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Ishihara JI, Mekubo T, Kusaka C, Kondo S, Oiko R, Igarashi K, Aiba H, Ishikawa S, Ogasawara N, Oshima T, Takahashi H. A critical role of the periplasm in copper homeostasis in Gram-negative bacteria. Biosystems 2023; 231:104980. [PMID: 37453610 DOI: 10.1016/j.biosystems.2023.104980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 06/18/2023] [Accepted: 07/07/2023] [Indexed: 07/18/2023]
Abstract
Copper is essential for life, but is toxic in excess. Copper homeostasis is achieved in the cytoplasm and the periplasm as a unique feature of Gram-negative bacteria. Especially, it has become clear the role of the periplasm and periplasmic proteins regarding whole-cell copper homeostasis. Here, we addressed the role of the periplasm and periplasmic proteins in copper homeostasis using a Systems Biology approach integrating experiments with models. Our analysis shows that most of the copper-bound molecules localize in the periplasm but not cytoplasm, suggesting that Escherichia coli utilizes the periplasm to sense the copper concentration in the medium and sequester copper ions. In particular, a periplasmic multi-copper oxidase CueO and copper-responsive transcriptional factor CusS contribute both to protection against Cu(I) toxicity and to incorporating copper into the periplasmic components/proteins. We propose that Gram-negative bacteria have evolved mechanisms to sense and store copper in the periplasm to expand their living niches.
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Affiliation(s)
- Jun-Ichi Ishihara
- Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba City, Chiba, 260-8673, Japan
| | - Tomohiro Mekubo
- Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5, Takayama-cho, Ikoma, Nara, 630-0192, Japan
| | - Chikako Kusaka
- Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5, Takayama-cho, Ikoma, Nara, 630-0192, Japan
| | - Suguru Kondo
- Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5, Takayama-cho, Ikoma, Nara, 630-0192, Japan
| | - Ryotaro Oiko
- Graduate School of Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu City, Toyama, 939-0398, Japan
| | - Kensuke Igarashi
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohiraku, Sapporo, Hokkaido, 062-8517, Japan
| | - Hirofumi Aiba
- Graduate School of Pharmaceutical Sciences, Nagoya University, Pharmaceutical Sciences Building, Furocho, Chikusa-ku, Aichi, 464-8601, Japan
| | - Shu Ishikawa
- Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku Kobe, 657-8501, Japan
| | - Naotake Ogasawara
- Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5, Takayama-cho, Ikoma, Nara, 630-0192, Japan
| | - Taku Oshima
- Graduate School of Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu City, Toyama, 939-0398, Japan.
| | - Hiroki Takahashi
- Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba City, Chiba, 260-8673, Japan; Molecular Chirality Research Center, Chiba University, Chiba, Japan; Plant Molecular Science Center, Chiba University, Chiba, Japan.
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2
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Li YQ, Wang MJ, Luo CB. Highly efficient polyhydroxyalkanoate production from lignin using genetically engineered Halomonas sp. Y3. BIORESOURCE TECHNOLOGY 2023; 370:128526. [PMID: 36572161 DOI: 10.1016/j.biortech.2022.128526] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 12/20/2022] [Accepted: 12/21/2022] [Indexed: 06/17/2023]
Abstract
Lignin degradation represents a significant challenge in biological valorization, but it is suffering from insufficiency, putting barriers to efficient lignin conversion. Herein, the study first develops a highly efficient laccase secretion apparatus, enabling high enzyme activity of 184 U/mL, complementing the biochemical limits on lignin depolymerization well in Halomonas sp. Y3. Further engineering of PHA biosynthesis produces a significantly high PHA titer of 286, 742, and 868 mg/L from alkaline lignin, catechol, and protocatechuate, respectively. The integration of laccase-secretion and PHA production modules enables a record titer of 693 and 1209 mg/L in converting lignin and lignin-containing stream to PHA, respectively. The titer is improved furtherly to 740 and 1314 mg/L by developing a non-sterilized fermentation. This study advances a cheaper and greener production of valuable chemicals from lignin by constructing a biosynthetic platform for PHA production and provides novel insight into the lignin conversion by extremophilic microbes.
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Affiliation(s)
- Yuan-Qiu Li
- College of Life Science, Leshan Normal University, Leshan 614000, China; College of Life Sciences, Capital Normal University, Beijing 100064, China
| | - Ming-Jun Wang
- College of Life Science, Leshan Normal University, Leshan 614000, China
| | - Chao-Bing Luo
- College of Life Science, Leshan Normal University, Leshan 614000, China.
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3
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Kram W, Rebl H, de la Cruz JE, Haag A, Renner J, Epting T, Springer A, Soria F, Wienecke M, Hakenberg OW. Interactive Effects of Copper-Doped Urological Implants with Tissue in the Urinary Tract for the Inhibition of Cell Adhesion and Encrustation in the Animal Model Rat. Polymers (Basel) 2022; 14:polym14163324. [PMID: 36015581 PMCID: PMC9412396 DOI: 10.3390/polym14163324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 07/25/2022] [Accepted: 07/28/2022] [Indexed: 11/20/2022] Open
Abstract
The insertion of a ureteral stent provides acute care by restoring urine flow and alleviating urinary retention or dysfunction. The problems of encrustation, bacterial colonization and biofilm formation become increasingly important when ureteral stents are left in place for a longer period of time. One way to reduce encrustation and bacterial adherence is to modify the stent surface with a diamond-like carbon coating, in combination with copper doping. The biocompatibilities of the Elastollan® base material and the a-C:H/Cu-mulitilayer coating were tested in synthetic urine. The copper content in bladder tissue was determined by atomic absorption spectroscopy and in blood and in urine by inductively coupled plasma mass spectrometry. Encrustations on the materials were analyzed by scanning electron microscopy, energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. A therapeutic window for copper ions of 0.5–1.0 mM was determined to kill bacteria without affecting human urothelial cells. In the rat animal model, it was found that copper release did not reach toxic concentrations in the affecting tissue of the urinary tract or in the blood. The encrustation behavior of the surfaces showed that the roughness of the amorphous carbon layer with the copper doping is probably the causal factor for the higher encrustation.
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Affiliation(s)
- Wolfgang Kram
- Department of Urology, Rostock University Medical Center, Schillingallee 35, 18057 Rostock, Germany
- Correspondence:
| | - Henrike Rebl
- Department of Cell Biology, Rostock University Medical Center, Schillingallee 69, 18057 Rostock, Germany
| | - Julia E. de la Cruz
- Jesús Usón Minimally Invasive Surgery Centre, Carretera N-521, Km. 41.8, 10071 Cáceres, Spain
| | - Antonia Haag
- Department of Urology, Rostock University Medical Center, Schillingallee 35, 18057 Rostock, Germany
| | - Jürgen Renner
- Institute for Polymer- and Production Technologies e. V., Alter Holzhafen 19, 23966 Wismar, Germany
| | - Thomas Epting
- Institute for Clinical Chemistry and Laboratory Medicine, Medical Center, Faculty of Medicine, University of Freiburg, Hugstetterstraße 55, 79106 Freiburg, Germany
| | - Armin Springer
- Electron Microscopy Center, Rostock University Medical Center, Strempelstraße 14, 18057 Rostock, Germany
| | - Federico Soria
- Jesús Usón Minimally Invasive Surgery Centre, Carretera N-521, Km. 41.8, 10071 Cáceres, Spain
| | | | - Oliver W. Hakenberg
- Department of Urology, Rostock University Medical Center, Schillingallee 35, 18057 Rostock, Germany
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4
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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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Virieux-Petit M, Hammer-Dedet F, Aujoulat F, Jumas-Bilak E, Romano-Bertrand S. From Copper Tolerance to Resistance in Pseudomonas aeruginosa towards Patho-Adaptation and Hospital Success. Genes (Basel) 2022; 13:genes13020301. [PMID: 35205346 PMCID: PMC8872213 DOI: 10.3390/genes13020301] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 01/27/2022] [Accepted: 02/01/2022] [Indexed: 02/01/2023] Open
Abstract
The hospital environment constitutes a reservoir of opportunistic pathogens responsible for healthcare-associated infections (HCAI) such as Pseudomonas aeruginosa (Pa). Pa persistence within technological niches, the increasing emergence of epidemic high-risk clones in HCAI, the epidemiological link between plumbing strains and clinical strains, make it a major nosocomial pathogen. Therefore, understanding the mechanisms of Pa adaptation to hospital water systems would be useful in preventing HCAI. This review deciphers how copper resistance contributes to Pa adaptation and persistence in a hospital environment, especially within copper water systems, and ultimately to its success as a causative agent of HCAI. Numerous factors are involved in copper homeostasis in Pa, among which active efflux conferring copper tolerance, and copper-binding proteins regulating the copper compartmentalization between periplasm and cytoplasm. The functional harmony of copper homeostasis is regulated by several transcriptional regulators. The genomic island GI-7 appeared as especially responsible for the copper resistance in Pa. Mechanisms of copper and antibiotic cross-resistance and co-resistance are also identified, with potential co-regulation processes between them. Finally, copper resistance of Pa confers selective advantages in colonizing and persisting in hospital environments but also appears as an asset at the host/pathogen interface that helps in HCAI occurrence.
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Affiliation(s)
- Maxine Virieux-Petit
- HydroSciences Montpellier, IRD, CNRS, Montpellier University, 34093 Montpellier, France; (M.V.-P.); (F.H.-D.); (F.A.); (E.J.-B.)
| | - Florence Hammer-Dedet
- HydroSciences Montpellier, IRD, CNRS, Montpellier University, 34093 Montpellier, France; (M.V.-P.); (F.H.-D.); (F.A.); (E.J.-B.)
| | - Fabien Aujoulat
- HydroSciences Montpellier, IRD, CNRS, Montpellier University, 34093 Montpellier, France; (M.V.-P.); (F.H.-D.); (F.A.); (E.J.-B.)
| | - Estelle Jumas-Bilak
- HydroSciences Montpellier, IRD, CNRS, Montpellier University, 34093 Montpellier, France; (M.V.-P.); (F.H.-D.); (F.A.); (E.J.-B.)
- Hospital Hygiene and Infection Control Team, University Hospital of Montpellier, 34093 Montpellier, France
| | - Sara Romano-Bertrand
- HydroSciences Montpellier, IRD, CNRS, Montpellier University, 34093 Montpellier, France; (M.V.-P.); (F.H.-D.); (F.A.); (E.J.-B.)
- Hospital Hygiene and Infection Control Team, University Hospital of Montpellier, 34093 Montpellier, France
- UMR 5151 HSM, Equipe Pathogènes Hydriques Santé et Environnements, U.F.R. des Sciences Pharmaceutiques et Biologiques, Université Montpellier, 15, Avenue Charles Flahault, BP 14491, CEDEX 5, 34093 Montpellier, France
- Correspondence: ; Tel.: +33-4-11-75-94-30
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Hofmann L, Hirsch M, Ruthstein S. Advances in Understanding of the Copper Homeostasis in Pseudomonas aeruginosa. Int J Mol Sci 2021; 22:2050. [PMID: 33669570 PMCID: PMC7922089 DOI: 10.3390/ijms22042050] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 02/10/2021] [Accepted: 02/15/2021] [Indexed: 12/12/2022] Open
Abstract
Thirty-five thousand people die as a result of more than 2.8 million antibiotic-resistant infections in the United States of America per year. Pseudomonas aeruginosa (P. aeruginosa) is classified a serious threat, the second-highest threat category of the U.S. Department of Health and Human Services. Among others, the World Health Organization (WHO) encourages the discovery and development of novel antibiotic classes with new targets and mechanisms of action without cross-resistance to existing classes. To find potential new target sites in pathogenic bacteria, such as P. aeruginosa, it is inevitable to fully understand the molecular mechanism of homeostasis, metabolism, regulation, growth, and resistances thereof. P. aeruginosa maintains a sophisticated copper defense cascade comprising three stages, resembling those of public safety organizations. These stages include copper scavenging, first responder, and second responder. Similar mechanisms are found in numerous pathogens. Here we compare the copper-dependent transcription regulators cueR and copRS of Escherichia coli (E. coli) and P. aeruginosa. Further, phylogenetic analysis and structural modelling of mexPQ-opmE reveal that this efflux pump is unlikely to be involved in the copper export of P. aeruginosa. Altogether, we present current understandings of the copper homeostasis in P. aeruginosa and potential new target sites for antimicrobial agents or a combinatorial drug regimen in the fight against multidrug resistant pathogens.
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Affiliation(s)
| | | | - Sharon Ruthstein
- Institute of Nanotechnology and Advanced Materials & Department of Chemistry, Faculty of Exact Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel; (L.H.); (M.H.)
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7
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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: 7] [Impact Index Per Article: 1.8] [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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8
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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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9
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Li K, Xia C, Qiao Y, Liu X. Dose-response relationships between copper and its biocompatibility/antibacterial activities. J Trace Elem Med Biol 2019; 55:127-135. [PMID: 31345350 DOI: 10.1016/j.jtemb.2019.06.015] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 06/06/2019] [Accepted: 06/19/2019] [Indexed: 11/22/2022]
Abstract
BACKGROUND Copper has already been widely used in the modification of biomaterials because it possesses multifunctional biological effects like osteogenic, angiogenic and antibacterial activities. However, it is still not clear how different cell lines and bacteria will respond to different concentrations of Cu2+, which is very critical to the application of copper-doped implants. METHODS This study aimed to explore the dose-response relationships of Cu2+ and its biological effects in vitro. Rat bone marrow mesenchymal stem cell (rBMSCs), mouse osteoblastic cell line (MC3T3-E1), and human umbilical vein endothelial cells (HUVECs) were used to evaluate cellular behaviors. Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) were used to evaluate bacterial behaviors. RESULTS Results showed that the HUVECs exhibited significantly higher tolerance to copper ions than MC3T3-E1 and rBMSCs. The IC50 values of copper for HUVECs, MC3T3-E1 and HUVECs were approximated to 327.9 μM, 134.6 μM, and 0.7 μM, respectively. Besides, the threshold concentration of copper for effective inhibition against bacteria growth is 37 μM. When the concentration exceeded the threshold value, antibacterial activity could increase dramatically. CONCLUSIONS These results altogether establish a technological foundation for the application of copper-doped biomaterials in bone growth and remodeling.
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Affiliation(s)
- Kunqiang Li
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China; Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chao Xia
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China; Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yuqin Qiao
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China.
| | - Xuanyong Liu
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China; Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
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10
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Novoa-Aponte L, Ramírez D, Argüello JM. The interplay of the metallosensor CueR with two distinct CopZ chaperones defines copper homeostasis in Pseudomonas aeruginosa. J Biol Chem 2019; 294:4934-4945. [PMID: 30718281 DOI: 10.1074/jbc.ra118.006316] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 01/31/2019] [Indexed: 12/27/2022] Open
Abstract
Copper homeostasis in pathogenic bacteria is critical for cuproprotein assembly and virulence. However, in vivo biochemical analyses of these processes are challenging, which has prevented defining and quantifying the homeostatic interplay between Cu+-sensing transcriptional regulators, chaperones, and sequestering molecules. The cytoplasm of Pseudomonas aeruginosa contains a Cu+-sensing transcriptional regulator, CueR, and two homologous metal chaperones, CopZ1 and CopZ2, forming a unique system for studying Cu+ homeostasis. We found here that both chaperones exchange Cu+, albeit at a slow rate, reaching equilibrium after 3 h, a time much longer than P. aeruginosa duplication time. Therefore, they appeared as two separate cellular Cu+ pools. Although both chaperones transferred Cu+ to CueR in vitro, experiments in vivo indicated that CopZ1 metallates CueR, eliciting the translation of Cu+ efflux transporters involved in metal tolerance. Although this observation was consistent with the relative Cu+ affinities of the three proteins (CopZ1 < CueR < CopZ2), in vitro and in silico analyses also indicated a stronger interaction between CopZ1 and CueR that was independent of Cu+ In contrast, CopZ2 function was defined by its distinctly high abundance during Cu2+ stress. Under resting conditions, CopZ2 remained largely in its apo form. Metal stress quickly induced CopZ2 expression, and its holo form predominated, reaching levels commensurate with the cytoplasmic Cu+ levels. In summary, these results show that CopZ1 acts as chaperone delivering Cu+ to the CueR sensor, whereas CopZ2 functions as a fast-response Cu+-sequestering storage protein. We propose that equivalent proteins likely play similar roles in most bacterial systems.
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Affiliation(s)
- Lorena Novoa-Aponte
- From the Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts 01605
| | - David Ramírez
- From the Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts 01605
| | - José M Argüello
- From the Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts 01605
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11
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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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