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Lê-Bury P, Echenique-Rivera H, Pizarro-Cerdá J, Dussurget O. Determinants of bacterial survival and proliferation in blood. FEMS Microbiol Rev 2024; 48:fuae013. [PMID: 38734892 PMCID: PMC11163986 DOI: 10.1093/femsre/fuae013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 04/29/2024] [Accepted: 05/10/2024] [Indexed: 05/13/2024] Open
Abstract
Bloodstream infection is a major public health concern associated with high mortality and high healthcare costs worldwide. Bacteremia can trigger fatal sepsis whose prevention, diagnosis, and management have been recognized as a global health priority by the World Health Organization. Additionally, infection control is increasingly threatened by antimicrobial resistance, which is the focus of global action plans in the framework of a One Health response. In-depth knowledge of the infection process is needed to develop efficient preventive and therapeutic measures. The pathogenesis of bloodstream infection is a dynamic process resulting from the invasion of the vascular system by bacteria, which finely regulate their metabolic pathways and virulence factors to overcome the blood immune defenses and proliferate. In this review, we highlight our current understanding of determinants of bacterial survival and proliferation in the bloodstream and discuss their interactions with the molecular and cellular components of blood.
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Affiliation(s)
- Pierre Lê-Bury
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Yersinia Research Unit, 28 rue du Dr Roux, 75015 Paris, France
- Université Paris-Saclay, Inserm, CEA, Center for Immunology of Viral, Autoimmune, Hematological and Bacterial Diseases (IMVA-HB/IDMIT), 18 route du Panorama, 92260 Fontenay-aux-Roses, France
| | - Hebert Echenique-Rivera
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Yersinia Research Unit, 28 rue du Dr Roux, 75015 Paris, France
| | - Javier Pizarro-Cerdá
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Yersinia Research Unit, 28 rue du Dr Roux, 75015 Paris, France
- Institut Pasteur, Université Paris Cité, Yersinia National Reference Laboratory, WHO Collaborating Research & Reference Centre for Plague FRA-146, 28 rue du Dr Roux, 75015 Paris, France
| | - Olivier Dussurget
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Yersinia Research Unit, 28 rue du Dr Roux, 75015 Paris, France
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Agaras BC, Grossi CEM, Ulloa RM. Unveiling the Secrets of Calcium-Dependent Proteins in Plant Growth-Promoting Rhizobacteria: An Abundance of Discoveries Awaits. PLANTS (BASEL, SWITZERLAND) 2023; 12:3398. [PMID: 37836138 PMCID: PMC10574481 DOI: 10.3390/plants12193398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 09/20/2023] [Accepted: 09/22/2023] [Indexed: 10/15/2023]
Abstract
The role of Calcium ions (Ca2+) is extensively documented and comprehensively understood in eukaryotic organisms. Nevertheless, emerging insights, primarily derived from studies on human pathogenic bacteria, suggest that this ion also plays a pivotal role in prokaryotes. In this review, our primary focus will be on unraveling the intricate Ca2+ toolkit within prokaryotic organisms, with particular emphasis on its implications for plant growth-promoting rhizobacteria (PGPR). We undertook an in silico exploration to pinpoint and identify some of the proteins described in the existing literature, including prokaryotic Ca2+ channels, pumps, and exchangers that are responsible for regulating intracellular Calcium concentration ([Ca2+]i), along with the Calcium-binding proteins (CaBPs) that play a pivotal role in sensing and transducing this essential cation. These investigations were conducted in four distinct PGPR strains: Pseudomonas chlororaphis subsp. aurantiaca SMMP3, P. donghuensis SVBP6, Pseudomonas sp. BP01, and Methylobacterium sp. 2A, which have been isolated and characterized within our research laboratories. We also present preliminary experimental data to evaluate the influence of exogenous Ca2+ concentrations ([Ca2+]ex) on the growth dynamics of these strains.
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Affiliation(s)
- Betina Cecilia Agaras
- Laboratory of Physiology and Genetics of Plant Probiotic Bacteria (LFGBBP), Centre of Biochemistry and Microbiology of Soils, National University of Quilmes, Bernal B1876BXD, Argentina
- National Scientific and Technical Research Council (CONICET), Buenos Aires C1425FQB, Argentina;
| | - Cecilia Eugenia María Grossi
- National Scientific and Technical Research Council (CONICET), Buenos Aires C1425FQB, Argentina;
- Laboratory of Plant Signal Transduction, Institute of Genetic Engineering and Molecular Biology (INGEBI), National Scientific and Technical Research Council (CONICET), Buenos Aires C1425FQB, Argentina
| | - Rita María Ulloa
- National Scientific and Technical Research Council (CONICET), Buenos Aires C1425FQB, Argentina;
- Laboratory of Plant Signal Transduction, Institute of Genetic Engineering and Molecular Biology (INGEBI), National Scientific and Technical Research Council (CONICET), Buenos Aires C1425FQB, Argentina
- Biochemistry Department, Faculty of Exact and Natural Sciences, University of Buenos Aires (FCEN-UBA), Buenos Aires C1428EGA, Argentina
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3
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He Y, Pan J, Huang D, Sanford RA, Peng S, Wei N, Sun W, Shi L, Jiang Z, Jiang Y, Hu Y, Li S, Li Y, Li M, Dong Y. Distinct microbial structure and metabolic potential shaped by significant environmental gradient impacted by ferrous slag weathering. ENVIRONMENT INTERNATIONAL 2023; 178:108067. [PMID: 37393724 DOI: 10.1016/j.envint.2023.108067] [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: 04/03/2023] [Revised: 06/23/2023] [Accepted: 06/25/2023] [Indexed: 07/04/2023]
Abstract
Alkaline ferrous slags pose global environmental issues and long-term risks to ambient environments. To explore the under-investigated microbial structure and biogeochemistry in such unique ecosystems, combined geochemical, microbial, ecological and metagenomic analyses were performed in the areas adjacent to a ferrous slag disposal plant in Sichuan, China. Different levels of exposure to ultrabasic slag leachate had resulted in a significant geochemical gradient of pH (8.0-12.4), electric potential (-126.9 to 437.9 mV), total organic carbon (TOC, 1.5-17.3 mg/L), and total nitrogen (TN, 0.17-1.01 mg/L). Distinct microbial communities were observed depending on their exposure to the strongly alkaline leachate. High pH and Ca2+ concentrations were associated with low microbial diversity and enrichment of bacterial classes Gamma-proteobacteria and Deinococci in the microbial communities exposed to the leachate. Combined metagenomic analyses of 4 leachate-unimpacted and 2-impacted microbial communities led to the assembly of one Serpentinomonas pangenome and 81 phylogenetically diversified metagenome assembled genomes (MAGs). The prevailing taxa in the leachate-impacted habitats (e.g., Serpentinomonas and Meiothermus spp.) were phylogenetically related to those in active serpentinizing ecosystems, suggesting the analogous processes between the man-made and natural systems. More importantly, they accounted for significant abundance of most functional genes associated with environmental adaptation and major element cycling. Their metabolic potential (e.g., cation/H+ antiporters, carbon fixation on lithospheric carbon source, and respiration coupling sulfur oxidization and oxygen or nitrate reduction) may support these taxa to survive and prosper in these unique geochemical niches. This study provides fundamental understandings of the adaptive strategies of microorganisms in response to the strong environmental perturbation by alkali tailings. It also contributes to a better comprehension of how to remediate environments affected by alkaline industrial material.
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Affiliation(s)
- Yu He
- School of Environmental Studies, China University of Geosciences, China
| | - Jie Pan
- Archaeal Biology Center, Institute for Advanced Studies, Shenzhen University, China; Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, China
| | - Dongmei Huang
- School of Environmental Studies, China University of Geosciences, China; Yejin Geological Team of Hubei Geological Bureau, China
| | - Robert A Sanford
- Department of Earth Science & Environmental Change, University of Illinois Urbana-Champaign, Champaign, IL, United States
| | - Shuming Peng
- Institute of Ecological Environment, Chengdu University of Technology, China
| | - Na Wei
- Department of Civil and Environmental Engineering, University of Illinois Urbana-Champaign, Champaign, IL, United States
| | - Weimin Sun
- Guangdong Institute of Eco-environmental and Soil Science, Guangdong, China
| | - Liang Shi
- School of Environmental Studies, China University of Geosciences, China; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, China; State Environmental Protection Key Laboratory of Source Apportionment and Control of Aquatic Pollution, Ministry of Ecology and Environment, China
| | - Zhou Jiang
- School of Environmental Studies, China University of Geosciences, China
| | - Yongguang Jiang
- School of Environmental Studies, China University of Geosciences, China
| | - Yidan Hu
- School of Environmental Studies, China University of Geosciences, China
| | - Shuyi Li
- School of Environmental Studies, China University of Geosciences, China
| | - Yongzhe Li
- School of Environmental Studies, China University of Geosciences, China
| | - Meng Li
- Archaeal Biology Center, Institute for Advanced Studies, Shenzhen University, China; Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, China.
| | - Yiran Dong
- School of Environmental Studies, China University of Geosciences, China; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, China; State Environmental Protection Key Laboratory of Source Apportionment and Control of Aquatic Pollution, Ministry of Ecology and Environment, China; Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, China; Hubei Key Laboratory of Wetland Evolution and Ecology Restoration, China.
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4
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Niu W, Zhou W, Lu S, Vu T, Jayaraman V, Faraldo-Gómez JD, Zheng L. Ca 2+ efflux facilitated by co-transport of inorganic phosphate anion in the H +/Ca 2+ antiporter YfkE. Commun Biol 2023; 6:573. [PMID: 37248347 PMCID: PMC10227063 DOI: 10.1038/s42003-023-04944-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 05/15/2023] [Indexed: 05/31/2023] Open
Abstract
Ca2+ is an important signaling messenger. In microorganisms, fungi, and plants, H+/Ca2+ antiporters (CAX) are known to play key roles in the homeostasis of intracellular Ca2+ by catalyzing its efflux across the cell membrane. Here, we reveal that the bacterial CAX homolog YfkE transports Ca2+ in two distinct modes: a low-flux H+/Ca2+ exchange mode and a high-flux mode in which Ca2+ and phosphate ions are co-transported (1:1) in exchange for H+. Coupling with phosphate greatly accelerates the Ca2+ efflux activity of YfkE. Our studies reveal that Ca2+ and phosphate bind to adjacent sites in a central translocation pathway and lead to mechanistic insights that explain how this CAX alters its conserved alpha-repeat motifs to adopt phosphate as a specific "transport chaperon" for Ca2+ translocation. This finding uncovers a co-transport mechanism within the CAX family that indicates this class of proteins contributes to the cellular homeostasis of both Ca2+ and phosphate.
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Affiliation(s)
- Wei Niu
- Department of Biochemistry and Molecular Biology, Center for Membrane Biology, the University of Texas Health Science Center at Houston McGovern Medical School, Houston, TX, USA
| | - Wenchang Zhou
- Theoretical Molecular Biophysics Laboratory, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Shuo Lu
- Department of Biochemistry and Molecular Biology, Center for Membrane Biology, the University of Texas Health Science Center at Houston McGovern Medical School, Houston, TX, USA
| | - Trung Vu
- Department of Biochemistry and Molecular Biology, Center for Membrane Biology, the University of Texas Health Science Center at Houston McGovern Medical School, Houston, TX, USA
| | - Vasanthi Jayaraman
- Department of Biochemistry and Molecular Biology, Center for Membrane Biology, the University of Texas Health Science Center at Houston McGovern Medical School, Houston, TX, USA
| | - José D Faraldo-Gómez
- Theoretical Molecular Biophysics Laboratory, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA.
| | - Lei Zheng
- Department of Biochemistry and Molecular Biology, Center for Membrane Biology, the University of Texas Health Science Center at Houston McGovern Medical School, Houston, TX, USA.
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5
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Dao TH, Iverson A, Neville SL, Johnson MDL, McDevitt CA, Rosch JW. The role of CopA in Streptococcus pyogenes copper homeostasis and virulence. J Inorg Biochem 2023; 240:112122. [PMID: 36639322 PMCID: PMC10161136 DOI: 10.1016/j.jinorgbio.2023.112122] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 01/03/2023] [Accepted: 01/04/2023] [Indexed: 01/09/2023]
Abstract
Maintenance of intracellular metal homeostasis during interaction with host niches is critical to the success of bacterial pathogens. To prevent infection, the mammalian innate immune response employs metal-withholding and metal-intoxication mechanisms to limit bacterial propagation. The first-row transition metal ion copper serves critical roles at the host-pathogen interface and has been associated with antimicrobial activity since antiquity. Despite lacking any known copper-utilizing proteins, streptococci have been reported to accumulate significant levels of copper. Here, we report that loss of CopA, a copper-specific exporter, confers increased sensitivity to copper in Streptococcus pyogenes strain HSC5, with prolonged exposure to physiological levels of copper resulting in reduced viability during stationary phase cultivation. This defect in stationary phase survival was rescued by supplementation with exogeneous amino acids, indicating the pathogen had altered nutritional requirements during exposure to copper stress. Furthermore, S. pyogenes HSC5 ΔcopA was substantially attenuated during murine soft-tissue infection, demonstrating the importance of copper efflux at the host-pathogen interface. Collectively, these data indicate that copper can severely reduce the viability of stationary phase S. pyogenes and that active efflux mechanisms are required to survive copper stress in vitro and during infection.
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Affiliation(s)
- Tina H Dao
- St. Jude Children's Research Hospital, Department of Infectious Diseases, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Amy Iverson
- St. Jude Children's Research Hospital, Department of Infectious Diseases, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Stephanie L Neville
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria 3000, Australia
| | - Michael D L Johnson
- St. Jude Children's Research Hospital, Department of Infectious Diseases, 262 Danny Thomas Place, Memphis, TN 38105, USA; Department of Immunobiology, BIO5 Institute, Valley Fever Center for Excellence, and Asthma and Airway Disease Research Center, University of Arizona College of Medicine - Tucson, Tucson, AZ 85724, USA
| | - Christopher A McDevitt
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria 3000, Australia
| | - Jason W Rosch
- St. Jude Children's Research Hospital, Department of Infectious Diseases, 262 Danny Thomas Place, Memphis, TN 38105, USA.
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6
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The Activity of Calcium Glycerophosphate and Fluoride against Cariogenic Biofilms of Streptococcus mutans and Candida albicans Formed In Vitro. Antibiotics (Basel) 2023; 12:antibiotics12020422. [PMID: 36830332 PMCID: PMC9952171 DOI: 10.3390/antibiotics12020422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 01/03/2023] [Accepted: 01/06/2023] [Indexed: 02/25/2023] Open
Abstract
This study evaluated the effects of calcium glycerophosphate (CaGP), with or without fluoride (F), on dual-species biofilms of Streptococcus mutans and Candida albicans. The biofilms were treated three times with 0.125, 0.25, and 0.5% CaGP solutions, with or without 500 ppm F (NaF). Additionally, 500 and 1100 ppm F-solutions and artificial saliva served as controls. After the final treatment, the microbial viability and biofilm structure, metabolic activity, total biomass production, and the composition of the extracellular matrix composition were analyzed. Regardless of the presence of F, 0.25 and 0.5% CaGP promoted a higher biomass production and metabolic activity increase than the controls (p < 0.05). F-free CaGP solutions reduced bacterial cell population significantly more than the 500 ppm F group or the negative control (p < 0.05). All the groups reduced the proteins, and 0.5% CaGP combined with F led to the highest reduction in the carbohydrate and nucleic acids content of the extracellular matrix (p < 0.05). It can be concluded that CaGP alone affected the number of bacterial cells and, when combined with F, reduced its production of biomass, metabolic activity, and the expression of the extracellular matrix components.
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7
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Molina Hernandez JB, Scotti L, Valbonetti L, Gioia L, Paparella A, Paludi D, Aceto A, Ciriolo MR, Chaves Lopez C. Effect of membrane depolarization against Aspergillus niger GM31 resistant by ultra nanoclusters characterized by Ag 2+ and Ag 3+ oxidation state. Sci Rep 2023; 13:2716. [PMID: 36792916 PMCID: PMC9932144 DOI: 10.1038/s41598-023-29918-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 02/13/2023] [Indexed: 02/17/2023] Open
Abstract
To date, the impossibility of treating resistant forms of bacteria and fungi (AMR) with traditional drugs is a cause for global alarm. We have made the green synthesis of Argirium silver ultra nanoclusters (Argirium-SUNCs) very effective against resistant bacteria (< 1 ppm) and mature biofilm (0.6 ppm). In vitro and preclinical tests indicate that SUNCs are approximately 10 times less toxic in human cells than bacteria. Unique chemical-physical characteristics such as particle size < 2 nm, a core composed of Ag0, and a shell of Ag +, Ag2+ , Ag3+ never observed before in stable form in ultra pure water, explain their remarkable redox properties Otto Cars (Lancet Glob. Health 9:6, 2021). Here we show that Argirium-SUNCs have strong antimicrobial properties also against resistant Aspergillus niger GM31 mycelia and spore inactivation (0.6 ppm). The membrane depolarization is a primary target leading to cell death as already observed in bacteria. Being effective against both bacteria and fungi Argirium-SUNCs represent a completely different tool for the treatment of infectious diseases.
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Affiliation(s)
- Junior Bernardo Molina Hernandez
- grid.17083.3d0000 0001 2202 794XFaculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Teramo, Italy
| | - Luca Scotti
- Department of Medical, Oral and Biotechnological Sciences, "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy.
| | - Luca Valbonetti
- grid.17083.3d0000 0001 2202 794XFaculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Teramo, Italy
| | - Luisa Gioia
- grid.17083.3d0000 0001 2202 794XFaculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Teramo, Italy
| | - Antonello Paparella
- grid.17083.3d0000 0001 2202 794XFaculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Teramo, Italy
| | - Domenico Paludi
- grid.17083.3d0000 0001 2202 794XFaculty of Veterinary Medicine, University of Teramo, Teramo, Italy
| | - Antonio Aceto
- grid.412451.70000 0001 2181 4941Department of Medical, Oral and Biotechnological Sciences, “G. d’Annunzio” University of Chieti-Pescara, Chieti, Italy
| | - Maria Rosa Ciriolo
- grid.6530.00000 0001 2300 0941Department of Biology, University of Rome “Tor Vergata”, Via della Ricerca Scientifica 1, 00133 Rome, Italy
| | - Clemencia Chaves Lopez
- grid.17083.3d0000 0001 2202 794XFaculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Teramo, Italy
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Abstract
Living systems are built from a small subset of the atomic elements, including the bulk macronutrients (C,H,N,O,P,S) and ions (Mg,K,Na,Ca) together with a small but variable set of trace elements (micronutrients). Here, we provide a global survey of how chemical elements contribute to life. We define five classes of elements: those that are (i) essential for all life, (ii) essential for many organisms in all three domains of life, (iii) essential or beneficial for many organisms in at least one domain, (iv) beneficial to at least some species, and (v) of no known beneficial use. The ability of cells to sustain life when individual elements are absent or limiting relies on complex physiological and evolutionary mechanisms (elemental economy). This survey of elemental use across the tree of life is encapsulated in a web-based, interactive periodic table that summarizes the roles chemical elements in biology and highlights corresponding mechanisms of elemental economy.
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Affiliation(s)
- Kaleigh A Remick
- Department of Microbiology, Cornell University, New York, NY, United States
| | - John D Helmann
- Department of Microbiology, Cornell University, New York, NY, United States.
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9
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Cao Z, Cui L, Liu Q, Liu F, Zhao Y, Guo K, Hu T, Zhang F, Sheng X, Wang X, Peng Z, Dai M. Phenotypic and Genotypic Characterization of Multidrug-Resistant Enterobacter hormaechei Carrying qnrS Gene Isolated from Chicken Feed in China. Microbiol Spectr 2022; 10:e0251821. [PMID: 35467399 PMCID: PMC9241693 DOI: 10.1128/spectrum.02518-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 03/27/2022] [Indexed: 11/20/2022] Open
Abstract
Multidrug resistance (MDR) in Enterobacteriaceae including resistance to quinolones is rising worldwide. The plasmid-mediated quinolone resistance (PMQR) gene qnrS is prevalent in Enterobacteriaceae. However, the qnrS gene is rarely found in Enterobacter hormaechei (E. hormaechei). Here, we reported one multidrug resistant E. hormaechei strain M1 carrying the qnrS1 and blaTEM-1 genes. This study was to analyze the characteristics of MDR E. hormaechei strain M1. The E. hormaechei strain M1 was identified as Enterobacter cloacae complex by biochemical assay and 16S rRNA sequencing. The whole genome was sequenced by the Oxford Nanopore method. Taxonomy of the E. hormaechei was based on multilocus sequence typing (MLST). The qnrS with the other antibiotic resistance genes were coexisted on IncF plasmid (pM1). Besides, the virulence factors associated with pathogenicity were also located on pM1. The qnrS1 gene was located between insertion element IS2A (upstream) and transposition element ISKra4 (downstream). The comparison result of IncF plasmids revealed that they had a common plasmid backbone. Susceptibility experiment revealed that the E. hormaechei M1 showed extensive resistance to the clinical antimicrobials. The conjugation transfer was performed by filter membrane incubation method. The competition and plasmid stability assays suggested the host bacteria carrying qnrS had an energy burden. As far as we know, this is the first report that E. hormaechei carrying qnrS was isolated from chicken feed. The chicken feed and poultry products could serve as a vehicle for these MDR bacteria, which could transfer between animals and humans through the food chain. We need to pay close attention to the epidemiology of E. hormaechei and prevent their further dissemination. IMPORTANCE Enterobacter hormaechei is an opportunistic pathogen. It can cause infections in humans and animals. Plasmid-mediated quinolone resistance (PMQR) gene qnrS can be transferred intergenus, which is leading to increase the quinolone resistance levels in Enterobacteriaceae. Chicken feed could serve as a vehicle for the MDR E. hormaechei. Therefore, antibiotic-resistance genes (ARGs) might be transferred to the intestinal flora after entering the gastrointestinal tract with the feed. Furthermore, antibiotic-resistant bacteria (ARB) were also excreted into environment with feces, posing a huge threat to public health. This requires us to monitor the ARB and antibiotic-resistant plasmids in the feed. Here, we demonstrated the characteristics of one MDR E. hormaechei isolate from chicken feed. The plasmid carrying the qnrS gene is a conjugative plasmid with transferability. The presence of plasmid carrying antibiotic-resistance genes requires the maintenance of antibiotic pressure. In addition, the E. hormaechei M1 belonged to new sequence type (ST). These data show the MDR E. hormaechei M1 is a novel strain that requires our further research.
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Affiliation(s)
- Zhengzheng Cao
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
- MOA Key Laboratory of Food Safety Evaluation/National Reference Laboratory of Veterinary Drug Residue (HZAU), Huazhong Agricultural University, Wuhan, China
| | - Luqing Cui
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
- MOA Key Laboratory of Food Safety Evaluation/National Reference Laboratory of Veterinary Drug Residue (HZAU), Huazhong Agricultural University, Wuhan, China
| | - Quan Liu
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
- MOA Key Laboratory of Food Safety Evaluation/National Reference Laboratory of Veterinary Drug Residue (HZAU), Huazhong Agricultural University, Wuhan, China
| | - Fangjia Liu
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
- MOA Key Laboratory of Food Safety Evaluation/National Reference Laboratory of Veterinary Drug Residue (HZAU), Huazhong Agricultural University, Wuhan, China
| | - Yue Zhao
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
- MOA Key Laboratory of Food Safety Evaluation/National Reference Laboratory of Veterinary Drug Residue (HZAU), Huazhong Agricultural University, Wuhan, China
| | - Kaixuan Guo
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
- MOA Key Laboratory of Food Safety Evaluation/National Reference Laboratory of Veterinary Drug Residue (HZAU), Huazhong Agricultural University, Wuhan, China
| | - Tianyu Hu
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
- MOA Key Laboratory of Food Safety Evaluation/National Reference Laboratory of Veterinary Drug Residue (HZAU), Huazhong Agricultural University, Wuhan, China
| | - Fan Zhang
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
- MOA Key Laboratory of Food Safety Evaluation/National Reference Laboratory of Veterinary Drug Residue (HZAU), Huazhong Agricultural University, Wuhan, China
| | - Xijing Sheng
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
- MOA Key Laboratory of Food Safety Evaluation/National Reference Laboratory of Veterinary Drug Residue (HZAU), Huazhong Agricultural University, Wuhan, China
| | - Xiangru Wang
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Zhong Peng
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
| | - Menghong Dai
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
- MOA Key Laboratory of Food Safety Evaluation/National Reference Laboratory of Veterinary Drug Residue (HZAU), Huazhong Agricultural University, Wuhan, China
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10
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The ctpF Gene Encoding a Calcium P-Type ATPase of the Plasma Membrane Contributes to Full Virulence of Mycobacterium tuberculosis. Int J Mol Sci 2022; 23:ijms23116015. [PMID: 35682696 PMCID: PMC9180918 DOI: 10.3390/ijms23116015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 05/22/2022] [Accepted: 05/24/2022] [Indexed: 12/04/2022] Open
Abstract
Identification of alternative attenuation targets of Mycobacterium tuberculosis (Mtb) is pivotal for designing new candidates for live attenuated anti-tuberculosis (TB) vaccines. In this context, the CtpF P-type ATPase of Mtb is an interesting target; specifically, this plasma membrane enzyme is involved in calcium transporting and response to oxidative stress. We found that a mutant of MtbH37Rv lacking ctpF expression (MtbΔctpF) displayed impaired proliferation in mouse alveolar macrophages (MH-S) during in vitro infection. Further, the levels of tumor necrosis factor and interferon-gamma in MH-S cells infected with MtbΔctpF were similar to those of cells infected with the parental strain, suggesting preservation of the immunogenic capacity. In addition, BALB/c mice infected with Mtb∆ctpF showed median survival times of 84 days, while mice infected with MtbH37Rv survived 59 days, suggesting reduced virulence of the mutant strain. Interestingly, the expression levels of ctpF in a mouse model of latent TB were significantly higher than in a mouse model of progressive TB, indicating that ctpF is involved in Mtb persistence in the dormancy state. Finally, the possibility of complementary mechanisms that counteract deficiencies in Ca2+ transport mediated by P-type ATPases is suggested. Altogether, our results demonstrate that CtpF could be a potential target for Mtb attenuation.
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Machine Learning Establishes Single-Cell Calcium Dynamics as an Early Indicator of Antibiotic Response. Microorganisms 2021; 9:microorganisms9051000. [PMID: 34063175 PMCID: PMC8148219 DOI: 10.3390/microorganisms9051000] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/28/2021] [Accepted: 04/30/2021] [Indexed: 11/17/2022] Open
Abstract
Changes in bacterial physiology necessarily precede cell death in response to antibiotics. Herein we investigate the early disruption of Ca2+ homeostasis as a marker for antibiotic response. Using a machine learning framework, we quantify the temporal information encoded in single-cell Ca2+ dynamics. We find Ca2+ dynamics distinguish kanamycin sensitive and resistant cells before changes in gross cell phenotypes such as cell growth or protein stability. The onset time (pharmacokinetics) and probability (pharmacodynamics) of these aberrant Ca2+ dynamics are dose and time-dependent, even at the resolution of single-cells. Of the compounds profiled, we find Ca2+ dynamics are also an indicator of Polymyxin B activity. In Polymyxin B treated cells, we find aberrant Ca2+ dynamics precedes the entry of propidium iodide marking membrane permeabilization. Additionally, we find modifying membrane voltage and external Ca2+ concentration alters the time between these aberrant dynamics and membrane breakdown suggesting a previously unappreciated role of Ca2+ in the membrane destabilization during Polymyxin B treatment. In conclusion, leveraging live, single-cell, Ca2+ imaging coupled with machine learning, we have demonstrated the discriminative capacity of Ca2+ dynamics in identifying antibiotic-resistant bacteria.
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12
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Hansen SB, Dyla M, Neumann C, Quistgaard EMH, Andersen JL, Kjaergaard M, Nissen P. The Crystal Structure of the Ca 2+-ATPase 1 from Listeria monocytogenes reveals a Pump Primed for Dephosphorylation. J Mol Biol 2021; 433:167015. [PMID: 33933469 DOI: 10.1016/j.jmb.2021.167015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 04/19/2021] [Accepted: 04/22/2021] [Indexed: 12/18/2022]
Abstract
Many bacteria export intracellular calcium using active transporters homologous to the sarco/endoplasmic reticulum Ca2+-ATPase (SERCA). Here we present three crystal structures of Ca2+-ATPase 1 from Listeria monocytogenes (LMCA1). Structures with BeF3- mimicking a phosphoenzyme state reveal a closed state, which is intermediate between the outward-open E2P and the proton-occluded E2-P* conformations known for SERCA. It suggests that LMCA1 in the E2P state is pre-organized for dephosphorylation upon Ca2+ release, consistent with the rapid dephosphorylation observed in single-molecule studies. An arginine side-chain occupies the position equivalent to calcium binding site I in SERCA, leaving a single Ca2+ binding site in LMCA1, corresponding to SERCA site II. Observing no putative transport pathways dedicated to protons, we infer a direct proton counter transport through the Ca2+ exchange pathways. The LMCA1 structures provide insight into the evolutionary divergence and conserved features of this important class of ion transporters.
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Affiliation(s)
- Sara Basse Hansen
- Department of Molecular Biology and Genetics, Aarhus University, Denmark; The Danish Research Institute for Translational Neuroscience (DANDRITE), Nordic EMBL Partnership for Molecular Medicine, Denmark
| | - Mateusz Dyla
- Department of Molecular Biology and Genetics, Aarhus University, Denmark; The Danish Research Institute for Translational Neuroscience (DANDRITE), Nordic EMBL Partnership for Molecular Medicine, Denmark
| | - Caroline Neumann
- Department of Molecular Biology and Genetics, Aarhus University, Denmark; The Danish Research Institute for Translational Neuroscience (DANDRITE), Nordic EMBL Partnership for Molecular Medicine, Denmark
| | - Esben Meldgaard Hoegh Quistgaard
- Department of Molecular Biology and Genetics, Aarhus University, Denmark; The Danish Research Institute for Translational Neuroscience (DANDRITE), Nordic EMBL Partnership for Molecular Medicine, Denmark
| | - Jacob Lauwring Andersen
- Department of Molecular Biology and Genetics, Aarhus University, Denmark; The Danish Research Institute for Translational Neuroscience (DANDRITE), Nordic EMBL Partnership for Molecular Medicine, Denmark
| | - Magnus Kjaergaard
- Department of Molecular Biology and Genetics, Aarhus University, Denmark; The Danish Research Institute for Translational Neuroscience (DANDRITE), Nordic EMBL Partnership for Molecular Medicine, Denmark; Aarhus Institute of Advanced Studies (AIAS), Denmark; The Danish National Research Foundation Center for Proteins in Memory (PROMEMO), Denmark
| | - Poul Nissen
- Department of Molecular Biology and Genetics, Aarhus University, Denmark; The Danish Research Institute for Translational Neuroscience (DANDRITE), Nordic EMBL Partnership for Molecular Medicine, Denmark; The Danish National Research Foundation Center for Proteins in Memory (PROMEMO), Denmark.
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13
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Effect of electroporation in a continuous flow system on bioaccumulation of magnesium, zinc and calcium ions in Lactobacillus rhamnosus B 442 cells. Bioelectrochemistry 2021; 140:107769. [PMID: 33631416 DOI: 10.1016/j.bioelechem.2021.107769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 01/21/2021] [Accepted: 02/03/2021] [Indexed: 11/23/2022]
Abstract
Biomass of Lactobacillus rhamnosus B 442 was subjected to the continuous electroporation using an electroporator with a flow chamber (length of 10 cm, distance between electrodes 0.25 cm, stream width 0.25 cm, flow speed 10 mL/min) to improve accumulation of calcium, magnesium and zinc in the cells. For all tested ions, the following parameters were applied: voltage of 250 V (E = 1 kV/cm), 570 V (E = 2.28 kV/cm), 950 V (E = 3.8 kV/cm), and 1400 V (E = 5.6 kV/cm, the positive control), a frequency of 10 Hz, a pulse width of 100 µs and 30 electrical pulses. The use of PEF increased the accumulation of magnesium, zinc and calcium by 39, 73 and 162%, respectively, compared to the control. Positive correlation was found between ion accumulation and membrane permeability for zinc and magnesium. For calcium, the initial increase in permeability resulted in higher ion accumulation, but with a further increase of this parameter at 3.8 kV/cm, its decrease was observed caused by a drop in cell viability. Total number of bacteria ranged from 1.67 × 108 (for the cultures supplemented with calcium) to 1.34 × 1012 cfu/mL (for the cultures supplemented with magnesium).
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14
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Genome-Wide Functional Screen for Calcium Transients in Escherichia coli Identifies Increased Membrane Potential Adaptation to Persistent DNA Damage. J Bacteriol 2021; 203:JB.00509-20. [PMID: 33199283 DOI: 10.1128/jb.00509-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 11/07/2020] [Indexed: 12/12/2022] Open
Abstract
Calcium plays numerous critical roles in signaling and homeostasis in eukaryotic cells. Far less is known about calcium signaling in bacteria than in eukaryotic cells, and few genes controlling influx and efflux have been identified. Previous work in Escherichia coli showed that calcium influx was induced by voltage depolarization, which was enhanced by mechanical stimulation, which suggested a role in bacterial mechanosensation. To identify proteins and pathways affecting calcium handling in bacteria, we designed a live-cell screen to monitor calcium dynamics in single cells across a genome-wide knockout panel in E. coli The screen measured cells from the Keio collection of knockouts and quantified calcium transients across the population. Overall, we found 143 gene knockouts that decreased levels of calcium transients and 32 gene knockouts that increased levels of transients. Knockouts of proteins involved in energy production and regulation appeared, as expected, as well as knockouts of proteins of a voltage sink, F1Fo-ATPase. Knockouts of exopolysaccharide and outer membrane synthesis proteins showed reduced transients which refined our model of electrophysiology-mediated mechanosensation. Additionally, knockouts of proteins associated with DNA repair had reduced calcium transients and voltage. However, acute DNA damage did not affect voltage, and the results suggested that only long-term adaptation to DNA damage decreased membrane potential and calcium transients. Our work showed a distinct separation between the acute and long-term DNA damage responses in bacteria, which also has implications for mitochondrial DNA damage in eukaryotes.IMPORTANCE All eukaryotic cells use calcium as a critical signaling molecule. There is tantalizing evidence that bacteria also use calcium for cellular signaling, but much less is known about the molecular actors and physiological roles. To identify genes regulating cytoplasmic calcium in Escherichia coli, we created a single-cell screen for modulators of calcium dynamics. The genes uncovered in this screen helped refine a model for voltage-mediated bacterial mechanosensation. Additionally, we were able to more carefully dissect the mechanisms of adaptation to long-term DNA damage, which has implications for both bacteria and mitochondria in the face of unrepaired DNA.
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15
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Setting the Stage: Genes Controlling Mechanosensation and Ca 2+ Signaling in Escherichia coli. J Bacteriol 2021; 203:JB.00595-20. [PMID: 33199281 DOI: 10.1128/jb.00595-20] [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] [Indexed: 11/20/2022] Open
Abstract
Although mechanistic understanding of calcium signaling in bacteria remains inchoate, current evidence clearly links Ca2+ signaling with membrane potential and mechanosensation. Adopting a radically new approach, Luder et al. scanned the Keio collection of Escherichia coli gene knockouts (R. Luder, G. N. Bruni, and J. M. Kralj, J Bacteriol 203:e00509-20, 2021, https://doi.org/10.1128/JB.00509-20) to identify mutations that cause changes in Ca2+ transients. They identify genes associating Ca2+ signaling with outer membrane biogenesis, proton motive force, and, surprisingly, long-term DNA damage. Their work has major implications for electrophysiological communication between bacteria and their environment.
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16
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Saravanan A, Maruthapandi M, Das P, Ganguly S, Margel S, Luong JHT, Gedanken A. Applications of N-Doped Carbon Dots as Antimicrobial Agents, Antibiotic Carriers, and Selective Fluorescent Probes for Nitro Explosives. ACS APPLIED BIO MATERIALS 2020; 3:8023-8031. [DOI: 10.1021/acsabm.0c01104] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Arumugam Saravanan
- Bar-Ilan Institute for Nanotechnology and Advanced Materials (BINA), Bar-Ilan University, Ramat-Gan, 5290002, Israel
- Department of Chemistry, Bar-Ilan University, Ramat-Gan, 5290002, Israel
| | - Moorthy Maruthapandi
- Bar-Ilan Institute for Nanotechnology and Advanced Materials (BINA), Bar-Ilan University, Ramat-Gan, 5290002, Israel
- Department of Chemistry, Bar-Ilan University, Ramat-Gan, 5290002, Israel
| | - Poushali Das
- Bar-Ilan Institute for Nanotechnology and Advanced Materials (BINA), Bar-Ilan University, Ramat-Gan, 5290002, Israel
- Department of Chemistry, Bar-Ilan University, Ramat-Gan, 5290002, Israel
| | - Sayan Ganguly
- Bar-Ilan Institute for Nanotechnology and Advanced Materials (BINA), Bar-Ilan University, Ramat-Gan, 5290002, Israel
- Department of Chemistry, Bar-Ilan University, Ramat-Gan, 5290002, Israel
| | - Shlomo Margel
- Bar-Ilan Institute for Nanotechnology and Advanced Materials (BINA), Bar-Ilan University, Ramat-Gan, 5290002, Israel
- Department of Chemistry, Bar-Ilan University, Ramat-Gan, 5290002, Israel
| | - John H. T. Luong
- School of Chemistry, University College Cork, Cork T12 YN60, Ireland
| | - Aharon Gedanken
- Bar-Ilan Institute for Nanotechnology and Advanced Materials (BINA), Bar-Ilan University, Ramat-Gan, 5290002, Israel
- Department of Chemistry, Bar-Ilan University, Ramat-Gan, 5290002, Israel
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17
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Liu X, Kimmey JM, Matarazzo L, de Bakker V, Van Maele L, Sirard JC, Nizet V, Veening JW. Exploration of Bacterial Bottlenecks and Streptococcus pneumoniae Pathogenesis by CRISPRi-Seq. Cell Host Microbe 2020; 29:107-120.e6. [PMID: 33120116 DOI: 10.1016/j.chom.2020.10.001] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 08/27/2020] [Accepted: 09/29/2020] [Indexed: 02/07/2023]
Abstract
Streptococcus pneumoniae is an opportunistic human pathogen that causes invasive diseases, including pneumonia, with greater health risks upon influenza A virus (IAV) co-infection. To facilitate pathogenesis studies in vivo, we developed an inducible CRISPR interference system that enables genome-wide fitness testing in one sequencing step (CRISPRi-seq). We applied CRISPRi-seq to assess bottlenecks and identify pneumococcal genes important in a murine pneumonia model. A critical bottleneck occurs at 48 h with few bacteria causing systemic infection. This bottleneck is not present during IAV superinfection, facilitating identification of pneumococcal pathogenesis-related genes. Top in vivo essential genes included purA, encoding adenylsuccinate synthetase, and the cps operon required for capsule production. Surprisingly, CRISPRi-seq indicated no fitness-related role for pneumolysin during superinfection. Interestingly, although metK (encoding S-adenosylmethionine synthetase) was essential in vitro, it was dispensable in vivo. This highlights advantages of CRISPRi-seq over transposon-based genetic screens, as all genes, including essential genes, can be tested for pathogenesis potential.
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Affiliation(s)
- Xue Liu
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Biophore Building, Lausanne 1015, Switzerland
| | - Jacqueline M Kimmey
- Division of Host-Microbe Systems and Therapeutics, Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, CA, USA; Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - Laura Matarazzo
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur Lille, U1019 - UMR 9017 - CIIL - Center for Infection and Immunity of Lille, F-59000 Lille, France
| | - Vincent de Bakker
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Biophore Building, Lausanne 1015, Switzerland
| | - Laurye Van Maele
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur Lille, U1019 - UMR 9017 - CIIL - Center for Infection and Immunity of Lille, F-59000 Lille, France
| | - Jean-Claude Sirard
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur Lille, U1019 - UMR 9017 - CIIL - Center for Infection and Immunity of Lille, F-59000 Lille, France
| | - Victor Nizet
- Division of Host-Microbe Systems and Therapeutics, Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, CA, USA; Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Jan-Willem Veening
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Biophore Building, Lausanne 1015, Switzerland.
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Garg R, Borbora SM, Bansia H, Rao S, Singh P, Verma R, Balaji KN, Nagaraja V. Mycobacterium tuberculosis Calcium Pump CtpF Modulates the Autophagosome in an mTOR-Dependent Manner. Front Cell Infect Microbiol 2020; 10:461. [PMID: 33042857 PMCID: PMC7525011 DOI: 10.3389/fcimb.2020.00461] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 07/28/2020] [Indexed: 12/17/2022] Open
Abstract
Calcium is a very important second messenger, whose concentration in various cellular compartments is under tight regulation. A disturbance in the levels of calcium in these compartments can play havoc in the cell, as it regulates various cellular processes by direct or indirect mechanisms. Here, we have investigated the functional importance of a calcium transporting P2A ATPase, CtpF of Mycobacterium tuberculosis (Mtb) in the pathogen's interaction with the host. Among its uncanny ways of dealing with the host with umpteen strategies for survival and persistence in humans, CtpF is identified as a new player. The levels of ctpF are upregulated in macrophage stresses like hypoxia, high nitric oxide levels and acidic pH. Using confocal microscopy and fluorimetry, we show that CtpF effluxes calcium in macrophages in early stages of Mtb infection. Downregulation of ctpF expression by conditional knockdown resulted in perturbation of host calcium levels and consequent decreased activation of mTOR. We present a mechanism how calcium efflux by the pathogen inhibits mTOR-dependent autophagy and enhances bacterial survival. Our work highlights how Mtb engages its metal efflux pumps to exploit host autophagic process for its proliferation.
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Affiliation(s)
- Rajni Garg
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India.,Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
| | - Salik Miskat Borbora
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Harsh Bansia
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Sandhya Rao
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Prakruti Singh
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Rinkee Verma
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | | | - Valakunja Nagaraja
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India.,Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
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19
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Rojas JJ, Vargas-Lagos C, Martínez D, Oyarzún-Salazar R, Pontigo JP, Morera F, Vargas-Chacoff L. Francisella noatunensis subsp. noatunensis triggers calcium metabolism gene modulation in Eleginops maclovinus. Comp Biochem Physiol A Mol Integr Physiol 2020; 250:110805. [PMID: 32927078 DOI: 10.1016/j.cbpa.2020.110805] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 08/10/2020] [Accepted: 09/07/2020] [Indexed: 11/30/2022]
Abstract
Francisella noatunensis subsp. noatunensis is the responsible agent of Francisellosis, a bacterial disease that affects an important amount of aquatic farmed species. Eleginops maclovinus is a fish that cohabits with salmonids cages in Chile and can also act as a vector of this bacterial disease. In the present study, we evaluated calcium metabolism in the liver of E. maclovinus injected intraperitoneally with different doses of F. noatunensis subsp. noatunensis (low 1.5 × 101, medium 1.5 × 105 and high doses 1.5 × 1010 cells/μL). Fish were sampled at 1, 3, 7, 14, 21 and 28 days post injection (dpi). No mortalities nor clinical signs were observed. Plasma calcium levels were higher in the high doses group of F. noatunensis subsp. noatunensis at day 7 and 14 compared to the control group (fish injected with bacterial medium alone). Hypercalcemic factors increased at day 14 and 21 for the medium and low dose (parathyroid hormone-related protein precursor), while vitamin D3 receptor increased its expression at times 1, 3 and 7 for the low dose. On the other hand, hypocalcemic factors such as calcitonin receptor and stanniocalcin increased its expression at time 7 and 14, respectively. Calmodulin involved in calcium storage decreased its expression during all experimental days in fish subjected to high bacterial dose. Proteins involved in calcium transport, such as L-type voltage-gated calcium channel and trpv5 increased their transcription at day 1 and 14, compared to calcium sensing-receptor and plasma membrane Ca2 +- ATPase that showed peak expression at times 14 and 28. The results suggest a clear alteration of calcium metabolism, mainly in high bacterial doses. This study provides new knowledge about the calcium metabolism in fish infected with bacteria.
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Affiliation(s)
- Juan José Rojas
- Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile; Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile; Centro FONDAP-IDEAL, Universidad Austral de Chile, Valdivia, Chile.
| | - Carolina Vargas-Lagos
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile; Centro FONDAP-IDEAL, Universidad Austral de Chile, Valdivia, Chile
| | - Danixa Martínez
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile; Centro FONDAP-IDEAL, Universidad Austral de Chile, Valdivia, Chile
| | - Ricardo Oyarzún-Salazar
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile; Centro FONDAP-IDEAL, Universidad Austral de Chile, Valdivia, Chile; Universidad Austral de Chile, Puerto Montt, Chile
| | - Juan Pablo Pontigo
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile; Laboratorio de Biotecnología Aplicada, Facultad de Medicina Veterinaria, Universidad San Sebastián, Puerto Montt, Chile
| | - Francisco Morera
- Instituto de Farmacología y Morfofisiología, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Luis Vargas-Chacoff
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile; Centro FONDAP-IDEAL, Universidad Austral de Chile, Valdivia, Chile.
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20
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Maruthapandi M, Sharma K, Luong JHT, Gedanken A. Antibacterial activities of microwave-assisted synthesized polypyrrole/chitosan and poly (pyrrole-N-(1-naphthyl) ethylenediamine) stimulated by C-dots. Carbohydr Polym 2020; 243:116474. [PMID: 32532398 DOI: 10.1016/j.carbpol.2020.116474] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Revised: 05/10/2020] [Accepted: 05/16/2020] [Indexed: 11/26/2022]
Abstract
Polypyrrole grafted with chitosan (PPy-g-CS) and poly (pyrrole-N-(1-naphthyl) ethylenediamine, a copolymer, (COP) have been synthesized by a one-step microwave procedure with carbon dots(C-Dots) as initiators. The electrostatic interaction between the positively charged polymers and negatively charged microbial cell membranes is widely anticipated to be responsible for cellular lysis. However, Escherichia coli exposed to PPy-g-CS (zeta potential = +46.9 mV) was completely perished after 3 h while COP (zeta potential = +64.1 mV) exhibited no antimicrobial effect. The two polymers were capable of eradicating Staphylococcus aureus, implying the charged effect is the main mechanism of cell death. The two polymers could also chelate calcium and other nutrients as well as form an external barrier to suppress the penetration of essential nutrients to support microbial survival and proliferation. In particular, pyrrole grafted chitosan was reasoned to stack onto the bacterial surface to impede the mass transfer and suppress the bacterial metabolic activity. The binding of chitosan to teichoic acids, essential acids of Gram-positive bacteria, would provoke a sequence of events and lead to bacterial death.
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Affiliation(s)
- Moorthy Maruthapandi
- Bar-Ilan Institute for Nanotechnology and Advanced Materials, Department of Chemistry, Bar-Ilan University, Ramat-Gan, 52900, Israel
| | - Kusha Sharma
- Bar-Ilan Institute for Nanotechnology and Advanced Materials, Department of Chemistry, Bar-Ilan University, Ramat-Gan, 52900, Israel
| | | | - Aharon Gedanken
- Bar-Ilan Institute for Nanotechnology and Advanced Materials, Department of Chemistry, Bar-Ilan University, Ramat-Gan, 52900, Israel.
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Ma J, Veltman B, Tietel Z, Tsror L, Liu Y, Eltzov E. Monitoring of infection volatile markers using CMOS-based luminescent bioreporters. Talanta 2020; 219:121333. [PMID: 32887066 DOI: 10.1016/j.talanta.2020.121333] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 06/16/2020] [Accepted: 06/23/2020] [Indexed: 11/28/2022]
Abstract
Over the past two decades, whole-cell biosensors (WCBs) have been widely used in the environmental field, with only few applications proposed for use in agricultural. This study describes the development and optimization of a WCB for the detection of volatile organic compounds (VOCs) that is produced specifically by infected potato tubers. First, the effect of calcium-alginate matrix formation (beads vs. tablets) on the membrane uniformity and sensing efficiency was evaluated. Then, important parameters in the immobilization process were examined for their effect on the sensitivity to the presence of VOCs. The highest sensitivity to the target VOC was obtained by 20 min polymerization of bacterial suspension with optical density of 0.2 at 600 nm, dissolved in low-viscosity sodium alginate (1.5% w/v) and exposure to VOC at 4 °C. After optimization, the lowest limit of detection for three infection-sourced VOCs (nonanal, 3-methyl-1-butanol, and 1-octen-3-ol) was 0.17-, 2.03-, and 2.09-mg/L, respectively, and the sensor sensitivity was improved by 8.9-, 3.1- and 2-fold, respectively. Then, the new optimized immobilization protocol was implemented for the CMOS-based application, which increased the sensor sensitivity to VOC by 3-fold during real-time measurement. This is the first step in creating a sensor for real-time monitoring of crop quality by identifying changes in VOC patterns.
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Affiliation(s)
- Junning Ma
- Department of Postharvest Science, Institute of Postharvest and Food Sciences, The Volcani Center, Agricultural Research Organization, Bet Dagan, 50250, Israel; Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Boris Veltman
- Department of Postharvest Science, Institute of Postharvest and Food Sciences, The Volcani Center, Agricultural Research Organization, Bet Dagan, 50250, Israel; Institute of Biochemistry, Food Science and Nutrition, Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100, Israel
| | - Zipora Tietel
- Food Quality and Safety, Agricultural Research Organization, Gilat Research Center, MP Negev, Israel
| | - Leah Tsror
- Department of Plant Pathology, Institute of Plant Protection, Agricultural Research Organization, Gilat Research Center, Negev, Israel
| | - Yang Liu
- Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Evgeni Eltzov
- Department of Postharvest Science, Institute of Postharvest and Food Sciences, The Volcani Center, Agricultural Research Organization, Bet Dagan, 50250, Israel; Agro-Nanotechnology Research Center, Agriculture Research Organization, The Volcani Center, Rishon LeZion, 7505101, Israel.
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22
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Rules of Expansion: an Updated Consensus Operator Site for the CopR-CopY Family of Bacterial Copper Exporter System Repressors. mSphere 2020; 5:5/3/e00411-20. [PMID: 32461276 PMCID: PMC7253601 DOI: 10.1128/msphere.00411-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Many Gram-positive bacteria respond to copper stress by upregulating a copper export system controlled by a copper-sensitive repressor, CopR-CopY. The previous operator sequence for this family of proteins had been identified as TACANNTGTA. Here, using several recombinant proteins and mutations in various DNA fragments, we define those 10 bases as necessary but not sufficient for binding and in doing so, refine the cop operon operator to the 16-base sequence RNYKACANNTGTMRNY. Due to the sheer number of repressors that have been said to bind to the original 10 bases, including many antibiotic resistance repressors such as BlaI and MecI, we feel that this study highlights the need to reexamine many of these sites of the past and use added stringency for verifying operators in the future. Copper is broadly toxic to bacteria. As such, bacteria have evolved specialized copper export systems (cop operons) often consisting of a DNA-binding/copper-responsive regulator (which can be a repressor or activator), a copper chaperone, and a copper exporter. For those bacteria using DNA-binding copper repressors, few studies have examined the regulation of this operon regarding the operator DNA sequence needed for repressor binding. In Streptococcus pneumoniae (the pneumococcus), CopY is the copper repressor for the cop operon. Previously, homologs of pneumococcal CopY have been characterized to bind a 10-base consensus sequence T/GACANNTGTA known as the cop box. Using this motif, we sought to determine whether genes outside the cop operon are also regulated by the CopY repressor, which was previously shown in Lactococcus lactis. We found that S. pneumoniae CopY did not bind to cop operators upstream of these candidate genes in vitro. During this process, we found that the cop box sequence is necessary but not sufficient for CopY binding. Here, we propose an updated operator sequence for the S. pneumoniaecop operon to be ATTGACAAATGTAGAT binding CopY with a dissociation constant (Kd) of ∼28 nM. We demonstrate strong cross-species interaction between some CopY proteins and CopY operators, suggesting strong evolutionary conservation. Taken together with our binding studies and bioinformatics data, we propose the consensus operator RNYKACANNYGTMRNY for the bacterial CopR-CopY copper repressor homologs. IMPORTANCE Many Gram-positive bacteria respond to copper stress by upregulating a copper export system controlled by a copper-sensitive repressor, CopR-CopY. The previous operator sequence for this family of proteins had been identified as TACANNTGTA. Here, using several recombinant proteins and mutations in various DNA fragments, we define those 10 bases as necessary but not sufficient for binding and in doing so, refine the cop operon operator to the 16-base sequence RNYKACANNTGTMRNY. Due to the sheer number of repressors that have been said to bind to the original 10 bases, including many antibiotic resistance repressors such as BlaI and MecI, we feel that this study highlights the need to reexamine many of these sites of the past and use added stringency for verifying operators in the future.
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Waters LS. Bacterial manganese sensing and homeostasis. Curr Opin Chem Biol 2020; 55:96-102. [PMID: 32086169 PMCID: PMC9997548 DOI: 10.1016/j.cbpa.2020.01.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 12/11/2019] [Accepted: 01/14/2020] [Indexed: 12/17/2022]
Abstract
Manganese (Mn) plays a complex role in the survival of pathogenic and symbiotic bacteria in eukaryotic hosts and is also important for free-living bacteria to thrive in stressful environments. This review summarizes new aspects of regulatory strategies to control intracellular Mn levels and gives an overview of several newly identified families of bacterial Mn transporters. Recent illustrative examples of advances in quantification of intracellular Mn pools and characterization of the effects of Mn perturbations are highlighted. These discoveries help define mechanisms of Mn selectivity and toxicity and could enable new strategies to combat pathogenic bacteria and promote growth of desirable bacteria.
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Affiliation(s)
- Lauren S Waters
- Department of Chemistry, University of Wisconsin, Oshkosh, WI, 54901, USA.
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24
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King MM, Kayastha BB, Franklin MJ, Patrauchan MA. Calcium Regulation of Bacterial Virulence. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1131:827-855. [PMID: 31646536 DOI: 10.1007/978-3-030-12457-1_33] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Calcium (Ca2+) is a universal signaling ion, whose major informational role shaped the evolution of signaling pathways, enabling cellular communications and responsiveness to both the intracellular and extracellular environments. Elaborate Ca2+ regulatory networks have been well characterized in eukaryotic cells, where Ca2+ regulates a number of essential cellular processes, ranging from cell division, transport and motility, to apoptosis and pathogenesis. However, in bacteria, the knowledge on Ca2+ signaling is still fragmentary. This is complicated by the large variability of environments that bacteria inhabit with diverse levels of Ca2+. Yet another complication arises when bacterial pathogens invade a host and become exposed to different levels of Ca2+ that (1) are tightly regulated by the host, (2) control host defenses including immune responses to bacterial infections, and (3) become impaired during diseases. The invading pathogens evolved to recognize and respond to the host Ca2+, triggering the molecular mechanisms of adhesion, biofilm formation, host cellular damage, and host-defense resistance, processes enabling the development of persistent infections. In this review, we discuss: (1) Ca2+ as a determinant of a host environment for invading bacterial pathogens, (2) the role of Ca2+ in regulating main events of host colonization and bacterial virulence, and (3) the molecular mechanisms of Ca2+ signaling in bacterial pathogens.
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Affiliation(s)
- Michelle M King
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | - Biraj B Kayastha
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | - Michael J Franklin
- Department of Microbiology and Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA
| | - Marianna A Patrauchan
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA.
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25
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Identification of Mycobacterium tuberculosis CtpF as a target for designing new antituberculous compounds. Bioorg Med Chem 2019; 28:115256. [PMID: 31879181 DOI: 10.1016/j.bmc.2019.115256] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 12/04/2019] [Accepted: 12/06/2019] [Indexed: 01/08/2023]
Abstract
The emergence of tuberculosis (TB) produced by multi-drug resistance (MDR) and extensively-drug resistance (XDR) Mycobacterium tuberculosis (Mtb), encourages the development of new antituberculous compounds, as well as the identification of novel drug targets. In this regard, plasma membrane P-type ATPases are interesting targets because they play a crucial role in ion homeostasis and mycobacterial survival. We focused on Mtb CtpF, a calcium P-type ATPase that responds to a broad number of intraphagosomal conditions, as a novel target. In this study, we evaluated the capacity of cyclopiazonic acid (CPA), a well-known inhibitor of the sarco-endoplasmic reticulum Ca2+-ATPase (SERCA), to inhibit the ATPase activity of CtpF and the Mtb growth demonstrating that CtpF is a druggable target. A homology modeling of CtpF was generated for molecular docking studies of CtpF with CPA and key pharmacophoric features were identified, which were used to perform a pharmacophore-based virtual screening of the ZINC database, and to identify CtpF inhibitor candidates. Molecular docking-based virtual screening and MM-BGSA calculations of candidates allowed identifying six compounds with the best binding energies. The compounds displayed in vitro minimum inhibitory concentrations (MIC) ranging from 50 to 100 μg/mL, growth inhibitions from 29.5 to 64.0% on Mtb, and inhibitions of Ca2+-dependent ATPase activity in Mtb membrane vesicles (IC50) ranging from 4.1 to 35.8 μM. The compound ZINC63908257 was the best candidate by displaying a MIC of 50 μg/mL and a Ca2+ P-type ATPase inhibition of 45% with IC50 = 4.4 μM. Overall, the results indicate that CtpF is a druggable target for designing new antituberculous compounds.
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26
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Maya-Hoyos M, Rosales C, Novoa-Aponte L, Castillo E, Soto CY. The P-type ATPase CtpF is a plasma membrane transporter mediating calcium efflux in Mycobacterium tuberculosis cells. Heliyon 2019; 5:e02852. [PMID: 31788573 PMCID: PMC6879984 DOI: 10.1016/j.heliyon.2019.e02852] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 10/29/2019] [Accepted: 11/08/2019] [Indexed: 11/25/2022] Open
Abstract
Among the 12 P-type ATPases encoded by the genome of Mycobacterium tuberculosis (Mtb), CtpF responds to the greatest number of stress conditions, including oxidative stress, hypoxia, and infection. CtpF is the mycobacterial homolog of the sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) of higher eukaryotes. Its expression is regulated by the global regulator of latency, DosR. However, the role that CtpF plays in the mycobacterial plasma membrane remains unknown. In this study, different functional analyses showed that CtpF is associated with calcium pumping from mycobacterial cells. Specifically, Mtb CtpF expression in Mycobacterium smegmatis cells prevents Ca2+ accumulation compared with wild type (WT) cells. In addition, plasma membrane vesicles from recombinant membranes, in which the direction of ion transport is inverted, accumulate more Ca2+ compared with vesicles obtained from the WT strain. This findings support the hypothesis that CtpF contributes to calcium efflux from mycobacterial cells. Accordingly, Mtb cells defective in ctpF (MtbΔctpF) accumulate more Ca2+ compared with WT cells, while the Ca2+-dependent ATPase activity is significantly lower in the mutant cells. Interestingly, the deletion of ctpF in Mtb impairs the tolerance of the bacteria to oxidative and nitrosative stress. Overall, our results indicate that CtpF is associated with calcium pumping from mycobacterial cells and the response to oxidative stress.
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Affiliation(s)
| | | | | | | | - Carlos Y. Soto
- Chemistry Department, Faculty of Sciences, Universidad Nacional de Colombia, Ciudad Universitaria, Bogotá, Colombia
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27
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Martin JE, Le MT, Bhattarai N, Capdevila DA, Shen J, Winkler ME, Giedroc DP. A Mn-sensing riboswitch activates expression of a Mn2+/Ca2+ ATPase transporter in Streptococcus. Nucleic Acids Res 2019; 47:6885-6899. [PMID: 31165873 PMCID: PMC6649816 DOI: 10.1093/nar/gkz494] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 05/08/2019] [Accepted: 05/31/2019] [Indexed: 12/27/2022] Open
Abstract
Maintaining manganese (Mn) homeostasis is important for the virulence of numerous bacteria. In the human respiratory pathogen Streptococcus pneumoniae, the Mn-specific importer PsaBCA, exporter MntE, and transcriptional regulator PsaR establish Mn homeostasis. In other bacteria, Mn homeostasis is controlled by yybP-ykoY family riboswitches. Here, we characterize a yybP-ykoY family riboswitch upstream of the mgtA gene encoding a PII-type ATPase in S. pneumoniae, suggested previously to function in Ca2+ efflux. We show that the mgtA riboswitch aptamer domain adopts a canonical yybP-ykoY structure containing a three-way junction that is compacted in the presence of Ca2+ or Mn2+ at a physiological Mg2+ concentration. Although Ca2+ binds to the RNA aptamer with higher affinity than Mn2+, in vitro activation of transcription read-through of mgtA by Mn2+ is much greater than by Ca2+. Consistent with this result, mgtA mRNA and protein levels increase ≈5-fold during cellular Mn stress, but only in genetic backgrounds of S. pneumoniae and Bacillus subtilis that exhibit Mn2+ sensitivity, revealing that this riboswitch functions as a failsafe 'on' signal to prevent Mn2+ toxicity in the presence of high cellular Mn2+. In addition, our results suggest that the S. pneumoniae yybP-ykoY riboswitch functions to regulate Ca2+ efflux under these conditions.
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Affiliation(s)
- Julia E Martin
- Department of Biological Sciences, Idaho State University, Pocatello, ID 83209, USA
| | - My T Le
- Department of Cell Biology, Faculty of Biological Sciences, Vietnam National University, Hanoi, Vietnam
| | - Nabin Bhattarai
- Department of Biological Sciences, Idaho State University, Pocatello, ID 83209, USA
| | | | - Jiangchuan Shen
- Department of Cellular and Molecular Biochemistry, Indiana University, Bloomington, IN 47405, USA
| | - Malcolm E Winkler
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - David P Giedroc
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
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28
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Transcriptional activation by MafR, a global regulator of Enterococcus faecalis. Sci Rep 2019; 9:6146. [PMID: 30992530 PMCID: PMC6467988 DOI: 10.1038/s41598-019-42484-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 04/01/2019] [Indexed: 12/26/2022] Open
Abstract
Proteins that act as global transcriptional regulators play key roles in bacterial adaptation to new niches. These proteins recognize multiple DNA sites across the bacterial genome by different mechanisms. Enterococcus faecalis is able to survive in various niches of the human host, either as a commensal or as a leading cause of serious infections. Nonetheless, the regulatory pathways involved in its adaptive responses remain poorly understood. We reported previously that the MafR protein of E. faecalis causes genome-wide changes in the transcriptome. Here we demonstrate that MafR functions as a transcription activator. In vivo, MafR increased the activity of the P12294 and P11486 promoters and also the transcription levels of the two genes controlled by those promoters. These genes are predicted to encode a calcium-transporting P-type ATPase and a QueT transporter family protein, respectively. Thus, MafR could have a regulatory role in calcium homeostasis and queuosine synthesis. Furthermore, MafR recognized in vitro specific DNA sites that overlap the −35 element of each target promoter. The MafR binding sites exhibit a low sequence identity, suggesting that MafR uses a shape readout mechanism to achieve DNA-binding specificity.
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29
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D'Elia JA, Weinrauch LA. Calcium Ion Channels: Roles in Infection and Sepsis Mechanisms of Calcium Channel Blocker Benefits in Immunocompromised Patients at Risk for Infection. Int J Mol Sci 2018; 19:E2465. [PMID: 30134544 PMCID: PMC6164603 DOI: 10.3390/ijms19092465] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 08/08/2018] [Accepted: 08/14/2018] [Indexed: 01/08/2023] Open
Abstract
Immunosuppression may occur for a number of reasons related to an individual's frailty, debility, disease or from therapeutic iatrogenic intervention or misadventure. A large percentage of morbidity and mortality in immunodeficient populations is related to an inadequate response to infectious agents with slow response to antibiotics, enhancements of antibiotic resistance in populations, and markedly increased prevalence of acute inflammatory response, septic and infection related death. Given known relationships between intracellular calcium ion concentrations and cytotoxicity and cellular death, we looked at currently available data linking blockade of calcium ion channels and potential decrease in expression of sepsis among immunosuppressed patients. Notable are relationships between calcium, calcium channel, vitamin D mechanisms associated with sepsis and demonstration of antibiotic-resistant pathogens that may utilize channels sensitive to calcium channel blocker. We note that sepsis shock syndrome represents loss of regulation of inflammatory response to infection and that vitamin D, parathyroid hormone, fibroblast growth factor, and klotho interact with sepsis defense mechanisms in which movement of calcium and phosphorus are part of the process. Given these observations we consider that further investigation of the effect of relatively inexpensive calcium channel blockade agents of infections in immunosuppressed populations might be worthwhile.
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Affiliation(s)
- John A D'Elia
- E P Joslin Research Laboratory, Kidney and Hypertension Section, Joslin Diabetes Center, Department of Medicine, Mount Auburn Hospital, Harvard Medical School, Boston and Cambridge, 521 Mount Auburn Street Watertown, MA 02472, USA. jd'
| | - Larry A Weinrauch
- E P Joslin Research Laboratory, Kidney and Hypertension Section, Joslin Diabetes Center, Department of Medicine, Mount Auburn Hospital, Harvard Medical School, Boston and Cambridge, 521 Mount Auburn Street Watertown, MA 02472, USA.
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30
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Dai S, Jin Y, Li T, Weng Y, Xu X, Zhang G, Li J, Pang R, Tian B, Hua Y. DR1440 is a potential iron efflux protein involved in maintenance of iron homeostasis and resistance of Deinococcus radiodurans to oxidative stress. PLoS One 2018; 13:e0202287. [PMID: 30106993 PMCID: PMC6091924 DOI: 10.1371/journal.pone.0202287] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Accepted: 07/31/2018] [Indexed: 01/18/2023] Open
Abstract
Iron acquisition by bacteria is well studied, but iron export from bacteria is less understood. Herein, we identified dr1440 with a P-type ATPase motif as a potential exporter of iron from Deinococcus radiodurans, a bacterium known for its extreme resistance to radiation and oxidants. The DR1440 was located in cell membrane as demonstrated by fluorescence labelling analysis. Mutation of dr1440 resulted in cellular accumulation of iron ions, and expression level of dr1440 was up-regulated significantly under iron ion or hydrogen peroxide stress in the wild-type strain, implicating DR1440 as a potential iron efflux protein. The dr1440 mutant displayed higher sensitivity to iron ions and oxidative stresses including hydrogen peroxide, hypochlorous acid, and gamma-ray irradiation compared with the wild-type strain. The high amount of iron in the mutant strain resulted in severe protein carbonylation, suggesting that DR1440 might contribute to intracellular protein protection against reactive oxygen species (ROS) generated from ferrous ion-mediated Fenton-reaction. Mutations of S297A and C299A led to intracellular accumulation of iron, indicating that S297 and C299 might be important functional residues of DR1440. Thus, DR1440 is a potential iron efflux protein involved in iron homeostasis and oxidative stress-resistance of D. radiodurans.
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Affiliation(s)
- Shang Dai
- Key Laboratory for Nuclear-Agricultural Sciences of Chinese Ministry of Agriculture and Zhejiang Province, Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou, China
| | - Ye Jin
- Key Laboratory for Nuclear-Agricultural Sciences of Chinese Ministry of Agriculture and Zhejiang Province, Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou, China
| | - Tao Li
- Key Laboratory for Nuclear-Agricultural Sciences of Chinese Ministry of Agriculture and Zhejiang Province, Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou, China
| | - Yulan Weng
- Key Laboratory for Nuclear-Agricultural Sciences of Chinese Ministry of Agriculture and Zhejiang Province, Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou, China
| | - Xiaolin Xu
- Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi, Xinjiang, China
| | - Genlin Zhang
- Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi, Xinjiang, China
| | - Jiulong Li
- Key Laboratory for Nuclear-Agricultural Sciences of Chinese Ministry of Agriculture and Zhejiang Province, Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou, China
| | - Renjiang Pang
- Key Laboratory for Nuclear-Agricultural Sciences of Chinese Ministry of Agriculture and Zhejiang Province, Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou, China
| | - Bing Tian
- Key Laboratory for Nuclear-Agricultural Sciences of Chinese Ministry of Agriculture and Zhejiang Province, Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou, China
- * E-mail:
| | - Yuejin Hua
- Key Laboratory for Nuclear-Agricultural Sciences of Chinese Ministry of Agriculture and Zhejiang Province, Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou, China
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31
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Dyla M, Terry DS, Kjaergaard M, Sørensen TLM, Lauwring Andersen J, Andersen JP, Rohde Knudsen C, Altman RB, Nissen P, Blanchard SC. Dynamics of P-type ATPase transport revealed by single-molecule FRET. Nature 2017; 551:346-351. [PMID: 29144454 DOI: 10.1038/nature24296] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 09/18/2017] [Indexed: 01/05/2023]
Abstract
Phosphorylation-type (P-type) ATPases are ubiquitous primary transporters that pump cations across cell membranes through the formation and breakdown of a phosphoenzyme intermediate. Structural investigations suggest that the transport mechanism is defined by conformational changes in the cytoplasmic domains of the protein that are allosterically coupled to transmembrane helices so as to expose ion binding sites to alternate sides of the membrane. Here, we have used single-molecule fluorescence resonance energy transfer to directly observe conformational changes associated with the functional transitions in the Listeria monocytogenes Ca2+-ATPase (LMCA1), an orthologue of eukaryotic Ca2+-ATPases. We identify key intermediates with no known crystal structures and show that Ca2+ efflux by LMCA1 is rate-limited by phosphoenzyme formation. The transport process involves reversible steps and an irreversible step that follows release of ADP and extracellular release of Ca2+.
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Affiliation(s)
- Mateusz Dyla
- Centre for Membrane Pumps in Cells and Disease - PUMPKIN, Danish National Research Foundation & Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic-EMBL Partnership for Molecular Medicine, Aarhus University, DK-8000 Aarhus C, Denmark.,Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus C, Denmark.,Interdisciplinary Nanoscience Center (iNANO), Aarhus University, DK-8000 Aarhus C, Denmark
| | - Daniel S Terry
- Department of Physiology and Biophysics, Weill Cornell Medicine, Cornell University, New York, New York 10021, USA
| | - Magnus Kjaergaard
- Centre for Membrane Pumps in Cells and Disease - PUMPKIN, Danish National Research Foundation & Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic-EMBL Partnership for Molecular Medicine, Aarhus University, DK-8000 Aarhus C, Denmark.,Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus C, Denmark.,Interdisciplinary Nanoscience Center (iNANO), Aarhus University, DK-8000 Aarhus C, Denmark.,Aarhus Institute of Advanced Studies (AIAS), Aarhus University, DK-8000 Aarhus C, Denmark
| | - Thomas L-M Sørensen
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK
| | - Jacob Lauwring Andersen
- Centre for Membrane Pumps in Cells and Disease - PUMPKIN, Danish National Research Foundation & Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic-EMBL Partnership for Molecular Medicine, Aarhus University, DK-8000 Aarhus C, Denmark.,Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Jens P Andersen
- Department of Biomedicine, Aarhus University, DK-8000 Aarhus C, Denmark
| | | | - Roger B Altman
- Department of Physiology and Biophysics, Weill Cornell Medicine, Cornell University, New York, New York 10021, USA
| | - Poul Nissen
- Centre for Membrane Pumps in Cells and Disease - PUMPKIN, Danish National Research Foundation & Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic-EMBL Partnership for Molecular Medicine, Aarhus University, DK-8000 Aarhus C, Denmark.,Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus C, Denmark.,Interdisciplinary Nanoscience Center (iNANO), Aarhus University, DK-8000 Aarhus C, Denmark
| | - Scott C Blanchard
- Department of Physiology and Biophysics, Weill Cornell Medicine, Cornell University, New York, New York 10021, USA
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32
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Plattner H, Verkhratsky A. Inseparable tandem: evolution chooses ATP and Ca2+ to control life, death and cellular signalling. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0419. [PMID: 27377729 DOI: 10.1098/rstb.2015.0419] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/29/2016] [Indexed: 01/01/2023] Open
Abstract
From the very dawn of biological evolution, ATP was selected as a multipurpose energy-storing molecule. Metabolism of ATP required intracellular free Ca(2+) to be set at exceedingly low concentrations, which in turn provided the background for the role of Ca(2+) as a universal signalling molecule. The early-eukaryote life forms also evolved functional compartmentalization and vesicle trafficking, which used Ca(2+) as a universal signalling ion; similarly, Ca(2+) is needed for regulation of ciliary and flagellar beat, amoeboid movement, intracellular transport, as well as of numerous metabolic processes. Thus, during evolution, exploitation of atmospheric oxygen and increasingly efficient ATP production via oxidative phosphorylation by bacterial endosymbionts were a first step for the emergence of complex eukaryotic cells. Simultaneously, Ca(2+) started to be exploited for short-range signalling, despite restrictions by the preset phosphate-based energy metabolism, when both phosphates and Ca(2+) interfere with each other because of the low solubility of calcium phosphates. The need to keep cytosolic Ca(2+) low forced cells to restrict Ca(2+) signals in space and time and to develop energetically favourable Ca(2+) signalling and Ca(2+) microdomains. These steps in tandem dominated further evolution. The ATP molecule (often released by Ca(2+)-regulated exocytosis) rapidly grew to be the universal chemical messenger for intercellular communication; ATP effects are mediated by an extended family of purinoceptors often linked to Ca(2+) signalling. Similar to atmospheric oxygen, Ca(2+) must have been reverted from a deleterious agent to a most useful (intra- and extracellular) signalling molecule. Invention of intracellular trafficking further increased the role for Ca(2+) homeostasis that became critical for regulation of cell survival and cell death. Several mutually interdependent effects of Ca(2+) and ATP have been exploited in evolution, thus turning an originally unholy alliance into a fascinating success story.This article is part of the themed issue 'Evolution brings Ca(2+) and ATP together to control life and death'.
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Affiliation(s)
- Helmut Plattner
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Alexei Verkhratsky
- Faculty of Biological Sciences, University of Manchester, Manchester M13 9PT, UK Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain Department of Neurosciences, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain University of Nizhny Novgorod, Nizhny Novgorod 603022, Russia
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33
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Astasov-Frauenhoffer M, Varenganayil MM, Decho AW, Waltimo T, Braissant O. Exopolysaccharides regulate calcium flow in cariogenic biofilms. PLoS One 2017; 12:e0186256. [PMID: 29023506 PMCID: PMC5638444 DOI: 10.1371/journal.pone.0186256] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2017] [Accepted: 09/28/2017] [Indexed: 11/18/2022] Open
Abstract
Caries-associated biofilms induce loss of calcium from tooth surfaces in the presence of dietary carbohydrates. Exopolysaccharides (EPS) provide a matrix scaffold and an abundance of primary binding sites within biofilms. The role of EPS in binding calcium in cariogenic biofilms is only partially understood. Thus, the aim of the present study is to investigate the relationship between the calcium dissolution rates and calcium tolerance of caries-associated bacteria and yeast as well as to examine the properties of EPS to quantify its binding affinity for dissolved calcium. Calcium dissolution was measured by dissolution zones on Pikovskaya's agar. Calcium tolerance was assessed by isothermal microcalorimetry (IMC) by adding CaCl2 to the bacterial cultures. Acid-base titration and Fourier transform infrared (FTIR) spectroscopy were used to identify possible functional groups responsible for calcium binding, which was assessed by isothermal titration calorimetry (ITC). Lactobacillus spp. and mutans streptococci demonstrated calcium dissolution in the presence of different carbohydrates. All strains that demonstrated high dissolution rates also revealed higher rates of calcium tolerance by IMC. In addition, acidic functional groups were predominantly identified as possible binding sites for calcium ions by acid-base titration and FTIR. Finally, ITC revealed EPS to have a higher binding affinity for calcium compared, for example, to lactic acid. In conclusion, this study illustrates the role of EPS in terms of the calcium tolerance of cariogenic microbiota by determining the ability of EPS to control free calcium concentrations within the biofilms as a self-regulating mode of action in the pathogenesis of dental caries.
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Affiliation(s)
- Monika Astasov-Frauenhoffer
- Department of Preventive Dentistry and Oral Microbiology, University Center for Dental Medicine, University of Basel, Basel, Switzerland
- * E-mail:
| | - Muth M. Varenganayil
- Department of Preventive Dentistry and Oral Microbiology, University Center for Dental Medicine, University of Basel, Basel, Switzerland
| | - Alan W. Decho
- Department of Environmental Health Sciences, Arnold School of Public Health, Columbia, South Carolina, United States
| | - Tuomas Waltimo
- Department of Preventive Dentistry and Oral Microbiology, University Center for Dental Medicine, University of Basel, Basel, Switzerland
| | - Olivier Braissant
- Center of Biomechanics & Biocalorimetry, c/o Department Biomedical Engineering (DBE), University of Basel, Allschwil, Switzerland
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A Novel Calcium Uptake Transporter of Uncharacterized P-Type ATPase Family Supplies Calcium for Cell Surface Integrity in Mycobacterium smegmatis. mBio 2017; 8:mBio.01388-17. [PMID: 28951477 PMCID: PMC5615198 DOI: 10.1128/mbio.01388-17] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ca2+ plays an important role in the physiology of bacteria. Intracellular Ca2+ concentrations are tightly maintained in the nanomolar range. Molecular mechanisms of Ca2+ uptake in bacteria remain elusive. Here we show that CtpE is responsible for Ca2+ uptake in Mycobacterium smegmatis. It represents a previously uncharacterized P-type ATPase family in bacteria. Disruption of ctpE in M. smegmatis resulted in a mutant with impaired growth under Ca2+-deficient conditions. The growth defect of the mutant could be rescued by Ca2+ or by ectopic expression of ctpE from M. smegmatis or the orthologous gene (Rv0908) from Mycobacterium tuberculosis H37Rv. Radioactive transport assays revealed that CtpE is a Ca2+-specific transporter. Ca2+ deficiency increased expression of ctpE, resulting in increased 45Ca2+ accumulation in cells. ctpE is a gene that is part of an operon, which is negatively regulated by Ca2+. The ctpE mutant also showed hypersensitivity to polymyxin B, increased biofilm formation, and higher cell aggregation, indicating cell envelope defects. Our work establishes, for the first time, the presence of Ca2+ uptake pumps of the energy-dependent P-type ATPase superfamily in bacteria and also implicates that intracellular Ca2+ is essential for growth and cell envelope integrity in M. smegmatis. Ca2+ is essential for gene regulation, enzymatic activity, and maintenance of structural integrity of cell walls in bacteria. Bacteria maintain intracellular calcium concentrations in a narrow range, creating a gradient with low cytoplasmic calcium concentration and high extracellular calcium concentration. Due to this steep gradient, active pumps belonging to family 2 of P-type ATPases and antiporters are used for Ca2+ efflux, whereas Ca2+ uptake is usually carried out by channels. Molecular mechanisms of Ca2+ uptake in bacteria are still elusive and are mainly limited to a nonproteinaceous channel in Escherichia coli and a pH-dependent channel protein from Bacillus subtilis. Energy-dependent active transporters are not reported for Ca2+ uptake from any organism. Here we show that CtpE belonging to a family of previously uncharacterized bacterial P-type ATPases is involved in specific uptake of Ca2+ into Mycobacterium smegmatis. We also demonstrate that intracellular Ca2+ obtained through CtpE is essential for growth and maintenance of cell surface properties under Ca2+-deficient conditions.
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Sharma A, Flores-Vallejo RDC, Cardoso-Taketa A, Villarreal ML. Antibacterial activities of medicinal plants used in Mexican traditional medicine. JOURNAL OF ETHNOPHARMACOLOGY 2017; 208:264-329. [PMID: 27155134 DOI: 10.1016/j.jep.2016.04.045] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2015] [Revised: 04/24/2016] [Accepted: 04/25/2016] [Indexed: 05/17/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE We provide an extensive summary of the in vitro antibacterial properties of medicinal plants popularly used in Mexico to treat infections, and we discuss the ethnomedical information that has been published for these species. MATERIALS AND METHODS We carried out a bibliographic investigation by analyzing local and international peer-reviewed papers selected by consulting internationally accepted scientific databases from 1995 to 2014. We provide specific information about the evaluated plant parts, the type of extracts, the tested bacterial strains, and the inhibitory concentrations for each one of the species. We recorded the ethnomedical information for the active species, as well as their popular names and local distribution. Information about the plant compounds that has been identified is included in the manuscript. This review also incorporates an extensive summary of the available toxicological reports on the recorded species, as well as the worldwide registries of plant patents used for treating bacterial infections. In addition, we provide a list with the top plant species with antibacterial activities in this review RESULTS: We documented the in vitro antibacterial activities of 343 plant species pertaining to 92 botanical families against 72 bacterial species, focusing particularly on Staphylococcus aureus, Mycobacterium tuberculosis, Escherichia coli and Pseudomonas aeruginosa. The plant families Asteraceae, Fabaceae, Lamiaceae and Euphorbiaceae included the largest number of active species. Information related to popular uses reveals that the majority of the plants, in addition to treating infections, are used to treat other conditions. The distribution of Mexican plants extended from those that were reported to grow in just one state to those that grow in all 32 Mexican states. From 75 plant species, 225 compounds were identified. Out of the total plant species, only 140 (40.57%) had at least one report about their toxic effects. From 1994 to July 2014 a total of 11,836 worldwide antibacterial patents prepared from different sources were recorded; only 36 antibacterial patents from plants were registered over the same time period. We offered some insights on the most important findings regarding the antibacterial effects, current state of the art, and research perspectives of top plant species with antibacterial activities in vitro. CONCLUSIONS Studies of the antibacterial in vitro activity of medicinal plants popularly used in Mexico to treat infections indicate that both the selection of plant material and the investigation methodologies vary. Standardized experimental procedures as well as in vivo pharmacokinetic studies to document the effectiveness of plant extracts and compounds are necessary. This review presents extensive information about the medicinal plants possessing antibacterial activity that has been scientifically studied and are popularly used in Mexico. We anticipate that this review will be of use for future studies because it constitutes a valuable information tool for selecting the most significant plants and their potential antibacterial properties.
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Affiliation(s)
- Ashutosh Sharma
- Escuela de Ingeniería en Alimentos, Biotecnología y Agronomía (ESIABA), Tecnológico de Monterrey, Campus Querétaro, México
| | - Rosario Del Carmen Flores-Vallejo
- Centro de Investigación en Biotecnología, Universidad Autónoma del Estado de Morelos, Avenida Universidad 1001, Col. Chamilpa, Cuernavaca Morelos 62209, México
| | - Alexandre Cardoso-Taketa
- Centro de Investigación en Biotecnología, Universidad Autónoma del Estado de Morelos, Avenida Universidad 1001, Col. Chamilpa, Cuernavaca Morelos 62209, México
| | - María Luisa Villarreal
- Centro de Investigación en Biotecnología, Universidad Autónoma del Estado de Morelos, Avenida Universidad 1001, Col. Chamilpa, Cuernavaca Morelos 62209, México
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Abstract
Electrically excitable cells harness voltage-coupled calcium influx to transmit intracellular signals, typically studied in neurons and cardiomyocytes. Despite intense study in higher organisms, investigations of voltage and calcium signaling in bacteria have lagged due to their small size and a lack of sensitive tools. Only recently were bacteria shown to modulate their membrane potential on the timescale of seconds, and little is known about the downstream effects from this modulation. In this paper, we report on the effects of electrophysiology in individual bacteria. A genetically encoded calcium sensor expressed in Escherichia coli revealed calcium transients in single cells. A fusion sensor that simultaneously reports voltage and calcium indicated that calcium influx is induced by voltage depolarizations, similar to metazoan action potentials. Cytoplasmic calcium levels and transients increased upon mechanical stimulation with a hydrogel, and single cells altered protein concentrations dependent on the mechanical environment. Blocking voltage and calcium flux altered mechanically induced changes in protein concentration, while inducing calcium flux reproduced these changes. Thus, voltage and calcium relay a bacterial sense of touch and alter cellular lifestyle. Although the calcium effectors remain unknown, these data open a host of new questions about E. coli, including the identity of the underlying molecular players, as well as other signals conveyed by voltage and calcium. These data also provide evidence that dynamic voltage and calcium exists as a signaling modality in the oldest domain of life, and therefore studying electrophysiology beyond canonical electrically excitable cells could yield exciting new findings.
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Gratz N, Loh LN, Mann B, Gao G, Carter R, Rosch J, Tuomanen EI. Pneumococcal neuraminidase activates TGF-β signalling. MICROBIOLOGY-SGM 2017; 163:1198-1207. [PMID: 28749326 PMCID: PMC5817201 DOI: 10.1099/mic.0.000511] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Neuraminidase A (NanA) is an important virulence factor that is anchored to the pneumococcal cell wall and cleaves sialic acid on host substrates. We noted that a secreted allele of NanA was over-represented in invasive pneumococcal isolates and promoted the development of meningitis when swapped into the genome of non-meningitis isolates replacing cell wall-anchored NanA. Both forms of recombinant NanA directly activated transforming growth factor (TGF)-β, increased SMAD signalling and promoted loss of endothelial tight junction ZO-1. However, in assays using whole bacteria, only the cell-bound NanA decreased expression of ZO-1 and showed NanA dependence of bacterial invasion of endothelial cells. We conclude that NanA secretion versus retention on the cell surface does not influence neurotropism of clinical isolates. However, we describe a new NanA-TGF-β signalling axis that leads to decreased blood-brain barrier integrity and enhances bacterial invasion.
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Affiliation(s)
- Nina Gratz
- Departments of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Lip Nam Loh
- Departments of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Beth Mann
- Departments of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Geli Gao
- Departments of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Robert Carter
- Computational Biology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Jason Rosch
- Departments of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Elaine I. Tuomanen
- Departments of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
- *Correspondence: Elaine I. Tuomanen,
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Biochemical characterization of the bacterial peroxidase from the human pathogen Neisseria gonorrhoeae. J Inorg Biochem 2017; 171:108-119. [PMID: 28388513 DOI: 10.1016/j.jinorgbio.2017.03.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 02/21/2017] [Accepted: 03/19/2017] [Indexed: 10/19/2022]
Abstract
Neisseria gonorrhoeae is an obligate human pathogen that expresses an array of molecular systems to detoxify reactive oxygen species as defense mechanisms during colonization and infection. One of these is the bacterial peroxidase that reduces H2O2 to water in its periplasm. The soluble form of this enzyme was heterologously expressed in E. coli in the holo-form binding two c-types hemes, a high-potential E heme and a low-potential P heme, with redox potentials of (+310mV) and (-190mV/-300mV), respectively in the presence of calcium ions, at pH7.5. Visible and EPR spectroscopic analysis together with activity assays indicate the presence of a calcium dependent reductive activation mechanism in thgonorrhoeaeNeisseria gonorrhoeae bacterial peroxidase, in which P heme is bis-His coordinated low-spin in the fully oxidized state of the enzyme, and becomes penta-coordinated high-spin upon reduction of E heme in the presence of calcium ions. The activated enzyme has a high affinity for H2O2 (KM of 4±1μM), with maximum activity being attained at pH7.0 and 37°C, with the rate-limiting step in the catalytic cycle being the electron transfer between the two hemes. In this enzyme, dimer formation is not promoted at high ionic strength, thus differing from the classical bacterial peroxidases. These results contribute to the understanding of the involvement of Neisseria gonorrhoeae bacterial peroxidase has a first line defense mechanism against exogenously produced hydrogen peroxide in the host environment.
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RelA Mutant Enterococcus faecium with Multiantibiotic Tolerance Arising in an Immunocompromised Host. mBio 2017; 8:mBio.02124-16. [PMID: 28049149 PMCID: PMC5210501 DOI: 10.1128/mbio.02124-16] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Serious bacterial infections in immunocompromised patients require highly effective antibacterial therapy for cure, and thus, this setting may reveal novel mechanisms by which bacteria circumvent antibiotics in the absence of immune pressure. Here, an infant with leukemia developed vancomycin-resistant Enterococcus faecium (VRE) bacteremia that persisted for 26 days despite appropriate antibiotic therapy. Sequencing of 22 consecutive VRE isolates identified the emergence of a single missense mutation (L152F) in relA, which constitutively activated the stringent response, resulting in elevated baseline levels of the alarmone guanosine tetraphosphate (ppGpp). Although the mutant remained susceptible to both linezolid and daptomycin in clinical MIC testing and during planktonic growth, it demonstrated tolerance to high doses of both antibiotics when growing in a biofilm. This biofilm-specific gain in resistance was reflected in the broad shift in transcript levels caused by the mutation. Only an experimental biofilm-targeting ClpP-activating antibiotic was able to kill the mutant strain in an established biofilm. The relA mutation was associated with a fitness trade-off, forming smaller and less-well-populated biofilms on biological surfaces. We conclude that clinically relevant relA mutations can emerge during prolonged VRE infection, causing baseline activation of the stringent response, subsequent antibiotic tolerance, and delayed eradication in an immunocompromised state. The increasing prevalence of antibiotic-resistant bacterial pathogens is a major challenge currently facing the medical community. Such pathogens are of particular importance in immunocompromised patients as these individuals may favor emergence of novel resistance determinants due to lack of innate immune defenses and intensive antibiotic exposure. During the course of chemotherapy, a patient developed prolonged bacteremia with vancomycin-resistant Enterococcus faecium that failed to clear despite multiple front-line antibiotics. The consecutive bloodstream isolates were sequenced, and a single missense mutation identified in the relA gene, the mediator of the stringent response. Strains harboring the mutation had elevated baseline levels of the alarmone and displayed heightened resistance to the bactericidal activity of multiple antibiotics, particularly in a biofilm. Using a new class of compounds that modulate ClpP activity, the biofilms were successfully eradicated. These data represent the first clinical emergence of mutations in the stringent response in vancomycin-resistant entereococci.
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Dyla M, Andersen JL, Kjaergaard M, Birkedal V, Terry DS, Altman RB, Blanchard SC, Nissen P, Knudsen CR. Engineering a Prototypic P-type ATPase Listeria monocytogenes Ca(2+)-ATPase 1 for Single-Molecule FRET Studies. Bioconjug Chem 2016; 27:2176-87. [PMID: 27501274 DOI: 10.1021/acs.bioconjchem.6b00387] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Approximately 30% of the ATP generated in the living cell is utilized by P-type ATPase primary active transporters to generate and maintain electrochemical gradients across biological membranes. P-type ATPases undergo large conformational changes during their functional cycle to couple ATP hydrolysis in the cytoplasmic domains to ion transport across the membrane. The Ca(2+)-ATPase from Listeria monocytogenes, LMCA1, was found to be a suitable model of P-type ATPases and was engineered to facilitate single-molecule FRET studies of transport-related structural changes. Mutational analyses of the endogenous cysteine residues in LMCA1 were performed to reduce background labeling without compromising activity. Pairs of cysteines were introduced into the optimized low-reactivity background, and labeled with maleimide derivatives of Cy3 and Cy5 resulting in site-specifically double-labeled protein with moderate activity. Ensemble and confocal single-molecule FRET studies revealed changes in FRET distribution related to structural changes during the transport cycle, consistent with those observed by X-ray crystallography for the sarco/endoplasmic reticulum Ca(2+) ATPase (SERCA). Notably, the cytosolic headpiece of LMCA1 was found to be distinctly more compact in the E1 state than in the E2 state. Thus, the established experimental system should allow future real-time FRET studies of the structural dynamics of LMCA1 as a representative P-type ATPase.
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Affiliation(s)
- Mateusz Dyla
- Centre for Membrane Pumps in Cells and Disease - PUMPKIN. Danish National Research Foundation & Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic-EMBL Partnership for Molecular Medicine, and Department of Molecular Biology and Genetics, Aarhus University , Gustav Wieds Vej 10C, DK-8000 Aarhus C, Denmark.,Interdisciplinary Nanoscience Center (iNANO), Aarhus University , Gustav Wieds Vej 14, DK-8000 Aarhus C, Denmark
| | - Jacob Lauwring Andersen
- Centre for Membrane Pumps in Cells and Disease - PUMPKIN. Danish National Research Foundation & Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic-EMBL Partnership for Molecular Medicine, and Department of Molecular Biology and Genetics, Aarhus University , Gustav Wieds Vej 10C, DK-8000 Aarhus C, Denmark
| | - Magnus Kjaergaard
- Centre for Membrane Pumps in Cells and Disease - PUMPKIN. Danish National Research Foundation & Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic-EMBL Partnership for Molecular Medicine, and Department of Molecular Biology and Genetics, Aarhus University , Gustav Wieds Vej 10C, DK-8000 Aarhus C, Denmark.,Interdisciplinary Nanoscience Center (iNANO), Aarhus University , Gustav Wieds Vej 14, DK-8000 Aarhus C, Denmark.,AIAS, Aarhus Institute of Advanced Studies, Aarhus University , DK-8000 Aarhus C, Denmark
| | - Victoria Birkedal
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University , Gustav Wieds Vej 14, DK-8000 Aarhus C, Denmark
| | - Daniel S Terry
- Department of Physiology and Biophysics, Weill Cornell Medicine , New York, New York 10021, United States
| | - Roger B Altman
- Department of Physiology and Biophysics, Weill Cornell Medicine , New York, New York 10021, United States
| | - Scott C Blanchard
- Department of Physiology and Biophysics, Weill Cornell Medicine , New York, New York 10021, United States
| | - Poul Nissen
- Centre for Membrane Pumps in Cells and Disease - PUMPKIN. Danish National Research Foundation & Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic-EMBL Partnership for Molecular Medicine, and Department of Molecular Biology and Genetics, Aarhus University , Gustav Wieds Vej 10C, DK-8000 Aarhus C, Denmark.,Interdisciplinary Nanoscience Center (iNANO), Aarhus University , Gustav Wieds Vej 14, DK-8000 Aarhus C, Denmark
| | - Charlotte R Knudsen
- Centre for Membrane Pumps in Cells and Disease - PUMPKIN. Danish National Research Foundation & Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic-EMBL Partnership for Molecular Medicine, and Department of Molecular Biology and Genetics, Aarhus University , Gustav Wieds Vej 10C, DK-8000 Aarhus C, Denmark
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Dynamic capsule restructuring by the main pneumococcal autolysin LytA in response to the epithelium. Nat Commun 2016; 7:10859. [PMID: 26924467 PMCID: PMC4773454 DOI: 10.1038/ncomms10859] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 01/21/2016] [Indexed: 11/16/2022] Open
Abstract
Bacterial pathogens produce complex carbohydrate capsules to protect against bactericidal immune molecules. Paradoxically, the pneumococcal capsule sensitizes the bacterium to antimicrobial peptides found on epithelial surfaces. Here we show that upon interaction with antimicrobial peptides, encapsulated pneumococci survive by removing capsule from the cell surface within minutes in a process dependent on the suicidal amidase autolysin LytA. In contrast to classical bacterial autolysis, during capsule shedding, LytA promotes bacterial survival and is dispersed circumferentially around the cell. However, both autolysis and capsule shedding depend on the cell wall hydrolytic activity of LytA. Capsule shedding drastically increases invasion of epithelial cells and is the main pathway by which pneumococci reduce surface bound capsule during early acute lung infection of mice. The previously unrecognized role of LytA in removing capsule to combat antimicrobial peptides may explain why nearly all clinical isolates of pneumococci conserve this enzyme despite the lethal selective pressure of antibiotics. Pneumococci produce a carbohydrate capsule that protects them against components of the host immune system but sensitizes them to host antimicrobial peptides. Here, Kietzman et al. show that pneumococci respond to antimicrobial peptides by capsule shedding, which requires the main autolysin LytA.
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Cao H, Qin H, Zhao Y, Jin G, Lu T, Meng F, Zhang X, Liu X. Nano-thick calcium oxide armed titanium: boosts bone cells against methicillin-resistant Staphylococcus aureus. Sci Rep 2016; 6:21761. [PMID: 26899567 PMCID: PMC4761977 DOI: 10.1038/srep21761] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 01/28/2016] [Indexed: 11/09/2022] Open
Abstract
Since the use of systemic antibiotics for preventing acute biomaterial-associated infections (BAIs) may build up bacterial resistance and result in huge medical costs and unpredictable mortality, new precaution strategies are required. Here, it demonstrated that titanium armed with a nano-thick calcium oxide layer was effective on averting methicillin-resistant Staphylococcus aureus (MRSA) infections in rabbits. The calcium oxide layer was constructed by, firstly, injecting of metallic calcium into titanium via a plasma immersion ion implantation process, and then transforming the outer most surface into oxide by exposing to the atmosphere. Although the calcium oxide armed titanium had a relative low reduction rate (~74%) in growth of MRSA in vitro, it could markedly promote the osteogenic differentiation of bone marrow stem cells (BMSCs), restore local bone integration against the challenge of MRSA, and decrease the incidence of MRSA infection with a rate of 100% (compared to the titanium control). This study demonstrated for the first time that calcium, as one of the major elements in a human body, could be engineered to avert MRSA infections, which is promising as a safe precaution of disinfection for implantable biomedical devices.
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Affiliation(s)
- Huiliang Cao
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
| | - Hui Qin
- Department of Orthopedics, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai 200233, China
| | - Yaochao Zhao
- Department of Orthopedics, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai 200233, China
| | - Guodong Jin
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
| | - Tao Lu
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
| | - Fanhao Meng
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
| | - Xianlong Zhang
- Department of Orthopedics, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai 200233, China
| | - Xuanyong Liu
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
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A novel type bacterial flagellar motor that can use divalent cations as a coupling ion. Sci Rep 2016; 6:19773. [PMID: 26794857 PMCID: PMC4726428 DOI: 10.1038/srep19773] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 12/18/2015] [Indexed: 12/25/2022] Open
Abstract
The bacterial flagellar motor is a sophisticated nanomachine embedded in the cell envelope and powered by an electrochemical gradient of H(+), Na(+), or K(+)across the cytoplasmic membrane. Here we describe a new member of the bacterial flagellar stator channel family (MotAB1 of Paenibacillus sp. TCA20 (TCA-MotAB1)) that is coupled to divalent cations (Ca(2+)and Mg(2+)). In the absence of divalent cations of alkaline earth metals, no swimming was observed in Paenibacillus sp. TCA20, which grows optimally in Ca(2+)-rich environments. This pattern was confirmed by swimming assays of a stator-free Bacillus subtilis mutant expressing TCA-MotAB1. Both a stator-free and major Mg(2+)uptake system-deleted B. subtilis mutant expressing TCA-MotAB1 complemented both growth and motility deficiency under low Mg(2+)conditions and exhibited [Mg(2+)]in identical to that of the wild-type. This is the first report of a flagellar motor that can use Ca(2+)and Mg(2+)as coupling ions. These findings will promote the understanding of the operating principles of flagellar motors and molecular mechanisms of ion selectivity.
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Guragain M, Campbell A, Patrauchan M. Measurement of Intracellular Calcium Concentration in Pseudomonas aeruginosa. Bio Protoc 2016. [DOI: 10.21769/bioprotoc.2041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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Role of copper efflux in pneumococcal pathogenesis and resistance to macrophage-mediated immune clearance. Infect Immun 2015; 83:1684-94. [PMID: 25667262 DOI: 10.1128/iai.03015-14] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In bacteria, the intracellular levels of metals are mediated by tightly controlled acquisition and efflux systems. This is particularly true of copper, a trace element that is universally toxic in excess. During infection, the toxic properties of copper are exploited by the mammalian host to facilitate bacterial clearance. To better understand the role of copper during infection, we characterized the contribution of the cop operon to copper homeostasis and virulence in Streptococcus pneumoniae. Deletion of either the exporter, encoded by copA, or the chaperone, encoded by cupA, led to hypersensitivity to copper stress. We further demonstrated that loss of the copper exporter encoded by copA led to decreased virulence in pulmonary, intraperitoneal, and intravenous models of infection. Deletion of copA resulted in enhanced macrophage-mediated bacterial clearance in vitro. The attenuation phenotype of the copA mutant in the lung was found to be dependent on pulmonary macrophages, underscoring the importance of copper efflux in evading immune defenses. Overall, these data provide insight into the role of the cop operon in pneumococcal pathogenesis.
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Kunoh T, Suzuki T, Shiraishi T, Kunoh H, Takada J. Treatment of leptothrix cells with ultrapure water poses a threat to their viability. BIOLOGY 2015; 4:50-66. [PMID: 25634812 PMCID: PMC4381217 DOI: 10.3390/biology4010050] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 01/16/2015] [Accepted: 01/19/2015] [Indexed: 11/23/2022]
Abstract
The genus Leptothrix, a type of Fe/Mn-oxidizing bacteria, is characterized by its formation of an extracellular and microtubular sheath. Although almost all sheaths harvested from natural aquatic environments are hollow, a few chained bacterial cells are occasionally seen within some sheaths of young stage. We previously reported that sheaths of Leptothrix sp. strain OUMS1 cultured in artificial media became hollow with aging due to spontaneous autolysis within the sheaths. In this study, we investigated environmental conditions that lead the OUMS1 cells to die. Treatment of the cells with ultrapure water or acidic buffers (pH 6.0) caused autolysis of the cells. Under these conditions, the plasma membrane and cytoplasm of cells were drastically damaged, resulting in leakage of intracellular electrolytes and relaxation of genomic DNA. The autolysis was suppressed by the presence of Ca2+. The hydrolysis of peptidoglycan by the lysozyme treatment similarly caused autolysis of the cells and was suppressed also by the presence of Ca2+. However, it remains unclear whether the acidic pH-dependent autolysis is attributable to damage of peptidoglycan. It was observed that L. discophora strain SP-6 cells also underwent autolysis when suspended in ultrapure water; it is however, uncertain whether this phenomenon is common among other members of the genus Leptothrix.
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Affiliation(s)
- Tatsuki Kunoh
- Core Research for Evolutionary Science and Technology (CREST), Japan Science and Technology Agency (JST), Okayama 700-8530, Japan.
| | - Tomoko Suzuki
- Core Research for Evolutionary Science and Technology (CREST), Japan Science and Technology Agency (JST), Okayama 700-8530, Japan.
| | | | - Hitoshi Kunoh
- Core Research for Evolutionary Science and Technology (CREST), Japan Science and Technology Agency (JST), Okayama 700-8530, Japan.
| | - Jun Takada
- Core Research for Evolutionary Science and Technology (CREST), Japan Science and Technology Agency (JST), Okayama 700-8530, Japan.
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47
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Calcium binding proteins and calcium signaling in prokaryotes. Cell Calcium 2014; 57:151-65. [PMID: 25555683 DOI: 10.1016/j.ceca.2014.12.006] [Citation(s) in RCA: 136] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 12/08/2014] [Accepted: 12/09/2014] [Indexed: 11/20/2022]
Abstract
With the continued increase of genomic information and computational analyses during the recent years, the number of newly discovered calcium binding proteins (CaBPs) in prokaryotic organisms has increased dramatically. These proteins contain sequences that closely resemble a variety of eukaryotic calcium (Ca(2+)) binding motifs including the canonical and pseudo EF-hand motifs, Ca(2+)-binding β-roll, Greek key motif and a novel putative Ca(2+)-binding domain, called the Big domain. Prokaryotic CaBPs have been implicated in diverse cellular activities such as division, development, motility, homeostasis, stress response, secretion, transport, signaling and host-pathogen interactions. However, the majority of these proteins are hypothetical, and only few of them have been studied functionally. The finding of many diverse CaBPs in prokaryotic genomes opens an exciting area of research to explore and define the role of Ca(2+) in organisms other than eukaryotes. This review presents the most recent developments in the field of CaBPs and novel advancements in the role of Ca(2+) in prokaryotes.
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A Mur regulator protein in the extremophilic bacterium Deinococcus radiodurans. PLoS One 2014; 9:e106341. [PMID: 25243898 PMCID: PMC4171365 DOI: 10.1371/journal.pone.0106341] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 07/29/2014] [Indexed: 12/11/2022] Open
Abstract
Ferric uptake regulator (Fur) is a transcriptional regulator that controls the expression of genes involved in the uptake of iron and manganese, as well as vital nutrients, and is essential for intracellular redox cycling. We identified a unique Fur homolog (DR0865) from Deinococcus radiodurans, which is known for its extreme resistance to radiation and oxidants. A dr0865 mutant (Mt-0865) showed a higher sensitivity to manganese stress, hydrogen peroxide, gamma irradiation and ultraviolet (UV) irradiation than the wild-type R1 strain. Cellular manganese (Mn) ion (Mn2+) analysis showed that Mn2+, copper (Cu2+), and ferric (Fe3+) ions accumulated significantly in the mutant, which suggests that the dr0865 gene is not only involved in the regulation of Mn2+ homeostasis, but also affects the uptake of other ions. In addition, transcriptome profiles under MnCl2 stress showed that the expression of many genes involved in Mn metabolism was significantly different in the wild-type R1 and DR0865 mutant (Mt-0865). Furthermore, we found that the dr0865 gene serves as a positive regulator of the manganese efflux pump gene mntE (dr1236), and as a negative regulator of Mn ABC transporter genes, such as dr2283, dr2284 and dr2523. Therefore, it plays an important role in maintaining the homoeostasis of intracellular Mn (II), and also other Mn2+, zinc (Zn2+) and Cu2+ ions. Based on its role in manganese homeostasis, DR0865 likely belongs to the Mur sub-family of Fur homolog.
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Draft Genome Sequence of Calcium-Dependent Paenibacillus sp. Strain TCA20, Isolated from a Hot Spring Containing a High Concentration of Calcium Ions. GENOME ANNOUNCEMENTS 2014; 2:2/5/e00866-14. [PMID: 25189580 PMCID: PMC4155585 DOI: 10.1128/genomea.00866-14] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Calcium-dependent Paenibacillus sp. strain TCA20 was isolated from a water sample of a hot spring containing a high concentration of calcium ions. Here, we report the draft genome sequence of this bacterium, which may be the basis for the research of calcium ion homeostasis.
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An obligately aerobic soil bacterium activates fermentative hydrogen production to survive reductive stress during hypoxia. Proc Natl Acad Sci U S A 2014; 111:11479-84. [PMID: 25049411 DOI: 10.1073/pnas.1407034111] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Oxygen availability is a major factor and evolutionary force determining the metabolic strategy of bacteria colonizing an environmental niche. In the soil, conditions can switch rapidly between oxia and anoxia, forcing soil bacteria to remodel their energy metabolism accordingly. Mycobacterium is a dominant genus in the soil, and all its species are obligate aerobes. Here we show that an obligate aerobe, the soil actinomycete Mycobacterium smegmatis, adopts an anaerobe-type strategy by activating fermentative hydrogen production to adapt to hypoxia. This process is controlled by the two-component system DosR-DosS/DosT, an oxygen and redox sensor that is well conserved in mycobacteria. We show that DosR tightly regulates the two [NiFe]-hydrogenases: Hyd3 (MSMEG_3931-3928) and Hyd2 (MSMEG_2719-2718). Using genetic manipulation and high-sensitivity GC, we demonstrate that Hyd3 facilitates the evolution of H2 when oxygen is depleted. Combined activity of Hyd2 and Hyd3 was necessary to maintain an optimal NAD(+)/NADH ratio and enhanced adaptation to and survival of hypoxia. We demonstrate that fermentatively-produced hydrogen can be recycled when fumarate or oxygen become available, suggesting Mycobacterium smegmatis can switch between fermentation, anaerobic respiration, and aerobic respiration. Hydrogen metabolism enables this obligate aerobe to rapidly meet its energetic needs when switching between microoxic and anoxic conditions and provides a competitive advantage in low oxygen environments.
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