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Avendaño R, Muñoz-Montero S, Rojas-Gätjens D, Fuentes-Schweizer P, Vieto S, Montenegro R, Salvador M, Frew R, Kim J, Chavarría M, Jiménez JI. Production of selenium nanoparticles occurs through an interconnected pathway of sulphur metabolism and oxidative stress response in Pseudomonas putida KT2440. Microb Biotechnol 2023; 16:931-946. [PMID: 36682039 PMCID: PMC10128140 DOI: 10.1111/1751-7915.14215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 12/20/2022] [Accepted: 12/22/2022] [Indexed: 01/23/2023] Open
Abstract
The soil bacterium Pseudomonas putida KT2440 has been shown to produce selenium nanoparticles aerobically from selenite; however, the molecular actors involved in this process are unknown. Here, through a combination of genetic and analytical techniques, we report the first insights into selenite metabolism in this bacterium. Our results suggest that the reduction of selenite occurs through an interconnected metabolic network involving central metabolic reactions, sulphur metabolism, and the response to oxidative stress. Genes such as sucA, D2HGDH and PP_3148 revealed that the 2-ketoglutarate and glutamate metabolism is important to convert selenite into selenium. On the other hand, mutations affecting the activity of the sulphite reductase decreased the bacteria's ability to transform selenite. Other genes related to sulphur metabolism (ssuEF, sfnCE, sqrR, sqr and pdo2) and stress response (gqr, lsfA, ahpCF and sadI) were also identified as involved in selenite transformation. Interestingly, suppression of genes sqrR, sqr and pdo2 resulted in the production of selenium nanoparticles at a higher rate than the wild-type strain, which is of biotechnological interest. The data provided in this study brings us closer to understanding the metabolism of selenium in bacteria and offers new targets for the development of biotechnological tools for the production of selenium nanoparticles.
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Affiliation(s)
- Roberto Avendaño
- Centro Nacional de Innovaciones Biotecnológicas (CENIBiot), CeNAT-CONARE, San José, Costa Rica
| | | | - Diego Rojas-Gätjens
- Centro Nacional de Innovaciones Biotecnológicas (CENIBiot), CeNAT-CONARE, San José, Costa Rica
| | - Paola Fuentes-Schweizer
- Escuela de Química, Universidad de Costa Rica, San José, Costa Rica.,Centro de Electroquímica y Energía Química (CELEQ), Universidad de Costa Rica, San José, Costa Rica
| | - Sofía Vieto
- Centro Nacional de Innovaciones Biotecnológicas (CENIBiot), CeNAT-CONARE, San José, Costa Rica
| | - Rafael Montenegro
- Centro Nacional de Innovaciones Biotecnológicas (CENIBiot), CeNAT-CONARE, San José, Costa Rica
| | - Manuel Salvador
- Biotechnology Applications, IDENER Research & Development, Seville, Spain
| | - Rufus Frew
- Department of Chemistry, University of Leicester, Leicester, UK
| | - Juhyun Kim
- School of Life Sciences, BK21 FOUR KNU Creative BioResearch Group, KNU Institute for Microorganisms, Kyungpook National University, Daegu, Korea
| | - Max Chavarría
- Centro Nacional de Innovaciones Biotecnológicas (CENIBiot), CeNAT-CONARE, San José, Costa Rica.,Escuela de Química, Universidad de Costa Rica, San José, Costa Rica.,Centro de Investigaciones en Productos Naturales (CIPRONA), Universidad de Costa Rica, San José, Costa Rica
| | - Jose I Jiménez
- Department of Life Sciences, Imperial College London, London, UK
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2
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Szechyńska-Hebda M, Ghalami RZ, Kamran M, Van Breusegem F, Karpiński S. To Be or Not to Be? Are Reactive Oxygen Species, Antioxidants, and Stress Signalling Universal Determinants of Life or Death? Cells 2022; 11:cells11244105. [PMID: 36552869 PMCID: PMC9777155 DOI: 10.3390/cells11244105] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 12/10/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022] Open
Abstract
In the environmental and organism context, oxidative stress is complex and unavoidable. Organisms simultaneously cope with a various combination of stress factors in natural conditions. For example, excess light stress is accompanied by UV stress, heat shock stress, and/or water stress. Reactive oxygen species (ROS) and antioxidant molecules, coordinated by electrical signalling (ES), are an integral part of the stress signalling network in cells and organisms. They together regulate gene expression to redirect energy to growth, acclimation, or defence, and thereby, determine cellular stress memory and stress crosstalk. In plants, both abiotic and biotic stress increase energy quenching, photorespiration, stomatal closure, and leaf temperature, while toning down photosynthesis and transpiration. Locally applied stress induces ES, ROS, retrograde signalling, cell death, and cellular light memory, then acclimation and defence responses in the local organs, whole plant, or even plant community (systemic acquired acclimation, systemic acquired resistance, network acquired acclimation). A simplified analogy can be found in animals where diseases vs. fitness and prolonged lifespan vs. faster aging, are dependent on mitochondrial ROS production and ES, and body temperature is regulated by sweating, temperature-dependent respiration, and gene regulation. In this review, we discuss the universal features of stress factors, ES, the cellular production of ROS molecules, ROS scavengers, hormones, and other regulators that coordinate life and death.
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Affiliation(s)
- Magdalena Szechyńska-Hebda
- Department of Plant Genetics, Breeding and Biotechnology, Institute of Biology, Warsaw University of Life Sciences, Nowoursynowska 159, 02-776 Warsaw, Poland
- W. Szafer Institute of Botany of the Polish Academy of Sciences, Lubicz 46, 31-512 Kraków, Poland
- Correspondence: or (M.S.-H.); (S.K.)
| | - Roshanak Zarrin Ghalami
- Department of Plant Genetics, Breeding and Biotechnology, Institute of Biology, Warsaw University of Life Sciences, Nowoursynowska 159, 02-776 Warsaw, Poland
| | - Muhammad Kamran
- Department of Plant Genetics, Breeding and Biotechnology, Institute of Biology, Warsaw University of Life Sciences, Nowoursynowska 159, 02-776 Warsaw, Poland
| | - Frank Van Breusegem
- UGent Department of Plant Biotechnology and Bioinformatics, VIB-UGent Center for Plant Systems Biology Ghent University, Technologiepark-Zwijnaarde 71, 9052 Ghent, Belgium
| | - Stanisław Karpiński
- Department of Plant Genetics, Breeding and Biotechnology, Institute of Biology, Warsaw University of Life Sciences, Nowoursynowska 159, 02-776 Warsaw, Poland
- Correspondence: or (M.S.-H.); (S.K.)
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3
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Kasthuri T, Barath S, Nandhakumar M, Karutha Pandian S. Proteomic profiling spotlights the molecular targets and the impact of the natural antivirulent umbelliferone on stress response, virulence factors, and the quorum sensing network of Pseudomonas aeruginosa. Front Cell Infect Microbiol 2022; 12:998540. [PMID: 36530435 PMCID: PMC9748083 DOI: 10.3389/fcimb.2022.998540] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 10/18/2022] [Indexed: 12/05/2022] Open
Abstract
Pseudomonas aeruginosa easily adapts to newer environments and acquires several genome flexibilities to overcome the effect of antibiotics during therapeutics, especially in cystic fibrosis patients. During adaptation to the host system, the bacteria employ various tactics including virulence factor production and biofilm formation to escape from the host immune system and resist antibiotics. Hence, identifying alternative strategies to combat recalcitrant pathogens is imperative for the successful elimination of drug-resistant microbes. In this context, this study portrays the anti-virulence efficacy of umbelliferone (UMB) against P. aeruginosa. UMB (7-hydroxy coumarin) is pervasively found among the plant family of Umbelliferae and Asteraceae. The UMB impeded biofilm formation in the P. aeruginosa reference strain and clinical isolates on polystyrene and glass surfaces at the concentration of 125 µg/ml. Global proteomic analysis of UMB-treated cells revealed the downregulation of major virulence-associated proteins such as RhlR, LasA, AlgL, FliD, Tpx, HtpG, KatA, FusA1, Tsf, PhzM, PhzB2, CarB, DctP, MtnA, and MscL. A functional interaction study, gene ontology, and KEGG pathway analysis revealed that UMB could modulate the global regulators, enzymes, co-factors, and transcription factors related to quorum sensing (QS), stress tolerance, siderophore production, motility, and microcolony formation. In vitro biochemical assays further affirmed the anti-virulence efficacy of UMB by reducing pyocyanin, protease, elastase, and catalase production in various strains of P. aeruginosa. Besides the antibiofilm activity, UMB-treated cells exhibited enhanced antibiotic susceptibility to various antibiotics including amikacin, kanamycin, tobramycin, ciprofloxacin, and cefotaxime. Furthermore, in vitro cytotoxicity analysis revealed the biocompatibility of UMB, and the IC50 value was determined to be 249.85 µg/ml on the HepG2 cell line. Altogether, the study substantiates the anti-virulence efficacy of UMB against P. aeruginosa, and the proteomic analysis reveals the differential expression of the regulators related to QS, stress response, and motility factors.
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M S, N RP, Rajendrasozhan S. Bacterial redox response factors in the management of environmental oxidative stress. World J Microbiol Biotechnol 2022; 39:11. [PMID: 36369499 DOI: 10.1007/s11274-022-03456-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 11/02/2022] [Indexed: 11/13/2022]
Abstract
Bacteria evolved to survive in the available environmental chemosphere via several cellular mechanisms. A rich pool of antioxidants and stress regulators plays a significant role in the survival of bacteria in unfavorable environmental conditions. Most of the microbes exhibit resistant phenomena in toxic environment niches. Naturally, bacteria possess efficient thioredoxin reductase, glutaredoxin, and peroxiredoxin redox systems to handle environmental oxidative stress. Further, an array of transcriptional regulators senses the oxidative stress conditions. Transcription regulators, such as OxyR, SoxRS, PerR, UspA, SsrB, MarA, OhrR, SarZ, etc., sense and transduce bacterial oxidative stress responses. The redox-sensitive transcription regulators continuously recycle the utilized antioxidant enzymes during oxidative stress. These regulators promote the expression of antioxidant enzymes such as superoxide dismutase, catalase, and peroxides that overcome oxidative insults. Therefore, the transcriptional regulations maintain steady-state activities of antioxidant enzymes representing the resistance against host cell/environmental oxidative insults. Further, the redox system provides reducing equivalents to synthesize biomolecules, thereby contributing to cellular repair mechanisms. The inactive transcriptional regulators in the undisturbed cells are activated by oxidative stress. The oxidized transcriptional regulators modulate the expression of antioxidant and cellular repair enzymes to survive in extreme environmental conditions. Therefore, targeting these antioxidant systems and response regulators could alter cellular redox homeostasis. This review presents the mechanisms of different redox systems that favor bacterial survival in extreme environmental oxidative stress conditions.
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Affiliation(s)
- Sudharsan M
- Department of Biochemistry and Biotechnology, Annamalai University, Annamalainagar, Chidambaram, Tamil Nadu, 608 002, India
| | - Rajendra Prasad N
- Department of Biochemistry and Biotechnology, Annamalai University, Annamalainagar, Chidambaram, Tamil Nadu, 608 002, India.
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5
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OxyR Positively Influences Phaseolotoxin Synthesis and Pyoverdin Production in Pseudomonas savastanoi pv. phaseolicola NPS3121. Microorganisms 2022; 10:microorganisms10112123. [DOI: 10.3390/microorganisms10112123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Revised: 10/22/2022] [Accepted: 10/23/2022] [Indexed: 11/17/2022] Open
Abstract
Phaseolotoxin is a major virulence factor of the bean pathogen bacterium P. savastanoi pv. phaseolicola. This toxin plays a key role in the development of the halo blight disease in bean plants. So far, the signal transduction pathways involved in the synthesis of phaseolotoxin have not been elucidated. The influence of regulation mechanisms related to the oxidative stress response, in particular the OxyR protein, it has been suggested to be involved in this process.. In this study we evaluated the role of OxyR in P. savastanoi pv. phaseolicola, mainly compared to the synthesis of phaseolotoxin and the virulence of this phytopathogen. Generation of the oxyR-mutant, pathogenicity and virulence tests, and analyses of gene expression by RT-PCR assays were performed. The results showed that OxyR exerts an effect on the synthesis of phaseolotoxin and positively influences the expression of the Pht and Pbo cluster genes. Likewise, OxyR influences the production of pyoverdine by the control of the expression of the genes encoding the PvdS sigma factor, involved in the synthesis of this pigment. This study is the first report on members of the OxyR regulon of P. savastanoi pv. phaseolicola NPS3121.
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6
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Guo J, Jiang Y, Hu Y, Jiang Z, Dong Y, Shi L. The Roles of DmsEFAB and MtrCAB in Extracellular Reduction of Iodate by Shewanella oneidensis MR-1 with Lactate as the Sole Electron Donor. Environ Microbiol 2022; 24:5039-5050. [PMID: 35837844 DOI: 10.1111/1462-2920.16130] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 06/27/2022] [Accepted: 07/06/2022] [Indexed: 11/26/2022]
Abstract
To investigate their roles in extracellular reduction of iodate (IO3 - ) with lactate as an electron donor, the gene clusters of dmsEFAB, mtrCAB, mtrDEF, and so4360-4357 in Shewanella oneidensis MR-1were systematically deleted. Deletions of dmsEFAB and/or mtrCAB gene clusters diminished the bacterial ability to reduce IO3 - . Furthermore, DmsEFAB and MtrCAB worked collaboratively to reduce IO3 - of which DmsEFAB played a more dominant role than MtrCAB. MtrCAB was involved in detoxifying the reaction intermediate hydrogen peroxide (H2 O2 ). The reaction intermediate hypoiodous acid (HIO) was also found to inhibit microbial IO3 - reduction. SO4360-4357 and MtrDEF, however, were not involved in IO3 - reduction. Collectively, these results suggest a novel mechanism of extracellular reduction of IO3 - at molecular level, in which DmsEFAB reduces IO3 - to HIO and H2 O2 . The latter is further reduced to H2 O by MtrCAB to facilitate the DmsEFAB-mediated IO3 - reduction. The extracellular electron transfer pathway of S. oneidensis MR-1is believed to mediate electron transfer from bacterial cytoplasmic membrane, across the cell envelope to the DmsEFAB and MtrCAB on the bacterial outer membrane.
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Affiliation(s)
- Jinzhi Guo
- Department of Biological Sciences and Technology, School of Environmental Studies, Ministry of Ecology and Environment, China University of Geosciences, Wuhan, Hubei, China
| | - Yongguang Jiang
- Department of Biological Sciences and Technology, School of Environmental Studies, Ministry of Ecology and Environment, China University of Geosciences, Wuhan, Hubei, China
| | - Yidan Hu
- Department of Biological Sciences and Technology, School of Environmental Studies, Ministry of Ecology and Environment, China University of Geosciences, Wuhan, Hubei, China
| | - Zhou Jiang
- Department of Biological Sciences and Technology, School of Environmental Studies, Ministry of Ecology and Environment, China University of Geosciences, Wuhan, Hubei, China
| | - Yiran Dong
- Department of Biological Sciences and Technology, School of Environmental Studies, Ministry of Ecology and Environment, China University of Geosciences, Wuhan, Hubei, China.,State Key Laboratory of Biogeology and Environmental Geology, Ministry of Ecology and Environment, China University of Geosciences, Wuhan, Hubei, China.,Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, Ministry of Ecology and Environment, China University of Geosciences, Wuhan, Hubei, China
| | - Liang Shi
- Department of Biological Sciences and Technology, School of Environmental Studies, Ministry of Ecology and Environment, China University of Geosciences, Wuhan, Hubei, China.,State Key Laboratory of Biogeology and Environmental Geology, Ministry of Ecology and Environment, China University of Geosciences, Wuhan, Hubei, China.,Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, Ministry of Ecology and Environment, China University of Geosciences, Wuhan, Hubei, China.,State Environmental Protection Key Laboratory of Source Apportionment and Control of Aquatic Pollution, Ministry of Ecology and Environment, China University of Geosciences, Wuhan, Hubei, China
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7
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Cappelli EA, do Espírito Santo Cucinelli A, Simpson-Louredo L, Canellas MEF, Antunes CA, Burkovski A, da Silva JFR, Mattos-Guaraldi AL, Saliba AM, dos Santos LS. Insights of OxyR role in mechanisms of host-pathogen interaction of Corynebacterium diphtheriae. Braz J Microbiol 2022; 53:583-594. [PMID: 35169995 PMCID: PMC9151940 DOI: 10.1007/s42770-022-00710-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 02/08/2022] [Indexed: 02/01/2023] Open
Abstract
Corynebacterium diphtheriae, the leading causing agent of diphtheria, has been increasingly related to invasive diseases, including sepsis, endocarditis, pneumonia, and osteomyelitis. Oxidative stress defense is required not only for successful growth and survival under environmental conditions but also in the regulation of virulence mechanisms of human pathogenic species, by promoting mucosal colonization, survival, dissemination, and defense against the innate immune system. OxyR, functioning as a negative and/or positive transcriptional regulator, has been included among the major bacterial coordinators of antioxidant response. OxyR was first reported as a repressor of catalase expression in C. diphtheriae. However, the involvement of OxyR in C. diphtheriae pathogenesis remains unclear. Accordingly, this work aimed to investigate the role of OxyR in mechanisms of host-pathogen interaction of C. diphtheriae through the disruption of the OxyR of the diphtheria toxin (DT)-producing C. diphtheriae CDC-E8392 strain. The effects of OxyR gene disruption were analyzed through interaction assays with human epithelial cell lines (HEp-2 and pneumocytes A549) and by the induction of experimental infections in Caenorhabditis elegans nematodes and Swiss Webster mice. The OxyR disruption exerted influence on NO production and mechanism accountable for the expression of the aggregative-adherence pattern (AA) expressed by CDC-E8392 strain on human epithelial HEp-2 cells. Moreover, invasive potential and intracytoplasmic survival within HEp-2 cells, as well as the arthritogenic potential in mice, were found affected by the OxyR disruption. In conclusion, data suggest that OxyR is implicated in mechanisms of host-pathogen interaction of C. diphtheriae.
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Affiliation(s)
- Elisabete Alves Cappelli
- grid.412211.50000 0004 4687 5267Department of Microbiology, Immunology and Parasitology, Faculty of Medical Science, Rio de Janeiro State University, Rio de Janeiro, Brazil
| | - Andrezza do Espírito Santo Cucinelli
- grid.412211.50000 0004 4687 5267Department of Microbiology, Immunology and Parasitology, Faculty of Medical Science, Rio de Janeiro State University, Rio de Janeiro, Brazil
| | - Liliane Simpson-Louredo
- grid.412211.50000 0004 4687 5267Department of Microbiology, Immunology and Parasitology, Faculty of Medical Science, Rio de Janeiro State University, Rio de Janeiro, Brazil
| | - Maria Eurydice Freire Canellas
- grid.412211.50000 0004 4687 5267Department of Microbiology, Immunology and Parasitology, Faculty of Medical Science, Rio de Janeiro State University, Rio de Janeiro, Brazil
| | - Camila Azevedo Antunes
- grid.412211.50000 0004 4687 5267Department of Microbiology, Immunology and Parasitology, Faculty of Medical Science, Rio de Janeiro State University, Rio de Janeiro, Brazil ,grid.5330.50000 0001 2107 3311Microbiology Division, Department of Biology, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Andreas Burkovski
- grid.5330.50000 0001 2107 3311Microbiology Division, Department of Biology, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Jemima Fuentes Ribeiro da Silva
- grid.412211.50000 0004 4687 5267Department of Histology and Embryology, Roberto Alcantara Gomes Biology Institute, Rio de Janeiro State University, Rio de Janeiro, Brazil
| | - Ana Luíza Mattos-Guaraldi
- grid.412211.50000 0004 4687 5267Department of Microbiology, Immunology and Parasitology, Faculty of Medical Science, Rio de Janeiro State University, Rio de Janeiro, Brazil
| | - Alessandra Mattos Saliba
- grid.412211.50000 0004 4687 5267Department of Microbiology, Immunology and Parasitology, Faculty of Medical Science, Rio de Janeiro State University, Rio de Janeiro, Brazil
| | - Louisy Sanches dos Santos
- grid.412211.50000 0004 4687 5267Department of Microbiology, Immunology and Parasitology, Faculty of Medical Science, Rio de Janeiro State University, Rio de Janeiro, Brazil
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Wang H, Shang F, Shen J, Xu J, Chen X, Ni J, Yu L, Xue T. LsrR, the effector of AI-2 quorum sensing, is vital for the H 2O 2 stress response in mammary pathogenic Escherichia coli. Vet Res 2021; 52:127. [PMID: 34600565 PMCID: PMC8487509 DOI: 10.1186/s13567-021-00998-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Accepted: 09/11/2021] [Indexed: 12/12/2022] Open
Abstract
Mammary pathogenic Escherichia coli (MPEC) is an important causative agent of mastitis in dairy cows that results in reduced milk quality and production, and is responsible for severe economic losses in the dairy industry worldwide. Oxidative stress, as an imbalance between reactive oxygen species (ROS) and antioxidants, is a stress factor that is common in most bacterial habitats. The presence of ROS can damage cellular sites, including iron-sulfur clusters, cysteine and methionine protein residues, and DNA, and may cause bacterial cell death. Previous studies have reported that Autoinducer 2 (AI-2) can regulate E. coli antibiotic resistance and pathogenicity by mediating the intracellular receptor protein LsrR. This study explored the regulatory mechanism of LsrR on the H2O2 stress response in MPEC, showing that the transcript levels of lsrR significantly decreased under H2O2 stress conditions. The survival cell count of lsrR mutant XW10/pSTV28 was increased about 3080-fold when compared with that of the wild-type WT/pSTV28 in the presence of H2O2 and overexpression of lsrR (XW10/pUClsrR) resulted in a decrease in bacterial survival rates under these conditions. The β-galactosidase reporter assays showed that mutation of lsrR led to a remarkable increase in expression of the promoters of ahpCF, katG and oxyR, while lsrR-overexpressing significantly reduced the expression of ahpCF and katG. The electrophoretic mobility shift assays confirmed that LsrR could directly bind to the promoter regions of ahpCF and katG. These results revealed the important role played by LsrR in the oxidative stress response of MPEC.
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Affiliation(s)
- Hui Wang
- School of Life Sciences, Anhui Agricultural University, Hefei, 230036, Anhui, China
| | - Fei Shang
- School of Life Sciences, Anhui Agricultural University, Hefei, 230036, Anhui, China
| | - Jiawei Shen
- School of Life Sciences, Anhui Agricultural University, Hefei, 230036, Anhui, China
| | - Jingyi Xu
- School of Life Sciences, Anhui Agricultural University, Hefei, 230036, Anhui, China
| | - Xiaolin Chen
- School of Life Sciences, Anhui Agricultural University, Hefei, 230036, Anhui, China
| | - Jingtian Ni
- School of Life Sciences, Anhui Agricultural University, Hefei, 230036, Anhui, China
| | - Lumin Yu
- School of Life Sciences, Anhui Agricultural University, Hefei, 230036, Anhui, China. .,Institute of Microbe and Host Health, Linyi University, Linyi, 276005, Shandong, China.
| | - Ting Xue
- School of Life Sciences, Anhui Agricultural University, Hefei, 230036, Anhui, China.
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Abstract
Bacteria that colonize animals must overcome, or coexist, with the reactive oxygen species products of inflammation, a front-line defense of innate immunity. Among these is the neutrophilic oxidant bleach, hypochlorous acid (HOCl), a potent antimicrobial that plays a primary role in killing bacteria through nonspecific oxidation of proteins, lipids, and DNA. Here, we report that in response to increasing HOCl levels, Escherichia coli regulates biofilm production via activation of the diguanylate cyclase DgcZ. We identify the mechanism of DgcZ sensing of HOCl to be direct oxidation of its regulatory chemoreceptor zinc-binding (CZB) domain. Dissection of CZB signal transduction reveals that oxidation of the conserved zinc-binding cysteine controls CZB Zn2+ occupancy, which in turn regulates the catalysis of c-di-GMP by the associated GGDEF domain. We find DgcZ-dependent biofilm formation and HOCl sensing to be regulated in vivo by the conserved zinc-coordinating cysteine. Additionally, point mutants that mimic oxidized CZB states increase total biofilm. A survey of bacterial genomes reveals that many pathogenic bacteria that manipulate host inflammation as part of their colonization strategy possess CZB-regulated diguanylate cyclases and chemoreceptors. Our findings suggest that CZB domains are zinc-sensitive regulators that allow host-associated bacteria to perceive host inflammation through reactivity with HOCl.
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10
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Liu X, Ye Y, Zhu Y, Wang L, Yuan L, Zhu J, Sun A. Involvement of RpoN in Regulating Motility, Biofilm, Resistance, and Spoilage Potential of Pseudomonas fluorescens. Front Microbiol 2021; 12:641844. [PMID: 34135871 PMCID: PMC8202526 DOI: 10.3389/fmicb.2021.641844] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 03/30/2021] [Indexed: 11/17/2022] Open
Abstract
Pseudomonas fluorescens is a typical spoiler of proteinaceous foods, and it is characterized by high spoilage activity. The sigma factor RpoN is a well-known regulator controlling nitrogen assimilation and virulence in many pathogens. However, its exact role in regulating the spoilage caused by P. fluorescens is unknown. Here, an in-frame deletion mutation of rpoN was constructed to investigate its global regulatory function through phenotypic and RNA-seq analysis. The results of phenotypic assays showed that the rpoN mutant was deficient in swimming motility, biofilm formation, and resistance to heat and nine antibiotics, while the mutant increased the resistance to H2O2. Moreover, the rpoN mutant markedly reduced extracellular protease and total volatile basic nitrogen (TVB-N) production in sterilized fish juice at 4°C; meanwhile, the juice with the rpoN mutant showed significantly higher sensory scores than that with the wild-type strain. To identify RpoN-controlled genes, RNA-seq-dependent transcriptomics analysis of the wild-type strain and the rpoN mutant was performed. A total of 1224 genes were significantly downregulated, and 474 genes were significantly upregulated by at least two folds at the RNA level in the rpoN mutant compared with the wild-type strain, revealing the involvement of RpoN in several cellular processes, mainly flagellar mobility, adhesion, polysaccharide metabolism, resistance, and amino acid transport and metabolism; this may contribute to the swimming motility, biofilm formation, stress and antibiotic resistance, and spoilage activities of P. fluorescens. Our results provide insights into the regulatory role of RpoN of P. fluorescens in food spoilage, which can be valuable to ensure food quality and safety.
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Affiliation(s)
- Xiaoxiang Liu
- School of Basic Medical Sciences and Forensic Medicine, Hangzhou Medical College, Hangzhou, China
| | - Yifan Ye
- School of Basic Medical Sciences and Forensic Medicine, Hangzhou Medical College, Hangzhou, China
| | - Yin Zhu
- School of Basic Medical Sciences and Forensic Medicine, Hangzhou Medical College, Hangzhou, China
| | - Lifang Wang
- School of Basic Medical Sciences and Forensic Medicine, Hangzhou Medical College, Hangzhou, China
| | - Leyang Yuan
- Zhejiang Museum of Natural History, Hangzhou, China
| | - Junli Zhu
- College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, China
| | - Aihua Sun
- School of Basic Medical Sciences and Forensic Medicine, Hangzhou Medical College, Hangzhou, China
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11
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Wan F, Feng X, Yin J, Gao H. Distinct H 2O 2-Scavenging System in Yersinia pseudotuberculosis: KatG and AhpC Act Together to Scavenge Endogenous Hydrogen Peroxide. Front Microbiol 2021; 12:626874. [PMID: 34025596 PMCID: PMC8139631 DOI: 10.3389/fmicb.2021.626874] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Accepted: 03/22/2021] [Indexed: 01/09/2023] Open
Abstract
To colonize in the digestive tract of animals and humans, Yersinia pseudotuberculosis has to deal with reactive oxygen species (ROS) produced by host cells and microbiota. However, an understanding of the ROS-scavenging systems and their regulation in this bacterium remains largely elusive. In this study, we identified OxyR as the master transcriptional regulator mediating cellular responses to hydrogen peroxide (H2O2) in Y. pseudotuberculosis through genomics and transcriptomics analyses. OxyR activates transcription of diverse genes, especially the core members of its regulon, including those encoding catalases, peroxidases, and thiol reductases. The data also suggest that sulfur species and manganese may play a particular role in the oxidative stress response of Y. pseudotuberculosis. Among the three H2O2-scavenging systems in Y. pseudotuberculosis, catalase/peroxidase KatE functions as the primary scavenger for high levels of H2O2; NADH peroxidase alkyl hydroperoxide reductase (AhpR) and catalase KatG together are responsible for removing low levels of H2O2. The simultaneous loss of both AhpC (the peroxidatic component of AhpR) and KatG results in activation of OxyR. Moreover, we found that AhpC, unlike its well-characterized Escherichia coli counterpart, has little effect on protecting cells against toxicity of organic peroxides. These findings provide not only novel insights into the structural and functional diversity of bacterial H2O2-scavenging systems but also a basic understanding of how Y. pseudotuberculosis copes with oxidative stress.
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Affiliation(s)
- Fen Wan
- College of Laboratory Medicine, Hangzhou Medical College, Hangzhou, China
| | - Xue Feng
- Institute of Microbiology and College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Jianhua Yin
- College of Biotechnology and Bioengineering, Zhenjiang University of Technology, Hangzhou, China
| | - Haichun Gao
- Institute of Microbiology and College of Life Sciences, Zhejiang University, Hangzhou, China
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Feng X, Guo K, Gao H. Plasticity of the peroxidase AhpC links multiple substrates to diverse disulfide-reducing pathways in Shewanella oneidensis. J Biol Chem 2020; 295:11118-11130. [PMID: 32532818 DOI: 10.1074/jbc.ra120.014010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 05/29/2020] [Indexed: 12/25/2022] Open
Abstract
AhpC is a bacterial representative of 2-Cys peroxiredoxins (Prxs) with broad substrate specificity and functional plasticity. However, details underpinning these two important attributes of AhpC remain unclear. Here, we studied the functions and mechanisms of regulation of AhpC in the facultative Gram-negative anaerobic bacterium Shewanella oneidensis, in which AhpC's physiological roles can be conveniently assessed through its suppression of a plating defect due to the genetic loss of a major catalase. We show that successful suppression can be achieved only when AhpC is produced in a dose- and time-dependent manner through a complex mechanism involving activation of the transcriptional regulator OxyR, transcription attenuation, and translation reduction. By analyzing AhpC truncation variants, we demonstrate that reactivity with organic peroxides (OPs) rather than H2O2 is resilient to mutagenesis, implying that OP reduction is the core catalytic function of AhpC. Intact AhpC could be recycled only by its cognate reductase AhpF, and AhpC variants lacking the Prx domain or the extreme C-terminal five residues became promiscuous electron acceptors from the thioredoxin reductase TrxR and the GSH reductase Gor in addition to AhpF, implicating an additional dimension to functional plasticity of AhpC. Finally, we show that the activity of S. oneidensis AhpC is less affected by mutations than that of its Escherichia coli counterpart. These findings suggest that the physiological roles of bacterial AhpCs are adapted to different oxidative challenges, depending on the organism, and that its functional plasticity is even more extensive than previously reported.
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Affiliation(s)
- Xue Feng
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Kailun Guo
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Haichun Gao
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
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Wang L, Yu H, Xu J, Ruan H, Zhang W. Deciphering the crucial roles of AraC-type transcriptional regulator Cgl2680 on NADPH metabolism and L-lysine production in Corynebacterium glutamicum. World J Microbiol Biotechnol 2020; 36:82. [PMID: 32458148 DOI: 10.1007/s11274-020-02861-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 05/20/2020] [Indexed: 11/28/2022]
Abstract
Lysine is widely used in food, medical and feed industries. The biosynthesis of L-lysine is closely related to NADPH level, but the regulation mechanism between the biosynthesis of L-lysine in C. glutamicum and the cofactor NADPH is still not clear. Here, a high intracellular NADPH level strain C. glutamicum XQ-5Δpgi::(zwf-gnd) was constructed by blocking the glycolytic pathway and overexpressing the pentose phosphate pathway in the lysine-producing strain C. glutamicum XQ-5, and the intracellular NADPH level in strain XQ-5Δpgi::(zwf-gnd) was increased from 3.57 × 10-5 nmol/(104 cells) to 1.8 × 10-4 nmol/(104 cell). Transcriptome analyses pointed to Cgl2680 as an important regulator of NADPH levels and L-lysine biosynthesis in C. glutamicum. By knocking out the gene Cgl2680, the intracellular NADPH level of the recombinant C. glutamicum lysCfbr ΔCgl2680 was raised from 7.95 × 10-5 nmol/(104 cells) to 2.04 × 10-4 nmol/(104 cells), consequently leading to a 2.3-fold increase in the NADPH/NADP+ ratio. These results indicated that the regulator Cgl2680 showed the negative regulation for NADPH regeneration. In addition, Cgl2680-deficient strain C. glutamicum lysCfbr ΔCgl2680 showed the increase of yield of both L-lysine and L-leucine as well as the increase of H2O2 tolerance. Collectively, our data demonstrated that Cgl2680 plays an important role in negatively regulating NADPH regeneration, and these results provides new insights for breeding L-lysine or L-leucine high-yielding strain.
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Affiliation(s)
- Luping Wang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800# Lihu Road, WuXi, 214122, People's Republic of China
| | - Haibo Yu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800# Lihu Road, WuXi, 214122, People's Republic of China
| | - Jianzhong Xu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800# Lihu Road, WuXi, 214122, People's Republic of China.
| | - Haozhe Ruan
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800# Lihu Road, WuXi, 214122, People's Republic of China
| | - Weiguo Zhang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800# Lihu Road, WuXi, 214122, People's Republic of China.
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Distinct Roles of Shewanella oneidensis Thioredoxin in Regulation of Cellular Responses to Hydrogen and Organic Peroxides. Appl Environ Microbiol 2019; 85:AEM.01700-19. [PMID: 31444207 DOI: 10.1128/aem.01700-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 08/21/2019] [Indexed: 12/26/2022] Open
Abstract
The thioredoxin (Trx) and glutaredoxin (Grx) antioxidant systems are deeply involved in bacterial response to oxidative stress, but to date, we know surprisingly little about the roles of these systems in response to reactive oxygen species (ROS) other than hydrogen peroxide (H2O2). In this study, we used Shewanella oneidensis, an environmental bacterium, as a research model to investigate the roles of Trx and Grx in oxidative stress response because it has functionally intertwined ROS responsive regulators OxyR and OhrR. We found that Trx1 is the major thiol/disulfide redox system and that in its absence a Grx system becomes essential under normal conditions. Although overshadowed by Trx1 in the wild type, Trx2 can fully replace Trx1 in physiology when overproduced. Trx1 is required for OxyR to function as a repressor but, more importantly, plays a critical role in the cellular response to organic peroxide (OP) by mediating the redox status of OhrR but not OP scavenger OhrA. While none of the trx and grx genes are OxyR dependent, trxA and trxC are affected by OhrR indirectly. Additional data suggest that depletion of glutathione is likely the cue to trigger induced expression of trxA and trxC These findings underscore the particular importance of Trx in the bacterial OP stress response.IMPORTANCE The Trx and Grx systems are deeply involved in bacterial responses to H2O2-induced oxidative stress. However, little is known about their roles in response to other ROS, such as organic peroxides (OPs). In this study, we used S. oneidensis as a research model to investigate the interplay between Trx/Grx and OxyR/OhrR. We show that Trxs mediate the redox status of transcriptional OP-responding regulator OhrR. Although none of the trx or grx genes are directly controlled by OxyR or OhrR, expression of trxA and trxC is induced by tert-butyl hydroperoxide (t-BHP). We further show that the trxA and trxC genes respond to effects of glutathione (GSH) depletion rather than oxidation. These findings underscore the particular importance of Trx in the bacterial OP stress response.
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