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Jiang J, Ni L, Zhang X, Gokulnath P, Vulugundam G, Li G, Wang H, Xiao J. Moderate-Intensity Exercise Maintains Redox Homeostasis for Cardiovascular Health. Adv Biol (Weinh) 2023; 7:e2200204. [PMID: 36683183 DOI: 10.1002/adbi.202200204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 09/27/2022] [Indexed: 01/24/2023]
Abstract
It is well known that exercise is beneficial for cardiovascular health. Oxidative stress is the common pathological basis of many cardiovascular diseases. The overproduction of free radicals, both reactive oxygen species and reactive nitrogen species, can lead to redox imbalance and exacerbate oxidative damage to the cardiovascular system. Maintaining redox homeostasis and enhancing anti-oxidative capacity are critical mechanisms by which exercise protects against cardiovascular diseases. Moderate-intensity exercise is an effective means to maintain cardiovascular redox homeostasis. Moderate-intensity exercise reduces the risk of cardiovascular disease by improving mitochondrial function and anti-oxidative capacity. It also attenuates adverse cardiac remodeling and enhances cardiac function. This paper reviews the primary mechanisms of moderate-intensity exercise-mediated redox homeostasis in the cardiovascular system. Exploring the role of exercise-mediated redox homeostasis in the cardiovascular system is of great significance to the prevention and treatment of cardiovascular diseases.
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Affiliation(s)
- Jizong Jiang
- Cardiac Regeneration and Ageing Lab, Institute of Geriatrics (Shanghai University), Affiliated Nantong Hospital of Shanghai University (The Sixth People's Hospital of Nantong), School of Medicine, Shanghai University, Nantong, 226011, China.,Institute of Cardiovascular Sciences, Shanghai Engineering Research Center of Organ Repair, School of Life Science, Shanghai University, Shanghai, 200444, China
| | - Lingyan Ni
- Cardiac Regeneration and Ageing Lab, Institute of Geriatrics (Shanghai University), Affiliated Nantong Hospital of Shanghai University (The Sixth People's Hospital of Nantong), School of Medicine, Shanghai University, Nantong, 226011, China.,Institute of Cardiovascular Sciences, Shanghai Engineering Research Center of Organ Repair, School of Life Science, Shanghai University, Shanghai, 200444, China
| | - Xinxin Zhang
- Cardiac Regeneration and Ageing Lab, Institute of Geriatrics (Shanghai University), Affiliated Nantong Hospital of Shanghai University (The Sixth People's Hospital of Nantong), School of Medicine, Shanghai University, Nantong, 226011, China.,Institute of Cardiovascular Sciences, Shanghai Engineering Research Center of Organ Repair, School of Life Science, Shanghai University, Shanghai, 200444, China
| | - Priyanka Gokulnath
- Cardiovascular Division, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02114, USA
| | | | - Guoping Li
- Cardiovascular Division, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02114, USA
| | - Hongyun Wang
- Cardiac Regeneration and Ageing Lab, Institute of Geriatrics (Shanghai University), Affiliated Nantong Hospital of Shanghai University (The Sixth People's Hospital of Nantong), School of Medicine, Shanghai University, Nantong, 226011, China.,Institute of Cardiovascular Sciences, Shanghai Engineering Research Center of Organ Repair, School of Life Science, Shanghai University, Shanghai, 200444, China
| | - Junjie Xiao
- Cardiac Regeneration and Ageing Lab, Institute of Geriatrics (Shanghai University), Affiliated Nantong Hospital of Shanghai University (The Sixth People's Hospital of Nantong), School of Medicine, Shanghai University, Nantong, 226011, China.,Institute of Cardiovascular Sciences, Shanghai Engineering Research Center of Organ Repair, School of Life Science, Shanghai University, Shanghai, 200444, China
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Li G, Fan A, Peng G, Keyhani NO, Xin J, Cao Y, Xia Y. A bifunctional catalase-peroxidase,MakatG1, contributes to virulence ofMetarhizium acridumby overcoming oxidative stress on the host insect cuticle. Environ Microbiol 2017; 19:4365-4378. [DOI: 10.1111/1462-2920.13932] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Accepted: 09/14/2017] [Indexed: 01/24/2023]
Affiliation(s)
- Guohong Li
- School of Life Sciences; Chongqing University; Chongqing China
- Chongqing Engineering Research Center for Fungal Insecticides; Chongqing China
- Key Laboratory of Gene Function and Regulation Technologies under Chongqing Municipal Education Commission; Chongqing China
| | - Anni Fan
- School of Life Sciences; Chongqing University; Chongqing China
- Chongqing Engineering Research Center for Fungal Insecticides; Chongqing China
- Key Laboratory of Gene Function and Regulation Technologies under Chongqing Municipal Education Commission; Chongqing China
| | - Guoxiong Peng
- School of Life Sciences; Chongqing University; Chongqing China
- Chongqing Engineering Research Center for Fungal Insecticides; Chongqing China
- Key Laboratory of Gene Function and Regulation Technologies under Chongqing Municipal Education Commission; Chongqing China
| | - Nemat O. Keyhani
- School of Life Sciences; Chongqing University; Chongqing China
- Department of Microbiology and Cell Science; University of Florida; Gainesville FL USA
| | - Jiankang Xin
- School of Life Sciences; Chongqing University; Chongqing China
- Chongqing Engineering Research Center for Fungal Insecticides; Chongqing China
- Key Laboratory of Gene Function and Regulation Technologies under Chongqing Municipal Education Commission; Chongqing China
| | - Yueqing Cao
- School of Life Sciences; Chongqing University; Chongqing China
- Chongqing Engineering Research Center for Fungal Insecticides; Chongqing China
- Key Laboratory of Gene Function and Regulation Technologies under Chongqing Municipal Education Commission; Chongqing China
| | - Yuxian Xia
- School of Life Sciences; Chongqing University; Chongqing China
- Chongqing Engineering Research Center for Fungal Insecticides; Chongqing China
- Key Laboratory of Gene Function and Regulation Technologies under Chongqing Municipal Education Commission; Chongqing China
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Rittiroongrad S, Charoenlap N, Giengkam S, Vattanaviboon P, Mongkolsuk S. Agrobacterium tumefaciens estC, Encoding an Enzyme Containing Esterase Activity, Is Regulated by EstR, a Regulator in the MarR Family. PLoS One 2016; 11:e0168791. [PMID: 28036400 PMCID: PMC5201249 DOI: 10.1371/journal.pone.0168791] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 12/06/2016] [Indexed: 11/18/2022] Open
Abstract
Analysis of the A. tumefaciens genome revealed estC, which encodes an esterase located next to its transcriptional regulator estR, a regulator of esterase in the MarR family. Inactivation of estC results in a small increase in the resistance to organic hydroperoxides, whereas a high level of expression of estC from an expression vector leads to a reduction in the resistance to organic hydroperoxides and menadione. The estC gene is transcribed divergently from its regulator, estR. Expression analysis showed that only high concentrations of cumene hydroperoxide (CHP, 1 mM) induced expression of both genes in an EstR-dependent manner. The EstR protein acts as a CHP sensor and a transcriptional repressor of both genes. EstR specifically binds to the operator sites OI and OII overlapping the promoter elements of estC and estR. This binding is responsible for transcription repression of both genes. Exposure to organic hydroperoxide results in oxidation of the sensing cysteine (Cys16) residue of EstR, leading to a release of the oxidized repressor from the operator sites, thereby allowing transcription and high levels of expression of both genes. The estC is the first organic hydroperoxide-inducible esterase-encoding gene in alphaproteobacteria.
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Affiliation(s)
- Surawach Rittiroongrad
- Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok, Thailand
- Department of Biotechnology, and Center of Emerging Bacterial Infection, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Nisanart Charoenlap
- Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok, Thailand
- Center of Excellence on Environmental Health and Toxicology, Bangkok, Thailand
| | - Suparat Giengkam
- Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok, Thailand
| | - Paiboon Vattanaviboon
- Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok, Thailand
- Center of Excellence on Environmental Health and Toxicology, Bangkok, Thailand
- Program in Applied Biological Sciences: Environmental Health, Chulabhorn Graduate Institute, Bangkok, Thailand
| | - Skorn Mongkolsuk
- Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok, Thailand
- Department of Biotechnology, and Center of Emerging Bacterial Infection, Faculty of Science, Mahidol University, Bangkok, Thailand
- Center of Excellence on Environmental Health and Toxicology, Bangkok, Thailand
- Program in Applied Biological Sciences: Environmental Health, Chulabhorn Graduate Institute, Bangkok, Thailand
- * E-mail:
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Tondo ML, Delprato ML, Kraiselburd I, Fernández Zenoff MV, Farías ME, Orellano EG. KatG, the Bifunctional Catalase of Xanthomonas citri subsp. citri, Responds to Hydrogen Peroxide and Contributes to Epiphytic Survival on Citrus Leaves. PLoS One 2016; 11:e0151657. [PMID: 26990197 PMCID: PMC4807922 DOI: 10.1371/journal.pone.0151657] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 03/02/2016] [Indexed: 12/19/2022] Open
Abstract
Xanthomonas citri subsp. citri (Xcc) is the bacterium responsible for citrus canker. This bacterium is exposed to reactive oxygen species (ROS) at different points during its life cycle, including those normally produced by aerobic respiration or upon exposition to ultraviolet (UV) radiation. Moreover, ROS are key components of the host immune response. Among enzymatic ROS-detoxifying mechanisms, catalases eliminate H2O2, avoiding the potential damage caused by this specie. Xcc genome includes four catalase genes. In this work, we studied the physiological role of KatG, the only bifunctional catalase of Xcc, through the construction and characterization of a modified strain (XcckatG), carrying an insertional mutation in the katG gene. First, we evaluated the involvement of KatG in the bacterial adaptive response to H2O2. XcckatG cultures exhibited lower catalase activity than those of the wild-type strain, and this activity was not induced upon treatment with sub-lethal doses of H2O2. Moreover, the KatG-deficient mutant exhibited decreased tolerance to H2O2 toxicity compared to wild-type cells and accumulated high intracellular levels of peroxides upon exposure to sub-lethal concentrations of H2O2. To further study the role of KatG in Xcc physiology, we evaluated bacterial survival upon exposure to UV-A or UV-B radiation. In both conditions, XcckatG showed a high mortality in comparison to Xcc wild-type. Finally, we studied the development of bacterial biofilms. While structured biofilms were observed for the Xcc wild-type, the development of these structures was impaired for XcckatG. Based on these results, we demonstrated that KatG is responsible for Xcc adaptive response to H2O2 and a key component of the bacterial response to oxidative stress. Moreover, this enzyme plays an important role during Xcc epiphytic survival, being essential for biofilm formation and UV resistance.
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Affiliation(s)
- María Laura Tondo
- Molecular Biology Division, Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina
| | - María Laura Delprato
- Molecular Biology Division, Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina
| | - Ivana Kraiselburd
- Molecular Biology Division, Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina
| | - María Verónica Fernández Zenoff
- Planta Piloto de Procesos Industriales Microbiológicos, Consejo Nacional de Investigaciones Científicas y Técnicas, San Miguel de Tucumán, Tucumán, Argentina
| | - María Eugenia Farías
- Planta Piloto de Procesos Industriales Microbiológicos, Consejo Nacional de Investigaciones Científicas y Técnicas, San Miguel de Tucumán, Tucumán, Argentina
| | - Elena G. Orellano
- Molecular Biology Division, Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina
- * E-mail:
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Srijaruskul K, Charoenlap N, Namchaiw P, Chattrakarn S, Giengkam S, Mongkolsuk S, Vattanaviboon P. Regulation by SoxR of mfsA, Which Encodes a Major Facilitator Protein Involved in Paraquat Resistance in Stenotrophomonas maltophilia. PLoS One 2015; 10:e0123699. [PMID: 25915643 PMCID: PMC4411124 DOI: 10.1371/journal.pone.0123699] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2014] [Accepted: 03/06/2015] [Indexed: 11/18/2022] Open
Abstract
Stenotrophomonas maltophilia MfsA (Smlt1083) is an efflux pump in the major facilitator superfamily (MFS). Deletion of mfsA renders the strain more susceptible to paraquat, but no alteration in the susceptibility levels of other oxidants is observed. The expression of mfsA is inducible upon challenge with redox cycling/superoxide-generating drug (paraquat, menadione and plumbagin) treatments and is directly regulated by SoxR, which is a transcription regulator and sensor of superoxide-generating agents. Analysis of mfsA expression patterns in wild-type and a soxR mutant suggests that oxidized SoxR functions as a transcription activator of the gene. soxR (smlt1084) is located in a head-to-head fashion with mfsA, and these genes share the -10 motif of their promoter sequences. Purified SoxR specifically binds to the putative mfsA promoter motifs that contain a region that is highly homologous to the consensus SoxR binding site, and mutation of the SoxR binding site abolishes binding of purified SoxR protein. The SoxR box is located between the putative -35 and -10 promoter motifs of mfsA; and this position is typical for a promoter in which SoxR acts as a transcriptional activator. At the soxR promoter, the SoxR binding site covers the transcription start site of the soxR transcript; thus, binding of SoxR auto-represses its own transcription. Taken together, our results reveal for the first time that mfsA is a novel member of the SoxR regulon and that SoxR binds and directly regulates its expression.
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Affiliation(s)
- Kriangsuk Srijaruskul
- Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok, 10210, Thailand
- Program in Applied Biological Sciences: Environmental Health, Chulabhorn Graduate Institute, Bangkok, 10210, Thailand
| | - Nisanart Charoenlap
- Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok, 10210, Thailand
| | - Poommaree Namchaiw
- Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok, 10210, Thailand
| | - Sorayut Chattrakarn
- Program in Applied Biological Sciences: Environmental Health, Chulabhorn Graduate Institute, Bangkok, 10210, Thailand
| | - Suparat Giengkam
- Program in Applied Biological Sciences: Environmental Health, Chulabhorn Graduate Institute, Bangkok, 10210, Thailand
| | - Skorn Mongkolsuk
- Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok, 10210, Thailand
- Department of Biotechnology, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
- Center of Emerging Bacterial Infection, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
- Center of Excellence on Environmental Health and Toxicology, Bangkok, Thailand
| | - Paiboon Vattanaviboon
- Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok, 10210, Thailand
- Program in Applied Biological Sciences: Environmental Health, Chulabhorn Graduate Institute, Bangkok, 10210, Thailand
- * E-mail:
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6
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Leesukon P, Wirathorn W, Chuchue T, Charoenlap N, Mongkolsuk S. The selectable antibiotic marker, tetA(C), increases Pseudomonas aeruginosa susceptibility to the herbicide/superoxide generator, paraquat. Arch Microbiol 2013; 195:671-4. [PMID: 23907582 DOI: 10.1007/s00203-013-0913-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 07/11/2013] [Accepted: 07/15/2013] [Indexed: 11/29/2022]
Affiliation(s)
- Panithi Leesukon
- Molecular Medicine Graduate Program, Faculty of Science, Mahidol University, Bangkok, Thailand
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7
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Gene expression and physiological role of Pseudomonas aeruginosa methionine sulfoxide reductases during oxidative stress. J Bacteriol 2013; 195:3299-308. [PMID: 23687271 DOI: 10.1128/jb.00167-13] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Pseudomonas aeruginosa PAO1 has two differentially expressed methionine sulfoxide reductase genes: msrA (PA5018) and msrB (PA2827). The msrA gene is expressed constitutively at a high level throughout all growth phases, whereas msrB expression is highly induced by oxidative stress, such as sodium hypochlorite (NaOCl) treatment. Inactivation of either msrA or msrB or both genes (msrA msrB mutant) rendered the mutants less resistant than the parental PAO1 strain to oxidants such as NaOCl and H2O2. Unexpectedly, msr mutants have disparate resistance patterns when exposed to paraquat, a superoxide generator. The msrA mutant had a higher paraquat resistance level than the msrB mutant, which had a lower paraquat resistance level than the PAO1 strain. The expression levels of msrA showed an inverse correlation with the paraquat resistance level, and this atypical paraquat resistance pattern was not observed with msrB. Virulence testing using a Drosophila melanogaster model revealed that the msrA, msrB, and, to a greater extent, msrA msrB double mutants had an attenuated virulence phenotype. The data indicate that msrA and msrB are essential genes for oxidative stress protection and bacterial virulence. The pattern of expression and mutant phenotypes of P. aeruginosa msrA and msrB differ from previously characterized msr genes from other bacteria. Thus, as highly conserved genes, the msrA and msrB have diverse expression patterns and physiological roles that depend on the environmental niche where the bacteria thrive.
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Large scale expressed sequence tag (EST) analysis of Metarhizium acridum infecting Locusta migratoria reveals multiple strategies for fungal adaptation to the host cuticle. Curr Genet 2012; 58:265-79. [DOI: 10.1007/s00294-012-0382-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2012] [Revised: 09/21/2012] [Accepted: 09/21/2012] [Indexed: 12/18/2022]
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Pseudomonas syringae Catalases Are Collectively Required for Plant Pathogenesis. J Bacteriol 2012; 194:5054-64. [PMID: 22797762 DOI: 10.1128/jb.00999-12] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The bacterial pathogen Pseudomonas syringae pv. tomato DC3000 must detoxify plant-produced hydrogen peroxide (H(2)O(2)) in order to survive in its host plant. Candidate enzymes for this detoxification include the monofunctional catalases KatB and KatE and the bifunctional catalase-peroxidase KatG of DC3000. This study shows that KatG is the major housekeeping catalase of DC3000 and provides protection against menadione-generated endogenous H(2)O(2). In contrast, KatB rapidly and substantially accumulates in response to exogenous H(2)O(2). Furthermore, KatB and KatG have nonredundant roles in detoxifying exogenous H(2)O(2) and are required for full virulence of DC3000 in Arabidopsis thaliana. Therefore, the nonredundant ability of KatB and KatG to detoxify plant-produced H(2)O(2) is essential for the bacteria to survive in plants. Indeed, a DC3000 catalase triple mutant is severely compromised in its ability to grow in planta, and its growth can be partially rescued by the expression of katB, katE, or katG. Interestingly, our data demonstrate that although KatB and KatG are the major catalases involved in the virulence of DC3000, KatE can also provide some protection in planta. Thus, our results indicate that these catalases are virulence factors for DC3000 and are collectively required for pathogenesis.
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Jiang J, Jiang L, Zhang L, Luo H, Opiyo AM, Yu Z. Changes of protein profile in fresh-cut lotus tuber before and after browning. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2012; 60:3955-3965. [PMID: 22455495 DOI: 10.1021/jf205303y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Browning is a critical problem, which often limits the shelf life and marketability in fresh-cut lotus tuber. Proteome level changes in response to the browning metabolism were investigated using two-dimensional electrophoresis (2-DE) and MALDI-TOF-TOF. A total of 34 functional protein spots were identified by comparing 2-DE protein patterns of fresh-cut lotus tuber before and after browning. These 34 identified proteins could be classified into 7 functional groups based on the NCBI database, that is, material and energy metabolism (35%), stress response (20%), respiration metabolism (12%), cell structure (12%), signal transduction (6%), gene expression regulation (6%), and unclassified proteins (9%). The group with the greatest difference in protein expression was related to material metabolism and regulation, reactive oxygen species metabolism, and respiratory control. The distinct proteins included universal stress protein (USP), superoxide dismutase (SOD), peroxidase (POD), ferritin, and ATPase.
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Affiliation(s)
- Juan Jiang
- Key Laboratory of Food Processing and Quality Control, College of Food Science and Technology, Nanjing Agricultural University, Nanjing, People's Republic of China
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Novel roles of SoxR, a transcriptional regulator from Xanthomonas campestris, in sensing redox-cycling drugs and regulating a protective gene that have overall implications for bacterial stress physiology and virulence on a host plant. J Bacteriol 2011; 194:209-17. [PMID: 22056938 DOI: 10.1128/jb.05603-11] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
In Xanthomonas campestris pv. campestris, SoxR likely functions as a sensor of redox-cycling drugs and as a transcriptional regulator. Oxidized SoxR binds directly to its target site and activates the expression of xcc0300, a gene that has protective roles against the toxicity of redox-cycling compounds. In addition, SoxR acts as a noninducible repressor of its own expression. X. campestris pv. campestris requires SoxR both for protection against redox-cycling drugs and for full virulence on a host plant. The X. campestris model of the gene regulation and physiological roles of SoxR represents a novel variant of existing bacterial SoxR models.
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12
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The catalase-peroxidase KatG is required for virulence of Xanthomonas campestris pv. campestris in a host plant by providing protection against low levels of H2O2. J Bacteriol 2009; 191:7372-7. [PMID: 19783631 DOI: 10.1128/jb.00788-09] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Xanthomonas campestris pv. campestris katG encodes a catalase-peroxidase that has a role in protecting the bacterium against micromolar concentrations of H(2)O(2). A knockout mutation in katG that causes loss of catalase-peroxidase activity correlates with increased susceptibility to H(2)O(2) and a superoxide generator and is avirulent in a plant model system. katG expression is induced by oxidants in an OxyR-dependent manner.
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13
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Functional and expression analyses of the cop operon, required for copper resistance in Agrobacterium tumefaciens. J Bacteriol 2009; 191:5159-68. [PMID: 19502402 DOI: 10.1128/jb.00384-09] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The copper resistance determinant copARZ, which encodes a CPx-type copper ATPase efflux protein, a transcriptional regulator, and a putative intracellular copper chaperone, was functionally characterized for the phytopathogenic bacterium Agrobacterium tumefaciens. These genes are transcribed as an operon, and their expression is induced in response to increasing copper and silver ion concentrations in a copR-dependent fashion. Analysis of the copARZ promoter revealed a putative CopR binding box located within the spacer of the -35 and -10 promoter motifs. In vitro, purified CopR could specifically bind to the box. The inactivation of the copARZ operon or copZ reduces the level of resistance to copper but not to other metal ions. Also, the copARZ operon mutant shows increased sensitivity to the superoxide generators menadione and plumbagin. In addition, the loss of functional copZ does not affect the ability of copper ions to induce the copARZ promoter, indicating that CopZ is not involved in the copper-sensing mechanism of CopR. Altogether, the results demonstrate a crucial role for the copARZ operon as a component of the copper resistance machinery in A. tumefaciens.
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Hanyu M, Fujimoto H, Tejima K, Saeki K. Functional differences of two distinct catalases in Mesorhizobium loti MAFF303099 under free-living and symbiotic conditions. J Bacteriol 2009; 191:1463-71. [PMID: 19074374 PMCID: PMC2648221 DOI: 10.1128/jb.01583-08] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2008] [Accepted: 12/04/2008] [Indexed: 11/20/2022] Open
Abstract
Protection against reactive oxygen species (ROS) is important for legume-nodulating rhizobia during the establishment and maintenance of symbiosis, as well as under free-living conditions, because legume hosts might assail incoming microbes with ROS and because nitrogenase is extremely sensitive to ROS. We generated mutants of two potential catalase genes in Mesorhizobium loti MAFF303099 to investigate their physiological significance. Biochemical results indicated that genes with the locus tags mlr2101 and mlr6940 encoded a monofunctional catalase and a bifunctional catalase-peroxidase, respectively, that were named katE and katG. Under free-living conditions, the katG mutant demonstrated an extended generation time and elevated sensitivity to exogenous H(2)O(2), whereas the katE mutant exhibited no generation time extension and only a slight increase in sensitivity to exogenous H(2)O(2). However, the katE mutant showed a marked decrease in its survival rate during the stationary phase. With regard to symbiotic capacities with Lotus japonicus, the katG mutant was indistinguishable from the wild type; nevertheless, the mutants with disrupted katE formed nodules with decreased nitrogen fixation capacities (about 50 to 60%) compared to those formed by the wild type. These mutant phenotypes agreed with the expression profiles showing that transcription of katG, but not katE, was high during the exponential growth phase and that transcription levels of katE versus sigA were elevated during stationary phase and were approximately fourfold higher in bacteroids than mid-exponential-phase cells. Our results revealed functional separation of the two catalases, as well as the importance of KatE under conditions of strong growth limitation.
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Affiliation(s)
- Masaki Hanyu
- Department of Biological Sciences, Nara Women's University, Japan
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15
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Vattanaviboon P, Tanboon W, Mongkolsuk S. Physiological and expression analyses of Agrobacterium tumefaciens trxA, encoding thioredoxin. J Bacteriol 2007; 189:6477-81. [PMID: 17573482 PMCID: PMC1951901 DOI: 10.1128/jb.00623-07] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Exposure of Agrobacterium tumefaciens to menadione, cumene hydroperoxide, and diamide strongly induced trxA expression. The trxA mutant showed a reduction in the aerobic growth rate and plating efficiency and was cytochrome c oxidase negative. Atypically, the mutant has decreased resistance to menadione but an increased H2O2 resistance phenotype.
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Affiliation(s)
- Paiboon Vattanaviboon
- Laboratory of Biotechnology, Chulabhorn Research Institute, Lak Si, Bangkok 10210, Thailand.
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Eiamphungporn W, Charoenlap N, Vattanaviboon P, Mongkolsuk S. Agrobacterium tumefaciens soxR is involved in superoxide stress protection and also directly regulates superoxide-inducible expression of itself and a target gene. J Bacteriol 2006; 188:8669-73. [PMID: 17041041 PMCID: PMC1698218 DOI: 10.1128/jb.00856-06] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2006] [Accepted: 10/02/2006] [Indexed: 11/20/2022] Open
Abstract
Inactivation of Agrobacterium tumefaciens soxR increases sensitivity to superoxide generators. soxR expression is highly induced by superoxide stress and is autoregulated. SoxR also directly regulates the superoxide-inducible expression of atu5152. Taken together, the physiological role of soxR and the mechanism by which it regulates expression of target genes make the A. tumefaciens SoxR system different from other bacterial systems.
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Affiliation(s)
- Warawan Eiamphungporn
- Laboratory of Biotechnology, Chulabhorn Research Institute, Lak Si, Bangkok 10210, Thailand
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Chuchue T, Tanboon W, Prapagdee B, Dubbs JM, Vattanaviboon P, Mongkolsuk S. ohrR and ohr are the primary sensor/regulator and protective genes against organic hydroperoxide stress in Agrobacterium tumefaciens. J Bacteriol 2006; 188:842-51. [PMID: 16428387 PMCID: PMC1347339 DOI: 10.1128/jb.188.3.842-851.2006] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The genes involved in organic hydroperoxide protection in Agrobacterium tumefaciens were functionally evaluated. Gene inactivation studies and functional analyses have identified ohr, encoding a thiol peroxidase, as the gene primarily responsible for organic hydroperoxide protection in A. tumefaciens. An ohr mutant was sensitive to organic hydroperoxide killing and had a reduced capacity to metabolize organic hydroperoxides. ohr is located next to, and is divergently transcribed from, ohrR, encoding a sensor and transcription regulator of organic hydroperoxide stress. Transcription of both ohr and ohrR was induced by exposure to organic hydroperoxides but not by exposure to other oxidants. This induction required functional ohrR. The results of gel mobility shift and DNase I footprinting assays with purified OhrR, combined with in vivo promoter deletion analyses, confirmed that OhrR regulated both ohrR and ohr by binding to a single OhrR binding box that overlapped the ohrR and ohr promoters. ohrR and ohr are both required for the establishment of a novel cumene hydroperoxide-induced adaptive response. Inactivation or overexpression of other Prx family genes (prx1, prx2, prx3, bcp1, and bcp2) did not affect either the resistance to, or the ability to degrade, organic hydroperoxide. Taken together, the results of biochemical, gene regulation and physiological studies support the role of ohrR and ohr as the primary system in sensing and protecting A. tumefaciens from organic hydroperoxide stress.
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Affiliation(s)
- Tatsanee Chuchue
- Laboratory of Biotechnology, Chulabhorn Research Institute, Lak Si, Bangkok 10210, Thailand, Department of Biotechnology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
| | - Weerachai Tanboon
- Laboratory of Biotechnology, Chulabhorn Research Institute, Lak Si, Bangkok 10210, Thailand, Department of Biotechnology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
| | - Benjaphorn Prapagdee
- Laboratory of Biotechnology, Chulabhorn Research Institute, Lak Si, Bangkok 10210, Thailand, Department of Biotechnology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
| | - James M. Dubbs
- Laboratory of Biotechnology, Chulabhorn Research Institute, Lak Si, Bangkok 10210, Thailand, Department of Biotechnology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
| | - Paiboon Vattanaviboon
- Laboratory of Biotechnology, Chulabhorn Research Institute, Lak Si, Bangkok 10210, Thailand, Department of Biotechnology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
- Corresponding author. Mailing address: Laboratory of Biotechnology, Chulabhorn Research Institute, Lak Si, Bangkok 10210, Thailand. Phone: 662-574-0622, x1402. Fax: 662-574-2027. E-mail for S. Mongkolsuk: . E-mail for P. Vattanaviboon:
| | - Skorn Mongkolsuk
- Laboratory of Biotechnology, Chulabhorn Research Institute, Lak Si, Bangkok 10210, Thailand, Department of Biotechnology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
- Corresponding author. Mailing address: Laboratory of Biotechnology, Chulabhorn Research Institute, Lak Si, Bangkok 10210, Thailand. Phone: 662-574-0622, x1402. Fax: 662-574-2027. E-mail for S. Mongkolsuk: . E-mail for P. Vattanaviboon:
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Panek HR, O'Brian MR. KatG is the primary detoxifier of hydrogen peroxide produced by aerobic metabolism in Bradyrhizobium japonicum. J Bacteriol 2004; 186:7874-80. [PMID: 15547258 PMCID: PMC529082 DOI: 10.1128/jb.186.23.7874-7880.2004] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2004] [Accepted: 09/02/2004] [Indexed: 12/12/2022] Open
Abstract
Bacteria are exposed to reactive oxygen species from the environment and from those generated by aerobic metabolism. Catalases are heme proteins that detoxify H(2)O(2), and many bacteria contain more than one catalase enzyme. Also, the nonheme peroxidase alkyl hydroperoxide reductase (Ahp) is the major scavenger of endogenous H(2)O(2) in Escherichia coli. Here, we show that aerobically grown Bradyrhizobium japonicum cells express a single catalase activity. Four genes encoding putative catalases in the B. japonicum genome were identified, including a katG homolog encoding a catalase-peroxidase. Deletion of the katG gene resulted in loss of catalase activity in cell extracts and of exogenous H(2)O(2) consumption by whole cells. The katG strain had a severe aerobic growth phenotype but showed improved growth in the absence of O(2). By contrast, a B. japonicum ahpCD mutant grew well aerobically and consumed H(2)O(2) at wild-type rates. A heme-deficient hemA mutant expressed about one-third of the KatG activity as the wild type but grew well aerobically and scavenged low concentrations of exogenous H(2)O(2). However, cells of the hemA strain were deficient in consumption of high concentrations of H(2)O(2) and were very sensitive to killing by short exposure to H(2)O(2). In addition, KatG activity did not decrease as a result of mutation of the gene encoding the transcriptional activator OxyR. We conclude that aerobic metabolism produces toxic levels of H(2)O(2) in B. japonicum, which is detoxified primarily by KatG. Furthermore, the katG level sufficient for detoxification does not require OxyR.
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Affiliation(s)
- Heather R Panek
- Department of Biochemistry and Witebsky Center for Microbial Pathogenesis and Immunology, State University of New York at Buffalo, NY 14214, USA
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Prapagdee B, Eiamphungporn W, Saenkham P, Mongkolsuk S, Vattanaviboon P. Analysis of growth phase regulated KatA and CatE and their physiological roles in determining hydrogen peroxide resistance in Agrobacterium tumefaciens. FEMS Microbiol Lett 2004. [DOI: 10.1111/j.1574-6968.2004.tb09699.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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