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da Cunha ET, Pedrolo AM, Arisi ACM. Thermal and salt stress effects on the survival of plant growth-promoting bacteria Azospirillum brasilense in inoculants for maize cultivation. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2024; 104:5360-5367. [PMID: 38324183 DOI: 10.1002/jsfa.13366] [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: 07/31/2023] [Revised: 02/03/2024] [Accepted: 02/07/2024] [Indexed: 02/08/2024]
Abstract
BACKGROUND The plant growth-promoting bacteria (PGPB) Azospirillum brasilense is widely used as an inoculant for important grass crops, providing numerous benefits to the plants. However, one limitation to develop viable commercial inoculants is the control of PGPB survival, requiring strategies that guarantee their survival during handling and field application. The application of sublethal stress appears to be a promising strategy to increase bacterial cells tolerance to adverse environmental conditions since previous stress induces the activation of physiological protection in bacterial cell. In this work, we evaluated the effects of thermal and salt stresses on the survival of inoculant containing A. brasilense Ab-V5 and Ab-V6 strains and we monitored A. brasilense viability in inoculated maize roots after stress treatment of inoculant. RESULTS Thermal stress application (> 35 °C) in isolated cultures for both strains, as well as salt stress [sodium chloride (NaCl) concentrations > 0.3 mol L-1], resulted in growth rate decline. The A. brasilense enumeration in maize roots obtained by propidium monoazide quantitative polymerase chain reaction (PMA-qPCR), for inoculated maize seedlings grown in vitro for 7 days, showed that there is an increased number of viable cells after the salt stress treatment, indicating that A. brasilense Ab-V5 and Ab-V6 strains are able to adapt to salt stress (0.3 mol L-1 NaCl) growth conditions. CONCLUSION Azospirillum brasilense Ab-V5 and Ab-V6 strains had potential for osmoadaptation and salt stress, resulting in increased cell survival after inoculation in maize plants. © 2024 Society of Chemical Industry.
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Affiliation(s)
- Elisandra Triches da Cunha
- CAL CCA UFSC, Food Science and Technology Department, Agrarian Science Center, Federal University of Santa Catarina, Florianópolis, Brazil
| | - Ana Marina Pedrolo
- CAL CCA UFSC, Food Science and Technology Department, Agrarian Science Center, Federal University of Santa Catarina, Florianópolis, Brazil
| | - Ana Carolina Maisonnave Arisi
- CAL CCA UFSC, Food Science and Technology Department, Agrarian Science Center, Federal University of Santa Catarina, Florianópolis, Brazil
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Harkness RW, Zhao H, Toyama Y, Schuck P, Kay LE. Exploring Host-Guest Interactions within a 600 kDa DegP Protease Cage Complex Using Hydrodynamics Measurements and Methyl-TROSY NMR. J Am Chem Soc 2024; 146:8242-8259. [PMID: 38477967 DOI: 10.1021/jacs.3c13247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2024]
Abstract
The DegP protease-chaperone operates within the periplasm of Gram-negative bacteria, where it assists in the regulation of protein homeostasis, promotes virulence, and is essential to survival under stress. To carry out these tasks, DegP forms a network of preorganized apo oligomers that facilitate the capture of substrates within distributions of cage-like complexes which expand to encapsulate clients of various sizes. Although the architectures of DegP cage complexes are well understood, little is known about the structures, dynamics, and interactions of client proteins within DegP cages and the relationship between client structural dynamics and function. Here, we probe host-guest interactions within a 600 kDa DegP cage complex throughout the DegP activation cycle using a model α-helical client protein through a combination of hydrodynamics measurements, methyl-transverse relaxation optimized spectroscopy-based solution nuclear magnetic resonance studies, and proteolytic activity assays. We find that in the presence of the client, DegP cages assemble cooperatively with few intermediates. Our data further show that the N-terminal half of the bound client, which projects into the interior of the cages, is predominantly unfolded and flexible, and exchanges between multiple conformational states over a wide range of time scales. Finally, we show that a concerted structural transition of the protease domains of DegP occurs upon client engagement, leading to activation. Together, our findings support a model of DegP as a highly cooperative and dynamic molecular machine that stabilizes unfolded states of clients, primarily via interactions with their C-termini, giving rise to efficient cleavage.
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Affiliation(s)
- Robert W Harkness
- Department of Biochemistry, University of Toronto, Toronto M5S 1A8, Canada
- Department of Molecular Genetics, University of Toronto, Toronto M5S 1A8, Canada
- Department of Chemistry, University of Toronto, Toronto M5S 3H6, Canada
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto M5G 0A4, Canada
| | - Huaying Zhao
- Laboratory of Dynamics of Macromolecular Assembly, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Yuki Toyama
- Department of Biochemistry, University of Toronto, Toronto M5S 1A8, Canada
- Department of Molecular Genetics, University of Toronto, Toronto M5S 1A8, Canada
- Department of Chemistry, University of Toronto, Toronto M5S 3H6, Canada
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto M5G 0A4, Canada
| | - Peter Schuck
- Laboratory of Dynamics of Macromolecular Assembly, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Lewis E Kay
- Department of Biochemistry, University of Toronto, Toronto M5S 1A8, Canada
- Department of Molecular Genetics, University of Toronto, Toronto M5S 1A8, Canada
- Department of Chemistry, University of Toronto, Toronto M5S 3H6, Canada
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto M5G 0A4, Canada
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Song D, Qi X, Huang Y, Jia A, Liang Y, Man C, Yang X, Jiang Y. Comparative proteomics reveals the antibiotic resistance and virulence of Cronobacter isolated from powdered infant formula and its processing environment. Int J Food Microbiol 2023; 407:110374. [PMID: 37678039 DOI: 10.1016/j.ijfoodmicro.2023.110374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 07/31/2023] [Accepted: 08/29/2023] [Indexed: 09/09/2023]
Abstract
Cronobacter species are opportunistic foodborne pathogens that can cause neonatal meningitis, sepsis, and necrotizing enterocolitis. In this genus, certain level strains have high mortality to infant (Cronobacter sakazakii and Cronobacter malonaticus) and antibiotic tolerance. Cronobacter has strong environmental tolerance (acid resistance, high temperature resistance, UV resistance, antibiotic resistance, etc.) and can survive in a variety of environments. It has been isolated in various production environments and products in several countries. However, the relationships between Cronobacter antibiotic tolerance and virulence remain unclear, especially at the molecular level. In this study, 96 strains of Cronobacter were isolated from powdered infant formula and its processing environment and screened for antibiotic tolerance, and proteomic maps of the representative strains of Cronobacter with antibiotic tolerance were generated by analyzing proteomics data using multiple techniques to identify protein that are implicated in Cronobacter virulence and antibiotic resistance. The increase in antibiotic tolerance of Cronobacter had a certain increase in the production of enterotoxin and hemolysin. Only triple tolerated Cronobacter sakazakii decreased the utilization of sialic acid. A total of 16,131 intracellular proteins were detected in eight representative strains, and different proteomes were present in strains with different antibiotic tolerance, including 56 virulence-related proteins. Multiple virulence proteins regulated by unknown genes were also found in the eight isolated representative strains.
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Affiliation(s)
- Danliangmin Song
- Department of Food Science, Northeast Agricultural University, Harbin 150038, China
| | - Xuehe Qi
- Department of Food Science, Northeast Agricultural University, Harbin 150038, China.
| | - Yan Huang
- Department of Food Science, Northeast Agricultural University, Harbin 150038, China
| | - Ai Jia
- Department of Food Science, Northeast Agricultural University, Harbin 150038, China
| | - Yaqi Liang
- Department of Food Science, Northeast Agricultural University, Harbin 150038, China
| | - Chaoxin Man
- Key Laboratory of Dairy Science, Ministry of Education, Harbin 150030, China.
| | - Xinyan Yang
- Key Laboratory of Dairy Science, Ministry of Education, Harbin 150030, China.
| | - Yujun Jiang
- Department of Food Science, Northeast Agricultural University, Harbin 150038, China.
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Alves MJG, Mendonça JJ, Vitalino GM, Oliveira JP, Carvalho EX, Fracetto FJC, Fracetto GGM, Lira Junior MA. Screening Digitaria eriantha cv. Suvernola Endophytic Bacteria for Maize Growth Promotion. PLANTS (BASEL, SWITZERLAND) 2023; 12:2589. [PMID: 37514205 PMCID: PMC10385894 DOI: 10.3390/plants12142589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 07/05/2023] [Accepted: 07/07/2023] [Indexed: 07/30/2023]
Abstract
The search for sustainable agriculture has increased interest in using endophytic bacteria to reduce fertilizer use and increase stress resilience. Stress-adapted plants are a potential source of these bacteria. Some species of these plants have not yet been evaluated for this, such as pangolão grass, from which we considered endophytic bacteria as potential plant growth promoters. Bacteria from the root, colm, leaves, and rhizospheric soil were isolated, and 132 strains were evaluated for their in vitro biological nitrogen fixation, IAA and siderophores production, and phosphate solubilization. Each mechanism was also assessed under low N availability, water stress, and low-solubility Fe and P sources in maize greenhouse experiments. All strains synthesized IAA; 63 grew on N-free media, 114 synthesized siderophores, and 46 solubilized P, while 19 presented all four mechanisms. Overall, these strains had better performance than commercial inoculant in all experiments. Still, in vitro responses were not good predictors of in vivo effects, which indicates that the former should not be used for strain selection, since this could lead to not testing strains with good plant growth promotion potential. Their heterologous growth promotion in maize reinforces the potential of stress-adapted plant species as potential sources of strains for inoculants.
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Affiliation(s)
- Michelle J G Alves
- Departamento de Agronomia, Universidade Federal Rural de Pernambuco, Recife 52171-900, Brazil
| | - Johny Jesus Mendonça
- Departamento de Agronomia, Universidade Federal Rural de Pernambuco, Recife 52171-900, Brazil
- Programa de Pós-Graduação em Ciência do Solo, Universidade Federal do Rio Grande do Sul, Porto Alegre 91501-970, Brazil
| | - Gisely Moreira Vitalino
- Departamento de Agronomia, Universidade Federal Rural de Pernambuco, Recife 52171-900, Brazil
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da Cunha ET, Pedrolo AM, Arisi ACM. Effects of sublethal stress application on the survival of bacterial inoculants: a systematic review. Arch Microbiol 2023; 205:190. [PMID: 37055599 DOI: 10.1007/s00203-023-03542-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 04/04/2023] [Accepted: 04/05/2023] [Indexed: 04/15/2023]
Abstract
The use of commercial bacterial inoculants formulated with plant-growth promoting bacteria (PGPB) in agriculture has shown significant prominence in recent years due to growth-promotion benefits provided to plants through different mechanisms. However, the survival and viability of bacterial cells in inoculants are affected during use and may decrease their effectiveness. Physiological adaptation strategies have attracted attention to solve the viability problem. This review aims to provide an overview of research on selecting sublethal stress strategies to increase the effectiveness of bacterial inoculants. The searches were performed in November 2021 using Web of Science, Scopus, PubMed, and Proquest databases. The keywords "nitrogen-fixing bacteria", "plant growth-promoting rhizobacteria", "azospirillum", "pseudomonas", "rhizobium", "stress pre-conditioning", "adaptation", "metabolic physiological adaptation", "cellular adaptation", "increasing survival", "protective agent" and "protective strategy" were used in the searches. A total of 2573 publications were found, and 34 studies were selected for a deeper study of the subject. Based on the studies analysis, gaps and potential applications related to sublethal stress were identified. The most used strategies included osmotic, thermal, oxidative, and nutritional stress, and the primary cell response mechanism to stress was the accumulation of osmolytes, phytohormones, and exopolysaccharides (EPS). Under sublethal stress, the inoculant survival showed positive increments after lyophilization, desiccation, and long-term storage processes. The effectiveness of inoculant-plants interaction also had positive increments after sublethal stress, improving plant development, disease control, and tolerance to environmental stresses compared to unappealed inoculants.
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Affiliation(s)
- Elisandra Triches da Cunha
- CAL CCA UFSC, Food Science and Technology Department, Federal University of Santa Catarina, Rod. Admar Gonzaga, 1346, Florianópolis, SC, 88034-001, Brazil
| | - Ana Marina Pedrolo
- CAL CCA UFSC, Food Science and Technology Department, Federal University of Santa Catarina, Rod. Admar Gonzaga, 1346, Florianópolis, SC, 88034-001, Brazil
| | - Ana Carolina Maisonnave Arisi
- CAL CCA UFSC, Food Science and Technology Department, Federal University of Santa Catarina, Rod. Admar Gonzaga, 1346, Florianópolis, SC, 88034-001, Brazil.
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Borchert AJ, Bleem A, Beckham GT. RB-TnSeq identifies genetic targets for improved tolerance of Pseudomonas putida towards compounds relevant to lignin conversion. Metab Eng 2023; 77:208-218. [PMID: 37059293 DOI: 10.1016/j.ymben.2023.04.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 03/21/2023] [Accepted: 04/12/2023] [Indexed: 04/16/2023]
Abstract
Lignin-derived mixtures intended for bioconversion commonly contain high concentrations of aromatic acids, aliphatic acids, and salts. The inherent toxicity of these chemicals places a significant bottleneck upon the effective use of microbial systems for the valorization of these mixtures. Pseudomonas putida KT2440 can tolerate stressful quantities of several lignin-related compounds, making this bacterium a promising host for converting these chemicals to valuable bioproducts. Nonetheless, further increasing P. putida tolerance to chemicals in lignin-rich substrates has the potential to improve bioprocess performance. Accordingly, we employed random barcoded transposon insertion sequencing (RB-TnSeq) to reveal genetic determinants in P. putida KT2440 that influence stress outcomes during exposure to representative constituents found in lignin-rich process streams. The fitness information obtained from the RB-TnSeq experiments informed engineering of strains via deletion or constitutive expression of several genes. Namely, ΔgacAS, ΔfleQ, ΔlapAB, ΔttgR::Ptac:ttgABC, Ptac:PP_1150:PP_1152, ΔrelA, and ΔPP_1430 mutants showed growth improvement in the presence of single compounds, and some also exhibited greater tolerance when grown using a complex chemical mixture representative of a lignin-rich chemical stream. Overall, this work demonstrates the successful implementation of a genome-scale screening tool for the identification of genes influencing stress tolerance against notable compounds within lignin-enriched chemical streams, and the genetic targets identified herein offer promising engineering targets for improving feedstock tolerance in lignin valorization strains of P. putida KT2440.
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Affiliation(s)
- Andrew J Borchert
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA; Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Alissa Bleem
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA; Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Gregg T Beckham
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA; Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
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Proteolytic Activity of DegP Is Required for the Burkholderia Symbiont To Persist in Its Host Bean Bug. Microbiol Spectr 2023; 11:e0433022. [PMID: 36511662 PMCID: PMC9927360 DOI: 10.1128/spectrum.04330-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Symbiosis requires the adaptation of symbiotic bacteria to the host environment. Symbiotic factors for bacterial adaptation have been studied in various experimental models, including the Burkholderia-bean bug symbiosis model. Previously identified symbiotic factors of Burkholderia symbionts of bean bugs provided insight into the host environment being stressful to the symbionts. Because DegP, which functions as both a protease and a chaperone, supports bacterial growth under various stressful conditions, we hypothesized that DegP might be a novel symbiotic factor of Burkholderia symbionts in the symbiotic association with bean bugs. The expression level of degP was highly elevated in symbiotic Burkholderia cells in comparison with cultured cells. When the degP-deficient strain competed for symbiotic association against the wild-type strain, the ΔdegP strain showed no symbiotic competitiveness. In vivo monoinfection with the ΔdegP strain revealed a lower symbiont titer in the symbiotic organ than that of the wild-type strain, indicating that the ΔdegP strain failed to persist in the host. In in vitro assays, the ΔdegP strain showed susceptibility to heat and high-salt stressors and a decreased level of biofilm formation. To further determine the role of the proteolytic activity of DegP in symbiosis, we generated missense mutant DegPS248A exhibiting a defect in protease activity only. The ΔdegP strain complemented with degPS248A showed in vitro characteristics similar to those of the ΔdegP strain and failed to persist in the symbiotic organ. Together, the results of our study demonstrated that the proteolytic activity of DegP, which is involved in the stress resistance and biofilm formation of the Burkholderia symbiont, plays an essential role in symbiotic persistence in the host bean bug. IMPORTANCE Bacterial DegP has dual functions as a protease and a chaperone and supports bacterial growth under stressful conditions. In symbioses involving bacteria, bacterial symbionts encounter various stressors and may need functional DegP for symbiotic association with the host. Using the Burkholderia-bean bug symbiosis model, which is a useful model for identifying bacterial symbiotic factors, we demonstrated that DegP is indeed a symbiotic factor of Burkholderia persistence in its host bean bug. In vitro experiments to understand the symbiotic mechanisms of degP revealed that degP confers resistance to heat and high-salt stresses. In addition, degP supports biofilm formation, which is a previously identified persistence factor of the Burkholderia symbiont. Furthermore, using a missense mutation in a protease catalytic site of degP, we specifically elucidated that the proteolytic activity of degP plays essential roles in stress resistance, biofilm formation, and, thus, symbiotic persistence in the host bean bug.
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Dimitrova YN, Gutierrez JA, Huard K. It's ok to be outnumbered - sub-stoichiometric modulation of homomeric protein complexes. RSC Med Chem 2023; 14:22-46. [PMID: 36760737 PMCID: PMC9890894 DOI: 10.1039/d2md00212d] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 10/21/2022] [Indexed: 11/06/2022] Open
Abstract
An arsenal of molecular tools with increasingly diversified mechanisms of action is being developed by the scientific community to enable biological interrogation and pharmaceutical modulation of targets and pathways of ever increasing complexity. While most small molecules interact with the target of interest in a 1 : 1 relationship, a noteworthy number of recent examples were reported to bind in a sub-stoichiometric manner to a homomeric protein complex. This approach requires molecular understanding of the physiologically relevant protein assemblies and in-depth characterization of the compound's mechanism of action. The recent literature examples summarized here were selected to illustrate methods used to identify and characterize molecules with such mechanisms. The concept of one small molecule targeting a homomeric protein assembly is not new but the subject deserves renewed inspection in light of emerging technologies and increasingly diverse target biology, to ensure relevant in vitro systems are used and valuable compounds with potentially novel sub-stoichiometric mechanisms of action aren't overlooked.
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Affiliation(s)
| | | | - Kim Huard
- Genentech 1 DNA Way South San Francisco CA 94080 USA
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Liu S, Liu X, Shi Y, Zhuang S, Chen Q. RETRACTED: The adaptive mechanism of halophilic Brachybacterium muris in response to salt stress and its mitigation of copper toxicity in hydroponic plants. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 313:120124. [PMID: 36089137 DOI: 10.1016/j.envpol.2022.120124] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 08/27/2022] [Accepted: 09/03/2022] [Indexed: 06/15/2023]
Abstract
This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Authors who have indicated that there are significant errors with the scientific data upon which this study is based. Specifically, the authors have subsequently discovered that the 16S rDNA sequencing of Brachybacterium muris may not be reliable because of the limited identification methods from a few years ago. The authors are now repeating their experiments to reconfirm their data. The Authors take full responsibility for these errors and offer their sincere apologies.
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Affiliation(s)
- Siyu Liu
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, 310058, China
| | - Xiayu Liu
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, 310058, China
| | - Ying Shi
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, 310058, China.
| | - Shulin Zhuang
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Qihe Chen
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, 310058, China; Future Food Laboratory, Innovation Center of Yangtze River Delta, Zhejiang University, Jiashan, 310000, China.
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Cai J, Hao Y, Xu R, Zhang Y, Ma Y, Zhang Y, Wang Q. Differential binding of LuxR in response to temperature gauges switches virulence gene expression in Vibrio alginolyticus. Microbiol Res 2022; 263:127114. [PMID: 35878491 DOI: 10.1016/j.micres.2022.127114] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 06/04/2022] [Accepted: 07/05/2022] [Indexed: 12/26/2022]
Abstract
Vibrio pathogens must cope with temperature changes for proper thermo-adaptation and virulence gene expression. LuxR is a quorum-sensing (QS) master regulator of vibrios, playing roles in response to temperature alteration. However, the molecular mechanisms how LuxR is involved in adapting to different temperatures in bacteria have not been precisely elucidated. In this study, using chromatin immunoprecipitation and nucleotide sequencing (ChIP-seq), we identified 272 and 22 enriched loci harboring LuxR-binding peaks at ambient temperature (30 ˚C) and heat shock (42 ˚C) in the Vibrio alginolyticus genome, respectively. Analysis with the MEME (multiple EM for motif elicitation) algorithm indicated that the binding motifs of LuxR varied from temperatures. Three novel binding regions (the promoter of orf00292, orf00397 and fadD) of LuxR were identified and verified that the rising temperature causes the decreasing binding affinity of LuxR to these promoters. Meanwhile, the expression of orf00292, orf00397 and fadD were regulated by LuxR. Moreover, the weak binding of LuxR to the promoter of extracellular protease (Asp) was attributed to the attenuated Asp expression at thermal stress conditions. Taken together, our study demonstrated distinct binding characteristics of LuxR in response to temperature changes, thus highlighting LuxR as a thermo-sensor to switch and control virulence gene expression in V. alginolyticus.
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Affiliation(s)
- Jingxiao Cai
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Yuan Hao
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Rongjing Xu
- Yantai Tianyuan Aquatic Co. Ltd., Yantai, Shandong, China
| | - Yuanxing Zhang
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, China; Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai 200237, China
| | - Yue Ma
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China; Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai 200237, China; Shanghai Collaborative Innovation Center for Biomanufacturing, 130 Meilong Road, Shanghai 200237, China
| | - Yibei Zhang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China; Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai 200237, China.
| | - Qiyao Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China; Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai 200237, China; Shanghai Collaborative Innovation Center for Biomanufacturing, 130 Meilong Road, Shanghai 200237, China
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Essential role of extracytoplasmic proteins in the resistance of Gluconacetobacter diazotrophicus to cadmium. Res Microbiol 2022; 173:103922. [DOI: 10.1016/j.resmic.2022.103922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 01/20/2022] [Accepted: 01/21/2022] [Indexed: 11/23/2022]
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12
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Leandro MR, Andrade LF, de Souza Vespoli L, Soares FS, Moreira JR, Pimentel VR, Barbosa RR, de Oliveira MVV, Silveira V, de Souza Filho GA. Combination of osmotic stress and sugar stress response mechanisms is essential for Gluconacetobacter diazotrophicus tolerance to high-sucrose environments. Appl Microbiol Biotechnol 2021; 105:7463-7473. [PMID: 34542687 DOI: 10.1007/s00253-021-11590-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 09/01/2021] [Accepted: 09/02/2021] [Indexed: 11/25/2022]
Abstract
Sugar-rich environments represent an important challenge for microorganisms. The osmotic and molecular imbalances resulting from this condition severely limit microbial metabolism and growth. Gluconacetobacter diazotrophicus is one of the most sugar-tolerant prokaryotes, able to grow in the presence of sucrose concentrations up to 30%. However, the mechanisms that control its tolerance to such conditions remain poorly exploited. The present work investigated the key mechanisms of tolerance to high sugar in G. diazotrophicus. Comparative proteomics was applied to investigate the main functional pathways regulated in G. diazotrophicus when cultivated in the presence of high sucrose. Among 191 proteins regulated by high sucrose, regulatory pathways related to sugar metabolism, nutrient uptake, compatible solute synthesis, amino acid metabolism, and proteolytic system were highlighted. The role of these pathways on high-sucrose tolerance was investigated by mutagenesis analysis, which revealed that the knockout mutants zwf::Tn5 (sugar metabolism), tbdr::Tn5 (nutrient uptake), mtlK::Tn5 (compatible solute synthesis), pepN::Tn5 (proteolytic system), metH::Tn5 (amino acid metabolism), and ilvD::Tn5 (amino acid metabolism) became more sensitive to high sucrose. Together, our results identified mechanisms involved in response to high sugar in G. diazotrophicus, shedding light on the combination of osmotolerance and sugar-tolerance mechanisms. KEY POINTS: • G. diazotrophicus intensifies glycolysis to metabolize the excess of sugar. • G. diazotrophicus turns down the uptake of nutrients in response to high sugar. • G. diazotrophicus requires amino acid availability to resist high sugar.
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Affiliation(s)
- Mariana Ramos Leandro
- Laboratório de Biotecnologia (Setor de Biologia Integrativa), Universidade Estadual Do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, Rio de Janeiro, Brazil
| | - Leandro Fernandes Andrade
- Laboratório de Biotecnologia (Setor de Biologia Integrativa), Universidade Estadual Do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, Rio de Janeiro, Brazil
| | - Luciano de Souza Vespoli
- Laboratório de Biotecnologia (Setor de Biologia Integrativa), Universidade Estadual Do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, Rio de Janeiro, Brazil
| | - Fabiano Silva Soares
- Laboratório de Biotecnologia (Setor de Biologia Integrativa), Universidade Estadual Do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, Rio de Janeiro, Brazil
| | - Julia Rosa Moreira
- Laboratório de Biotecnologia (Setor de Biologia Integrativa), Universidade Estadual Do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, Rio de Janeiro, Brazil
| | - Vivian Ribeiro Pimentel
- Laboratório de Biotecnologia (Setor de Biologia Integrativa), Universidade Estadual Do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, Rio de Janeiro, Brazil
| | - Roberta Ribeiro Barbosa
- Laboratório de Biotecnologia (Setor de Biologia Integrativa), Universidade Estadual Do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, Rio de Janeiro, Brazil
| | - Marcos Vinícius Viana de Oliveira
- Laboratório de Biotecnologia (Setor de Biologia Integrativa), Universidade Estadual Do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, Rio de Janeiro, Brazil
| | - Vanildo Silveira
- Laboratório de Biotecnologia (Setor de Biologia Integrativa), Universidade Estadual Do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, Rio de Janeiro, Brazil
| | - Gonçalo Apolinário de Souza Filho
- Laboratório de Biotecnologia (Setor de Biologia Integrativa), Universidade Estadual Do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, Rio de Janeiro, Brazil.
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Harkness RW, Toyama Y, Ripstein ZA, Zhao H, Sever AIM, Luan Q, Brady JP, Clark PL, Schuck P, Kay LE. Competing stress-dependent oligomerization pathways regulate self-assembly of the periplasmic protease-chaperone DegP. Proc Natl Acad Sci U S A 2021. [PMID: 34362850 DOI: proc/self/fd/32] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
DegP is an oligomeric protein with dual protease and chaperone activity that regulates protein homeostasis and virulence factor trafficking in the periplasm of gram-negative bacteria. A number of oligomeric architectures adopted by DegP are thought to facilitate its function. For example, DegP can form a "resting" hexamer when not engaged to substrates, mitigating undesired proteolysis of cellular proteins. When bound to substrate proteins or lipid membranes, DegP has been shown to populate a variety of cage- or bowl-like oligomeric states that have increased proteolytic activity. Though a number of DegP's substrate-engaged structures have been robustly characterized, detailed mechanistic information underpinning its remarkable oligomeric plasticity and the corresponding interplay between these dynamics and biological function has remained elusive. Here, we have used a combination of hydrodynamics and NMR spectroscopy methodologies in combination with cryogenic electron microscopy to shed light on the apo-DegP self-assembly mechanism. We find that, in the absence of bound substrates, DegP populates an ensemble of oligomeric states, mediated by self-assembly of trimers, that are distinct from those observed in the presence of substrate. The oligomeric distribution is sensitive to solution ionic strength and temperature and is shifted toward larger oligomeric assemblies under physiological conditions. Substrate proteins may guide DegP toward canonical cage-like structures by binding to these preorganized oligomers, leading to changes in conformation. The properties of DegP self-assembly identified here suggest that apo-DegP can rapidly shift its oligomeric distribution in order to respond to a variety of biological insults.
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Affiliation(s)
- Robert W Harkness
- Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada; .,Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada.,Department of Chemistry, University of Toronto, Toronto, ON M5S 3H6, Canada.,Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | - Yuki Toyama
- Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada.,Department of Chemistry, University of Toronto, Toronto, ON M5S 3H6, Canada.,Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | - Zev A Ripstein
- Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada.,Department of Chemistry, University of Toronto, Toronto, ON M5S 3H6, Canada.,Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | - Huaying Zhao
- National Institute of Biomedical Imaging and Bioengineering, NIH, Bethesda, MD 20892
| | - Alexander I M Sever
- Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada.,Department of Chemistry, University of Toronto, Toronto, ON M5S 3H6, Canada.,Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | - Qing Luan
- Department of Chemistry & Biochemistry, University of Notre Dame, Notre Dame, IN 46556
| | - Jacob P Brady
- Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada.,Department of Chemistry, University of Toronto, Toronto, ON M5S 3H6, Canada.,Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | - Patricia L Clark
- Department of Chemistry & Biochemistry, University of Notre Dame, Notre Dame, IN 46556
| | - Peter Schuck
- National Institute of Biomedical Imaging and Bioengineering, NIH, Bethesda, MD 20892
| | - Lewis E Kay
- Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada; .,Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada.,Department of Chemistry, University of Toronto, Toronto, ON M5S 3H6, Canada.,Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
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Competing stress-dependent oligomerization pathways regulate self-assembly of the periplasmic protease-chaperone DegP. Proc Natl Acad Sci U S A 2021; 118:2109732118. [PMID: 34362850 DOI: 10.1073/pnas.2109732118] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
DegP is an oligomeric protein with dual protease and chaperone activity that regulates protein homeostasis and virulence factor trafficking in the periplasm of gram-negative bacteria. A number of oligomeric architectures adopted by DegP are thought to facilitate its function. For example, DegP can form a "resting" hexamer when not engaged to substrates, mitigating undesired proteolysis of cellular proteins. When bound to substrate proteins or lipid membranes, DegP has been shown to populate a variety of cage- or bowl-like oligomeric states that have increased proteolytic activity. Though a number of DegP's substrate-engaged structures have been robustly characterized, detailed mechanistic information underpinning its remarkable oligomeric plasticity and the corresponding interplay between these dynamics and biological function has remained elusive. Here, we have used a combination of hydrodynamics and NMR spectroscopy methodologies in combination with cryogenic electron microscopy to shed light on the apo-DegP self-assembly mechanism. We find that, in the absence of bound substrates, DegP populates an ensemble of oligomeric states, mediated by self-assembly of trimers, that are distinct from those observed in the presence of substrate. The oligomeric distribution is sensitive to solution ionic strength and temperature and is shifted toward larger oligomeric assemblies under physiological conditions. Substrate proteins may guide DegP toward canonical cage-like structures by binding to these preorganized oligomers, leading to changes in conformation. The properties of DegP self-assembly identified here suggest that apo-DegP can rapidly shift its oligomeric distribution in order to respond to a variety of biological insults.
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