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Shi X, Zou Y, Zhang Y, Ding G, Xiao Y, Lin S, Chen J. Salinity decline promotes growth and harmful blooms of a toxic alga by diverting carbon flow. GLOBAL CHANGE BIOLOGY 2024; 30:e17348. [PMID: 38822656 DOI: 10.1111/gcb.17348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 03/20/2024] [Accepted: 04/26/2024] [Indexed: 06/03/2024]
Abstract
Global climate change intensifies the water cycle and makes freshest waters become fresher and vice-versa. But how this change impacts phytoplankton in coastal, particularly harmful algal blooms (HABs), remains poorly understood. Here, we monitored a coastal bay for a decade and found a significant correlation between salinity decline and the increase of Karenia mikimotoi blooms. To examine the physiological linkage between salinity decreases and K. mikimotoi blooms, we compare chemical, physiological and multi-omic profiles of this species in laboratory cultures under high (33) and low (25) salinities. Under low salinity, photosynthetic efficiency and capacity as well as growth rate and cellular protein content were significantly higher than that under high salinity. More strikingly, the omics data show that low salinity activated the glyoxylate shunt to bypass the decarboxylation reaction in the tricarboxylic acid cycle, hence redirecting carbon from CO2 release to biosynthesis. Furthermore, the enhanced glyoxylate cycle could promote hydrogen peroxide metabolism, consistent with the detected decrease in reactive oxygen species. These findings suggest that salinity declines can reprogram metabolism to enhance cell proliferation, thus promoting bloom formation in HAB species like K. mikimotoi, which has important ecological implications for future climate-driven salinity declines in the coastal ocean with respect to HAB outbreaks.
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Affiliation(s)
- Xinguo Shi
- College of Biological Science and Engineering, Fuzhou University, Fuzhou, China
| | - Yazhen Zou
- College of Biological Science and Engineering, Fuzhou University, Fuzhou, China
| | - Yingjiao Zhang
- College of Geography and Oceanography, Minjiang University, Fuzhou, China
| | - Guangmao Ding
- Monitoring Center of Marine Environment and Fishery Resources, Fuzhou, China
| | - Yuchun Xiao
- College of Biological Science and Engineering, Fuzhou University, Fuzhou, China
| | - Senjie Lin
- Department of Marine Sciences, University of Connecticut, Groton, Connecticut, USA
| | - Jianfeng Chen
- College of Biological Science and Engineering, Fuzhou University, Fuzhou, China
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Xu Z, Wu G, Wang B, Zhao Y, Liu F. TrpR-Like Protein PXO_00831, Regulated by the Sigma Factor RpoD, Is Involved in Motility, Oxidative Stress Tolerance, and Virulence in Xanthomonas oryzae pv. oryzae. PHYTOPATHOLOGY 2023; 113:170-182. [PMID: 36095334 DOI: 10.1094/phyto-05-22-0165-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Xanthomonas oryzae pv. oryzae (Xoo) is a Gram-negative bacterium that causes bacterial leaf blight in rice. In this study, we identified a putative TrpR-like protein, PXO_TrpR (PXO_00831), in Xoo. This protein contains a tryptophan (Trp) repressor domain and is highly conserved in Xanthomonas. Auxotrophic assays and RT-qPCR confirmed that PXO_TrpR acts as a Trp repressor, negatively regulating the expression of Trp biosynthesis genes. Pathogenicity tests showed that PXO_trpR knockout in Xoo significantly reduced lesion development and disease symptoms in the leaves of susceptible rice. RNA-seq analysis and phenotypic tests revealed that the PXO_trpR mutant exhibited impaired cell motility and was more sensitive to H2O2 oxidative stress than the wild-type strain. Furthermore, we found that the sigma 70 factor RpoD controlled the transcription of PXO_trpR by directly binding to its promoter region. This study demonstrates the biological function and transcriptional mechanism of PXO_TrpR as a Trp repressor in Xoo and evaluates its novel pathogenic roles by regulating flagellar motility and the oxidative stress response.
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Affiliation(s)
- Zhizhou Xu
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Guichun Wu
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, Jiangsu 210014, China
- National Engineering Laboratory of Crop Stress Resistance Breeding, School of Life Sciences, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Bo Wang
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, Jiangsu 210014, China
| | - Yancun Zhao
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, Jiangsu 210014, China
| | - Fengquan Liu
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, Jiangsu 210014, China
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3
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Meireles DA, da Silva Neto JF, Domingos RM, Alegria TGP, Santos LCM, Netto LES. Ohr - OhrR, a neglected and highly efficient antioxidant system: Structure, catalysis, phylogeny, regulation, and physiological roles. Free Radic Biol Med 2022; 185:6-24. [PMID: 35452809 DOI: 10.1016/j.freeradbiomed.2022.04.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Revised: 03/09/2022] [Accepted: 04/02/2022] [Indexed: 12/24/2022]
Abstract
Ohrs (organic hydroperoxide resistance proteins) are antioxidant enzymes that play central roles in the response of microorganisms to organic peroxides. Here, we describe recent advances in the structure, catalysis, phylogeny, regulation, and physiological roles of Ohr proteins and of its transcriptional regulator, OhrR, highlighting their unique features. Ohr is extremely efficient in reducing fatty acid peroxides and peroxynitrite, two oxidants relevant in host-pathogen interactions. The highly reactive Cys residue of Ohr, named peroxidatic Cys (Cp), composes together with an arginine and a glutamate the catalytic triad. The catalytic cycle of Ohrs involves a condensation between a sulfenic acid (Cp-SOH) and the thiol of the second conserved Cys, leading to the formation of an intra-subunit disulfide bond, which is then reduced by dihydrolipoamide or lipoylated proteins. A structural switch takes place during catalysis, with the opening and closure of the active site by the so-called Arg-loop. Ohr is part of the Ohr/OsmC super-family that also comprises OsmC and Ohr-like proteins. Members of the Ohr, OsmC and Ohr-like subgroups present low sequence similarities among themselves, but share a high structural conservation, presenting two Cys residues in their active site. The pattern of gene expression is also distinct among members of the Ohr/OsmC subfamilies. The expression of ohr genes increases upon organic hydroperoxides treatment, whereas the signals for the upregulation of osmC are entry into the stationary phase and/or osmotic stress. For many ohr genes, the upregulation by organic hydroperoxides is mediated by OhrR, a Cys-based transcriptional regulator that only binds to its target DNAs in its reduced state. Since Ohrs and OhrRs are involved in virulence of some microorganisms and are absent in vertebrate and vascular plants, they may represent targets for novel therapeutic approaches based on the disruption of this key bacterial organic peroxide defense system.
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Affiliation(s)
- Diogo A Meireles
- Laboratório de Fisiologia e Bioquímica de Microrganismos (LFBM) da Universidade Estadual do Norte Fluminense Darcy Ribeiro, Brazil
| | - José F da Silva Neto
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (FMRP-USP), Brazil
| | | | - Thiago G P Alegria
- Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, Brazil
| | - Lene Clara M Santos
- Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, Brazil
| | - Luis Eduardo S Netto
- Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, Brazil.
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4
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Mondal HK, Maji UJ, Mohanty S, Sahoo PK, Maiti NK. Alteration of gut microbiota composition and function of Indian major carp, rohu (Labeo rohita) infected with Argulus siamensis. Microb Pathog 2022; 164:105420. [DOI: 10.1016/j.micpath.2022.105420] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 01/20/2022] [Accepted: 01/21/2022] [Indexed: 01/16/2023]
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Neira G, Vergara E, Cortez D, Holmes DS. A Large-Scale Multiple Genome Comparison of Acidophilic Archaea (pH ≤ 5.0) Extends Our Understanding of Oxidative Stress Responses in Polyextreme Environments. Antioxidants (Basel) 2021; 11:antiox11010059. [PMID: 35052563 PMCID: PMC8773360 DOI: 10.3390/antiox11010059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 12/19/2021] [Accepted: 12/23/2021] [Indexed: 11/16/2022] Open
Abstract
Acidophilic archaea thrive in anaerobic and aerobic low pH environments (pH < 5) rich in dissolved heavy metals that exacerbate stress caused by the production of reactive oxygen species (ROS) such as hydrogen peroxide (H2O2), hydroxyl radical (OH) and superoxide (O2−). ROS react with lipids, proteins and nucleic acids causing oxidative stress and damage that can lead to cell death. Herein, genes and mechanisms potentially involved in ROS mitigation are predicted in over 200 genomes of acidophilic archaea with sequenced genomes. These organisms are often be subjected to simultaneous multiple stresses such as high temperature, high salinity, low pH and high heavy metal loads. Some of the topics addressed include: (1) the phylogenomic distribution of these genes and what this can tell us about the evolution of these mechanisms in acidophilic archaea; (2) key differences in genes and mechanisms used by acidophilic versus non-acidophilic archaea and between acidophilic archaea and acidophilic bacteria and (3) how comparative genomic analysis predicts novel genes or pathways involved in oxidative stress responses in archaea and likely horizontal gene transfer (HGT) events.
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Affiliation(s)
- Gonzalo Neira
- Center for Bioinformatics and Genome Biology, Fundación Ciencia & Vida, Santiago 7780272, Chile; (G.N.); (E.V.); (D.C.)
| | - Eva Vergara
- Center for Bioinformatics and Genome Biology, Fundación Ciencia & Vida, Santiago 7780272, Chile; (G.N.); (E.V.); (D.C.)
| | - Diego Cortez
- Center for Bioinformatics and Genome Biology, Fundación Ciencia & Vida, Santiago 7780272, Chile; (G.N.); (E.V.); (D.C.)
| | - David S. Holmes
- Center for Bioinformatics and Genome Biology, Fundación Ciencia & Vida, Santiago 7780272, Chile; (G.N.); (E.V.); (D.C.)
- Facultad de Medicina y Ciencias, Universidad San Sebastián, Santiago 8420524, Chile
- Correspondence:
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6
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Si M, Su T, Chen C, Wei Z, Gong Z, Li G. OsmC in Corynebacterium glutamicum was a thiol-dependent organic hydroperoxide reductase. Int J Biol Macromol 2019; 136:642-652. [PMID: 31195044 DOI: 10.1016/j.ijbiomac.2019.06.047] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Revised: 06/08/2019] [Accepted: 06/08/2019] [Indexed: 11/26/2022]
Abstract
Bacterial antioxidants play a vital role in the detoxification of exogenous peroxides. Several antioxidant defenses including low-molecular-weight thiols (LMWTs) and protective enzymes were developed to help the bacterium withstand the adverse stress. Although osmotically induced bacterial protein C (OsmC), classified as the organic hydroperoxide reductase (Ohr)/OsmC superfamily, has been demonstrated in some mycobacterial species, including M. tuberculosis and M. smegmatis, its physiological and biochemical functions in C. glutamicum remained elusive. Here we found the lack of C. glutamicum osmC gene resulted in decreased cell viability and increased intracellular reactive oxygen species accumulation under organic hydroperoxides (OHPs) stress conditions. The osmC expression was induced in the multiple antibiotic resistance regulator MarR-dependent manner by OHPs, and not by other oxidants or osmotic stress. Peroxide reductase activity showed that OsmC had a narrow range of substrates-only degrading OHPs, and detoxified OHPs mainly by linking the alkyl hydroperoxide reductase (AhpD) system (AhpD/dihydrolipoamide dehydrogenase (Lpd)/dihydrolipoamide acyltransferase (SucB)). Site-directed mutagenesis confirmed Cys48 was the peroxidatic cysteine, while Cys114 was the resolving Cys residue that formed an intramolecular disulfide bond with oxidized Cys48. Therefore, C. glutamicum OsmC was a thiol-dependent OHP reductase and played important role of protection against OHPs together with Ohr.
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Affiliation(s)
- Meiru Si
- College of Life Sciences, Qufu Normal University, Qufu, Shandong 273165, China.
| | - Tao Su
- College of Life Sciences, Qufu Normal University, Qufu, Shandong 273165, China
| | - Can Chen
- College of Life Science and Agronomy, Zhoukou Normal University, Zhoukou, Henan 466001, China.
| | - Zengfan Wei
- College of Life Sciences, Qufu Normal University, Qufu, Shandong 273165, China
| | - Zhijin Gong
- College of Life Sciences, Qufu Normal University, Qufu, Shandong 273165, China
| | - Guizhi Li
- College of Life Sciences, Qufu Normal University, Qufu, Shandong 273165, China
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Ethanol Stimulates Trehalose Production through a SpoT-DksA-AlgU-Dependent Pathway in Pseudomonas aeruginosa. J Bacteriol 2019; 201:JB.00794-18. [PMID: 30936375 DOI: 10.1128/jb.00794-18] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 03/26/2019] [Indexed: 01/06/2023] Open
Abstract
Pseudomonas aeruginosa frequently resides among ethanol-producing microbes, making its response to the microbially produced concentrations of ethanol relevant to understanding its biology. Our transcriptome analysis found that genes involved in trehalose metabolism were induced by low concentrations of ethanol, and biochemical assays showed that levels of intracellular trehalose increased significantly upon growth with ethanol. The increase in trehalose was dependent on the TreYZ pathway but not other trehalose-metabolic enzymes (TreS or TreA). The sigma factor AlgU (AlgT), a homolog of RpoE in other species, was required for increased expression of the treZ gene and trehalose levels, but induction was not controlled by the well-characterized proteolysis of its anti-sigma factor, MucA. Growth with ethanol led to increased SpoT-dependent (p)ppGpp accumulation, which stimulates AlgU-dependent transcription of treZ and other AlgU-regulated genes through DksA, a (p)ppGpp and RNA polymerase binding protein. Ethanol stimulation of trehalose also required acylhomoserine lactone (AHL)-mediated quorum sensing (QS), as induction was not observed in a ΔlasR ΔrhlR strain. A network analysis using a model, eADAGE, built from publicly available P. aeruginosa transcriptome data sets (J. Tan, G. Doing, K. A. Lewis, C. E. Price, et al., Cell Syst 5:63-71, 2017, https://doi.org/10.1016/j.cels.2017.06.003) provided strong support for our model in which treZ and coregulated genes are controlled by both AlgU- and AHL-mediated QS. Consistent with (p)ppGpp- and AHL-mediated quorum-sensing regulation, ethanol, even when added at the time of culture inoculation, stimulated treZ transcript levels and trehalose production in cells from post-exponential-phase cultures but not in cells from exponential-phase cultures. These data highlight the integration of growth and cell density cues in the P. aeruginosa transcriptional response to ethanol.IMPORTANCE Pseudomonas aeruginosa is often found with bacteria and fungi that produce fermentation products, including ethanol. At concentrations similar to those produced by environmental microbes, we found that ethanol stimulated expression of trehalose-biosynthetic genes and cellular levels of trehalose, a disaccharide that protects against environmental stresses. The induction of trehalose by ethanol required the alternative sigma factor AlgU through DksA- and SpoT-dependent (p)ppGpp. Trehalose accumulation also required AHL quorum sensing and occurred only in post-exponential-phase cultures. This work highlights how cells integrate cell density and growth cues in their responses to products made by other microbes and reveals a new role for (p)ppGpp in the regulation of AlgU activity.
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Shafiei R, Leprince P, Sombolestani AS, Thonart P, Delvigne F. Effect of Sequential Acclimation to Various Carbon Sources on the Proteome of Acetobacter senegalensis LMG 23690 T and Its Tolerance to Downstream Process Stresses. Front Microbiol 2019; 10:608. [PMID: 30984138 PMCID: PMC6448019 DOI: 10.3389/fmicb.2019.00608] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 03/11/2019] [Indexed: 11/23/2022] Open
Abstract
Acetic acid bacteria are very vulnerable to environmental changes; hence, they should get acclimated to different kinds of stresses when they undergo downstream processing. In the present study, Acetobacter senegalensis LMG 23690T, a thermo-tolerant strain, was acclimated sequentially to different carbon sources including glucose (condition Glc), a mixture of glucose and ethanol (condition EtOH) and a mixture of glucose and acetic acid (condition GlcAA). Then, the effects of acclimation on the cell proteome profiles and some phenotypic characteristics such as growth in culture medium containing ethanol, and tolerance to freeze-drying process were evaluated. Based on the obtained results, despite the cells acclimated to Glc or EtOH conditions, 86% of acclimated cells to GlcAA condition were culturable and resumed growth with a short lag phase in a culture medium containing ethanol and acetic acid. Interestingly, if A. senegalensis LMG 23690T had been acclimated to condition GlcAA, 92% of cells exhibited active cellular dehydrogenases, and 59% of cells were culturable after freeze-drying process. Proteome profiles comparison by 2D-DiGE and MS analysis, revealed distinct physiological status between cells exposed to different acclimation treatments, possibly explaining the resulting diversity in phenotypic characteristics. Results of proteome analysis by 2D-DiGE also showed similarities between the differentially expressed proteins of acclimated cells to EtOH condition and the proteome of acclimated cells to GlcAA condition. Most of the differentially regulated proteins are involved in metabolism, folding, sorting, and degradation processes. In conclusion, acclimation under appropriate sub-lethal conditions can be used as a method to improve cell phenotypic characteristics such as viability, growth under certain conditions, and tolerance to downstream processes.
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Affiliation(s)
- Rasoul Shafiei
- Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, Iran
| | | | | | - Philippe Thonart
- Walloon Center for Industrial Biology, University of Liège, Liège, Belgium
| | - Frank Delvigne
- Microbial Processes and Interactions, Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
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Qayyum S, Sharma D, Bisht D, Khan AU. Identification of factors involved in Enterococcus faecalis biofilm under quercetin stress. Microb Pathog 2019; 126:205-211. [DOI: 10.1016/j.micpath.2018.11.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 11/08/2018] [Accepted: 11/09/2018] [Indexed: 10/27/2022]
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Zhou J, Liu X, Zhao ST, Hu JJ, Zhang JW, Wang JH, Peng XP, Qi XL, Cheng TL, Lu MZ. An assessment of transgenomics as a tool for gene discovery in Populus euphratica Oliv. PLANT MOLECULAR BIOLOGY 2018; 97:525-535. [PMID: 30051252 DOI: 10.1007/s11103-018-0755-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Accepted: 07/05/2018] [Indexed: 06/08/2023]
Abstract
Transgenomics for gene discovery in Populus euphratica. Transgenomics, a member of the omics family of methodologies, is characterized as the introduction of DNA from one organism into another on a genome-wide scale followed by the identification of recipients with altered phenotypes. This strategy allows investigators to identify the gene(s) involved in these phenotypic changes. It is particularly promising for woody plants that have a long life cycle and for which molecular tools are limited. In this study, we constructed a large-insert binary bacterial artificial chromosome library of Populus euphratica, a stress-tolerant poplar species, which included 55,296 clones with average insert sizes of about 127 kb. To date, 1077 of the clones have been transformed into Arabidopsis thaliana via Agrobacterium by the floral dip method. Of these, 69 transgenic lines showed phenotypic changes represented by diverse aspects of plant form and development, 22 of which were reproducibly associated with the same phenotypic change. One of the clones conferring transgenic plants with increased salt tolerance, 002A1F06, was further analyzed and the 127,284 bp insert in this clone harbored eight genes that have been previously reported to be involved in stress resistance. This study demonstrates that transgenomics is useful in the study of functional genomics of woody plants and in the identification of novel gene(s) responsible for economically important traits. Thus, transgenomics can also be used for validation of quantitative trait loci mapped by molecular markers.
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Affiliation(s)
- Jing Zhou
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
| | - Xin Liu
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
| | - Shu-Tang Zhao
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
| | - Jian-Jun Hu
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
| | - Jie-Wei Zhang
- Beijing Agro-Biotechnology Research Center, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China
| | - Jie-Hua Wang
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China
| | - Xiao-Peng Peng
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
| | - Xiao-Li Qi
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
| | - Tie-Long Cheng
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
| | - Meng-Zhu Lu
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China.
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Meireles DA, Domingos RM, Gaiarsa JW, Ragnoni EG, Bannitz-Fernandes R, da Silva Neto JF, de Souza RF, Netto LES. Functional and evolutionary characterization of Ohr proteins in eukaryotes reveals many active homologs among pathogenic fungi. Redox Biol 2017; 12:600-609. [PMID: 28391181 PMCID: PMC5384416 DOI: 10.1016/j.redox.2017.03.026] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 03/17/2017] [Accepted: 03/24/2017] [Indexed: 01/31/2023] Open
Abstract
Ohr and OsmC proteins comprise two subfamilies within a large group of proteins that display Cys-based, thiol dependent peroxidase activity. These proteins were previously thought to be restricted to prokaryotes, but we show here, using iterated sequence searches, that Ohr/OsmC homologs are also present in 217 species of eukaryotes with a massive presence in Fungi (186 species). Many of these eukaryotic Ohr proteins possess an N-terminal extension that is predicted to target them to mitochondria. We obtained recombinant proteins for four eukaryotic members of the Ohr/OsmC family and three of them displayed lipoyl peroxidase activity. Further functional and biochemical characterization of the Ohr homologs from the ascomycete fungus Mycosphaerella fijiensis Mf_1 (MfOhr), the causative agent of Black Sigatoka disease in banana plants, was pursued. Similarly to what has been observed for the bacterial proteins, we found that: (i) the peroxidase activity of MfOhr was supported by DTT or dihydrolipoamide (dithiols), but not by β-mercaptoethanol or GSH (monothiols), even in large excess; (ii) MfOhr displayed preference for organic hydroperoxides (CuOOH and tBOOH) over hydrogen peroxide; (iii) MfOhr presented extraordinary reactivity towards linoleic acid hydroperoxides (k=3.18 (±2.13)×108 M−1 s−1). Both Cys87 and Cys154 were essential to the peroxidase activity, since single mutants for each Cys residue presented no activity and no formation of intramolecular disulfide bond upon treatment with hydroperoxides. The pKa value of the Cysp residue was determined as 5.7±0.1 by a monobromobimane alkylation method. Therefore, eukaryotic Ohr peroxidases share several biochemical features with prokaryotic orthologues and are preferentially located in mitochondria. Ohr/OsmC proteins are also present in lower eukaryotic organisms. While Ohr proteins are massively present among Fungi, OsmC proteins are restricted to the cellular slime molds. Eukaryotic Ohr and OsmC present a thiol dependent peroxidase activity similar to the bacterial counterparts. Most of these eukaryotic enzymes are predominantly present in mitochondria.
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Affiliation(s)
- D A Meireles
- Departmento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil.
| | - R M Domingos
- Departmento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil
| | - J W Gaiarsa
- Departmento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil
| | - E G Ragnoni
- Departmento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil
| | - R Bannitz-Fernandes
- Departmento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil
| | - J F da Silva Neto
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - R F de Souza
- Departmento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP, Brazil
| | - L E S Netto
- Departmento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil.
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Characterisation of a New Family of Carboxyl Esterases with an OsmC Domain. PLoS One 2016; 11:e0166128. [PMID: 27851780 PMCID: PMC5113044 DOI: 10.1371/journal.pone.0166128] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 10/24/2016] [Indexed: 11/22/2022] Open
Abstract
Proteins in the serine esterase family are widely distributed in bacterial phyla and display activity against a range of biologically produced and chemically synthesized esters. A serine esterase from the psychrophilic bacterium Pseudoalteromonas arctica with a C-terminal OsmC-like domain was recently characterized; here we report on the identification and characterization of further putative esterases with OsmC-like domains constituting a new esterase family that is found in a variety of bacterial species from different environmental niches. All of these proteins contained the Ser-Asp-His motif common to serine esterases and a highly conserved pentapeptide nucleophilic elbow motif. We produced these proteins heterologously in Escherichia coli and demonstrated their activity against a range of esterase substrates. Two of the esterases characterized have activity of over two orders of magnitude higher than other members of the family, and are active over a wide temperature range. We determined the crystal structure of the esterase domain of the protein from Rhodothermus marinus and show that it conforms to the classical α/β hydrolase fold with an extended ‘lid’ region, which occludes the active site of the protein in the crystal. The expansion of characterized members of the esterase family and demonstration of activity over a wide-range of temperatures could be of use in biotechnological applications such as the pharmaceutical, detergent, bioremediation and dairy industries.
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Nývltová E, Smutná T, Tachezy J, Hrdý I. OsmC and incomplete glycine decarboxylase complex mediate reductive detoxification of peroxides in hydrogenosomes of Trichomonas vaginalis. Mol Biochem Parasitol 2016; 206:29-38. [PMID: 26794804 DOI: 10.1016/j.molbiopara.2016.01.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 01/05/2016] [Accepted: 01/12/2016] [Indexed: 01/30/2023]
Abstract
Osmotically inducible protein (OsmC) and organic hydroperoxide resistance protein (Ohr) are small, thiol-dependent peroxidases that comprise a family of prokaryotic protective proteins central to the defense against deleterious effects of organic hydroperoxides, which are reactive molecules that are formed during interactions between the host immune system and pathogens. Trichomonas vaginalis, a sexually transmitted parasite of humans, possesses OsmC homologues in its hydrogenosomes, anaerobic mitochondrial organelles that harbor enzymes and pathways that are sensitive to oxidative damage. The glycine decarboxylase complex (GDC), which consists of four proteins (i.e., L, H, P and T), is in eukaryotes exclusively mitochondrial enzymatic system that catalyzes oxidative decarboxylation and deamination of glycine. However, trichomonad hydrogenosomes contain only the L and H proteins, whose physiological functions are unknown. Here, we found that the hydrogenosomal L and H proteins constitute a lipoate-dependent redox system that delivers electrons from reduced nicotinamide adenine dinucleotide (NADH) to OsmC for the reductive detoxification of peroxides. Our searches of genome databases revealed that, in addition to prokaryotes, homologues of OsmC/Ohr family proteins with predicted mitochondrial localization are present in various eukaryotic lineages. Therefore, we propose that the novel OsmC-GDC-based redox system may not be limited to T. vaginalis.
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Affiliation(s)
- Eva Nývltová
- Department of Parasitology, Charles University in Prague, Faculty of Science, Prague, Czech Republic
| | - Tamara Smutná
- Department of Parasitology, Charles University in Prague, Faculty of Science, Prague, Czech Republic
| | - Jan Tachezy
- Department of Parasitology, Charles University in Prague, Faculty of Science, Prague, Czech Republic
| | - Ivan Hrdý
- Department of Parasitology, Charles University in Prague, Faculty of Science, Prague, Czech Republic.
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Gallo G, Renzone G, Palazzotto E, Monciardini P, Arena S, Faddetta T, Giardina A, Alduina R, Weber T, Sangiorgi F, Russo A, Spinelli G, Sosio M, Scaloni A, Puglia AM. Elucidating the molecular physiology of lantibiotic NAI-107 production in Microbispora ATCC-PTA-5024. BMC Genomics 2016; 17:42. [PMID: 26754974 PMCID: PMC4709908 DOI: 10.1186/s12864-016-2369-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2015] [Accepted: 01/06/2016] [Indexed: 11/24/2022] Open
Abstract
Background The filamentous actinomycete Microbispora ATCC-PTA-5024 produces the lantibiotic NAI-107, which is an antibiotic peptide effective against multidrug-resistant Gram-positive bacteria. In actinomycetes, antibiotic production is often associated with a physiological differentiation program controlled by a complex regulatory and metabolic network that may be elucidated by the integration of genomic, proteomic and bioinformatic tools. Accordingly, an extensive evaluation of the proteomic changes associated with NAI-107 production was performed on Microbispora ATCC-PTA-5024 by combining two-dimensional difference in gel electrophoresis, mass spectrometry and gene ontology approaches. Results Microbispora ATCC-PTA-5024 cultivations in a complex medium were characterized by stages of biomass accumulation (A) followed by biomass yield decline (D). NAI-107 production started at 90 h (A stage), reached a maximum at 140 h (D stage) and decreased thereafter. To reveal patterns of differentially represented proteins associated with NAI-107 production onset and maintenance, differential proteomic analyses were carried-out on biomass samples collected: i) before (66 h) and during (90 h) NAI-107 production at A stage; ii) during three time-points (117, 140, and 162 h) at D stage characterized by different profiles of NAI-107 yield accumulation (117 and 140 h) and decrement (162 h). Regulatory, metabolic and unknown-function proteins, were identified and functionally clustered, revealing that nutritional signals, regulatory cascades and primary metabolism shift-down trigger the accumulation of protein components involved in nitrogen and phosphate metabolism, cell wall biosynthesis/maturation, lipid metabolism, osmotic stress response, multi-drug resistance, and NAI-107 transport. The stimulating role on physiological differentiation of a TetR-like regulator, originally identified in this study, was confirmed by the construction of an over-expressing strain. Finally, the possible role of cellular response to membrane stability alterations and of multi-drug resistance ABC transporters as additional self-resistance mechanisms toward the lantibiotic was confirmed by proteomic and confocal microscopy experiments on a Microbispora ATCC-PTA-5024 lantibiotic-null producer strain which was exposed to an externally-added amount of NAI-107 during growth. Conclusion This study provides a net contribution to the elucidation of the regulatory, metabolic and molecular patterns controlling physiological differentiation in Microbispora ATCC-PTA-5024, supporting the relevance of proteomics in revealing protein players of antibiotic biosynthesis in actinomycetes. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2369-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Giuseppe Gallo
- Laboratory of Molecular Microbiology and Biotechnology, STEBICEF Department, University of Palermo, 90128, Palermo, Italy.
| | - Giovanni Renzone
- Proteomic and Mass Spectrometry Laboratory, ISPAAM, National Research Council, 80147, Naples, Italy
| | - Emilia Palazzotto
- Laboratory of Molecular Microbiology and Biotechnology, STEBICEF Department, University of Palermo, 90128, Palermo, Italy
| | | | - Simona Arena
- Proteomic and Mass Spectrometry Laboratory, ISPAAM, National Research Council, 80147, Naples, Italy
| | - Teresa Faddetta
- Laboratory of Molecular Microbiology and Biotechnology, STEBICEF Department, University of Palermo, 90128, Palermo, Italy
| | - Anna Giardina
- Laboratory of Molecular Microbiology and Biotechnology, STEBICEF Department, University of Palermo, 90128, Palermo, Italy
| | - Rosa Alduina
- Laboratory of Molecular Microbiology and Biotechnology, STEBICEF Department, University of Palermo, 90128, Palermo, Italy
| | - Tilmann Weber
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2970, Hørsholm, Denmark.,German Center for Infection Research (DZIF) partner site Tübingen, 72074, Tübingen, Germany
| | - Fabio Sangiorgi
- Sistema Informativo di Ateneo (SIA), Area Servizi di Rete, University of Palermo, 90128, Palermo, Italy
| | - Alessandro Russo
- Laboratory of Molecular Microbiology and Biotechnology, STEBICEF Department, University of Palermo, 90128, Palermo, Italy
| | - Giovanni Spinelli
- Laboratory of Molecular Microbiology and Biotechnology, STEBICEF Department, University of Palermo, 90128, Palermo, Italy
| | | | - Andrea Scaloni
- Proteomic and Mass Spectrometry Laboratory, ISPAAM, National Research Council, 80147, Naples, Italy
| | - Anna Maria Puglia
- Laboratory of Molecular Microbiology and Biotechnology, STEBICEF Department, University of Palermo, 90128, Palermo, Italy
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Jia B, Liu J, Van Duyet L, Sun Y, Xuan YH, Cheong GW. Proteome profiling of heat, oxidative, and salt stress responses in Thermococcus kodakarensis KOD1. Front Microbiol 2015; 6:605. [PMID: 26150806 PMCID: PMC4473059 DOI: 10.3389/fmicb.2015.00605] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 06/02/2015] [Indexed: 01/18/2023] Open
Abstract
The thermophilic species, Thermococcus kodakarensis KOD1, a model microorganism for studying hyperthermophiles, has adapted to optimal growth under conditions of high temperature and salinity. However, the environmental conditions for the strain are not always stable, and this strain might face different stresses. In the present study, we compared the proteome response of T. kodakarensis to heat, oxidative, and salt stresses using two-dimensional electrophoresis, and protein spots were identified through MALDI-TOF/MS. Fifty-nine, forty-two, and twenty-nine spots were induced under heat, oxidative, and salt stresses, respectively. Among the up-regulated proteins, four proteins (a hypothetical protein, pyridoxal biosynthesis lyase, peroxiredoxin, and protein disulphide oxidoreductase) were associated with all three stresses. Gene ontology analysis showed that these proteins were primarily involved metabolic and cellular processes. The KEGG pathway analysis suggested that the main metabolic pathways involving these enzymes were related to carbohydrate metabolism, secondary metabolite synthesis, and amino acid biosynthesis. These data might enhance our understanding of the functions and molecular mechanisms of thermophilic Archaea for survival and adaptation in extreme environments.
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Affiliation(s)
- Baolei Jia
- Department of Life Science, Chung-Ang University, Seoul South Korea ; Division of Applied Life Sciences and Research Institute of Natural Science, Gyeongsang National University Jinju, South Korea
| | - Jinliang Liu
- College of Plant Sciences, Jilin University Changchun, China
| | - Le Van Duyet
- Division of Applied Life Sciences and Research Institute of Natural Science, Gyeongsang National University Jinju, South Korea
| | - Ying Sun
- College of Plant Sciences, Jilin University Changchun, China
| | - Yuan H Xuan
- College of Plant Protection, Shenyang Agricultural University Shenyang, China
| | - Gang-Won Cheong
- Division of Applied Life Sciences and Research Institute of Natural Science, Gyeongsang National University Jinju, South Korea
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A 1-Cys Peroxiredoxin from a Thermophilic Archaeon Moonlights as a Molecular Chaperone to Protect Protein and DNA against Stress-Induced Damage. PLoS One 2015; 10:e0125325. [PMID: 25933432 PMCID: PMC4416765 DOI: 10.1371/journal.pone.0125325] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2014] [Accepted: 03/11/2015] [Indexed: 01/15/2023] Open
Abstract
Peroxiredoxins (Prxs) act against hydrogen peroxide (H2O2), organic peroxides, and peroxynitrite. Thermococcus kodakaraensis KOD1, an anaerobic archaeon, contains many antioxidant proteins, including three Prxs (Tk0537, Tk0815, and Tk1055). Only Tk0537 has been found to be induced in response to heat, osmotic, and oxidative stress. Tk0537 was found to belong to a 1-Cys Prx6 subfamily based on sequence analysis and was named 1-Cys TkPrx. Using gel filtration chromatography, electron microscopy, and blue-native polyacrylamide gel electrophoresis, we observed that 1-Cys TkPrx exhibits oligomeric forms with reduced peroxide reductase activity as well as decameric and dodecameric forms that can act as molecular chaperones by protecting both proteins and DNA from oxidative stress. Mutational analysis showed that a cysteine residue at the N-terminus (Cys46) was responsible for the peroxide reductase activity, and cysteine residues at the C-terminus (Cys205 and Cys211) were important for oligomerization. Based on our results, we propose that interconversion between different oligomers is important for regulating the different functions of 1-Cys TkPrx.
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Inactivation of the organic hydroperoxide stress resistance regulator OhrR enhances resistance to oxidative stress and isoniazid in Mycobacterium smegmatis. J Bacteriol 2014; 197:51-62. [PMID: 25313389 DOI: 10.1128/jb.02252-14] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The organic hydroperoxide stress resistance regulator (OhrR) is a MarR type of transcriptional regulator that primarily regulates the expression of organic hydroperoxide reductase (Ohr) in bacteria. In mycobacteria, the genes encoding these proteins exist in only a few species, which include the fast-growing organism Mycobacterium smegmatis. To delineate the roles of Ohr and OhrR in defense against oxidative stress in M. smegmatis, strains lacking the expression of these proteins were constructed by deleting the ohrR and ohr genes, independently and together, through homologous recombination. The OhrR mutant strain (MSΔohrR) showed severalfold upregulation of Ohr expression, which could be observed at both the transcript and protein levels. Similar upregulation of Ohr expression was also noticed in an M. smegmatis wild-type strain (MSWt) induced with cumene hydroperoxide (CHP) and t-butyl hydroperoxide (t-BHP). The elevated Ohr expression in MSΔohrR correlated with heightened resistance to oxidative stress due to CHP and t-BHP and to inhibitory effects due to the antituberculosis drug isoniazid (INH). Further, this mutant strain exhibited significantly enhanced survival in the intracellular compartments of macrophages. In contrast, the strains lacking either Ohr alone (MSΔohr) or both Ohr and OhrR (MSΔohr-ohrR) displayed limited or no resistance to hydroperoxides and INH. Additionally, these strains showed no significant differences in intracellular survival from the wild type. Electrophoretic mobility shift assays (EMSAs) revealed that the overexpressed and purified OhrR interacts with the ohr-ohrR intergenic region with a greater affinity and this interaction is contingent upon the redox state of the OhrR. These findings suggest that Ohr-OhrR is an important peroxide stress response system in M. smegmatis.
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Biochemical Characterization of Deblocking Aminopeptidases from the Hyperthermophilic ArchaeonThermococcus kodakarensisKOD1. Biosci Biotechnol Biochem 2014; 75:1160-6. [DOI: 10.1271/bbb.110114] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Functional characterization of osmotically inducible protein C (MG_427) from Mycoplasma genitalium. J Bacteriol 2013; 196:1012-9. [PMID: 24363346 DOI: 10.1128/jb.00954-13] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Mycoplasma genitalium is the smallest self-replicating bacterium and an important human pathogen responsible for a range of urogenital infections and pathologies. Due to its limited genome size, many genes conserved in other bacteria are missing in M. genitalium. Genes encoding catalase and superoxide dismutase are absent, and how this pathogen overcomes oxidative stress remains poorly understood. In this study, we characterized MG_427, a homolog of the conserved osmC, which encodes hydroperoxide peroxidase, shown to protect bacteria against oxidative stress. We found that recombinant MG_427 protein reduced organic and inorganic peroxide substrates. Also, we showed that a deletion mutant of MG_427 was highly sensitive to killing by tert-butyl hydroperoxide and H2O2 compared to the sensitivity of the wild type. Further, the fully complemented mutant strain reversed its oxidative sensitivity. Examination of the expression pattern of MG_427 during osmotic shock, oxidative stress, and other stress conditions revealed its lack of induction, distinguishing MG_427 from other previously characterized osmC genes.
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Genome-wide transcriptional response of the archaeon Thermococcus gammatolerans to cadmium. PLoS One 2012; 7:e41935. [PMID: 22848664 PMCID: PMC3407056 DOI: 10.1371/journal.pone.0041935] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Accepted: 06/26/2012] [Indexed: 12/16/2022] Open
Abstract
Thermococcus gammatolerans, the most radioresistant archaeon known to date, is an anaerobic and hyperthermophilic sulfur-reducing organism living in deep-sea hydrothermal vents. Knowledge of mechanisms underlying archaeal metal tolerance in such metal-rich ecosystem is still poorly documented. We showed that T. gammatolerans exhibits high resistance to cadmium (Cd), cobalt (Co) and zinc (Zn), a weaker tolerance to nickel (Ni), copper (Cu) and arsenate (AsO4) and that cells exposed to 1 mM Cd exhibit a cellular Cd concentration of 67 µM. A time-dependent transcriptomic analysis using microarrays was performed at a non-toxic (100 µM) and a toxic (1 mM) Cd dose. The reliability of microarray data was strengthened by real time RT-PCR validations. Altogether, 114 Cd responsive genes were revealed and a substantial subset of genes is related to metal homeostasis, drug detoxification, re-oxidization of cofactors and ATP production. This first genome-wide expression profiling study of archaeal cells challenged with Cd showed that T. gammatolerans withstands induced stress through pathways observed in both prokaryotes and eukaryotes but also through new and original strategies. T. gammatolerans cells challenged with 1 mM Cd basically promote: 1) the induction of several transporter/permease encoding genes, probably to detoxify the cell; 2) the upregulation of Fe transporters encoding genes to likely compensate Cd damages in iron-containing proteins; 3) the induction of membrane-bound hydrogenase (Mbh) and membrane-bound hydrogenlyase (Mhy2) subunits encoding genes involved in recycling reduced cofactors and/or in proton translocation for energy production. By contrast to other organisms, redox homeostasis genes appear constitutively expressed and only a few genes encoding DNA repair proteins are regulated. We compared the expression of 27 Cd responsive genes in other stress conditions (Zn, Ni, heat shock, γ-rays), and showed that the Cd transcriptional pattern is comparable to other metal stress transcriptional responses (Cd, Zn, Ni) but not to a general stress response.
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Cooper B, Chen R, Garrett WM, Murphy C, Chang C, Tucker ML, Bhagwat AA. Proteomic Pleiotropy of OpgGH, an Operon Necessary for Efficient Growth of Salmonella enterica serovar Typhimurium under Low-Osmotic Conditions. J Proteome Res 2012; 11:1720-7. [DOI: 10.1021/pr200933d] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
| | - Ruiqiang Chen
- Department of Cell Biology and
Molecular Genetics, University of Maryland, College Park, Maryland 20742, United States
| | | | | | - Caren Chang
- Department of Cell Biology and
Molecular Genetics, University of Maryland, College Park, Maryland 20742, United States
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Saikolappan S, Das K, Sasindran SJ, Jagannath C, Dhandayuthapani S. OsmC proteins of Mycobacterium tuberculosis and Mycobacterium smegmatis protect against organic hydroperoxide stress. Tuberculosis (Edinb) 2011; 91 Suppl 1:S119-27. [PMID: 22088319 DOI: 10.1016/j.tube.2011.10.021] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Bacterial antioxidants play a critical role in the detoxification of endogenously and host derived oxidative radicals during host-pathogen interactions. Recently, the osmotically induced bacterial protein C (OsmC) is included in the antioxidant category of enzymes as it shows structural and functional relationships with organic hydroperoxide reductase (Ohr) enzyme. A copy of the gene encoding OsmC is conserved across mycobacterial species, including Mycobacterium tuberculosis (Rv2923c) and Mycobacterium smegmatis (MSMEG2421), but its role in protecting these species against oxidative stress is unknown. To determine the role of OsmC in mycobacterial oxidative stress, we overexpressed and purified OsmCs of M. tuberculosis and M. smegmatis and assessed their ability to reduce peroxide substrates like hydrogen peroxide (H(2)O(2)), cumene hydroperoxide (CHP) and t-butyl hydroperoxide (t-BHP) in Ferrous Ion Oxidation in Xylenol (FOX) assay. This revealed that OsmCs from both species were capable of reducing both inorganic (H(2)O(2)) and organic (CHP and t-BHP) peroxides. Further, an M. smegmatis mutant (MS∆osmC) deficient in OsmC exhibited reduced reduction of CHP and t-BHP than the parental wild type strain, indicating that OsmC protein contributes significantly for the total peroxide reductase activity of mycobacteria. The MS∆osmC strain was also sensitive to organic hydroperoxides, which could be reversed by complementing with a plasmid borne osmC. Plasmid borne osmC also increased the resistance of M. smegmatis wild type strain to isoniazid (INH) but at a relatively lower level than ahpC, an organic hydroperoxide reductase. These results suggest that OsmC plays an important role in peroxide metabolism and protecting mycobacteria against oxidative stress.
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Affiliation(s)
- Sankaralingam Saikolappan
- Department of Microbiology and Immunology and Regional Academic Health Center, University of Texas Health Science Center at San Antonio, 1214 West Schunior St, Edinburg, TX 78541, United States
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Ambily Nath IV, Loka Bharathi PA. Diversity in transcripts and translational pattern of stress proteins in marine extremophiles. Extremophiles 2011; 15:129-53. [DOI: 10.1007/s00792-010-0348-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2010] [Accepted: 12/09/2010] [Indexed: 11/28/2022]
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Characterization of NADH oxidase/NADPH polysulfide oxidoreductase and its unexpected participation in oxygen sensitivity in an anaerobic hyperthermophilic archaeon. J Bacteriol 2010; 192:5192-202. [PMID: 20675490 DOI: 10.1128/jb.00235-10] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Many genomes of anaerobic hyperthermophiles encode multiple homologs of NAD(P)H oxidase that are thought to function in response to oxidative stress. We investigated one of the seven NAD(P)H oxidase homologs (TK1481) in the sulfur-reducing hyperthermophilic archaeon Thermococcus kodakarensis, focusing on the catalytic properties and roles in oxidative-stress defense and sulfur-dependent energy conservation. The recombinant form of TK1481 exhibited both NAD(P)H oxidase and NAD(P)H:polysulfide oxidoreductase activities. The enzyme also possessed low NAD(P)H peroxidase and NAD(P)H:elemental sulfur oxidoreductase activities under anaerobic conditions. A mutant form of the enzyme, in which the putative redox-active residue Cys43 was replaced by Ala, still showed NADH-dependent flavin adenine dinucleotide (FAD) reduction activity. Although it also retained successive oxidase and anaerobic peroxidase activities, the ability to reduce polysulfide and sulfur was completely lost, suggesting the specific reactivity of the Cys43 residue for sulfur. To evaluate the physiological function of TK1481, we constructed a gene deletant, ΔTK1481, and mutant KUTK1481C43A, into which two base mutations altering Cys43 of TK1481 to Ala were introduced. ΔTK1481 exhibited growth properties nearly identical to those of the parent strain, KU216, in sulfur-containing media. Interestingly, in the absence of elemental sulfur, the growth of ΔTK1481 was not affected by dissolved oxygen, whereas the growth of KU216 and KUTK1481C43A was significantly impaired. These results indicate that although TK1481 does not play a critical role in either sulfur reduction or the response to oxidative stress, the NAD(P)H oxidase activity of TK1481 unexpectedly participates in the oxygen sensitivity of the hyperthermophilic archaeon T. kodakarensis in the absence of sulfur.
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