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Saenkham-Huntsinger P, Ritter M, Donati GL, Mitchell AM, Subashchandrabose S. The inner membrane protein YhiM links copper and CpxAR envelope stress responses in uropathogenic E. coli. mBio 2024; 15:e0352223. [PMID: 38470052 PMCID: PMC11005409 DOI: 10.1128/mbio.03522-23] [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: 01/09/2024] [Accepted: 02/13/2024] [Indexed: 03/13/2024] Open
Abstract
Urinary tract infection (UTI) is a ubiquitous infectious condition, and uropathogenic Escherichia coli (UPEC) is the predominant causative agent of UTI. Copper (Cu) is implicated in innate immunity, including against UPEC. Cu is a trace element utilized as a co-factor, but excess Cu is toxic due to mismetalation of non-cognate proteins. E. coli precisely regulates Cu homeostasis via efflux systems. However, Cu import mechanisms into the bacterial cell are not clear. We hypothesized that Cu import defective mutants would exhibit increased resistance to Cu. This hypothesis was tested in a forward genetic screen with transposon (Tn5) insertion mutants in UPEC strain CFT073, and we identified 32 unique Cu-resistant mutants. Transposon and defined mutants lacking yhiM, which encodes a hypothetical inner membrane protein, were more resistant to Cu than parental strain. Loss of YhiM led to decreased cellular Cu content and increased expression of copA, encoding a Cu efflux pump. The CpxAR envelope stress response system was activated in the ΔyhiM mutant as indicated by increased expression of cpxP. Transcription of yhiM was regulated by CueR and CpxR, and the CpxAR system was essential for increased Cu resistance in the ΔyhiM mutant. Importantly, activation of CpxAR system in the ΔyhiM mutant was independent of NlpE, a known activator of this system. YhiM was required for optimal fitness of UPEC in a mouse model of UTI. Our findings demonstrate that YhiM is a critical mediator of Cu homeostasis and links bacterial adaptation to Cu stress with the CpxAR-dependent envelope stress response in UPEC.IMPORTANCEUPEC is a common bacterial infection. Bacterial pathogens are exposed to host-derived Cu during infection, including UTI. Here, we describe detection of genes involved in Cu homeostasis in UPEC. A UPEC mutant lacking YhiM, a membrane protein, exhibited dramatic increase in resistance to Cu. Our study demonstrates YhiM as a nexus between Cu stress and the CpxAR-dependent envelope stress response system. Importantly, our findings establish NlpE-independent activation of CpxAR system during Cu stress in UPEC. Collectively, YhiM emerges as a critical mediator of Cu homeostasis in UPEC and highlights the interlinked nature of bacterial adaptation to survival during Cu and envelope stress.
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Affiliation(s)
- Panatda Saenkham-Huntsinger
- Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Matthew Ritter
- Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - George L. Donati
- Department of Chemistry, Wake Forest University, Winston-Salem, North Carolina, USA
| | - Angela M. Mitchell
- Department of Biology, College of Science, Texas A&M University, College Station, Texas, USA
| | - Sargurunathan Subashchandrabose
- Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
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2
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Yang S, Hou LJ, Dong HP, Zhang JW, Gao DZ, Li XF, Zheng YL, Liang X, Liu M. Natural chalcopyrite mitigates nitrous oxide emissions in sediment from coastal wetlands. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:168766. [PMID: 38008310 DOI: 10.1016/j.scitotenv.2023.168766] [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: 08/30/2023] [Revised: 10/29/2023] [Accepted: 11/19/2023] [Indexed: 11/28/2023]
Abstract
Coastal wetlands are one of the most important natural sources of nitrous oxide (N2O). Previous studies have shown that copper-containing chemicals are able to reduce N2O emissions from these ecosystems. However, these chemicals may harm organisms present in coastal waters and sediment, and disturb the ecological balance of these areas. Here, we first investigated the physiological characteristics and genetic potential of denitrifying bacteria isolated from coastal wetlands. Based on an isolated denitrifier carrying a complete denitrification pathway, we tested the effect of the natural mineral chalcopyrite on N2O production by the bacteria. The results demonstrated that chalcopyrite addition lowers N2O emissions from the bacteria while increasing its N2 production rate. Among the four denitrification genes of the isolate, only nosZ gene expression was significantly upregulated following the addition of 2 mg L-1 chalcopyrite. Furthermore, chalcopyrite was applied to coastal wetland sediments. The N2O flux was significantly reduced in 50-100 mg L-1 chalcopyrite-amended sets relative to the controls. Notably, the dissolved Cu concentration in chalcopyrite-amended sediment remained within the limit set by the National Sewage Treatment Discharge Standard. qPCR and metagenomic analysis revealed that the abundance of N2O-reducing bacteria with the nosZ or nirK + nosZ genotype increased significantly in the chalcopyrite-amended groups relative to the controls, suggesting their active involvement in the reduction of N2O emissions. Our findings offer valuable insights for the use of natural chalcopyrite in large-scale field applications to reduce N2O emissions.
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Affiliation(s)
- Sai Yang
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200241, China
| | - Li-Jun Hou
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200241, China.
| | - Hong-Po Dong
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200241, China.
| | - Jia-Wei Zhang
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200241, China
| | - Deng-Zhou Gao
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200241, China
| | - Xiao-Fei Li
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200241, China
| | - Yan-Ling Zheng
- Key Laboratory of Geographic Information Science, Ministry of Education, East China Normal University, Shanghai 200241, China
| | - Xia Liang
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200241, China
| | - Min Liu
- Key Laboratory of Geographic Information Science, Ministry of Education, East China Normal University, Shanghai 200241, China
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3
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He B, Sachla AJ, Helmann JD. TerC proteins function during protein secretion to metalate exoenzymes. Nat Commun 2023; 14:6186. [PMID: 37794032 PMCID: PMC10550928 DOI: 10.1038/s41467-023-41896-1] [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: 05/08/2023] [Accepted: 09/14/2023] [Indexed: 10/06/2023] Open
Abstract
Cytosolic metalloenzymes acquire metals from buffered intracellular pools. How exported metalloenzymes are appropriately metalated is less clear. We provide evidence that TerC family proteins function in metalation of enzymes during export through the general secretion (Sec-dependent) pathway. Bacillus subtilis strains lacking MeeF(YceF) and MeeY(YkoY) have a reduced capacity for protein export and a greatly reduced level of manganese (Mn) in the secreted proteome. MeeF and MeeY copurify with proteins of the general secretory pathway, and in their absence the FtsH membrane protease is essential for viability. MeeF and MeeY are also required for efficient function of the Mn2+-dependent lipoteichoic acid synthase (LtaS), a membrane-localized enzyme with an extracytoplasmic active site. Thus, MeeF and MeeY, representative of the widely conserved TerC family of membrane transporters, function in the co-translocational metalation of Mn2+-dependent membrane and extracellular enzymes.
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Affiliation(s)
- Bixi He
- Department of Microbiology, Cornell University, 370 Wing Hall, 123 Wing Drive, Ithaca, NY, 14853-8101, USA
| | - Ankita J Sachla
- Department of Microbiology, Cornell University, 370 Wing Hall, 123 Wing Drive, Ithaca, NY, 14853-8101, USA
| | - John D Helmann
- Department of Microbiology, Cornell University, 370 Wing Hall, 123 Wing Drive, Ithaca, NY, 14853-8101, USA.
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4
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He B, Sachla AJ, Helmann JD. TerC Proteins Function During Protein Secretion to Metalate Exoenzymes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.10.536223. [PMID: 37090602 PMCID: PMC10120614 DOI: 10.1101/2023.04.10.536223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Cytosolic metalloenzymes acquire metals from buffered intracellular pools. How exported metalloenzymes are appropriately metalated is less clear. We provide evidence that TerC family proteins function in metalation of enzymes during export through the general secretion (Sec-dependent) pathway. Bacillus subtilis strains lacking MeeF(YceF) and MeeY(YkoY) have a reduced capacity for protein export and a greatly reduced level of manganese (Mn) in the secreted proteome. MeeF and MeeY copurify with proteins of the general secretory pathway, and in their absence the FtsH membrane protease is essential for viability. MeeF and MeeY are also required for efficient function of the Mn 2+ -dependent lipoteichoic acid synthase (LtaS), a membrane-localized enzyme with an extracytoplasmic active site. Thus, MeeF and MeeY, representative of the widely conserved TerC family of membrane transporters, function in the co-translocational metalation of Mn 2+ -dependent membrane and extracellular enzymes.
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Affiliation(s)
- Bixi He
- Department of Microbiology, Cornell University, 370 Wing Hall, 123 Wing Drive, Ithaca, New York 14853-8101, USA
| | - Ankita J. Sachla
- Department of Microbiology, Cornell University, 370 Wing Hall, 123 Wing Drive, Ithaca, New York 14853-8101, USA
| | - John D. Helmann
- Department of Microbiology, Cornell University, 370 Wing Hall, 123 Wing Drive, Ithaca, New York 14853-8101, USA
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Abuladze M, Asatiani N, Kartvelishvili T, Krivonos D, Popova N, Safonov A, Sapojnikova N, Yushin N, Zinicovscaia I. Adaptive Mechanisms of Shewanella xiamenensis DCB 2-1 Metallophilicity. TOXICS 2023; 11:304. [PMID: 37112530 PMCID: PMC10142276 DOI: 10.3390/toxics11040304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 03/14/2023] [Accepted: 03/22/2023] [Indexed: 06/19/2023]
Abstract
The dose-dependent effects of single metals (Zn, Ni, and Cu) and their combinations at steady time-actions on the cell viability of the bacteria Shewanella xiamenensis DCB 2-1, isolated from a radionuclide-contaminated area, have been estimated. The accumulation of metals by Shewanella xiamenensis DCB 2-1 in single and multi-metal systems was assessed using the inductively coupled plasma atomic emission spectroscopy. To estimate the response of the bacteria's antioxidant defense system, doses of 20 and 50 mg/L of single studied metals and 20 mg/L of each metal in their combinations (non-toxic doses, determined by the colony-forming viability assay) were used. Emphasis was given to catalase and superoxide dismutase since they form the primary line of defense against heavy metal action and their regulatory circuit of activity is crucial. The effect of metal ions on total thiol content, an indicator of cellular redox homeostasis, in bacterial cells was evaluated. Genome sequencing of Shewanella xiamenensis DCB 2-1 reveals genes responsible for heavy metal tolerance and detoxification, thereby improving understanding of the potential of the bacterial strain for bioremediation.
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Affiliation(s)
- Marina Abuladze
- Andronikashvili Institute of Physics, I. Javakhishvili Tbilisi State University, 6 Tamarashvili Str., 0162 Tbilisi, Georgia; (M.A.); (N.A.); (T.K.)
| | - Nino Asatiani
- Andronikashvili Institute of Physics, I. Javakhishvili Tbilisi State University, 6 Tamarashvili Str., 0162 Tbilisi, Georgia; (M.A.); (N.A.); (T.K.)
| | - Tamar Kartvelishvili
- Andronikashvili Institute of Physics, I. Javakhishvili Tbilisi State University, 6 Tamarashvili Str., 0162 Tbilisi, Georgia; (M.A.); (N.A.); (T.K.)
| | - Danil Krivonos
- Research Institute for Systems Biology and Medicine (RISBM), 18, Nauchniy Proezd, 117246 Moscow, Russia
- Department of Molecular and Translational Medicine, Moscow Institute of Physics and Technology, State University, 141700 Dolgoprudny, Russia
| | - Nadezhda Popova
- Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31, Leninsky Ave., 199071 Moscow, Russia; (N.P.); (A.S.)
| | - Alexey Safonov
- Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31, Leninsky Ave., 199071 Moscow, Russia; (N.P.); (A.S.)
| | - Nelly Sapojnikova
- Andronikashvili Institute of Physics, I. Javakhishvili Tbilisi State University, 6 Tamarashvili Str., 0162 Tbilisi, Georgia; (M.A.); (N.A.); (T.K.)
| | - Nikita Yushin
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, 6 Joliot-Curie Str., 141980 Dubna, Russia; (N.Y.); (I.Z.)
| | - Inga Zinicovscaia
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, 6 Joliot-Curie Str., 141980 Dubna, Russia; (N.Y.); (I.Z.)
- Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering, 30 Reactorului Str. MG-6, 077125 Bucharest, Romania
- The Institute of Chemistry, 3 Academiei Str., 2028 Chisinau, Moldova
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6
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Frei A, Verderosa AD, Elliott AG, Zuegg J, Blaskovich MAT. Metals to combat antimicrobial resistance. Nat Rev Chem 2023; 7:202-224. [PMID: 37117903 PMCID: PMC9907218 DOI: 10.1038/s41570-023-00463-4] [Citation(s) in RCA: 109] [Impact Index Per Article: 109.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/06/2023] [Indexed: 02/10/2023]
Abstract
Bacteria, similar to most organisms, have a love-hate relationship with metals: a specific metal may be essential for survival yet toxic in certain forms and concentrations. Metal ions have a long history of antimicrobial activity and have received increasing attention in recent years owing to the rise of antimicrobial resistance. The search for antibacterial agents now encompasses metal ions, nanoparticles and metal complexes with antimicrobial activity ('metalloantibiotics'). Although yet to be advanced to the clinic, metalloantibiotics are a vast and underexplored group of compounds that could lead to a much-needed new class of antibiotics. This Review summarizes recent developments in this growing field, focusing on advances in the development of metalloantibiotics, in particular, those for which the mechanism of action has been investigated. We also provide an overview of alternative uses of metal complexes to combat bacterial infections, including antimicrobial photodynamic therapy and radionuclide diagnosis of bacterial infections.
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Affiliation(s)
- Angelo Frei
- Community for Open Antimicrobial Drug Discovery, Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland, Australia.
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland.
| | - Anthony D Verderosa
- Community for Open Antimicrobial Drug Discovery, Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland, Australia
| | - Alysha G Elliott
- Community for Open Antimicrobial Drug Discovery, Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland, Australia
| | - Johannes Zuegg
- Community for Open Antimicrobial Drug Discovery, Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland, Australia
| | - Mark A T Blaskovich
- Community for Open Antimicrobial Drug Discovery, Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland, Australia.
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7
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Kim J, Lindahl PA. CUP1 Metallothionein from Healthy Saccharomyces cerevisiae Colocalizes to the Cytosol and Mitochondrial Intermembrane Space. Biochemistry 2023; 62:62-74. [PMID: 36503220 PMCID: PMC9813906 DOI: 10.1021/acs.biochem.2c00481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 10/26/2022] [Indexed: 12/14/2022]
Abstract
Liquid chromatography, mass spectrometry, and metal analyses of cytosol and mitochondrial filtrates from healthy copper-replete Saccharomyces cerevisiae cells revealed that metallothionein CUP1 was a notable copper-containing species in both compartments, with its abundance dependent upon the level of copper supplementation in the growth media. Electrospray ionization mass spectrometry of cytosol and soluble mitochondrial filtrates displayed a full isotopologue pattern of CUP1 in which the first eight amino acid residues were truncated and eight copper ions were bound. Neither apo-CUP1 nor intermediate copper-bound forms were detected, but chelator treatment could generate apo-CUP1. Mitoplasting revealed that mitochondrial CUP1 was located in the intermembrane space. Fluorescence microscopy demonstrated that 34 kDa CUP1-GFP entered the organelle, discounting the possibility that 7 kDa CUP1 enters folded and metalated through outer membrane pores. How CUP1 enters mitochondria remains unclear, as does its role within the organelle. Although speculative, mitochondrial CUP1 may limit the concentrations of low-molecular-mass copper complexes in the organelle.
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Affiliation(s)
- Joshua
E. Kim
- Department
of Chemistry, Texas A&M University, College Station, Texas 77843-3255, United States
| | - Paul A. Lindahl
- Department
of Chemistry, Texas A&M University, College Station, Texas 77843-3255, United States
- Department
of Biochemistry and Biophysics, Texas A&M
University, College Station, Texas 77843, United States
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8
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Zhang T, Zhang H. Electrochemical analysis for the rapid screening of copper-tolerant bacteria. Bioelectrochemistry 2022; 148:108276. [DOI: 10.1016/j.bioelechem.2022.108276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 09/15/2022] [Accepted: 09/20/2022] [Indexed: 11/16/2022]
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9
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Abstract
Copper is essential to most living beings but also highly toxic and as such is an important player at the host-pathogen interface. Bacteria have thus developed homeostatic mechanisms to tightly control its intracellular concentration. Known Cu export and import systems are under transcriptional control, whereas posttranscriptional regulatory mechanisms are yet to be characterized. We identified a three-gene operon, bp2923-bfrG-bp2921, downregulated by copper and notably encoding a TonB-dependent transporter in Bordetella pertussis. We show here that the protein encoded by the first gene, which is a member of the DUF2946 protein family, represents a new type of upstream Open Reading Frame (uORF) involved in posttranscriptional regulation of the downstream genes. In the absence of copper, the entire operon is transcribed and translated. Perception of copper by the nascent bp2923-coded protein via its conserved CXXC motif triggers Rho-dependent transcription termination between the first and second genes by relieving translation arrest on a conserved C-terminal RAPP motif. Homologs of bp2923 are widespread in bacterial genomes, where they head operons predicted to participate in copper homeostasis. This work has thus unveiled a new mode of genetic regulation by a transition metal and identified a regulatory function for a member of an uncharacterized family of bacterial proteins that we have named CruR, for copper-responsive upstream regulator.
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10
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Novoa-Aponte L, Argüello JM. Unique underlying principles shaping copper homeostasis networks. J Biol Inorg Chem 2022; 27:509-528. [PMID: 35802193 PMCID: PMC9470648 DOI: 10.1007/s00775-022-01947-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 05/27/2022] [Indexed: 12/27/2022]
Abstract
Abstract Copper is essential in cells as a cofactor for key redox enzymes. Bacteria have acquired molecular components that sense, uptake, distribute, and expel copper ensuring that cuproenzymes are metallated and steady-state metal levels are maintained. Toward preventing deleterious reactions, proteins bind copper ions with high affinities and transfer the metal via ligand exchange, warranting that copper ions are always complexed. Consequently, the directional copper distribution within cell compartments and across cell membranes requires specific dynamic interactions and metal exchange between cognate holo-apo protein partners. These metal exchange reactions are determined by thermodynamic and kinetics parameters and influenced by mass action. Then, copper distribution can be conceptualized as a molecular system of singular interacting elements that maintain a physiological copper homeostasis. This review focuses on the impact of copper high-affinity binding and exchange reactions on the homeostatic mechanisms, the conceptual models to describe the cell as a homeostatic system, the various molecule functions that contribute to copper homeostasis, and the alternative system architectures responsible for copper homeostasis in model bacteria. Graphical Abstract ![]()
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Affiliation(s)
- Lorena Novoa-Aponte
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, 60 Prescott St, Worcester, MA, 01605, USA.,Genetics and Metabolism Section, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD, 20892, USA
| | - José M Argüello
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, 60 Prescott St, Worcester, MA, 01605, USA.
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11
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Méndez AAE, Mendoza JI, Echarren ML, Terán I, Checa SK, Soncini FC. Evolution of Copper Homeostasis and Virulence in Salmonella. Front Microbiol 2022; 13:823176. [PMID: 35369444 PMCID: PMC8966772 DOI: 10.3389/fmicb.2022.823176] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 01/14/2022] [Indexed: 11/24/2022] Open
Abstract
Salmonella enterica sv. Typhimurium modulates the expression of factors essential for virulence, contributing to its survival against the surge of copper (Cu) in the Salmonella-containing vacuole. This bactericidal host innate immune component primarily targets the bacterial envelope, where most cuproproteins are localized. While in most enteric species periplasmic Cu homeostasis is maintained by the CusR/CusS-controlled CusCFBA efflux system encoded in the cus locus, we noticed that these genes were lost from the Salmonella-core genome. At the same time, Salmonella acquired cueP, coding for a periplasmic Cu chaperone. As cus, cueP was shown to be essential for bacterial survival in a copper-rich environment under anaerobiosis, suggesting that it can functionally substitute the CusCFBA system. In the present study, the whole Escherichia coli cus locus was reintroduced to the chromosome of the Salmonella wild-type or the ΔcueP strain. While the integrated cus locus did not affect Cu resistance under aerobic conditions, it increases Cu tolerance under anaerobiosis, irrespective of the presence or absence of cueP. In contrast to the Cus system, CueP expression is higher at high copper concentrations and persisted over time, suggesting separate functions. Finally, we observed that, regardless of the presence or absence of cus, a mutant deleted of cueP shows a deficiency in replication inside macrophages compared to the wild-type strain. Our results demonstrate that CueP and CusCFBA exert redundant functions for metal resistance, but not for intracellular survival, and therefore for the virulence of this pathogen.
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Affiliation(s)
- Andrea A E Méndez
- Instituto de Biología Molecular y Celular de Rosario, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Rosario, Argentina
| | - Julián I Mendoza
- Instituto de Biología Molecular y Celular de Rosario, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Rosario, Argentina
| | - María Laura Echarren
- Instituto de Biología Molecular y Celular de Rosario, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Rosario, Argentina
| | - Ignacio Terán
- Instituto de Biología Molecular y Celular de Rosario, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Rosario, Argentina
| | - Susana K Checa
- Instituto de Biología Molecular y Celular de Rosario, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Rosario, Argentina
| | - Fernando C Soncini
- Instituto de Biología Molecular y Celular de Rosario, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Rosario, Argentina
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12
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Hyre A, Casanova-Hampton K, Subashchandrabose S. Copper Homeostatic Mechanisms and Their Role in the Virulence of Escherichia coli and Salmonella enterica. EcoSal Plus 2021; 9:eESP00142020. [PMID: 34125582 PMCID: PMC8669021 DOI: 10.1128/ecosalplus.esp-0014-2020] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
Abstract
Copper is an essential micronutrient that also exerts toxic effects at high concentrations. This review summarizes the current state of knowledge on copper handling and homeostasis systems in Escherichia coli and Salmonella enterica. We describe the mechanisms by which transcriptional regulators, efflux pumps, detoxification enzymes, metallochaperones, and ancillary copper response systems orchestrate cellular response to copper stress. E. coli and S. enterica are important pathogens of humans and animals. We discuss the critical role of copper during killing of these pathogens by macrophages and in nutritional immunity at the bacterial-pathogen-host interface. In closing, we identify opportunities to advance our understanding of the biological roles of copper in these model enteric bacterial pathogens.
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Affiliation(s)
- Amanda Hyre
- Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX
- Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, NC
| | - Kaitlin Casanova-Hampton
- Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX
| | - Sargurunathan Subashchandrabose
- Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX
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13
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Lin S, Song Y, Huo Y, Wang Q, Liu X, Gao Y, Fan W, Huo M. Cu transport and distribution in different cellular fractions of Klebsiella oxytoca strain CAV 1374. JOURNAL OF HAZARDOUS MATERIALS 2021; 419:126416. [PMID: 34153614 DOI: 10.1016/j.jhazmat.2021.126416] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/31/2021] [Accepted: 06/14/2021] [Indexed: 06/13/2023]
Abstract
This study elucidated copper (Cu) transport and trafficking mechanisms at the cellular interface using the Cu-resistant strain Klebsiella oxytoca CAV 1374. The optimum conditions for biosorption were determined by investigating uptake rates due to initial pH, initial Cu concentrations, and maximum tolerated concentrations (MTC) of Cu. Cellular fraction analysis and depth-profiling XPS were used to comprehensively evaluate the spatial-temporal distribution of Cu on cellular interfaces during biosorption. Potential uptake mechanisms were then further examined by biosorption kinetics analyses, ion exchange experiments, FTIR analysis, and K+ channel blocking experiments. The results indicated that Cu was primarily absorbed by extracellular polymeric substances through chemical interactions and little Cu penetrated inside cells under low Cu stress conditions (≤20 mg/L). In contrast, an intracellular rate-controlling physical interaction was predominant under high Cu stress conditions (≥30 mg/L). Further, Cu2+ could be bound by functional groups, followed first by replacement of Ca2+ at the cell surface. Subsequently, some of the Cu2+ in cell walls was reduced to Cu+, and only Cu+ could then penetrate into cell membranes. These results indicate that strain Klebsiella oxytoca CAV 1374 is a suitable biosorbent agent for Cu removal and can provide critical insights into Cu-uptake mechanisms of microorganisms.
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Affiliation(s)
- Shanshan Lin
- School of Environment, Northeast Normal University, Changchun 130117, China
| | - Yinghao Song
- School of Environment, Northeast Normal University, Changchun 130117, China
| | - Yang Huo
- School of Environment, Northeast Normal University, Changchun 130117, China
| | - Qi Wang
- School of Environment, Northeast Normal University, Changchun 130117, China
| | - Xiangru Liu
- School of Environment, Northeast Normal University, Changchun 130117, China
| | - Ya Gao
- School of Environment, Northeast Normal University, Changchun 130117, China
| | - Wei Fan
- School of Environment, Northeast Normal University, Changchun 130117, China.
| | - Mingxin Huo
- School of Environment, Northeast Normal University, Changchun 130117, China
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14
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Betts HD, Neville SL, McDevitt CA, Sumby CJ, Harris HH. The biochemical fate of Ag + ions in Staphylococcus aureus, Escherichia coli, and biological media. J Inorg Biochem 2021; 225:111598. [PMID: 34517168 DOI: 10.1016/j.jinorgbio.2021.111598] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 08/03/2021] [Accepted: 08/28/2021] [Indexed: 01/16/2023]
Abstract
Silver is commonly included in a range of household and medical items to provide bactericidal action. Despite this, the chemical fate of the metal in both mammalian and bacterial systems remains poorly understood. Here, we applied a metallomics approach using X-ray absorption spectroscopy (XAS) and size-exclusion chromatography hyphenated with inductively coupled plasma mass spectrometry (SEC-ICP-MS) to advance our understanding of the biochemical fate of silver ions in bacterial culture and cells, and the chemistry associated with these interactions. When silver ions were added to lysogeny broth, silver was exclusively associated with moderately-sized species (~30 kDa) and bound by thiolate ligands. In two representative bacterial pathogens cultured in lysogeny broth including sub-lethal concentrations of ionic silver, silver was found in cells to be predominantly coordinated by thiolate species. The silver biomacromolecule-binding profile in Staphylococcus aureus and Escherichia coli was complex, with silver bound by a range of species spanning from 20 kDa to >1220 kDa. In bacterial cells, silver was nonuniformly colocalised with copper-bound proteins, suggesting that cellular copper processing may, in part, confuse silver for nutrient copper. Notably, in the treated cells, silver was not detected bound to low molecular weight compounds such as glutathione or bacillithiol.
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Affiliation(s)
- Harley D Betts
- Department of Chemistry, The University of Adelaide, South Australia 5005, Australia
| | - Stephanie L Neville
- The Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Victoria 3000, Australia
| | - Christopher A McDevitt
- The Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Victoria 3000, Australia
| | - Christopher J Sumby
- Department of Chemistry, The University of Adelaide, South Australia 5005, Australia
| | - Hugh H Harris
- Department of Chemistry, The University of Adelaide, South Australia 5005, Australia,.
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15
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Casanova-Hampton K, Carey A, Kassam S, Garner A, Donati GL, Thangamani S, Subashchandrabose S. A genome-wide screen reveals the involvement of enterobactin-mediated iron acquisition in Escherichia coli survival during copper stress. Metallomics 2021; 13:6355450. [PMID: 34415046 PMCID: PMC8419524 DOI: 10.1093/mtomcs/mfab052] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Accepted: 08/16/2021] [Indexed: 11/24/2022]
Abstract
Copper (Cu) is a key transition metal that is involved in many important biological processes in a cell. Cu is also utilized by the immune system to hamper pathogen growth during infection. However, genome-level knowledge on the mechanisms involved in adaptation to Cu stress is limited. Here, we report the results of a genome-wide reverse genetic screen for Cu-responsive phenotypes in Escherichia coli. Our screen has identified novel genes involved in adaptation to Cu stress in E. coli. We detected multiple genes involved in the biosynthesis and uptake of enterobactin, a siderophore utilized for high-affinity TonB-dependent acquisition of iron (Fe), as critical players in survival under Cu intoxication. We demonstrated the specificity of Cu-dependent killing by chelation of Cu and by genetic complementation of tonB. Notably, TonB is involved in protection from Cu in both laboratory and uropathogenic strains of E. coli. Cu stress leads to increased expression of the genes involved in Fe uptake, indicating that Fur regulon is derepressed during exposure to excess Cu. Trace element analyses revealed that Fe homeostasis is dysregulated during Cu stress. Taken together, our data supports a model in which lack of enterobactin-dependent Fe uptake leads to exacerbation of Cu toxicity, and elucidates the intricate connection between the homeostasis of Cu and Fe in a bacterial cell.
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Affiliation(s)
- Kaitlin Casanova-Hampton
- Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - Alexis Carey
- Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - Sarah Kassam
- Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - Alyssa Garner
- Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - George L Donati
- Department of Chemistry, Wake Forest University, Winston-Salem, NC, USA
| | - Shankar Thangamani
- Department of Pathology and Population Medicine, College of Veterinary Medicine, Midwestern University, Glendale, AZ, USA
| | - Sargurunathan Subashchandrabose
- Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
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16
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Zhen ZH, Qin S, Ren QM, Wang Y, Ma YY, Wang YC. Reciprocal Effect of Copper and Iron Regulation on the Proteome of Synechocystis sp. PCC 6803. Front Bioeng Biotechnol 2021; 9:673402. [PMID: 34041232 PMCID: PMC8141849 DOI: 10.3389/fbioe.2021.673402] [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: 02/27/2021] [Accepted: 04/14/2021] [Indexed: 11/13/2022] Open
Abstract
Cyanobacteria can acclimate to changing copper and iron concentrations in the environment via metal homeostasis, but a general mechanism for interpreting their dynamic relationships is sparse. In this study, we assessed growth and chlorophyll fluorescence of Synechocystis sp. PCC 6803 and investigated proteomic responses to copper and iron deductions. Results showed that copper and iron exerted reciprocal effect on the growth and photosynthesis of Synechocystis sp. PCC 6803 at combinations of different concentrations. And some proteins involved in the uptake of copper and iron and the photosynthetic electron transport system exhibit Cu-Fe proteomic association. The protein abundance under copper and iron deduction affected the photosynthetic electronic activity of Synechocystis sp. PCC 6803 and eventually affected the growth and photosynthesis. Based on these results, we hypothesize that the Cu-Fe proteomic association of Synechocystis sp. PCC 6803 can be elucidated via the uptake system of outer membrane-periplasmic space-inner plasma membrane-thylakoid membrane, and this association is mainly required to maintain electron transfer. This study provides a broader view regarding the proteomic association between Cu and Fe in cyanobacteria, which will shed light on the role of these two metal elements in cyanobacterial energy metabolism and biomass accumulation.
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Affiliation(s)
- Zhang-He Zhen
- Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Song Qin
- Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
| | - Qing-Min Ren
- Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Yu Wang
- Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China
| | - Yu-Ying Ma
- Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China
| | - Yin-Chu Wang
- Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
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17
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Giachino A, Focarelli F, Marles-Wright J, Waldron KJ. Synthetic biology approaches to copper remediation: bioleaching, accumulation and recycling. FEMS Microbiol Ecol 2021; 97:6021318. [PMID: 33501489 DOI: 10.1093/femsec/fiaa249] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 12/02/2020] [Indexed: 12/20/2022] Open
Abstract
One of the current aims of synthetic biology is the development of novel microorganisms that can mine economically important elements from the environment or remediate toxic waste compounds. Copper, in particular, is a high-priority target for bioremediation owing to its extensive use in the food, metal and electronic industries and its resulting common presence as an environmental pollutant. Even though microbe-aided copper biomining is a mature technology, its application to waste treatment and remediation of contaminated sites still requires further research and development. Crucially, any engineered copper-remediating chassis must survive in copper-rich environments and adapt to copper toxicity; they also require bespoke adaptations to specifically extract copper and safely accumulate it as a human-recoverable deposit to enable biorecycling. Here, we review current strategies in copper bioremediation, biomining and biorecycling, as well as strategies that extant bacteria use to enhance copper tolerance, accumulation and mineralization in the native environment. By describing the existing toolbox of copper homeostasis proteins from naturally occurring bacteria, we show how these modular systems can be exploited through synthetic biology to enhance the properties of engineered microbes for biotechnological copper recovery applications.
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Affiliation(s)
- Andrea Giachino
- Faculty of Medical Sciences, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, United Kingdom
| | - Francesca Focarelli
- Faculty of Medical Sciences, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, United Kingdom
| | - Jon Marles-Wright
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, United Kingdom
| | - Kevin J Waldron
- Faculty of Medical Sciences, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, United Kingdom
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18
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Fathollahi A, Khasteganan N, Coupe SJ, Newman AP. A meta-analysis of metal biosorption by suspended bacteria from three phyla. CHEMOSPHERE 2021; 268:129290. [PMID: 33383280 DOI: 10.1016/j.chemosphere.2020.129290] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 12/07/2020] [Accepted: 12/09/2020] [Indexed: 06/12/2023]
Abstract
Biosorption of heavy metals by bacterial biomass has been the subject of significant research interest in last decades due to its efficiency, relatively low cost and minimal negative effects for the surrounding environment. In this meta-analysis, the biosorption efficiencies of different bacterial strains for Cu(II), Cd(II), Zn(II), Cr(III), Mn(II), Pb(II) and Ni(II) were evaluated. Optimum conditions for the biosorption process such as initial metal concentration, temperature, pH, contact time, metal type, biomass dosage and bacterial phyla, were evaluated for each heavy metal. According to the results, the efficiencies of bacterial biomass for removal of heavy metal were as follows: Cd(II) > Cr(III) > Pb(II) > Zn(II) > Cu(II) > Ni(II) > Mn(II). Firmicute phyla showed the highest overall (living and dead) biosorption efficiency for heavy metals. Living biomass of Proteobacteria had the best biosorption performance. Living bacterial biomass was significantly more efficient in biosorption of Cu(II), Zn(II) and Pb(II) than dead biomass. The maximum biosorption efficiency of bacterial strains for Cd(II), Pb(II) and Zn(II) was achieved at pH values between 6 and 7.5. High temperatures (>35 °C) reduced the removal efficiencies for Cu(II) and Zn(II) and increased the efficiencies for Cd(II) and Cr(III) ions. The maximum biosorption efficiency of non-essential heavy metals occurred with short contact times (<2 h). Essential metals such as Zn and Cu were more efficiently removed with long biosorption durations (>24 h). The mean biosorption capacity of bacterial biomass was between 71.26 and 125.88 mg g-1. No publication bias existed according to Egger's and Begg's test results.
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Affiliation(s)
- Alireza Fathollahi
- Centre for Agroecology Water and Resilience (CAWR), Coventry University, Wolston Lane, Ryton on Dunsmore, CV8 3LG, UK.
| | | | - Stephen J Coupe
- Centre for Agroecology Water and Resilience (CAWR), Coventry University, Wolston Lane, Ryton on Dunsmore, CV8 3LG, UK
| | - Alan P Newman
- Faculty of Engineering and Computing, Coventry University, Coventry, UK
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19
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The Two-Component System CopRS Maintains Subfemtomolar Levels of Free Copper in the Periplasm of Pseudomonas aeruginosa Using a Phosphatase-Based Mechanism. mSphere 2020; 5:5/6/e01193-20. [PMID: 33361129 PMCID: PMC7763554 DOI: 10.1128/msphere.01193-20] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Copper is a micronutrient required as cofactor in redox enzymes. When free, copper is toxic, mismetallating proteins and generating damaging free radicals. Two-component systems control periplasmic Cu+ homeostasis in Gram-negative bacteria. In characterized systems such as Escherichia coli CusRS, upon Cu+ binding to the periplasmic sensing region of CusS, a cytoplasmic phosphotransfer domain of the sensor phosphorylates the response regulator CusR. This drives the expression of efflux transporters, chaperones, and redox enzymes to ameliorate metal toxic effects. Here, we show that the Pseudomonas aeruginosa two-component sensor histidine kinase CopS exhibits a Cu-dependent phosphatase activity that maintains CopR in a nonphosphorylated state when the periplasmic Cu levels are below the activation threshold of CopS. Upon Cu+ binding to the sensor, the phosphatase activity is blocked and the phosphorylated CopR activates transcription of the CopRS regulon. Supporting the model, mutagenesis experiments revealed that the ΔcopS strain exhibits maximal expression of the CopRS regulon, lower intracellular Cu+ levels, and increased Cu tolerance compared to wild-type cells. The invariant phosphoacceptor residue His235 of CopS was not required for the phosphatase activity itself but was necessary for its Cu dependency. To sense the metal, the periplasmic domain of CopS binds two Cu+ ions at its dimeric interface. Homology modeling of CopS based on CusS structure (four Ag+ binding sites) clearly supports the different binding stoichiometries in the two systems. Interestingly, CopS binds Cu+/2+ with 3 × 10−14 M affinity, pointing to the absence of free (hydrated) Cu+/2+ in the periplasm. IMPORTANCE Copper is a micronutrient required as cofactor in redox enzymes. When free, copper is toxic, mismetallating proteins and generating damaging free radicals. Consequently, copper overload is a strategy that eukaryotic cells use to combat pathogens. Bacteria have developed copper-sensing transcription factors to control copper homeostasis. The cell envelope is the first compartment that has to cope with copper stress. Dedicated two-component systems control the periplasmic response to metal overload. This paper shows that the sensor kinase of the copper-sensing two-component system present in Pseudomonadales exhibits a signal-dependent phosphatase activity controlling the activation of its cognate response regulator, distinct from previously described periplasmic Cu sensors. Importantly, the data show that the system is activated by copper levels compatible with the absence of free copper in the cell periplasm. These observations emphasize the diversity of molecular mechanisms that have evolved in bacteria to manage the copper cellular distribution.
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20
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Betts HD, Whitehead C, Harris HH. Silver in biology and medicine: opportunities for metallomics researchers. Metallomics 2020; 13:6029133. [PMID: 33570135 DOI: 10.1093/mtomcs/mfaa001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 12/06/2020] [Indexed: 12/13/2022]
Abstract
The antibacterial properties of silver have been known for centuries and the threat of antibiotic-resistant bacteria has led to renewed focus on the noble metal. Silver is now commonly included in a range of household and medical items to imbue them with bactericidal properties. Despite this, the chemical fate of the metal in biological systems is poorly understood. Silver(I) is a soft metal with high affinity for soft donor atoms and displays much similarity to the chemistry of Cu(I). In bacteria, interaction of silver with the cell wall/membrane, DNA, and proteins and enzymes can lead to cell death. Additionally, the intracellular generation of reactive oxygen species by silver is posited to be a significant antimicrobial action. While the antibacterial action of silver is well known, bacteria found in silver mines display resistance against it through use of a protein ensemble thought to have been specifically developed for the metal, highlighting the need for judicious use. In mammals, ∼10-20% of ingested silver is retained by the body and thought to predominantly localize in the liver or kidneys. Chronic exposure can result in argyria, a condition characterized by blue staining of the skin, resulting from subdermal deposition of silver [as Ag(0)/sulfides], but more insidious side effects, such as inclusions in the brain, seizures, liver/kidney damage, and immunosuppression, have also been reported. Here, we hope to highlight the current understanding of the biological chemistry of silver and the necessity for continued study of these systems to fill existing gaps in knowledge.
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Affiliation(s)
- Harley D Betts
- Department of Chemistry, The University of Adelaide, North Terrace, SA 5005, Australia
| | - Carole Whitehead
- Department of Chemistry, The University of Adelaide, North Terrace, SA 5005, Australia
| | - Hugh H Harris
- Department of Chemistry, The University of Adelaide, North Terrace, SA 5005, Australia
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21
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Andrei A, Öztürk Y, Khalfaoui-Hassani B, Rauch J, Marckmann D, Trasnea PI, Daldal F, Koch HG. Cu Homeostasis in Bacteria: The Ins and Outs. MEMBRANES 2020; 10:E242. [PMID: 32962054 PMCID: PMC7558416 DOI: 10.3390/membranes10090242] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 09/11/2020] [Accepted: 09/15/2020] [Indexed: 12/16/2022]
Abstract
Copper (Cu) is an essential trace element for all living organisms and used as cofactor in key enzymes of important biological processes, such as aerobic respiration or superoxide dismutation. However, due to its toxicity, cells have developed elaborate mechanisms for Cu homeostasis, which balance Cu supply for cuproprotein biogenesis with the need to remove excess Cu. This review summarizes our current knowledge on bacterial Cu homeostasis with a focus on Gram-negative bacteria and describes the multiple strategies that bacteria use for uptake, storage and export of Cu. We furthermore describe general mechanistic principles that aid the bacterial response to toxic Cu concentrations and illustrate dedicated Cu relay systems that facilitate Cu delivery for cuproenzyme biogenesis. Progress in understanding how bacteria avoid Cu poisoning while maintaining a certain Cu quota for cell proliferation is of particular importance for microbial pathogens because Cu is utilized by the host immune system for attenuating pathogen survival in host cells.
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Affiliation(s)
- Andreea Andrei
- Institut für Biochemie und Molekularbiologie, ZBMZ, Medizinische Fakultät, Albert-Ludwigs Universität Freiburg; Stefan Meier Str. 17, 79104 Freiburg, Germany; (A.A.); (Y.O.); (J.R.); (D.M.)
- Fakultät für Biologie, Albert-Ludwigs Universität Freiburg; Schänzlestrasse 1, 79104 Freiburg, Germany
| | - Yavuz Öztürk
- Institut für Biochemie und Molekularbiologie, ZBMZ, Medizinische Fakultät, Albert-Ludwigs Universität Freiburg; Stefan Meier Str. 17, 79104 Freiburg, Germany; (A.A.); (Y.O.); (J.R.); (D.M.)
| | | | - Juna Rauch
- Institut für Biochemie und Molekularbiologie, ZBMZ, Medizinische Fakultät, Albert-Ludwigs Universität Freiburg; Stefan Meier Str. 17, 79104 Freiburg, Germany; (A.A.); (Y.O.); (J.R.); (D.M.)
| | - Dorian Marckmann
- Institut für Biochemie und Molekularbiologie, ZBMZ, Medizinische Fakultät, Albert-Ludwigs Universität Freiburg; Stefan Meier Str. 17, 79104 Freiburg, Germany; (A.A.); (Y.O.); (J.R.); (D.M.)
| | | | - Fevzi Daldal
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA;
| | - Hans-Georg Koch
- Institut für Biochemie und Molekularbiologie, ZBMZ, Medizinische Fakultät, Albert-Ludwigs Universität Freiburg; Stefan Meier Str. 17, 79104 Freiburg, Germany; (A.A.); (Y.O.); (J.R.); (D.M.)
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22
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Applying Statistical Design of Experiments To Understanding the Effect of Growth Medium Components on Cupriavidus necator H16 Growth. Appl Environ Microbiol 2020; 86:AEM.00705-20. [PMID: 32561588 PMCID: PMC7440812 DOI: 10.1128/aem.00705-20] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 05/31/2020] [Indexed: 01/06/2023] Open
Abstract
Chemically defined media (CDM) for cultivation of C. necator vary in components and compositions. This lack of consensus makes it difficult to optimize new processes for the bacterium. This study employed statistical design of experiments (DOE) to understand how basic components of defined media affect C. necator growth. Our growth model predicts that C. necator can be cultivated to high cell density with components held at low concentrations, arguing that CDM for large-scale cultivation of the bacterium for industrial purposes will be economically competitive. Although existing CDM for the bacterium are without amino acids, addition of a few amino acids to growth medium shortened lag phase of growth. The interactions highlighted by our growth model show how factors can interact with each other during a process to positively or negatively affect process output. This approach is efficient, relying on few well-structured experimental runs to gain maximum information on a biological process, growth. Cupriavidus necator H16 is gaining significant attention as a microbial chassis for range of biotechnological applications. While the bacterium is a major producer of bioplastics, its lithoautotrophic and versatile metabolic capabilities make the bacterium a promising microbial chassis for biofuels and chemicals using renewable resources. It remains necessary to develop appropriate experimental resources to permit controlled bioengineering and system optimization of this microbe. In this study, we employed statistical design of experiments to gain understanding of the impact of components of defined media on C. necator growth and built a model that can predict the bacterium’s cell density based on medium components. This highlighted medium components, and interaction between components, having the most effect on growth: fructose, amino acids, trace elements, CaCl2, and Na2HPO4 contributed significantly to growth (t values of <−1.65 or >1.65); copper and histidine were found to interact and must be balanced for robust growth. Our model was experimentally validated and found to correlate well (r2 = 0.85). Model validation at large culture scales showed correlations between our model-predicted growth ranks and experimentally determined ranks at 100 ml in shake flasks (ρ = 0.87) and 1 liter in a bioreactor (ρ = 0.90). Our approach provides valuable and quantifiable insights on the impact of medium components on cell growth and can be applied to model other C. necator responses that are crucial for its deployment as a microbial chassis. This approach can be extended to other nonmodel microbes of medical and industrial biotechnological importance. IMPORTANCE Chemically defined media (CDM) for cultivation of C. necator vary in components and compositions. This lack of consensus makes it difficult to optimize new processes for the bacterium. This study employed statistical design of experiments (DOE) to understand how basic components of defined media affect C. necator growth. Our growth model predicts that C. necator can be cultivated to high cell density with components held at low concentrations, arguing that CDM for large-scale cultivation of the bacterium for industrial purposes will be economically competitive. Although existing CDM for the bacterium are without amino acids, addition of a few amino acids to growth medium shortened lag phase of growth. The interactions highlighted by our growth model show how factors can interact with each other during a process to positively or negatively affect process output. This approach is efficient, relying on few well-structured experimental runs to gain maximum information on a biological process, growth.
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23
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Zhang Q, Fang G, Chen W, Zhong X, Long Y, Qin H, Ye J. The molecular effects of ultrasound on the expression of cellular proteome. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 720:137439. [PMID: 32143036 DOI: 10.1016/j.scitotenv.2020.137439] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 02/18/2020] [Accepted: 02/18/2020] [Indexed: 06/10/2023]
Abstract
High frequency and low intensity, diagnostic ultrasound methods are recognized to be safe in epidemiology and pathology but the bioeffects of these methods on molecular and proteomic levels are unknown. As a representative organism that can directly reflect the molecular response to stresses, Escherichia coli was selected for exposure to ultrasound probes C1-5, M5s and 9 L for 10 min and 20 min. ITRAQ was used to measure the expression of the cellular proteome. The results showed that both the frequency and time of exposure to ultrasound affected the proteome expression. Fifty biological processes were affected and nineteen metabolic processes, including carbohydrate metabolism, asparagine metabolism and phosphate import were differentially regulated. Lower frequency ultrasound caused copper export and iron‑sulfur cluster biosynthesis upregulation. Nine proteins (GlpD, AsnB, TdcB, CopA, IscR, IscU, IscS, IscA, RecA) were key for the adaption to ultrasound. Accordingly, the results of the potential risks based on the calculation of the orthologous genome clarified that relevant pathways and potentially sensitive individuals were worthy of further study. These findings offer insights into reveal the bioeffects of ultrasound at the metabolic network and proteomic levels.
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Affiliation(s)
- Qinglin Zhang
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 510632, China
| | - Guiting Fang
- Department of Ultrasound, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Weijian Chen
- Department of Ultrasound, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Xing Zhong
- Department of Ultrasound, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Yan Long
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 510632, China
| | - Huaming Qin
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 510632, China
| | - Jinshao Ye
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 510632, China.
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24
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Giachino A, Waldron KJ. Copper tolerance in bacteria requires the activation of multiple accessory pathways. Mol Microbiol 2020; 114:377-390. [DOI: 10.1111/mmi.14522] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 04/18/2020] [Accepted: 04/20/2020] [Indexed: 12/17/2022]
Affiliation(s)
- Andrea Giachino
- Biosciences Institute Faculty of Medical Sciences Newcastle University Newcastle upon Tyne UK
| | - Kevin J. Waldron
- Biosciences Institute Faculty of Medical Sciences Newcastle University Newcastle upon Tyne UK
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25
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Selamoglu N, Önder Ö, Öztürk Y, Khalfaoui-Hassani B, Blaby-Haas CE, Garcia BA, Koch HG, Daldal F. Comparative differential cuproproteomes of Rhodobacter capsulatus reveal novel copper homeostasis related proteins. Metallomics 2020; 12:572-591. [PMID: 32149296 PMCID: PMC7192791 DOI: 10.1039/c9mt00314b] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 02/28/2020] [Indexed: 12/20/2022]
Abstract
Copper (Cu) is an essential, but toxic, micronutrient for living organisms and cells have developed sophisticated response mechanisms towards both the lack and the excess of Cu in their environments. In this study, we achieved a global view of Cu-responsive changes in the prokaryotic model organism Rhodobacter capsulatus using label-free quantitative differential proteomics. Semi-aerobically grown cells under heterotrophic conditions in minimal medium (∼0.3 μM Cu) were compared with cells supplemented with either 5 μM Cu or with 5 mM of the Cu-chelator bathocuproine sulfonate. Mass spectrometry based bottom-up proteomics of unfractionated cell lysates identified 2430 of the 3632 putative proteins encoded by the genome, producing a robust proteome dataset for R. capsulatus. Use of biological and technical replicates for each growth condition yielded high reproducibility and reliable quantification for 1926 of the identified proteins. Comparison of cells grown under Cu-excess or Cu-depleted conditions to those grown under minimal Cu-sufficient conditions revealed that 75 proteins exhibited statistically significant (p < 0.05) abundance changes, ranging from 2- to 300-fold. A subset of the highly Cu-responsive proteins was orthogonally probed using molecular genetics, validating that several of them were indeed involved in cellular Cu homeostasis.
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Affiliation(s)
- Nur Selamoglu
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA.
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26
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Pantidos N, Horsfall L. Understanding the role of SilE in the production of metal nanoparticles by Morganella psychrotolerans using MicroScale Thermophoresis. N Biotechnol 2020; 55:1-4. [PMID: 31539639 DOI: 10.1016/j.nbt.2019.09.002] [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: 11/23/2018] [Revised: 09/06/2019] [Accepted: 09/14/2019] [Indexed: 10/26/2022]
Abstract
Metal nanoparticle synthesis has been observed in several species of bacteria but the underlying mechanisms of synthesis are not well understood. Morganella psychrotolerans is a Gram-negative psychrophilic bacterium that is able to tolerate relatively high concentrations of Cu and Ag ions, and it is through the associated resistance pathways that this species is able to convert metal ions to nanoparticles. The purpose of this study was to investigate the mechanism of nanoparticle synthesis, looking at the interaction of the metal binding protein SilE with metal ions using MicroScale Thermophoresis (MST). MST assays give a rapid and accurate determination of binding affinities, allowing for the testing of SilE with a range of environmentally significant metal ions. The binding affinities (Kd) of Ag+ and Cu2+ were measured as 0.17 mM and 0.13 mM respectively, consistent with the observations of strong binding reported in the literature, whereas the binding to Al3+ and Co2+ was measured as Kd values of 4.19 mM and 1.35 mM respectively.
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Affiliation(s)
- Nikolaos Pantidos
- School of Biological Sciences and Centre for Science at Extreme Conditions, University of Edinburgh, The King's Buildings, Alexander Crum Brown Road, Roger Land Building, Edinburgh, EH9 3FF, United Kingdom
| | - Louise Horsfall
- School of Biological Sciences and Centre for Science at Extreme Conditions, University of Edinburgh, The King's Buildings, Alexander Crum Brown Road, Roger Land Building, Edinburgh, EH9 3FF, United Kingdom.
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27
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Fisher OS, Sendzik MR, Ross MO, Lawton TJ, Hoffman BM, Rosenzweig AC. PCu AC domains from methane-oxidizing bacteria use a histidine brace to bind copper. J Biol Chem 2019; 294:16351-16363. [PMID: 31527086 PMCID: PMC6827282 DOI: 10.1074/jbc.ra119.010093] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 09/09/2019] [Indexed: 01/07/2023] Open
Abstract
Copper is critically important for methanotrophic bacteria because their primary metabolic enzyme, particulate methane monooxygenase (pMMO), is copper-dependent. In addition to pMMO, many other copper proteins are encoded in the genomes of methanotrophs, including proteins that contain periplasmic copper-Achaperone (PCuAC) domains. Using bioinformatics analyses, we identified three distinct classes of PCuAC domain-containing proteins in methanotrophs, termed PmoF1, PmoF2, and PmoF3. PCuAC domains from other types of bacteria bind a single Cu(I) ion via an HXnMX21/22HXM motif, which is also present in PmoF3, but PmoF1 and PmoF2 lack this motif entirely. Instead, the PCuAC domains of PmoF1 and PmoF2 bind only Cu(II), and PmoF1 binds additional Cu(II) ions in a His-rich extension to its PCuAC domain. Crystal structures of the PmoF1 and PmoF2 PCuAC domains reveal that Cu(II) is coordinated by an N-terminal histidine brace HX10H motif. This binding site is distinct from those of previously characterized PCuAC domains but resembles copper centers in CopC proteins and lytic polysaccharide monooxygenase (LPMO) enzymes. Bioinformatics analysis of the entire PCuAC family reveals previously unappreciated diversity, including sequences that contain both the HXnMX21/22HXM and HX10H motifs, and sequences that lack either set of copper-binding ligands. These findings provide the first characterization of an additional class of copper proteins from methanotrophs, further expand the PCuAC family, and afford new insight into the biological significance of histidine brace-mediated copper coordination.
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Affiliation(s)
- Oriana S. Fisher
- Departments of Molecular Biosciences and of Chemistry, Northwestern University, Evanston, Illinois 60208
| | - Madison R. Sendzik
- Departments of Molecular Biosciences and of Chemistry, Northwestern University, Evanston, Illinois 60208
| | - Matthew O. Ross
- Departments of Molecular Biosciences and of Chemistry, Northwestern University, Evanston, Illinois 60208
| | - Thomas J. Lawton
- Departments of Molecular Biosciences and of Chemistry, Northwestern University, Evanston, Illinois 60208
| | - Brian M. Hoffman
- Departments of Molecular Biosciences and of Chemistry, Northwestern University, Evanston, Illinois 60208
| | - Amy C. Rosenzweig
- Departments of Molecular Biosciences and of Chemistry, Northwestern University, Evanston, Illinois 60208, To whom correspondence should be addressed:
Depts. of Molecular Biosciences and Chemistry, Northwestern University, Evanston, IL 60208. Tel.:
847-467-5301; Fax:
847-467-6489; E-mail:
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28
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The cbb 3-type cytochrome oxidase assembly factor CcoG is a widely distributed cupric reductase. Proc Natl Acad Sci U S A 2019; 116:21166-21175. [PMID: 31570589 DOI: 10.1073/pnas.1913803116] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Copper (Cu)-containing proteins execute essential functions in prokaryotic and eukaryotic cells, but their biogenesis is challenged by high Cu toxicity and the preferential presence of Cu(II) under aerobic conditions, while Cu(I) is the preferred substrate for Cu chaperones and Cu-transport proteins. These proteins form a coordinated network that prevents Cu accumulation, which would lead to toxic effects such as Fenton-like reactions and mismetalation of other metalloproteins. Simultaneously, Cu-transport proteins and Cu chaperones sustain Cu(I) supply for cuproprotein biogenesis and are therefore essential for the biogenesis of Cu-containing proteins. In eukaryotes, Cu(I) is supplied for import and trafficking by cell-surface exposed metalloreductases, but specific cupric reductases have not been identified in bacteria. It was generally assumed that the reducing environment of the bacterial cytoplasm would suffice to provide sufficient Cu(I) for detoxification and cuproprotein synthesis. Here, we identify the proposed cbb 3-type cytochrome c oxidase (cbb 3-Cox) assembly factor CcoG as a cupric reductase that binds Cu via conserved cysteine motifs and contains 2 low-potential [4Fe-4S] clusters required for Cu(II) reduction. Deletion of ccoG or mutation of the cysteine residues results in defective cbb 3-Cox assembly and Cu sensitivity. Furthermore, anaerobically purified CcoG catalyzes Cu(II) but not Fe(III) reduction in vitro using an artificial electron donor. Thus, CcoG is a bacterial cupric reductase and a founding member of a widespread class of enzymes that generate Cu(I) in the bacterial cytosol by using [4Fe-4S] clusters.
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29
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Antoine R, Rivera-Millot A, Roy G, Jacob-Dubuisson F. Relationships Between Copper-Related Proteomes and Lifestyles in β Proteobacteria. Front Microbiol 2019; 10:2217. [PMID: 31608037 PMCID: PMC6769254 DOI: 10.3389/fmicb.2019.02217] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 09/11/2019] [Indexed: 12/25/2022] Open
Abstract
Copper is an essential transition metal whose redox properties are used for a variety of enzymatic oxido-reductions and in electron transfer chains. It is also toxic to living beings, and therefore its cellular concentration must be strictly controlled. We have performed in silico analyses of the predicted proteomes of more than one hundred species of β proteobacteria to characterize their copper-related proteomes, including cuproproteins, i.e., proteins with active-site copper ions, copper chaperones, and copper-homeostasis systems. Copper-related proteomes represent between 0 and 1.48% of the total proteomes of β proteobacteria. The numbers of cuproproteins are globally proportional to the proteome sizes in all phylogenetic groups and strongly linked to aerobic respiration. In contrast, environmental bacteria have considerably larger proportions of copper-homeostasis systems than the other groups of bacteria, irrespective of their proteome sizes. Evolution toward commensalism, obligate, host-restricted pathogenesis or symbiosis is globally reflected in the loss of copper-homeostasis systems. In endosymbionts, defense systems and copper chaperones have disappeared, whereas residual cuproenzymes are electron transfer proteins for aerobic respiration. Lifestyle is thus a major determinant of the size and composition of the copper-related proteome, and it is particularly reflected in systems involved in copper homeostasis. Analyses of the copper-related proteomes of a number of species belonging to the Burkholderia, Bordetella, and Neisseria genera indicates that commensals are in the process of shedding their copper-homeostasis systems and chaperones to greater extents yet than pathogens.
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Affiliation(s)
| | | | | | - Françoise Jacob-Dubuisson
- Université de Lille, CNRS, INSERM, CHU Lille, Institut Pasteur de Lille, U1019 – UMR 8204 – Center for Infection and Immunity of Lille, Lille, France
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Canonica F, Hennecke H, Glockshuber R. Biochemical pathway for the biosynthesis of the Cu A center in bacterial cytochrome c oxidase. FEBS Lett 2019; 593:2977-2989. [PMID: 31449676 DOI: 10.1002/1873-3468.13587] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 08/21/2019] [Accepted: 08/22/2019] [Indexed: 01/25/2023]
Abstract
The di-copper center CuA is an essential metal cofactor in cytochrome oxidase (Cox) of mitochondria and many prokaryotes, mediating one-electron transfer from cytochrome c to the site for oxygen reduction. CuA is located in subunit II (CoxB) of Cox and protrudes into the periplasm of Gram-negative bacteria or the mitochondrial intermembrane space. How the two copper ions are brought together to build CoxB·CuA is the subject of this review. It had been known that the reductase TlpA and the metallochaperones ScoI and PcuC are required for CuA formation in bacteria, but the mechanism of copper transfer has emerged only recently for the Bradyrhizobium diazoefficiens system. It consists of the following steps: (a) TlpA keeps the active site cysteine pair of CoxB in its dithiol state as a prerequisite for metal insertion; (b) ScoI·Cu2+ rapidly forms a transient complex with apo-CoxB; (c) PcuC, loaded with Cu1+ and Cu2+ , dissociates this complex to CoxB·Cu2+ , and a second PcuC·Cu1+ ·Cu2+ transfers Cu1+ to CoxB·Cu2+ , yielding mature CoxB·CuA . Variants of this pathway might exist in other bacteria or mitochondria.
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Affiliation(s)
- Fabia Canonica
- Institute of Molecular Biology and Biophysics, ETH Zurich, Switzerland
| | | | - Rudi Glockshuber
- Institute of Molecular Biology and Biophysics, ETH Zurich, Switzerland
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31
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A Mutagenic Screen Identifies a TonB-Dependent Receptor Required for the Lanthanide Metal Switch in the Type I Methanotroph "Methylotuvimicrobium buryatense" 5GB1C. J Bacteriol 2019; 201:JB.00120-19. [PMID: 31085692 DOI: 10.1128/jb.00120-19] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 05/07/2019] [Indexed: 12/23/2022] Open
Abstract
Several of the metabolic enzymes in methanotrophic bacteria rely on metals for both their expression and their catalysis. The MxaFI methanol dehydrogenase enzyme complex uses calcium as a cofactor to oxidize methanol, while the alternative methanol dehydrogenase XoxF uses lanthanide metals such as lanthanum and cerium for the same function. Lanthanide metals, abundant in the earth's crust, strongly repress the transcription of mxaF yet activate the transcription of xoxF This regulatory program, called the "lanthanide switch," is central to methylotrophic metabolism, but only some of its components are known. To uncover additional components of the lanthanide switch, we developed a chemical mutagenesis system in the type I gammaproteobacterial methanotroph "Methylotuvimicrobium buryatense" 5GB1C and designed a selection system for mutants unable to repress the mxaF promoter in the presence of lanthanum. Whole-genome resequencing for multiple lanthanide switch mutants identified several unique point mutations in a single gene encoding a TonB-dependent receptor, which we have named LanA. The LanA TonB-dependent receptor is absolutely required for the lanthanide switch and controls the expression of a small set of genes. While mutation of the lanA gene does not affect the amount of cell-associated lanthanum, it is essential for growth in the absence of the MxaF methanol dehydrogenase, suggesting that LanA is involved in lanthanum uptake to supply the XoxF methanol dehydrogenase with its critical metal ion cofactor. The discovery of this novel component of the lanthanide regulatory system highlights the complexity of this circuit and suggests that further components are likely involved.IMPORTANCE Lanthanide metals, or rare earth elements, are abundant in nature and used heavily in technological devices. Biological interactions with lanthanides are just beginning to be unraveled. Until very recently, microbial mechanisms of lanthanide metal interaction and uptake were unknown. The TonB-dependent receptor LanA is the first lanthanum receptor identified in a methanotroph. Sequence homology searches with known metal transporters and regulators could not be used to identify LanA or other lanthanide metal switch components, and this method for mutagenesis and selection was required to identify the receptor. This work advances the knowledge of microbe-metal interactions in environmental niches that impact atmospheric methane levels and are thus relevant to climate change.
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32
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Hunsaker EW, Franz KJ. Emerging Opportunities To Manipulate Metal Trafficking for Therapeutic Benefit. Inorg Chem 2019; 58:13528-13545. [PMID: 31247859 DOI: 10.1021/acs.inorgchem.9b01029] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The indispensable requirement for metals in life processes has led to the evolution of sophisticated mechanisms that allow organisms to maintain dynamic equilibria of these ions. This dynamic control of the level, speciation, and availability of a variety of metal ions allows organisms to sustain biological processes while avoiding toxicity. When functioning properly, these mechanisms allow cells to return to their metal homeostatic set points following shifts in the metal availability or other stressors. These periods of transition, when cells are in a state of flux in which they work to regain homeostasis, present windows of opportunity to pharmacologically manipulate targets associated with metal-trafficking pathways in ways that could either facilitate a return to homeostasis and the recovery of cellular function or further push cells outside of homeostasis and into cellular distress. The purpose of this Viewpoint is to highlight emerging opportunities for chemists and chemical biologists to develop compounds to manipulate metal-trafficking processes for therapeutic benefit.
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Affiliation(s)
- Elizabeth W Hunsaker
- Department of Chemistry , Duke University , French Family Science Center, 124 Science Drive , Durham , North Carolina 27708 , United States
| | - Katherine J Franz
- Department of Chemistry , Duke University , French Family Science Center, 124 Science Drive , Durham , North Carolina 27708 , United States
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33
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Quesille-Villalobos AM, Parra A, Maza F, Navarrete P, González M, Latorre M, Toro M, Reyes-Jara A. The Combined Effect of Cold and Copper Stresses on the Proliferation and Transcriptional Response of Listeria monocytogenes. Front Microbiol 2019; 10:612. [PMID: 30984140 PMCID: PMC6447683 DOI: 10.3389/fmicb.2019.00612] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 03/11/2019] [Indexed: 11/13/2022] Open
Abstract
Listeria monocytogenes is a foodborne pathogen that can cause severe disease in susceptible humans. This microorganism has the ability to adapt to hostile environmental conditions such as the low temperatures used by the food industry for controlling microorganisms. Bacteria are able to adjust their transcriptional response to adapt to stressful conditions in order to maintain cell homeostasis. Understanding the transcriptional response of L. monocytogenes to stressing conditions could be relevant to develop new strategies to control the pathogen. A possible alternative for controlling microorganisms in the food industry could be to use copper as an antimicrobial agent. The present study characterized three L. monocytogenes strains (List2-2, Apa13-2, and Al152-2A) adapted to low temperature and challenged with different copper concentrations. Similar MIC-Cu values were observed among studied strains, but growth kinetic parameters revealed that strain List2-2 was the least affected by the presence of copper at 8°C. This strain was selected for a global transcriptional response study after a 1 h exposition to 0.5 mM of CuSO4 × 5H2O at 8 and 37°C. The results showed that L. monocytogenes apparently decreases its metabolism in response to copper, and this reduction is greater at 8°C than at 37°C. The most affected metabolic pathways were carbohydrates, lipids and nucleotides synthesis. Finally, 15 genes were selected to evaluate the conservation of the transcriptional response in the other two strains. Results indicated that only genes related to copper homeostasis showed a high degree of conservation between the strains studied, suggesting that a low number of genes is implicated in the response to copper stress in L. monocytogenes. These results contribute to the understanding of the molecular mechanisms used by bacteria to overcome a combination of stresses. This study concluded that the application of copper in low concentrations in cold environments may help to control foodborne pathogens as L. monocytogenes in the industry.
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Affiliation(s)
- Ana María Quesille-Villalobos
- Laboratorio de Microbiología y Probióticos, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile
| | - Angel Parra
- Laboratorio de Microbiología y Probióticos, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile
| | - Felipe Maza
- Laboratorio de Microbiología y Probióticos, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile
| | - Paola Navarrete
- Laboratorio de Microbiología y Probióticos, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile
- Millennium Nucleus in the Biology of Intestinal Microbiota, Santiago, Chile
| | - Mauricio González
- Laboratorio de Bioinformática y Expresión Génica, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile
- FONDAP Center for Genome Regulation (CGR), Santiago, Chile
- Mathomics, Center for Mathematical Modeling, Universidad de Chile, Santiago, Chile
| | - Mauricio Latorre
- Laboratorio de Bioinformática y Expresión Génica, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile
- FONDAP Center for Genome Regulation (CGR), Santiago, Chile
- Mathomics, Center for Mathematical Modeling, Universidad de Chile, Santiago, Chile
- Instituto de Ciencias de la Ingeniería, Universidad de O’Higgins, Rancagua, Chile
| | - Magaly Toro
- Laboratorio de Microbiología y Probióticos, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile
| | - Angélica Reyes-Jara
- Laboratorio de Microbiología y Probióticos, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile
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34
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Utz M, Andrei A, Milanov M, Trasnea PI, Marckmann D, Daldal F, Koch HG. The Cu chaperone CopZ is required for Cu homeostasis in Rhodobacter capsulatus and influences cytochrome cbb 3 oxidase assembly. Mol Microbiol 2019; 111:764-783. [PMID: 30582886 DOI: 10.1111/mmi.14190] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/19/2018] [Indexed: 12/19/2022]
Abstract
Cu homeostasis depends on a tightly regulated network of proteins that transport or sequester Cu, preventing the accumulation of this toxic metal while sustaining Cu supply for cuproproteins. In Rhodobacter capsulatus, Cu-detoxification and Cu delivery for cytochrome c oxidase (cbb3 -Cox) assembly depend on two distinct Cu-exporting P1B -type ATPases. The low-affinity CopA is suggested to export excess Cu and the high-affinity CcoI feeds Cu into a periplasmic Cu relay system required for cbb3 -Cox biogenesis. In most organisms, CopA-like ATPases receive Cu for export from small Cu chaperones like CopZ. However, whether these chaperones are also involved in Cu export via CcoI-like ATPases is unknown. Here we identified a CopZ-like chaperone in R. capsulatus, determined its cellular concentration and its Cu binding activity. Our data demonstrate that CopZ has a strong propensity to form redox-sensitive dimers via two conserved cysteine residues. A ΔcopZ strain, like a ΔcopA strain, is Cu-sensitive and accumulates intracellular Cu. In the absence of CopZ, cbb3 -Cox activity is reduced, suggesting that CopZ not only supplies Cu to P1B -type ATPases for detoxification but also for cuproprotein assembly via CcoI. This finding was further supported by the identification of a ~150 kDa CcoI-CopZ protein complex in native R. capsulatus membranes.
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Affiliation(s)
- Marcel Utz
- Faculty of Medicine, Institut für Biochemie und Molekularbiologie, ZBMZ, Albert-Ludwigs-Universität Freiburg, Stefan-Meier-Strasse 17, Freiburg, 79104, Germany
| | - Andreea Andrei
- Faculty of Medicine, Institut für Biochemie und Molekularbiologie, ZBMZ, Albert-Ludwigs-Universität Freiburg, Stefan-Meier-Strasse 17, Freiburg, 79104, Germany.,Fakultät für Biologie, Albert-Ludwigs-Universität Freiburg, Freiburg, 79104, Germany
| | - Martin Milanov
- Faculty of Medicine, Institut für Biochemie und Molekularbiologie, ZBMZ, Albert-Ludwigs-Universität Freiburg, Stefan-Meier-Strasse 17, Freiburg, 79104, Germany
| | - Petru-Iulian Trasnea
- Faculty of Medicine, Institut für Biochemie und Molekularbiologie, ZBMZ, Albert-Ludwigs-Universität Freiburg, Stefan-Meier-Strasse 17, Freiburg, 79104, Germany.,Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Dorian Marckmann
- Faculty of Medicine, Institut für Biochemie und Molekularbiologie, ZBMZ, Albert-Ludwigs-Universität Freiburg, Stefan-Meier-Strasse 17, Freiburg, 79104, Germany
| | - Fevzi Daldal
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Hans-Georg Koch
- Faculty of Medicine, Institut für Biochemie und Molekularbiologie, ZBMZ, Albert-Ludwigs-Universität Freiburg, Stefan-Meier-Strasse 17, Freiburg, 79104, Germany
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35
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Favre L, Ortalo-Magné A, Kerloch L, Pichereaux C, Misson B, Briand JF, Garnier C, Culioli G. Metabolomic and proteomic changes induced by growth inhibitory concentrations of copper in the biofilm-forming marine bacteriumPseudoalteromonas lipolytica. Metallomics 2019; 11:1887-1899. [DOI: 10.1039/c9mt00184k] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Copper exposure inP. lipolyticaTC8 revealed changes in cell membrane lipid composition and in copper cell homeostasis protein regulation.
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Affiliation(s)
| | | | | | - Carole Pichereaux
- Fédération de Recherche FR3450
- Agrobiosciences
- Interaction et Biodiversité (AIB)
- CNRS
- Toulouse
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