martínez-Vázquez
- Departamento de Productos Naturales, Instituto de Química, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - José Alberto Rivera-Chávez
- Departamento de Productos Naturales, Instituto de Química, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | | | - Israel Castillo-Juárez
- Laboratorio de Fitoquímica, Posgrado de Botánica, Colegio de Postgraduados, Texcoco, Mexico
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11
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Lybbert AC, Williams JL, Raghuvanshi R, Jones AD, Quinn RA. Mining Public Mass Spectrometry Data to Characterize the Diversity and Ubiquity of P. aeruginosa Specialized Metabolites. Metabolites 2020; 10:metabo10110445. [PMID: 33167332 PMCID: PMC7694397 DOI: 10.3390/metabo10110445] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 10/19/2020] [Accepted: 10/29/2020] [Indexed: 01/08/2023] Open
Abstract
Pseudomonas aeruginosa is a ubiquitous environmental bacterium that causes chronic infections of burn wounds and in the lungs of cystic fibrosis (CF) patients. Vital to its infection is a myriad of specialized metabolites that serve a variety of biological roles including quorum sensing, metal chelation and inhibition of other competing bacteria. This study employed newly available algorithms for searching individual tandem mass (MS/MS) spectra against the publicly available Global Natural Product Social Molecular Networking (GNPS) database to identify the chemical diversity of these compounds and their presence in environmental, laboratory and clinical samples. For initial characterization, the metabolomes of eight clinical isolates of P. aeruginosa were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and uploaded to GNPS for spectral searching. Quinolones, rhamnolipids, phenazines and siderophores were identified and characterized; including the discovery of modified forms of the iron chelator pyochelin. Quinolones were highly diverse with the three base forms Pseudomonas quinolone signal 2-heptyl-3-hydroxy-4(1H)-quinolone (PQS), 4-heptyl-4(1H)-quinolone (HHQ) and 2-heptyl-4-quinolone-N-oxide (HQNO) having extensive variation in the length of their acyl chain from as small as 3 carbons to as large as 17. Rhamnolipids were limited to either one or two sugars with a limited set of fatty acyl chains, but the base lipid form without the rhamnose was also detected. These specialized metabolites were identified from diverse sources including ant-fungal mutualist dens, soil, plants, human teeth, feces, various lung mucus samples and cultured laboratory isolates. Their prevalence in fecal samples was particularly notable as P. aeruginosa is not known as a common colonizer of the human gut. The chemical diversity of the compounds identified, particularly the quinolones, demonstrates a broad spectrum of chemical properties within these the metabolite groups with likely significant impacts on their biological functions. Mining public data with GNPS enables a new approach to characterize the chemical diversity of biological organisms, which includes enabling the discovery of new chemistry from pathogenic bacteria.
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Affiliation(s)
- Andrew C. Lybbert
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48823, USA; (A.C.L.); (J.L.W.); (R.R.); (A.D.J.)
| | - Justin L. Williams
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48823, USA; (A.C.L.); (J.L.W.); (R.R.); (A.D.J.)
- Department of Biology, University of Arkansas at Pine Bluff, Pine Bluff, AR 71601, USA
| | - Ruma Raghuvanshi
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48823, USA; (A.C.L.); (J.L.W.); (R.R.); (A.D.J.)
| | - A. Daniel Jones
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48823, USA; (A.C.L.); (J.L.W.); (R.R.); (A.D.J.)
| | - Robert A. Quinn
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48823, USA; (A.C.L.); (J.L.W.); (R.R.); (A.D.J.)
- Correspondence: ; Tel.: +1-517-353-1426
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12
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Shao X, Xie Y, Zhang Y, Liu J, Ding Y, Wu M, Wang X, Deng X. Novel therapeutic strategies for treating Pseudomonas aeruginosa infection. Expert Opin Drug Discov 2020; 15:1403-1423. [PMID: 32880507 DOI: 10.1080/17460441.2020.1803274] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
INTRODUCTION Persistent infections caused by the superbug Pseudomonas aeruginosa and its resistance to multiple antimicrobial agents are huge threats to patients with cystic fibrosis as well as those with compromised immune systems. Multidrug-resistant P. aeruginosa has posed a major challenge to conventional antibiotics and therapeutic approaches, which show limited efficacy and cause serious side effects. The public demand for new antibiotics is enormous; yet, drug development pipelines have started to run dry with limited targets available for inventing new antibacterial drugs. Consequently, it is important to uncover potential therapeutic targets. AREAS COVERED The authors review the current state of drug development strategies that are promising in terms of the development of novel and potent drugs to treat P. aeruginosa infection. EXPERT OPINION The prevention of P. aeruginosa infection is increasingly challenging. Furthermore, targeting key virulence regulators has great potential for developing novel anti-P. aeruginosa drugs. Additional promising strategies include bacteriophage therapy, immunotherapies, and antimicrobial peptides. Additionally, the authors believe that in the coming years, the overall network of molecular regulatory mechanism of P. aeruginosa virulence will be fully elucidated, which will provide more novel and promising drug targets for treating P. aeruginosa infections.
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Affiliation(s)
- Xiaolong Shao
- Department of Biomedical Sciences, City University of Hong Kong , Hong Kong SAR, China
| | - Yingpeng Xie
- Department of Biomedical Sciences, City University of Hong Kong , Hong Kong SAR, China
| | - Yingchao Zhang
- Department of Biomedical Sciences, City University of Hong Kong , Hong Kong SAR, China
| | - Jingui Liu
- Department of Biomedical Sciences, City University of Hong Kong , Hong Kong SAR, China
| | - Yiqing Ding
- Department of Biomedical Sciences, City University of Hong Kong , Hong Kong SAR, China
| | - Min Wu
- Department of Biomedical Sciences, University of North Dakota , Grand Forks, North Dakota, USA
| | - Xin Wang
- Department of Biomedical Sciences, City University of Hong Kong , Hong Kong SAR, China
| | - Xin Deng
- Department of Biomedical Sciences, City University of Hong Kong , Hong Kong SAR, China.,Shenzhen Research Institute, City University of Hong Kong , Shenzhen, China
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13
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Hierarchical Transcriptional Control of the LuxR Quorum-Sensing Regulon of Vibrio harveyi. J Bacteriol 2020; 202:JB.00047-20. [PMID: 32366592 DOI: 10.1128/jb.00047-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 04/30/2020] [Indexed: 11/20/2022] Open
Abstract
In vibrios, quorum sensing controls hundreds of genes that are required for cell density-specific behaviors including bioluminescence, biofilm formation, competence, secretion, and swarming motility. The central transcription factor in the quorum-sensing pathway is LuxR/HapR, which directly regulates ∼100 genes in the >400-gene regulon of Vibrio harveyi Among these directly controlled genes are 15 transcription factors, which we predicted would comprise the second tier in the hierarchy of the LuxR regulon. We confirmed that LuxR binds to the promoters of these genes in vitro and quantified the extent of LuxR activation or repression of transcript levels. Transcriptome sequencing (RNA-seq) indicates that most of these transcriptional regulators control only a few genes, with the exception of MetJ, which is a global regulator. The genes regulated by these transcription factors are predicted to be involved in methionine and thiamine biosynthesis, membrane stability, RNA processing, c-di-GMP degradation, sugar transport, and other cellular processes. These data support a hierarchical model in which LuxR directly regulates 15 transcription factors that drive the second level of the gene expression cascade to influence cell density-dependent metabolic states and behaviors in V. harveyi IMPORTANCE Quorum sensing is important for survival of bacteria in nature and influences the actions of bacterial groups. In the relatively few studied examples of quorum-sensing-controlled genes, these genes are associated with competition or cooperation in complex microbial communities and/or virulence in a host. However, quorum sensing in vibrios controls the expression of hundreds of genes, and their functions are mostly unknown or uncharacterized. In this study, we identify the regulators of the second tier of gene expression in the quorum-sensing system of the aquaculture pathogen Vibrio harveyi Our identification of regulatory networks and metabolic pathways controlled by quorum sensing can be extended and compared to other Vibrio species to understand the physiology, ecology, and pathogenesis of these organisms.
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14
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Pan X, Fan Z, Chen L, Liu C, Bai F, Wei Y, Tian Z, Dong Y, Shi J, Chen H, Jin Y, Cheng Z, Jin S, Lin J, Wu W. PvrA is a novel regulator that contributes to Pseudomonas aeruginosa pathogenesis by controlling bacterial utilization of long chain fatty acids. Nucleic Acids Res 2020; 48:5967-5985. [PMID: 32406921 PMCID: PMC7293031 DOI: 10.1093/nar/gkaa377] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 04/28/2020] [Accepted: 04/30/2020] [Indexed: 12/19/2022] Open
Abstract
During infection of a host, Pseudomonas aeruginosa orchestrates global gene expression to adapt to the host environment and counter the immune attacks. P. aeruginosa harbours hundreds of regulatory genes that play essential roles in controlling gene expression. However, their contributions to the bacterial pathogenesis remain largely unknown. In this study, we analysed the transcriptomic profile of P. aeruginosa cells isolated from lungs of infected mice and examined the roles of upregulated regulatory genes in bacterial virulence. Mutation of a novel regulatory gene pvrA (PA2957) attenuated the bacterial virulence in an acute pneumonia model. Chromatin immunoprecipitation (ChIP)-Seq and genetic analyses revealed that PvrA directly regulates genes involved in phosphatidylcholine utilization and fatty acid catabolism. Mutation of the pvrA resulted in defective bacterial growth when phosphatidylcholine or palmitic acid was used as the sole carbon source. We further demonstrated that palmitoyl coenzyme A is a ligand for the PvrA, enhancing the binding affinity of PvrA to its target promoters. An arginine residue at position 136 was found to be essential for PvrA to bind palmitoyl coenzyme A. Overall, our results revealed a novel regulatory pathway that controls genes involved in phosphatidylcholine and fatty acid utilization and contributes to the bacterial virulence.
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Affiliation(s)
- Xiaolei Pan
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Zheng Fan
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Lei Chen
- Department of Plant Biology and Ecology, College of Life Science Nankai University, Tianjin 300071 China
| | - Chang Liu
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Fang Bai
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Yu Wei
- State Key Laboratory of Medicinal Chemical Biology and College of Pharmacy, Nankai University, Tianjin 300071, China
| | - Zhenyang Tian
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Yuanyuan Dong
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Jing Shi
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Hao Chen
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Yongxin Jin
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Zhihui Cheng
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Shouguang Jin
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Jianping Lin
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China
- State Key Laboratory of Medicinal Chemical Biology and College of Pharmacy, Nankai University, Tianjin 300071, China
| | - Weihui Wu
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China
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15
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Overexpression of the Small RNA PA0805.1 in Pseudomonas aeruginosa Modulates the Expression of a Large Set of Genes and Proteins, Resulting in Altered Motility, Cytotoxicity, and Tobramycin Resistance. mSystems 2020; 5:5/3/e00204-20. [PMID: 32430407 PMCID: PMC7253367 DOI: 10.1128/msystems.00204-20] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
P. aeruginosa is an opportunistic pathogen of humans. With roughly 10% of its genes encoding transcriptional regulators, and hundreds of small noncoding RNAs (sRNAs) interspersed throughout the genome, P. aeruginosa is able to fine-tune its response to adapt and survive in the host and resist antimicrobial agents. Understanding mechanisms of genetic regulation is therefore crucial to combat pathogenesis. The previously uncharacterized sRNA PA0805.1 was overexpressed in P. aeruginosa strain PAO1, resulting in decreased motility, increased adherence, cytotoxicity, and tobramycin resistance. In contrast, a ΔPA0805.1 deletion mutant had increased susceptibility to tobramycin under swarming conditions. Omic approaches uncovered 1,121 transcriptomic and 258 proteomic changes in the overexpression strain compared with the empty-vector strain, which included 106 regulatory factors. Downstream of these regulators were upregulated adherence factors, multidrug efflux systems, and virulence factors in both transcriptomics and proteomics. This study provides insights into the role of the sRNA PA0805.1 in modulating bacterial adaptations. Pseudomonas aeruginosa is a motile species that initiates swarming motility in response to specific environmental cues, i.e., a semisolid surface with amino acids as a nitrogen source (relevant to the human lung). Swarming is an intricately regulated process, but to date posttranscriptional regulation has not been extensively investigated. Small noncoding RNAs (sRNAs) are hypothesized to play posttranscriptional regulatory roles, largely through suppression of translation, and we previously demonstrated 20 sRNA species that were dysregulated under swarming conditions. One of these, sRNA PA0805.1 (which was 5-fold upregulated under swarming conditions), when cloned, transformed into wild-type (WT) PAO1, and overexpressed, led to broad phenotypic changes, including reduced swarming, swimming, and twitching motilities, as well as increased adherence, cytotoxicity, and tobramycin resistance. A ΔPA0805.1 deletion mutant was more susceptible to tobramycin than the WT under swarming conditions. The strain overexpressing PA0805.1 was compared to the empty-vector strain by transcriptome sequencing (RNA-Seq) and proteomics under swarming conditions to determine sRNA targets. Broad transcriptional and proteomic profiles showed 1,121 differentially expressed genes and 258 proteins with significantly different abundance. Importantly, these included 106 transcriptional regulators, two-component regulatory systems, and sigma and anti-sigma factors. Downstream of these regulators were found downregulated type IV pilus genes, many upregulated adherence and virulence factors, and two multidrug efflux systems, mexXY and mexGHI-opmD. Therefore, the sRNA PA0805.1 appears to be a global regulator that influences diverse bacterial lifestyles, most likely through a regulatory cascade. IMPORTANCEP. aeruginosa is an opportunistic pathogen of humans. With roughly 10% of its genes encoding transcriptional regulators, and hundreds of small noncoding RNAs (sRNAs) interspersed throughout the genome, P. aeruginosa is able to fine-tune its response to adapt and survive in the host and resist antimicrobial agents. Understanding mechanisms of genetic regulation is therefore crucial to combat pathogenesis. The previously uncharacterized sRNA PA0805.1 was overexpressed in P. aeruginosa strain PAO1, resulting in decreased motility, increased adherence, cytotoxicity, and tobramycin resistance. In contrast, a ΔPA0805.1 deletion mutant had increased susceptibility to tobramycin under swarming conditions. Omic approaches uncovered 1,121 transcriptomic and 258 proteomic changes in the overexpression strain compared with the empty-vector strain, which included 106 regulatory factors. Downstream of these regulators were upregulated adherence factors, multidrug efflux systems, and virulence factors in both transcriptomics and proteomics. This study provides insights into the role of the sRNA PA0805.1 in modulating bacterial adaptations.
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16
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García-Reyes S, Soberón-Chávez G, Cocotl-Yanez M. The third quorum-sensing system of Pseudomonas aeruginosa: Pseudomonas quinolone signal and the enigmatic PqsE protein. J Med Microbiol 2020; 69:25-34. [PMID: 31794380 DOI: 10.1099/jmm.0.001116] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that produces several virulence factors such as lectin A, pyocyanin, elastase and rhamnolipids. These compounds are controlled transcriptionally by three quorum-sensing circuits, two based on the synthesis and detection of N-acyl-homoserine-lactone termed the Las and Rhl system and a third system named the Pseudomonas quinolone signal (PQS) system, which is responsible for generating 2-alkyl-4(1 h)-quinolones (AQs). The transcriptional regulator called PqsR binds to the promoter of pqsABCDE in the presence of PQS or HHQ creating a positive feedback-loop. PqsE, encoded in the operon for AQ synthesis, is a crucial protein for pyocyanin production, activating the Rhl system by a still not fully understood mechanism. In turn, the regulation of the PQS system is modulated by Las and Rhl systems, which act positively and negatively, respectively. This review focuses on the PQS system, from its discovery to its role in Pseudomonas pathogenesis, such as iron depletion and pyocyanin synthesis that involves the PqsE protein - an intriguing player of this system.
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Affiliation(s)
- Selene García-Reyes
- Departamento de Biología molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, Apdo Postal 70228, C.P. 04510, Ciudad de México, Mexico
| | - Gloria Soberón-Chávez
- Departamento de Biología molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, Apdo Postal 70228, C.P. 04510, Ciudad de México, Mexico
| | - Miguel Cocotl-Yanez
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México. Av. Universidad 3000, Cd. Universitaria, C.P. 04510, Coyoacán, Ciudad de México, Mexico
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17
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Teper D, Zhang Y, Wang N. TfmR, a novel TetR-family transcriptional regulator, modulates the virulence of Xanthomonas citri in response to fatty acids. MOLECULAR PLANT PATHOLOGY 2019; 20:701-715. [PMID: 30919570 PMCID: PMC6637906 DOI: 10.1111/mpp.12786] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The type III secretion system (T3SS) is required for Xanthomonas citri subsp. citri (Xcc) virulence by translocating effectors into host cytoplasm to promote disease development. The T3SS is controlled by the master transcriptional regulators HrpG and HrpX. While the function of HrpG and HrpX are well characterized, their upstream regulation remains elusive. By using transposon mutagenesis, we identified XAC3052, a TetR-family transcriptional regulator, which regulates T3SS gene expression. Deletion of XAC3052 caused significant reduction in the expression of T3SS and effector genes in vitro and in planta; as well as reduction of virulence in sweet orange (Citrus sinensis). Overexpression of hrpG restored the virulence of ∆XAC3052, suggesting that the loss of virulence is caused by reduction of T3SS gene expression. XAC3052 directly binds to the promoter region and represses the transcription of fadE, mhpC and fadH genes. FadE, MhpC and FadH are not involved in T3SS regulation, but involved in fatty acid catabolism. ∆XAC3052 displays altered fatty acid composition and retarded growth in environments limited in fatty acids. Exogenously supplemented long-chain fatty acids activate the fadE/mhpC promoter and suppress T3SS promoters in wild-type Xac but not in ∆XAC3052. Moreover, the binding of XAC3052 to its target promoter was disrupted by long-chain fatty acids in vitro. Herein, XAC3052 is designated as TfmR (T3SS and Fatty acid Mechanism Regulator). This study identifies a novel regulator of fatty acid metabolism and suggests that fatty acids play an important role in the metabolic control of virulence in Xcc.
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Affiliation(s)
- Doron Teper
- Citrus Research and Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural SciencesUniversity of Florida700 Experiment Station RoadLake Alfred33850USA
| | - Yanan Zhang
- Citrus Research and Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural SciencesUniversity of Florida700 Experiment Station RoadLake Alfred33850USA
| | - Nian Wang
- Citrus Research and Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural SciencesUniversity of Florida700 Experiment Station RoadLake Alfred33850USA
- China-USA Citrus Huanglongbing Joint Laboratory (A joint laboratory of The University of Florida’s Institute of Food and Agricultural Sciences and Gannan Normal University), National Navel Orange Engineering Research CenterGannan Normal UniversityGanzhou341000JiangxiChina
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18
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Novovic KD, Malesevic MJ, Filipic BV, Mirkovic NL, Miljkovic MS, Kojic MO, Jovčić BU. PsrA Regulator Connects Cell Physiology and Class 1 Integron Integrase Gene Expression Through the Regulation of lexA Gene Expression in Pseudomonas spp. Curr Microbiol 2019; 76:320-328. [DOI: 10.1007/s00284-019-01626-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 01/10/2019] [Indexed: 12/30/2022]
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19
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Witzgall F, Depke T, Hoffmann M, Empting M, Brönstrup M, Müller R, Blankenfeldt W. The Alkylquinolone Repertoire of Pseudomonas aeruginosa is Linked to Structural Flexibility of the FabH-like 2-Heptyl-3-hydroxy-4(1H)-quinolone (PQS) Biosynthesis Enzyme PqsBC. Chembiochem 2018; 19:1531-1544. [PMID: 29722462 DOI: 10.1002/cbic.201800153] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Indexed: 12/22/2022]
Abstract
Pseudomonas aeruginosa is a bacterial pathogen that causes life-threatening infections in immunocompromised patients. It produces a large armory of saturated and mono-unsaturated 2-alkyl-4(1H)-quinolones (AQs) and AQ N-oxides (AQNOs) that serve as signaling molecules to control the production of virulence factors and that are involved in membrane vesicle formation and iron chelation; furthermore, they also have, for example, antibiotic properties. It has been shown that the β-ketoacyl-acyl-carrier protein synthase III (FabH)-like heterodimeric enzyme PqsBC catalyzes the last step in the biosynthesis of the most abundant AQ congener, 2-heptyl-4(1H)-quinolone (HHQ), by condensing octanoyl-coenzyme A (CoA) with 2-aminobenzoylacetate (2-ABA), but the basis for the large number of other AQs/AQNOs produced by P. aeruginosa is not known. Here, we demonstrate that PqsBC uses different medium-chain acyl-CoAs to produce various saturated AQs/AQNOs and that it also biosynthesizes mono-unsaturated congeners. Further, we determined the structures of PqsBC in four different crystal forms at 1.5 to 2.7 Å resolution. Together with a previous report, the data reveal that PqsBC adopts open, intermediate, and closed conformations that alter the shape of the acyl-binding cavity and explain the promiscuity of PqsBC. The different conformations also allow us to propose a model for structural transitions that accompany the catalytic cycle of PqsBC that might have broader implications for other FabH-enzymes, for which such structural transitions have been postulated but have never been observed.
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Affiliation(s)
- Florian Witzgall
- Department Structure and Function of Proteins, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124, Braunschweig, Germany
| | - Tobias Depke
- Department Chemical Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124, Braunschweig, Germany
| | - Michael Hoffmann
- Department Microbial Natural Products, Helmholtz Institute for Pharmaceutical Research Saarland, Helmholtz Centre for Infection Research, Campus E8.1, 66123, Saarbrücken, Germany.,Department of Pharmacy, Saarland University, Campus E8.1, 66123, Saarbrücken, Germany
| | - Martin Empting
- Department Drug Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland, Helmholtz Centre for Infection Research, Campus E8.1, 66123, Saarbrücken, Germany.,Department of Pharmacy, Saarland University, Campus E8.1, 66123, Saarbrücken, Germany
| | - Mark Brönstrup
- Department Chemical Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124, Braunschweig, Germany
| | - Rolf Müller
- Department Microbial Natural Products, Helmholtz Institute for Pharmaceutical Research Saarland, Helmholtz Centre for Infection Research, Campus E8.1, 66123, Saarbrücken, Germany.,Department of Pharmacy, Saarland University, Campus E8.1, 66123, Saarbrücken, Germany
| | - Wulf Blankenfeldt
- Department Structure and Function of Proteins, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124, Braunschweig, Germany.,Institute for Biochemistry, Biotechnology and Bioinformatics, Technische Universität Braunschweig, Spielmannstrasse 7, 38106, Braunschweig, Germany
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Shahid I, Malik KA, Mehnaz S. A decade of understanding secondary metabolism in Pseudomonas spp. for sustainable agriculture and pharmaceutical applications. ACTA ACUST UNITED AC 2018. [DOI: 10.1007/s42398-018-0006-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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