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Li B, Zhang X, Wu G, Qin B, Tefsen B, Wells M. Toxins from harmful algal blooms: How copper and iron render chalkophore a predictor of microcystin production. WATER RESEARCH 2023; 244:120490. [PMID: 37659180 DOI: 10.1016/j.watres.2023.120490] [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: 05/24/2023] [Revised: 07/17/2023] [Accepted: 08/13/2023] [Indexed: 09/04/2023]
Abstract
Research on harmful algal blooms has focused on macronutrients, yet recent research increasingly indicates that understanding micronutrient roles is also important in the development of effective environmental management interventions. Here, we report results on metallophore production from mesocosms amended with copper and iron (enzymatic co-factors in photosynthetic electron transport) to probe questions of how cyanobacteria navigate the divide between copper nutrition, copper toxicity, and issues with iron bioavailability. These experiments utilized Microcystis, Chlorella and Desmodesmus spp., in mono- and mixed-cultures in lake water from a large, hypereutrophic lake (Taihu, China). To initiate experiments, copper and iron amendments were added to mesocosms containing algae that had been acclimated to achieve a state of copper and iron limitation. Mesocosms were analyzed over time for a range of analytes including algal growth parameters, algal assemblage progression, copper/iron concentrations and biomolecule production of chalkophore, siderophore and total microcystins. Community Trajectory Analysis and other multivariate methods were used for analysis resulting in our findings: 1) Microcystis spp. manage copper/iron requirements though a dynamically phased behavior of chalkophore/siderophore production according to their copper and iron limitation status (chalkophore correlates with Cu concentration, R2 = 0.99, and siderophore correlates with the sum of Cu and Fe concentrations, R2 = 0.98). 2) A strong correlation was observed between the production of chalkophore and the cyanobacterial toxin microcystin (R2 = 0.76)-Chalkophore is a predictor of microcystin production. 3) Based on our results and literature, we posit that Microcystis spp. produces microcystin in response to copper/iron availability to manage photosystem productivity and effect an energy-saving status. Results from this work underscore the importance of micronutrients in influencing harmful algal bloom progression and represents a major advance in understanding the ecological function for the cyanobacterial toxin microcystin as a hallmark of micronutrient limitation stress.
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Affiliation(s)
- Boling Li
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, Jiangsu, 215123, China
| | - Xiaokai Zhang
- Institute of Environmental Processes and Pollution Control, and School of Environmental and Civil Engineering, Jiangnan University, Wuxi, 214122, China
| | - Gongjie Wu
- Department of Biochemistry and Systems Biology, University of Liverpool, Brownlow Hill, Liverpool, L69 7ZX, UK; Department of Biological Sciences, Xi'an Jiaotong-Liverpool University, Suzhou, Jiangsu, 215123, China
| | - Boqiang Qin
- Taihu Laboratory for Lake Ecosystem Research, State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Boris Tefsen
- Microbiology, Department of Biology, Utrecht University, Padualaan 8, 3584 CH, Utrecht, the Netherlands; Ronin Institute, 127 Haddon Place, Montclair, NJ, 07043, USA.
| | - Mona Wells
- Ronin Institute, 127 Haddon Place, Montclair, NJ, 07043, USA; Meadows Center for Water and the Environment, Texas State University, San Marcos, Texas, 78666, USA.
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Splan KE, Choi SR, Claycomb RE, Eckart-Frank IK, Nagdev S, Rodemeier ME. Disruption of zinc (II) binding and dimeric protein structure of the XIAP-RING domain by copper (I) ions. J Biol Inorg Chem 2023:10.1007/s00775-023-02002-4. [PMID: 37268744 DOI: 10.1007/s00775-023-02002-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 04/15/2023] [Indexed: 06/04/2023]
Abstract
Modulation of metalloprotein structure and function via metal ion substitution may constitute a molecular basis for metal ion toxicity and/or metal-mediated functional control. The X-linked Inhibitor of Apoptosis Protein (XIAP) is a metalloprotein that requires zinc for proper structure and function. In addition to its role as a modulator of apoptosis, XIAP has been implicated in copper homeostasis. Given the similar coordination preferences of copper and zinc, investigation of XIAP structure and function upon interaction with copper is relevant. The Really Interesting New Gene (RING) domain of XIAP is representative of a class of zinc finger proteins that utilize a bi-nuclear zinc-binding motif to maintain proper structure and ubiquitin ligase function. Herein, we report the characterization of copper (I) binding to the Zn2-RING domain of XIAP. Electronic absorption studies that monitor copper-thiolate interactions demonstrate that the RING domain of XIAP binds 5-6 Cu(I) ions and that copper is thermodynamically preferred relative to zinc. Repetition of the experiments in the presence of the Zn(II)-specific dye Mag-Fura2 shows that Cu(I) addition results in Zn(II) ejection from the protein, even in the presence of glutathione. Loss of dimeric structure of the RING domain, which is a requirement for its ubiquitin ligase activity, upon copper substitution at the zinc-binding sites, was readily observed via size exclusion chromatography. These results provide a molecular basis for the modulation of RING function by copper and add to the growing body of literature that describe the impact of Cu(I) on zinc metalloprotein structure and function.
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Affiliation(s)
- Kathryn E Splan
- Department of Chemistry, Macalester College, 1600 Grand Avenue, Saint Paul, MN, 55105, USA.
| | - Sylvia R Choi
- Department of Chemistry, Macalester College, 1600 Grand Avenue, Saint Paul, MN, 55105, USA
| | - Ruth E Claycomb
- Department of Chemistry, Macalester College, 1600 Grand Avenue, Saint Paul, MN, 55105, USA
| | - Isaiah K Eckart-Frank
- Department of Chemistry, Macalester College, 1600 Grand Avenue, Saint Paul, MN, 55105, USA
| | - Shreya Nagdev
- Department of Chemistry, Macalester College, 1600 Grand Avenue, Saint Paul, MN, 55105, USA
| | - Madeline E Rodemeier
- Department of Chemistry, Macalester College, 1600 Grand Avenue, Saint Paul, MN, 55105, USA
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Lee J, Dalton RA, Baslé A, Vita N, Dennison C. Important Structural Features of Thiolate-Rich Four-Helix Bundles for Cu(I) Uptake and Removal. Inorg Chem 2023; 62:6617-6628. [PMID: 37057906 PMCID: PMC10155185 DOI: 10.1021/acs.inorgchem.2c04490] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Indexed: 04/15/2023]
Abstract
A family of bacterial copper storage proteins (the Csps) possess thiolate-lined four-helix bundles whose cores can be filled with Cu(I) ions. The majority of Csps are cytosolic (Csp3s), and in vitro studies carried out to date indicate that the Csp3s from Methylosinus trichosporium OB3b (MtCsp3), Bacillus subtilis (BsCsp3), and Streptomyces lividans (SlCsp3) are alike. Bioinformatics have highlighted homologues with potentially different Cu(I)-binding properties from these characterized "classical" Csp3s. Determination herein of the crystal structure of the protein (RkCsp3) from the methanotroph Methylocystis sp. strain Rockwell with Cu(I) bound identifies this as the first studied example of a new subgroup of Csp3s. The most significant structural difference from classical Csp3s is the presence of only two Cu(I) sites at the mouth of the bundle via which Cu(I) ions enter and leave. This is due to the absence of three Cys residues and a His-containing motif, which allow classical Csp3s to bind five to six Cu(I) ions in this region. Regardless, RkCsp3 exhibits rapid Cu(I) binding and the fastest measured Cu(I) removal rate for a Csp3 when using high-affinity ligands as surrogate partners. New experiments on classical Csp3s demonstrate that their His-containing motif is not essential for fast Cu(I) uptake and removal. Other structural features that could be important for these functionally relevant in vitro properties are discussed.
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Affiliation(s)
- Jaeick Lee
- Biosciences Institute, Newcastle University, Newcastle
upon Tyne NE2 4HH, U.K.
| | - Rosemary A. Dalton
- Biosciences Institute, Newcastle University, Newcastle
upon Tyne NE2 4HH, U.K.
| | - Arnaud Baslé
- Biosciences Institute, Newcastle University, Newcastle
upon Tyne NE2 4HH, U.K.
| | - Nicolas Vita
- Biosciences Institute, Newcastle University, Newcastle
upon Tyne NE2 4HH, U.K.
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Furukawa Y, Matsumoto K, Nakagome K, Shintani A, Sue K. Zinc-mediated interaction of copper chaperones through their heavy-metal associated domains. J Trace Elem Med Biol 2023; 75:127111. [PMID: 36435150 DOI: 10.1016/j.jtemb.2022.127111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 10/24/2022] [Accepted: 11/21/2022] [Indexed: 11/25/2022]
Abstract
BACKGROUND A copper chaperone CCS is a multi-domain protein that supplies a copper ion to Cu/Zn-superoxide dismutase (SOD1). Among the domains of CCS, the N-terminal domain (CCSdI) belongs to a heavy metal-associated (HMA) domain, in which a Cys-x-x-Cys (CxxC) motif binds a heavy metal ion. It has hence been expected that the HMA domain in CCS has a role in the metal trafficking; however, the CxxC motif in the domain is dispensable for supplying a copper ion to SOD1, leaving an open question on roles of CCSdI in CCS. METHODS To evaluate protein-protein interactions of CCS through CCSdI, yeast two-hybrid assay, a pull-down assay using recombinant proteins, and the analysis with fluorescence resonance energy transfer were performed. RESULTS We found that CCS specifically interacted with another copper chaperone HAH1, a HMA domain protein, through CCSdI. The interaction between CCSdI and HAH1 was not involved in the copper supply from CCS to SOD1 but was mediated by a zinc ion ligated with Cys residues of the CxxC motifs in CCSdI and HAH1. CONCLUSION While physiological significance of the interaction between copper chaperones awaits further investigation, we propose that CCSdI would have a role in the metal-mediated interaction with other proteins including heterologous copper chaperones.
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Affiliation(s)
| | - Kyoka Matsumoto
- Department of Chemistry, Keio University, Yokohama 223-8522, Japan
| | - Kenta Nakagome
- Department of Chemistry, Keio University, Yokohama 223-8522, Japan
| | - Atsuko Shintani
- Department of Chemistry, Keio University, Yokohama 223-8522, Japan
| | - Kaori Sue
- Department of Chemistry, Keio University, Yokohama 223-8522, Japan
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Emerging Trends of Nanotechnology and Genetic Engineering in Cyanobacteria to Optimize Production for Future Applications. LIFE (BASEL, SWITZERLAND) 2022; 12:life12122013. [PMID: 36556378 PMCID: PMC9781209 DOI: 10.3390/life12122013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 11/20/2022] [Accepted: 11/28/2022] [Indexed: 12/12/2022]
Abstract
Nanotechnology has the potential to revolutionize various fields of research and development. Multiple nanoparticles employed in a nanotechnology process are the magic elixir that provides unique features that are not present in the component's natural form. In the framework of contemporary research, it is inappropriate to synthesize microparticles employing procedures that include noxious elements. For this reason, scientists are investigating safer ways to produce genetically improved Cyanobacteria, which has many novel features and acts as a potential candidate for nanoparticle synthesis. In recent decades, cyanobacteria have garnered significant interest due to their prospective nanotechnological uses. This review will outline the applications of genetically engineered cyanobacteria in the field of nanotechnology and discuss its challenges and future potential. The evolution of cyanobacterial strains by genetic engineering is subsequently outlined. Furthermore, the recombination approaches that may be used to increase the industrial potential of cyanobacteria are discussed. This review provides an overview of the research undertaken to increase the commercial avenues of cyanobacteria and attempts to explain prospective topics for future research.
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Crystal Structure of the Human Copper Chaperone ATOX1 Bound to Zinc Ion. Biomolecules 2022; 12:biom12101494. [PMID: 36291703 PMCID: PMC9599288 DOI: 10.3390/biom12101494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 10/09/2022] [Accepted: 10/10/2022] [Indexed: 11/17/2022] Open
Abstract
The bioavailability of copper (Cu) in human cells may depend on a complex interplay with zinc (Zn) ions. We investigated the ability of the Zn ion to target the human Cu-chaperone Atox1, a small cytosolic protein capable of anchoring Cu(I), by a conserved surface-exposed Cys-X-X-Cys (CXXC) motif, and deliver it to Cu-transporting ATPases in the trans-Golgi network. The crystal structure of Atox1 loaded with Zn displays the metal ion bridging the CXXC motifs of two Atox1 molecules in a homodimer. The identity and location of the Zn ion were confirmed through the anomalous scattering of the metal by collecting X-ray diffraction data near the Zn K-edge. Furthermore, soaking experiments of the Zn-loaded Atox1 crystals with a strong chelating agent, such as EDTA, caused only limited removal of the metal ion from the tetrahedral coordination cage, suggesting a potential role of Atox1 in Zn metabolism and, more generally, that Cu and Zn transport mechanisms could be interlocked in human cells.
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Dragone M, Grazioso R, D’Abrosca G, Baglivo I, Iacovino R, Esposito S, Paladino A, Pedone PV, Russo L, Fattorusso R, Malgieri G, Isernia C. Copper (I) or (II) Replacement of the Structural Zinc Ion in the Prokaryotic Zinc Finger Ros Does Not Result in a Functional Domain. Int J Mol Sci 2022; 23:ijms231911010. [PMID: 36232306 PMCID: PMC9569694 DOI: 10.3390/ijms231911010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 09/09/2022] [Accepted: 09/15/2022] [Indexed: 11/16/2022] Open
Abstract
A strict interplay is known to involve copper and zinc in many cellular processes. For this reason, the results of copper’s interaction with zinc binding proteins are of great interest. For instance, copper interferences with the DNA-binding activity of zinc finger proteins are associated with the development of a variety of diseases. The biological impact of copper depends on the chemical properties of its two common oxidation states (Cu(I) and Cu(II)). In this framework, following the attention addressed to unveil the effect of metal ion replacement in zinc fingers and in zinc-containing proteins, we explore the effects of the Zn(II) to Cu(I) or Cu(II) replacement in the prokaryotic zinc finger domain. The prokaryotic zinc finger protein Ros, involved in the horizontal transfer of genes from A. tumefaciens to a host plant infected by it, belongs to a family of proteins, namely Ros/MucR, whose members have been recognized in different bacteria symbionts and pathogens of mammals and plants. Interestingly, the amino acids of the coordination sphere are poorly conserved in most of these proteins, although their sequence identity can be very high. In fact, some members of this family of proteins do not bind zinc or any other metal, but assume a 3D structure similar to that of Ros with the residues replacing the zinc ligands, forming a network of hydrogen bonds and hydrophobic interactions that surrogates the Zn-coordinating role. These peculiar features of the Ros ZF domain prompted us to study the metal ion replacement with ions that have different electronic configuration and ionic radius. The protein was intensely studied as a perfectly suited model of a metal-binding protein to study the effects of the metal ion replacement; it appeared to tolerate the Zn to Cd substitution, but not the replacement of the wildtype metal by Ni(II), Pb(II) and Hg(II). The structural characterization reported here gives a high-resolution description of the interaction of copper with Ros, demonstrating that copper, in both oxidation states, binds the protein, but the replacement does not give rise to a functional domain.
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Affiliation(s)
- Martina Dragone
- Department of Environmental, Biological and Pharmaceutical Science and Technology, University of Campania “Luigi Vanvitelli”, Via Vivaldi 43, 81100 Caserta, Italy
| | - Rinaldo Grazioso
- Department of Environmental, Biological and Pharmaceutical Science and Technology, University of Campania “Luigi Vanvitelli”, Via Vivaldi 43, 81100 Caserta, Italy
| | - Gianluca D’Abrosca
- Department of Environmental, Biological and Pharmaceutical Science and Technology, University of Campania “Luigi Vanvitelli”, Via Vivaldi 43, 81100 Caserta, Italy
| | - Ilaria Baglivo
- Department of Environmental, Biological and Pharmaceutical Science and Technology, University of Campania “Luigi Vanvitelli”, Via Vivaldi 43, 81100 Caserta, Italy
| | - Rosa Iacovino
- Department of Environmental, Biological and Pharmaceutical Science and Technology, University of Campania “Luigi Vanvitelli”, Via Vivaldi 43, 81100 Caserta, Italy
| | - Sabrina Esposito
- Department of Environmental, Biological and Pharmaceutical Science and Technology, University of Campania “Luigi Vanvitelli”, Via Vivaldi 43, 81100 Caserta, Italy
| | - Antonella Paladino
- Institute of Biostructures and Bioimaging, National Research Council (IBB-CNR), Via Pietro Castellino 111, 80131 Naples, Italy
| | - Paolo V. Pedone
- Department of Environmental, Biological and Pharmaceutical Science and Technology, University of Campania “Luigi Vanvitelli”, Via Vivaldi 43, 81100 Caserta, Italy
| | - Luigi Russo
- Department of Environmental, Biological and Pharmaceutical Science and Technology, University of Campania “Luigi Vanvitelli”, Via Vivaldi 43, 81100 Caserta, Italy
| | - Roberto Fattorusso
- Department of Environmental, Biological and Pharmaceutical Science and Technology, University of Campania “Luigi Vanvitelli”, Via Vivaldi 43, 81100 Caserta, Italy
| | - Gaetano Malgieri
- Department of Environmental, Biological and Pharmaceutical Science and Technology, University of Campania “Luigi Vanvitelli”, Via Vivaldi 43, 81100 Caserta, Italy
| | - Carla Isernia
- Department of Environmental, Biological and Pharmaceutical Science and Technology, University of Campania “Luigi Vanvitelli”, Via Vivaldi 43, 81100 Caserta, Italy
- Correspondence:
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Lee J, Dalton RA, Dennison C. Copper delivery to an endospore coat protein of Bacillus subtilis. Front Cell Dev Biol 2022; 10:916114. [PMID: 36133923 PMCID: PMC9484137 DOI: 10.3389/fcell.2022.916114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 07/26/2022] [Indexed: 11/13/2022] Open
Abstract
A family of cytosolic copper (Cu) storage proteins (the Csps) bind large quantities of Cu(I) via their Cys-lined four-helix bundles, and the majority are cytosolic (Csp3s). The presence of Csp3s in many bacteria appears inconsistent with the current dogma that bacteria, unlike eukaryotes, have evolved not to maintain intracellular pools of Cu due to its potential toxicity. Sporulation in Bacillus subtilis has been used to investigate if a Csp3 binds Cu(I) in the cytosol for a target enzyme. The activity of the Cu-requiring endospore multi-Cu oxidase BsCotA (a laccase) increases under Cu-replete conditions in wild type B. subtilis. In the strain lacking BsCsp3 lower BsCotA activity is observed and is unaffected by Cu levels. BsCsp3 loaded with Cu(I) readily activates apo-BsCotA in vitro. Experiments with a high affinity Cu(I) chelator demonstrate that Cu(I) transfer from Cu(I)-BsCsp3 must occur via an associative mechanism. BsCsp3 and BsCotA are both upregulated during late sporulation. We hypothesise that BsCsp3 acquires cuprous ions in the cytosol of B. subtilis for BsCotA.
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Zharmukhamedov SK, Shabanova MS, Rodionova MV, Huseynova IM, Karacan MS, Karacan N, Aşık KB, Kreslavski VD, Alwasel S, Allakhverdiev SI. Effects of Novel Photosynthetic Inhibitor [CuL2]Br2 Complex on Photosystem II Activity in Spinach. Cells 2022; 11:cells11172680. [PMID: 36078088 PMCID: PMC9455146 DOI: 10.3390/cells11172680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 08/24/2022] [Accepted: 08/25/2022] [Indexed: 11/25/2022] Open
Abstract
The effects of the novel [CuL2]Br2 complex (L = bis{4H-1,3,5-triazino [2,1-b]benzothiazole-2-amine,4-(2-imidazole)}copper(II) bromide complex) on the photosystem II (PSII) activity of PSII membranes isolated from spinach were studied. The absence of photosynthetic oxygen evolution by PSII membranes without artificial electron acceptors, but in the presence of [CuL2]Br2, has shown that it is not able to act as a PSII electron acceptor. In the presence of artificial electron acceptors, [CuL2]Br2 inhibits photosynthetic oxygen evolution. [CuL2]Br2 also suppresses the photoinduced changes of the PSII chlorophyll fluorescence yield (FV) related to the photoreduction of the primary quinone electron acceptor, QA. The inhibition of both characteristic PSII reactions depends on [CuL2]Br2 concentration. At all studied concentrations of [CuL2]Br2, the decrease in the FM level occurs exclusively due to a decrease in Fv. [CuL2]Br2 causes neither changes in the F0 level nor the retardation of the photoinduced rise in FM, which characterizes the efficiency of the electron supply from the donor-side components to QA through the PSII reaction center (RC). Artificial electron donors (sodium ascorbate, DPC, Mn2+) do not cancel the inhibitory effect of [CuL2]Br2. The dependences of the inhibitory efficiency of the studied reactions of PSII on [CuL2]Br2 complex concentration practically coincide. The inhibition constant Ki is about 16 µM, and logKi is 4.8. As [CuL2]Br2 does not change the aromatic amino acids’ intrinsic fluorescence of the PSII protein components, it can be proposed that [CuL2]Br2 has no significant effect on the native state of PSII proteins. The results obtained in the present study are compared to the literature data concerning the inhibitory effects of PSII Cu(II) aqua ions and Cu(II)-organic complexes.
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Affiliation(s)
- Sergey K. Zharmukhamedov
- Institute of Basic Biological Problems, FRC PSCBR RAS, 142290 Pushchino, Russia
- Correspondence: (S.K.Z.); (S.I.A.)
| | - Mehriban S. Shabanova
- Bionanotechnology Laboratory, Institute of Molecular Biology and Biotechnology, Azerbaijan National Academy of Sciences, AZ1073 Baku, Azerbaijan
| | - Margarita V. Rodionova
- K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, 127276 Moscow, Russia
| | - Irada M. Huseynova
- Bionanotechnology Laboratory, Institute of Molecular Biology and Biotechnology, Azerbaijan National Academy of Sciences, AZ1073 Baku, Azerbaijan
| | - Mehmet Sayım Karacan
- Department of Chemistry, Science Faculty, Gazi University, Teknikokullar, Ankara 06500, Turkey
| | - Nurcan Karacan
- Department of Chemistry, Science Faculty, Gazi University, Teknikokullar, Ankara 06500, Turkey
| | - Kübra Begüm Aşık
- Department of Chemistry, Science Faculty, Gazi University, Teknikokullar, Ankara 06500, Turkey
| | | | - Saleh Alwasel
- College of Science, King Saud University, Riyadh 12372, Saudi Arabia
| | - Suleyman I. Allakhverdiev
- Institute of Basic Biological Problems, FRC PSCBR RAS, 142290 Pushchino, Russia
- Bionanotechnology Laboratory, Institute of Molecular Biology and Biotechnology, Azerbaijan National Academy of Sciences, AZ1073 Baku, Azerbaijan
- K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, 127276 Moscow, Russia
- Department of Plant Physiology, Faculty of Biology, M.V. Lomonosov Moscow State University, Leninskie Gory 1-12, 119991 Moscow, Russia
- Correspondence: (S.K.Z.); (S.I.A.)
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10
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Mehlenbacher MR, Elsiesy R, Lakha R, Villones RLE, Orman M, Vizcarra CL, Meloni G, Wilcox DE, Austin RN. Metal binding and interdomain thermodynamics of mammalian metallothionein-3: enthalpically favoured Cu + supplants entropically favoured Zn 2+ to form Cu 4 + clusters under physiological conditions. Chem Sci 2022; 13:5289-5304. [PMID: 35655557 PMCID: PMC9093145 DOI: 10.1039/d2sc00676f] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 04/01/2022] [Indexed: 01/02/2023] Open
Abstract
Metallothioneins (MTs) are a ubiquitous class of small metal-binding proteins involved in metal homeostasis and detoxification. While known for their high affinity for d10 metal ions, there is a surprising dearth of thermodynamic data on metals binding to MTs. In this study, Zn2+ and Cu+ binding to mammalian metallothionein-3 (MT-3) were quantified at pH 7.4 by isothermal titration calorimetry (ITC). Zn2+ binding was measured by chelation titrations of Zn7MT-3, while Cu+ binding was measured by Zn2+ displacement from Zn7MT-3 with competition from glutathione (GSH). Titrations in multiple buffers enabled a detailed analysis that yielded condition-independent values for the association constant (K) and the change in enthalpy (ΔH) and entropy (ΔS) for these metal ions binding to MT-3. Zn2+ was also chelated from the individual α and β domains of MT-3 to quantify the thermodynamics of inter-domain interactions in metal binding. Comparative titrations of Zn7MT-2 with Cu+ revealed that both MT isoforms have similar Cu+ affinities and binding thermodynamics, indicating that ΔH and ΔS are determined primarily by the conserved Cys residues. Inductively coupled plasma mass spectrometry (ICP-MS) analysis and low temperature luminescence measurements of Cu-replete samples showed that both proteins form two Cu4 +-thiolate clusters when Cu+ displaces Zn2+ under physiological conditions. Comparison of the Zn2+ and Cu+ binding thermodynamics reveal that enthalpically-favoured Cu+, which forms Cu4 +-thiolate clusters, displaces the entropically-favoured Zn2+. These results provide a detailed thermodynamic analysis of d10 metal binding to these thiolate-rich proteins and quantitative support for, as well as molecular insight into, the role that MT-3 plays in the neuronal chemistry of copper.
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Affiliation(s)
| | - Rahma Elsiesy
- Department of Chemistry, Barnard College of Columbia University New York NY 10027 USA
| | - Rabina Lakha
- Department of Chemistry, Barnard College of Columbia University New York NY 10027 USA
| | - Rhiza Lyne E Villones
- Department of Chemistry and Biochemistry, University of Texas at Dallas Richardson TX 75080 USA
| | - Marina Orman
- Department of Chemistry, Barnard College of Columbia University New York NY 10027 USA
| | - Christina L Vizcarra
- Department of Chemistry, Barnard College of Columbia University New York NY 10027 USA
| | - Gabriele Meloni
- Department of Chemistry and Biochemistry, University of Texas at Dallas Richardson TX 75080 USA
| | - Dean E Wilcox
- Department of Chemistry, Dartmouth College Hanover NH 03755 USA
| | - Rachel N Austin
- Department of Chemistry, Barnard College of Columbia University New York NY 10027 USA
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Chakdar H, Thapa S, Srivastava A, Shukla P. Genomic and proteomic insights into the heavy metal bioremediation by cyanobacteria. JOURNAL OF HAZARDOUS MATERIALS 2022; 424:127609. [PMID: 34772552 DOI: 10.1016/j.jhazmat.2021.127609] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 10/16/2021] [Accepted: 10/24/2021] [Indexed: 06/13/2023]
Abstract
Heavy metals (HMs) pose a global ecological threat due to their toxic effects on aquatic and terrestrial life. Effective remediation of HMs from the environment can help to restore soil's fertility and ecological vigor, one of the key Sustainable Development Goals (SDG) set by the United Nations. The cyanobacteria have emerged as a potential option for bioremediation of HMs due to their unique adaptations and robust metabolic machineries. Generally, cyanobacteria deploy multifarious mechanisms such as biosorption, bioaccumulation, activation of metal transporters, biotransformation and induction of detoxifying enzymes to sequester and minimize the toxic effects of heavy metals. Therefore, understanding the physiological responses and regulation of adaptation mechanisms at molecular level is necessary to unravel the candidate genes and proteins which can be manipulated to improve the bioremediation efficiency of cyanobacteria. Chaperons, cellular metabolites (extracellular polymers, biosurfactants), transcriptional regulators, metal transporters, phytochelatins and metallothioneins are some of the potential targets for strain engineering. In the present review, we have discussed the potential of cyanobacteria for HM bioremediation and provided a deeper insight into their genomic and proteomic regulation of various tolerance mechanisms. These approaches might pave new possibilities of implementing genetic engineering strategies for improving bioremediation efficiency with a future perspective.
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Affiliation(s)
- Hillol Chakdar
- Microbial Technology Unit II, ICAR-National Bureau of Agriculturally Important Microorganisms (NBAIM), Mau 275103, Uttar Pradesh, India
| | - Shobit Thapa
- Microbial Technology Unit II, ICAR-National Bureau of Agriculturally Important Microorganisms (NBAIM), Mau 275103, Uttar Pradesh, India
| | - Amit Srivastava
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, ID 47907-2048, United States
| | - Pratyoosh Shukla
- School of Biotechnology, Institute of Science, Banaras Hindu University, Varanasi 221005, Uttar Pradesh, India; Enzyme Technology and Protein Bioinformatics Laboratory, Department of Microbiology, Maharshi Dayanand University, Rohtak 124001, Haryana, India.
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12
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Chen L, Li N, Zhang M, Sun M, Bian J, Yang B, Li Z, Wang J, Li F, Shi X, Wang Y, Yuan F, Zou P, Shan C, Wang J. APEX2-based Proximity Labeling of Atox1 Identifies CRIP2 as a Nuclear Copper-binding Protein that Regulates Autophagy Activation. Angew Chem Int Ed Engl 2021; 60:25346-25355. [PMID: 34550632 DOI: 10.1002/anie.202108961] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 08/25/2021] [Indexed: 01/05/2023]
Abstract
Mammalian cell nuclei contain copper, and cancer cells are known to accumulate aberrantly high copper levels, yet the mechanisms underlying nuclear accumulation and copper's broader functional significance remain poorly understood. Here, by combining APEX2-based proximity labeling focused on the copper chaperone Atox1 with mass spectrometry we identified a previously unrecognized nuclear copper binding protein, Cysteine-rich protein 2 (CRIP2), that interacts with Atox1 in the nucleus. We show that Atox1 transfers copper to CRIP2, which induces a change in CRIP2's secondary structure that ultimately promotes its ubiquitin-mediated proteasomal degradation. Finally, we demonstrate that depletion of CRIP2-as well as copper-induced CRIP2 degradation-elevates ROS levels and activates autophagy in H1299 cells. Thus, our study establishes that CRIP2 as an autophagic suppressor protein and implicates CRIP2-mediated copper metabolism in the activation of autophagy in cancer cells.
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Affiliation(s)
- Lin Chen
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, China
| | - Na Li
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, China
| | - Meiqi Zhang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, China
| | - Mingming Sun
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Nankai University, Tianjin, 300071, China
| | - Jiaxuan Bian
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, China
| | - Bo Yang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, China
| | - Zhengcunxiao Li
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, China
| | - Jiayu Wang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, China
| | - Fei Li
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, China
| | - Xiaomeng Shi
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, China
| | - Yuan Wang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, China
| | - Feng Yuan
- College of Chemistry and Molecular Engineering, Synthetic and Functional Biomolecules Center, Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Peking University, Beijing, 100871, China
| | - Peng Zou
- College of Chemistry and Molecular Engineering, Synthetic and Functional Biomolecules Center, Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Peking University, Beijing, 100871, China
| | - Changliang Shan
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Nankai University, Tianjin, 300071, China
| | - Jing Wang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, China
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13
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Chen L, Li N, Zhang M, Sun M, Bian J, Yang B, Li Z, Wang J, Li F, Shi X, Wang Y, Yuan F, Zou P, Shan C, Wang J. APEX2‐based Proximity Labeling of Atox1 Identifies CRIP2 as a Nuclear Copper‐binding Protein that Regulates Autophagy Activation. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202108961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Lin Chen
- State Key Laboratory of Natural and Biomimetic Drugs Department of Chemical Biology School of Pharmaceutical Sciences Peking University Beijing 100191 China
| | - Na Li
- State Key Laboratory of Natural and Biomimetic Drugs Department of Chemical Biology School of Pharmaceutical Sciences Peking University Beijing 100191 China
| | - Meiqi Zhang
- State Key Laboratory of Natural and Biomimetic Drugs Department of Chemical Biology School of Pharmaceutical Sciences Peking University Beijing 100191 China
| | - Mingming Sun
- State Key Laboratory of Medicinal Chemical Biology College of Pharmacy Nankai University Tianjin 300071 China
| | - Jiaxuan Bian
- State Key Laboratory of Natural and Biomimetic Drugs Department of Chemical Biology School of Pharmaceutical Sciences Peking University Beijing 100191 China
| | - Bo Yang
- State Key Laboratory of Natural and Biomimetic Drugs Department of Chemical Biology School of Pharmaceutical Sciences Peking University Beijing 100191 China
| | - Zhengcunxiao Li
- State Key Laboratory of Natural and Biomimetic Drugs Department of Chemical Biology School of Pharmaceutical Sciences Peking University Beijing 100191 China
| | - Jiayu Wang
- State Key Laboratory of Natural and Biomimetic Drugs Department of Chemical Biology School of Pharmaceutical Sciences Peking University Beijing 100191 China
| | - Fei Li
- State Key Laboratory of Natural and Biomimetic Drugs Department of Chemical Biology School of Pharmaceutical Sciences Peking University Beijing 100191 China
| | - Xiaomeng Shi
- State Key Laboratory of Natural and Biomimetic Drugs Department of Chemical Biology School of Pharmaceutical Sciences Peking University Beijing 100191 China
| | - Yuan Wang
- State Key Laboratory of Natural and Biomimetic Drugs Department of Chemical Biology School of Pharmaceutical Sciences Peking University Beijing 100191 China
| | - Feng Yuan
- College of Chemistry and Molecular Engineering Synthetic and Functional Biomolecules Center Beijing National Laboratory for Molecular Sciences Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education Peking University Beijing 100871 China
| | - Peng Zou
- College of Chemistry and Molecular Engineering Synthetic and Functional Biomolecules Center Beijing National Laboratory for Molecular Sciences Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education Peking University Beijing 100871 China
| | - Changliang Shan
- State Key Laboratory of Medicinal Chemical Biology College of Pharmacy Nankai University Tianjin 300071 China
| | - Jing Wang
- State Key Laboratory of Natural and Biomimetic Drugs Department of Chemical Biology School of Pharmaceutical Sciences Peking University Beijing 100191 China
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Potential Antioxidant and Anticancer Activities of Secondary Metabolites of Nostoc linckia Cultivated under Zn and Cu Stress Conditions. Processes (Basel) 2021. [DOI: 10.3390/pr9111972] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The objective of the present study is to determine the antioxidant and anticancer activities of Nostoc linckia extracts cultivated under heavy metal stress conditions (0.44, 0.88, and 1.76 mg/L for zinc and 0.158, 0.316, 0.632 mg/L for copper). Phycobiliprotein, phenolic compounds, flavonoids, and tannins were measured. Active ingredients of extracts were evaluated by GC-mass spectroscopy. The obtained results revealed that higher zinc and copper concentrations showed growth inhibition while 0.22 mg/L (Zn) and 0.079 mg/L (Cu) enhanced growth, reaching its maximum on the 25th day. Increases in catalase, lipids peroxidation, and antioxidants, as well as tannins and flavonoids, have been induced by integration of 0.88 mg/L (Zn) and 0.316 mg/L (Cu). Elevation of Zn concentration induced augmentation of antioxidant activity of crude extract (DPPH or ABTS), with superior activity at 0.44 mg/L zinc concentration (81.22%). The anticancer activity of Nostoc linckia extract (0.44 mg/L Zn) tested against four cancer cell lines: A549, Hela, HCT 116, and MCF-7. The extract at 500 µg/mL appeared the lowest cell viability of tested cell lines. The promising extract (0.44 mg/L Zn) recorded the lowest cell viability of 25.57% in cervical cell line, 29.74% in breast cell line, 33.10% in lung cell line and 34.53% in the colon cell line. The antioxidant active extract showed significant stability against pH with attributed increase in antioxidant activity in the range between 8–12. The extract can be used effectively as a natural antioxidant and anticancer after progressive testing.
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15
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Copper binding by a unique family of metalloproteins is dependent on kynurenine formation. Proc Natl Acad Sci U S A 2021; 118:2100680118. [PMID: 34074779 DOI: 10.1073/pnas.2100680118] [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] [Indexed: 11/18/2022] Open
Abstract
Some methane-oxidizing bacteria use the ribosomally synthesized, posttranslationally modified natural product methanobactin (Mbn) to acquire copper for their primary metabolic enzyme, particulate methane monooxygenase. The operons encoding the machinery to biosynthesize and transport Mbns typically include genes for two proteins, MbnH and MbnP, which are also found as a pair in other genomic contexts related to copper homeostasis. While the MbnH protein, a member of the bacterial diheme cytochrome c peroxidase (bCcP)/MauG superfamily, has been characterized, the structure and function of MbnP, the relationship between the two proteins, and their role in copper homeostasis remain unclear. Biochemical characterization of MbnP from the methanotroph Methylosinus trichosporium OB3b now reveals that MbnP binds a single copper ion, present in the +1 oxidation state, with high affinity. Copper binding to MbnP in vivo is dependent on oxidation of the first tryptophan in a conserved WxW motif to a kynurenine, a transformation that occurs through an interaction of MbnH with MbnP. The 2.04-Å-resolution crystal structure of MbnP reveals a unique fold and an unusual copper-binding site involving a histidine, a methionine, a solvent ligand, and the kynurenine. Although the kynurenine residue may not serve as a CuI primary-sphere ligand, being positioned ∼2.9 Å away from the CuI ion, its presence is required for copper binding. Genomic neighborhood analysis indicates that MbnP proteins, and by extension kynurenine-containing copper sites, are widespread and may play diverse roles in microbial copper homeostasis.
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16
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Current knowledge and recent advances in understanding metabolism of the model cyanobacterium Synechocystis sp. PCC 6803. Biosci Rep 2021; 40:222317. [PMID: 32149336 PMCID: PMC7133116 DOI: 10.1042/bsr20193325] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 03/05/2020] [Accepted: 03/06/2020] [Indexed: 02/06/2023] Open
Abstract
Cyanobacteria are key organisms in the global ecosystem, useful models for studying metabolic and physiological processes conserved in photosynthetic organisms, and potential renewable platforms for production of chemicals. Characterizing cyanobacterial metabolism and physiology is key to understanding their role in the environment and unlocking their potential for biotechnology applications. Many aspects of cyanobacterial biology differ from heterotrophic bacteria. For example, most cyanobacteria incorporate a series of internal thylakoid membranes where both oxygenic photosynthesis and respiration occur, while CO2 fixation takes place in specialized compartments termed carboxysomes. In this review, we provide a comprehensive summary of our knowledge on cyanobacterial physiology and the pathways in Synechocystis sp. PCC 6803 (Synechocystis) involved in biosynthesis of sugar-based metabolites, amino acids, nucleotides, lipids, cofactors, vitamins, isoprenoids, pigments and cell wall components, in addition to the proteins involved in metabolite transport. While some pathways are conserved between model cyanobacteria, such as Synechocystis, and model heterotrophic bacteria like Escherichia coli, many enzymes and/or pathways involved in the biosynthesis of key metabolites in cyanobacteria have not been completely characterized. These include pathways required for biosynthesis of chorismate and membrane lipids, nucleotides, several amino acids, vitamins and cofactors, and isoprenoids such as plastoquinone, carotenoids, and tocopherols. Moreover, our understanding of photorespiration, lipopolysaccharide assembly and transport, and degradation of lipids, sucrose, most vitamins and amino acids, and haem, is incomplete. We discuss tools that may aid our understanding of cyanobacterial metabolism, notably CyanoSource, a barcoded library of targeted Synechocystis mutants, which will significantly accelerate characterization of individual proteins.
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17
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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: 45] [Impact Index Per Article: 11.3] [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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18
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North ML, Wilcox DE. Shift from Entropic Cu 2+ Binding to Enthalpic Cu + Binding Determines the Reduction Thermodynamics of Blue Copper Proteins. J Am Chem Soc 2019; 141:14329-14339. [PMID: 31433629 DOI: 10.1021/jacs.9b06836] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The enthalpic and entropic components of Cu2+ and Cu+ binding to the blue copper protein azurin have been quantified with isothermal titration calorimetry (ITC) measurements and analysis, providing the first such experimental values for Cu+ binding to a protein. The high affinity of azurin for Cu2+ is entirely due to a very favorable binding entropy, while its even higher affinity for Cu+ is due to a favorable binding enthalpy and entropy. The binding thermodynamics provide insight into bond enthalpies at the blue copper site and entropic contributions from desolvation and proton displacement. These values were used in thermodynamic cycles to determine the enthalpic and entropic contributions to the free energy of reduction and thus the reduction potential. The reduction thermodynamics obtained with this method are in good agreement with previous results from temperature-dependent electrochemical measurements. The calorimetry method, however, provides new insight into contributions from the initial (oxidized) and final (reduced) states of the reduction. Since ITC measurements quantify the protons that are displaced upon metal binding, the proton transfer that is coupled with electron transfer is also determined with this method. Preliminary results for Cu2+ and Cu+ binding to the Phe114Pro variant of azurin demonstrate the insight about protein tuning of the reduction potential that is provided by the binding thermodynamics of each metal oxidation state.
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Affiliation(s)
- Molly L North
- Department of Chemistry , Dartmouth College , Hanover , New Hampshire 03755 , United States
| | - Dean E Wilcox
- Department of Chemistry , Dartmouth College , Hanover , New Hampshire 03755 , United States
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19
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Lee J, Dennison C. Cytosolic Copper Binding by a Bacterial Storage Protein and Interplay with Copper Efflux. Int J Mol Sci 2019; 20:ijms20174144. [PMID: 31450649 PMCID: PMC6747150 DOI: 10.3390/ijms20174144] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Revised: 08/06/2019] [Accepted: 08/12/2019] [Indexed: 01/06/2023] Open
Abstract
Escherichia coli has a well-characterized copper (Cu) transporting ATPase (CopA) that removes this potentially toxic metal ion from the cytosol. Growth of the strain lacking CopA (ΔcopA) is inhibited above 0.5 mM Cu, whilst a similar effect does not occur in wild type (WT) E. coli until over 2.5 mM Cu. Limited expression of CopA can restore growth to WT levels in ΔcopAE. coli in the presence of Cu. To study the influence of a bacterial cytosolic Cu storage protein (Csp3) on how E. coli handles Cu, the protein from Bacillus subtilis (BsCsp3) has been overexpressed in the WT and ΔcopA strains. BsCsp3 can protect both strains from Cu toxicity, promoting growth at up to ~1.5 and ~3.5 mM Cu, respectively. Higher levels of Csp3 expression are needed to provide resistance to Cu toxicity in ΔcopAE. coli. At 1.5 mM Cu, BsCsp3 purified from ΔcopAE. coli binds up to approximately four equivalents of Cu(I) per monomer. A similar number of Cu(I) equivalents can be bound by BsCsp3 purified from WT E. coli also grown at 1.5 mM Cu, a concentration that does not cause toxicity in this strain. Much lower amounts of BsCsp3 are produced in WT E. coli grown in the presence of 3.4 mM Cu, but the protein still counteracts toxicity and is almost half loaded with Cu(I). Csp3s can protect E. coli from Cu toxicity by sequestering cuprous ions in the cytosol. This appears to include an ability to acquire and withhold Cu(I) from the main efflux system in a heterologous host.
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Affiliation(s)
- Jaeick Lee
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Christopher Dennison
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
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20
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Angeleri M, Muth-Pawlak D, Wilde A, Aro EM, Battchikova N. Global proteome response ofSynechocystis6803 to extreme copper environments applied to control the activity of the induciblepetJpromoter. J Appl Microbiol 2019; 126:826-841. [DOI: 10.1111/jam.14182] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 12/18/2018] [Accepted: 12/19/2018] [Indexed: 12/18/2022]
Affiliation(s)
- M. Angeleri
- Molecular Plant Biology; Department of Biochemistry; University of Turku; Turku Finland
| | - D. Muth-Pawlak
- Molecular Plant Biology; Department of Biochemistry; University of Turku; Turku Finland
| | - A. Wilde
- Molecular Genetics of Prokaryotes; University of Freiburg; Freiburg Germany
| | - E.-M. Aro
- Molecular Plant Biology; Department of Biochemistry; University of Turku; Turku Finland
| | - N. Battchikova
- Molecular Plant Biology; Department of Biochemistry; University of Turku; Turku Finland
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21
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Dennison C. The Coordination Chemistry of Copper Uptake and Storage for Methane Oxidation. Chemistry 2018; 25:74-86. [PMID: 30281847 DOI: 10.1002/chem.201803444] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Indexed: 11/09/2022]
Abstract
Methanotrophs are remarkable bacteria that utilise large quantities of copper (Cu) to oxidize the potent greenhouse gas methane. To assist in providing the Cu they require for this process some methanotrophs can secrete the Cu-sequestering modified peptide methanobactin. These small molecules bind CuI with very high affinity and crystal structures have given insight into why this is the case, and also how the metal ion may be released within the cell. A much greater proportion of methanotrophs, genomes of which have been sequenced, possess a member of a newly discovered bacterial family of copper storage proteins (the Csps). These are tetramers of four-helix bundles whose cores are lined with Cys residues enabling the binding of large numbers of CuI ions. In methanotrophs, a Csp exported from the cytosol stores CuI for the active site of the ubiquitous enzyme that catalyses the oxidation of methane. The presence of cytosolic Csps, not only in methanotrophs but in a wide range of bacteria, challenges the dogma that these organisms have no requirement for Cu in this location. The properties of the Csps, with an emphasis on CuI binding and the structures of the sites formed, are the primary focus of this review.
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Affiliation(s)
- Christopher Dennison
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
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22
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Baslé A, El Ghazouani A, Lee J, Dennison C. Insight into Metal Removal from Peptides that Sequester Copper for Methane Oxidation. Chemistry 2018; 24:4515-4518. [PMID: 29365216 PMCID: PMC5947558 DOI: 10.1002/chem.201706035] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Indexed: 01/08/2023]
Abstract
Methanobactins (Mbns) are modified peptides that sequester copper (Cu) methanotrophs use to oxidize methane. Limited structural information is available for this class of natural products, as is an understanding of how cells are able to utilize Mbn-bound Cu. The crystal structure of Methylosinus sporium NR3K CuI -Mbn provides further information about the structural diversity of Mbns and the first insight into their Cu-release mechanism. Nitrogen ligands from oxazolone and pyrazinediol rings chelate CuI along with adjacent coordinating sulfurs from thioamides. In vitro solution data are consistent with a CuI -Mbn monomer as found for previously characterized Mbns. In the crystal structure, the N-terminal region has undergone a conformational change allowing the formation of a CuI2 -Mbn2 dimer with CuI sites bound by chelating units from adjacent chains. Such a structural alteration will facilitate CuI release from Mbns.
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Affiliation(s)
- Arnaud Baslé
- Institute for Cell and Molecular BiosciencesMedical SchoolNewcastle UniversityNewcastle upon TyneNE2 4HHUK
| | - Abdelnasser El Ghazouani
- Institute for Cell and Molecular BiosciencesMedical SchoolNewcastle UniversityNewcastle upon TyneNE2 4HHUK
| | - Jaeick Lee
- Institute for Cell and Molecular BiosciencesMedical SchoolNewcastle UniversityNewcastle upon TyneNE2 4HHUK
| | - Christopher Dennison
- Institute for Cell and Molecular BiosciencesMedical SchoolNewcastle UniversityNewcastle upon TyneNE2 4HHUK
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23
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Abstract
Copper is essential for most organisms as a cofactor for key enzymes involved in fundamental processes such as respiration and photosynthesis. However, copper also has toxic effects in cells, which is why eukaryotes and prokaryotes have evolved mechanisms for safe copper handling. A new family of bacterial proteins uses a Cys-rich four-helix bundle to safely store large quantities of Cu(I). The work leading to the discovery of these proteins, their properties and physiological functions, and how their presence potentially impacts the current views of bacterial copper handling and use are discussed in this review.
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Affiliation(s)
- Christopher Dennison
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, United Kingdom.
| | - Sholto David
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, United Kingdom
| | - Jaeick Lee
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, United Kingdom
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24
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Newby R, Lee LH, Perez JL, Tao X, Chu T. Characterization of zinc stress response in Cyanobacterium Synechococcus sp. IU 625. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2017; 186:159-170. [PMID: 28284152 DOI: 10.1016/j.aquatox.2017.03.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 02/28/2017] [Accepted: 03/01/2017] [Indexed: 06/06/2023]
Abstract
The ability of cyanobacteria to survive many environmental stress factors is a testament to their resilience in nature. Of these environmental stress factors, overexposure to zinc is important to study since excessive zinc intake can be a severe hazard. Zinc toxicity in freshwater has been demonstrated to affects organisms such as invertebrates, algae and cyanobacteria. Cyanobacteria which possess increased resistance to zinc have been isolated. It is therefore important to elucidate the mechanism of survival and response to determine what factors allow their survival; as well as any remediation implications they may have. To characterize the effects of zinc in freshwater cyanobacteria, we investigated the response of Synechococcus sp. IU 625 (S. IU 625) over 29days to various concentrations (10, 25, and 50mg/L) of ZnCl2. S. IU 625 was shown to be tolerant up to 25mg/L ZnCl2 exposure, with 10mg/L ZnCl2 having no outward physiological change and 50mg/L ZnCl2 proving lethal to the cells. To determine a potential mechanism Inductive Coupled Plasma-Mass Spectrometry (ICP-MS) and RNA-seq analysis were performed on zinc exposed cells. Analysis performed on days 4 and 7 indicated that response is dose-dependent, with 10mg/L ZnCl2 exhibiting nearly all zinc extracellular, corresponding with upregulation of cation transport response. Whereas the 25mg/L ZnCl2 exhibited half of total zinc sequestered by the cells, which corresponds with the upregulation of sequestering proteins such as metallothionein and the downregulation of genes involved with ATP synthesis and phycobilisome assembly. These analyses were combined with growth monitoring, microscopy, quantitative polymerase chain reaction (qPCR) and flow cytometry to present a full spectrum of mechanisms behind zinc response in S. IU 625.
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Affiliation(s)
- Robert Newby
- Department of Biological Sciences, Seton Hall University, South Orange, NJ, USA
| | - Lee H Lee
- Department of Biology, Montclair State University, Montclair, NJ, USA
| | - Jose L Perez
- Department of Biological Sciences, Seton Hall University, South Orange, NJ, USA
| | - Xin Tao
- Department of Biological Sciences, Seton Hall University, South Orange, NJ, USA
| | - Tinchun Chu
- Department of Biological Sciences, Seton Hall University, South Orange, NJ, USA.
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Vita N, Landolfi G, Baslé A, Platsaki S, Lee J, Waldron KJ, Dennison C. Bacterial cytosolic proteins with a high capacity for Cu(I) that protect against copper toxicity. Sci Rep 2016; 6:39065. [PMID: 27991525 PMCID: PMC5171941 DOI: 10.1038/srep39065] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 11/16/2016] [Indexed: 01/23/2023] Open
Abstract
Bacteria are thought to avoid using the essential metal ion copper in their cytosol due to its toxicity. Herein we characterize Csp3, the cytosolic member of a new family of bacterial copper storage proteins from Methylosinus trichosporium OB3b and Bacillus subtilis. These tetrameric proteins possess a large number of Cys residues that point into the cores of their four-helix bundle monomers. The Csp3 tetramers can bind a maximum of approximately 80 Cu(I) ions, mainly via thiolate groups, with average affinities in the (1–2) × 1017 M−1 range. Cu(I) removal from these Csp3s by higher affinity potential physiological partners and small-molecule ligands is very slow, which is unexpected for a metal-storage protein. In vivo data demonstrate that Csp3s prevent toxicity caused by the presence of excess copper. Furthermore, bacteria expressing Csp3 accumulate copper and are able to safely maintain large quantities of this metal ion in their cytosol. This suggests a requirement for storing copper in this compartment of Csp3-producing bacteria.
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Affiliation(s)
- Nicolas Vita
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Gianpiero Landolfi
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Arnaud Baslé
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Semeli Platsaki
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Jaeick Lee
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Kevin J Waldron
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Christopher Dennison
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
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26
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Zhao S, Wang X, Niu G, Dong W, Wang J, Fang Y, Lin Y, Liu L. Structural basis for copper/silver binding by theSynechocystismetallochaperone CopM. ACTA CRYSTALLOGRAPHICA SECTION D-STRUCTURAL BIOLOGY 2016; 72:997-1005. [DOI: 10.1107/s2059798316011943] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 07/21/2016] [Indexed: 11/11/2022]
Abstract
Copper homeostasis integrates multiple processes from sensing to storage and efflux out of the cell. CopM is a cyanobacterial metallochaperone, the gene for which is located upstream of a two-component system for copper resistance, but the molecular basis for copper recognition by this four-helical bundle protein is unknown. Here, crystal structures of CopM in apo, copper-bound and silver-bound forms are reported. Monovalent copper/silver ions are buried within the bundle core; divalent copper ions are found on the surface of the bundle. The monovalent copper/silver-binding site is constituted by two consecutive histidines and is conserved in a previously functionally unknown protein family. The structural analyses show two conformational states and suggest that flexibility in the first α-helix is related to the metallochaperone function. These results also reveal functional diversity from a protein family with a simple four-helical fold.
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DiSpirito AA, Semrau JD, Murrell JC, Gallagher WH, Dennison C, Vuilleumier S. Methanobactin and the Link between Copper and Bacterial Methane Oxidation. Microbiol Mol Biol Rev 2016; 80:387-409. [PMID: 26984926 PMCID: PMC4867365 DOI: 10.1128/mmbr.00058-15] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Methanobactins (mbs) are low-molecular-mass (<1,200 Da) copper-binding peptides, or chalkophores, produced by many methane-oxidizing bacteria (methanotrophs). These molecules exhibit similarities to certain iron-binding siderophores but are expressed and secreted in response to copper limitation. Structurally, mbs are characterized by a pair of heterocyclic rings with associated thioamide groups that form the copper coordination site. One of the rings is always an oxazolone and the second ring an oxazolone, an imidazolone, or a pyrazinedione moiety. The mb molecule originates from a peptide precursor that undergoes a series of posttranslational modifications, including (i) ring formation, (ii) cleavage of a leader peptide sequence, and (iii) in some cases, addition of a sulfate group. Functionally, mbs represent the extracellular component of a copper acquisition system. Consistent with this role in copper acquisition, mbs have a high affinity for copper ions. Following binding, mbs rapidly reduce Cu(2+) to Cu(1+). In addition to binding copper, mbs will bind most transition metals and near-transition metals and protect the host methanotroph as well as other bacteria from toxic metals. Several other physiological functions have been assigned to mbs, based primarily on their redox and metal-binding properties. In this review, we examine the current state of knowledge of this novel type of metal-binding peptide. We also explore its potential applications, how mbs may alter the bioavailability of multiple metals, and the many roles mbs may play in the physiology of methanotrophs.
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Affiliation(s)
- Alan A DiSpirito
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa, USA
| | - Jeremy D Semrau
- Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - J Colin Murrell
- Earth and Life Systems Alliance, School of Environmental Sciences, University of East Anglia, Norwich, United Kingdom
| | - Warren H Gallagher
- Department of Chemistry, University of Wisconsin-Eau Claire, Eau Claire, Wisconsin, USA
| | - Christopher Dennison
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Stéphane Vuilleumier
- Department of Microbiology, Genomics and the Environment, UMR 7156 UNISTRA-CNRS, Université de Strasbourg, Strasbourg, France
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Vita N, Platsaki S, Baslé A, Allen SJ, Paterson NG, Crombie AT, Murrell JC, Waldron KJ, Dennison C. A four-helix bundle stores copper for methane oxidation. Nature 2015; 525:140-3. [PMID: 26308900 PMCID: PMC4561512 DOI: 10.1038/nature14854] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 06/23/2015] [Indexed: 11/09/2022]
Abstract
Methane-oxidizing bacteria (methanotrophs) require large quantities of copper for the membrane-bound (particulate) methane monooxygenase. Certain methanotrophs are also able to switch to using the iron-containing soluble methane monooxygenase to catalyse methane oxidation, with this switchover regulated by copper. Methane monooxygenases are nature's primary biological mechanism for suppressing atmospheric levels of methane, a potent greenhouse gas. Furthermore, methanotrophs and methane monooxygenases have enormous potential in bioremediation and for biotransformations producing bulk and fine chemicals, and in bioenergy, particularly considering increased methane availability from renewable sources and hydraulic fracturing of shale rock. Here we discover and characterize a novel copper storage protein (Csp1) from the methanotroph Methylosinus trichosporium OB3b that is exported from the cytosol, and stores copper for particulate methane monooxygenase. Csp1 is a tetramer of four-helix bundles with each monomer binding up to 13 Cu(I) ions in a previously unseen manner via mainly Cys residues that point into the core of the bundle. Csp1 is the first example of a protein that stores a metal within an established protein-folding motif. This work provides a detailed insight into how methanotrophs accumulate copper for the oxidation of methane. Understanding this process is essential if the wide-ranging biotechnological applications of methanotrophs are to be realized. Cytosolic homologues of Csp1 are present in diverse bacteria, thus challenging the dogma that such organisms do not use copper in this location.
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Affiliation(s)
- Nicolas Vita
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Semeli Platsaki
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Arnaud Baslé
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Stephen J Allen
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Neil G Paterson
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK
| | - Andrew T Crombie
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - J Colin Murrell
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Kevin J Waldron
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Christopher Dennison
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
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Sautron E, Mayerhofer H, Giustini C, Pro D, Crouzy S, Ravaud S, Pebay-Peyroula E, Rolland N, Catty P, Seigneurin-Berny D. HMA6 and HMA8 are two chloroplast Cu+-ATPases with different enzymatic properties. Biosci Rep 2015; 35:e00201. [PMID: 26182363 PMCID: PMC4613667 DOI: 10.1042/bsr20150065] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 04/01/2015] [Accepted: 04/14/2015] [Indexed: 12/16/2022] Open
Abstract
Copper (Cu) plays a key role in the photosynthetic process as cofactor of the plastocyanin (PC), an essential component of the chloroplast photosynthetic electron transfer chain. Encoded by the nuclear genome, PC is translocated in its apo-form into the chloroplast and the lumen of thylakoids where it is processed to its mature form and acquires Cu. In Arabidopsis, Cu delivery into the thylakoids involves two transporters of the PIB-1 ATPases family, heavy metal associated protein 6 (HMA6) located at the chloroplast envelope and HMA8 at the thylakoid membrane. To gain further insight into the way Cu is delivered to PC, we analysed the enzymatic properties of HMA8 and compared them with HMA6 ones using in vitro phosphorylation assays and phenotypic tests in yeast. These experiments reveal that HMA6 and HMA8 display different enzymatic properties: HMA8 has a higher apparent affinity for Cu(+) but a slower dephosphorylation kinetics than HMA6. Modelling experiments suggest that these differences could be explained by the electrostatic properties of the Cu(+) releasing cavities of the two transporters and/or by the different nature of their cognate Cu(+) acceptors (metallochaperone/PC).
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Affiliation(s)
- Emeline Sautron
- CNRS, Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, 17 rue des Martyrs, F-38054 Grenoble, France
- Univ. Grenoble Alpes, F-38054 Grenoble, France
- CEA, DSV, iRTSV, F-38054 Grenoble, France
- INRA, LPCV, USC1359, 17 rue des Martyrs, F-38054 Grenoble, France
| | - Hubert Mayerhofer
- Univ. Grenoble Alpes, F-38054 Grenoble, France
- CEA, DSV, Institut de Biologie Structurale, F-38044 Grenoble, France
- CNRS, Institut de Biologie Structurale, UMR5075, 71, avenue des Martyrs, F-38044 Grenoble, France
| | - Cécile Giustini
- CNRS, Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, 17 rue des Martyrs, F-38054 Grenoble, France
- Univ. Grenoble Alpes, F-38054 Grenoble, France
- CEA, DSV, iRTSV, F-38054 Grenoble, France
- INRA, LPCV, USC1359, 17 rue des Martyrs, F-38054 Grenoble, France
| | - Danièle Pro
- CNRS, Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, 17 rue des Martyrs, F-38054 Grenoble, France
- Univ. Grenoble Alpes, F-38054 Grenoble, France
- CEA, DSV, iRTSV, F-38054 Grenoble, France
- INRA, LPCV, USC1359, 17 rue des Martyrs, F-38054 Grenoble, France
| | - Serge Crouzy
- Univ. Grenoble Alpes, F-38054 Grenoble, France
- CEA, DSV, iRTSV, F-38054 Grenoble, France
- *CNRS, Laboratoire de Chimie et Biologie des Métaux, UMR 5249, 17 rue des Martyrs, F-38054 Grenoble, France
| | - Stéphanie Ravaud
- Univ. Grenoble Alpes, F-38054 Grenoble, France
- CEA, DSV, Institut de Biologie Structurale, F-38044 Grenoble, France
- CNRS, Institut de Biologie Structurale, UMR5075, 71, avenue des Martyrs, F-38044 Grenoble, France
| | - Eva Pebay-Peyroula
- Univ. Grenoble Alpes, F-38054 Grenoble, France
- CEA, DSV, Institut de Biologie Structurale, F-38044 Grenoble, France
- CNRS, Institut de Biologie Structurale, UMR5075, 71, avenue des Martyrs, F-38044 Grenoble, France
| | - Norbert Rolland
- CNRS, Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, 17 rue des Martyrs, F-38054 Grenoble, France
- Univ. Grenoble Alpes, F-38054 Grenoble, France
- CEA, DSV, iRTSV, F-38054 Grenoble, France
- INRA, LPCV, USC1359, 17 rue des Martyrs, F-38054 Grenoble, France
| | - Patrice Catty
- Univ. Grenoble Alpes, F-38054 Grenoble, France
- CEA, DSV, iRTSV, F-38054 Grenoble, France
- *CNRS, Laboratoire de Chimie et Biologie des Métaux, UMR 5249, 17 rue des Martyrs, F-38054 Grenoble, France
| | - Daphné Seigneurin-Berny
- CNRS, Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, 17 rue des Martyrs, F-38054 Grenoble, France
- Univ. Grenoble Alpes, F-38054 Grenoble, France
- CEA, DSV, iRTSV, F-38054 Grenoble, France
- INRA, LPCV, USC1359, 17 rue des Martyrs, F-38054 Grenoble, France
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30
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Giner-Lamia J, López-Maury L, Florencio FJ. CopM is a novel copper-binding protein involved in copper resistance in Synechocystis sp. PCC 6803. Microbiologyopen 2014; 4:167-85. [PMID: 25545960 PMCID: PMC4335983 DOI: 10.1002/mbo3.231] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 11/13/2014] [Accepted: 11/20/2014] [Indexed: 01/15/2023] Open
Abstract
Copper resistance system in the cyanobacterium Synechocystis sp. PCC 6803 comprises two operons, copMRS and copBAC, which are expressed in response to copper in the media. copBAC codes for a heavy-metal efflux–resistance nodulation and division (HME-RND) system, while copMRS codes for a protein of unknown function, CopM, and a two-component system CopRS, which controls the expression of these two operons. Here, we report that CopM is a periplasmic protein able to bind Cu(I) with high affinity (KD ∼3 × 10−16). Mutants lacking copM showed a sensitive copper phenotype similar to mutants affected in copB, but lower than mutants of the two-component system CopRS, suggesting that CopBAC and CopM constitute two independent resistance mechanisms. Moreover, constitutive expression of copM is able to partially suppress the copper sensitivity of the copR mutant strain, pointing out that CopM per se is able to confer copper resistance. Furthermore, constitutive expression of copM was able to reduce total cellular copper content of the copR mutant to the levels determined in the wild-type (WT) strain. Finally, CopM was localized not only in the periplasm but also in the extracellular space, suggesting that CopM can also prevent copper accumulation probably by direct copper binding outside the cell.
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Affiliation(s)
- Joaquín Giner-Lamia
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla-CSIC, Américo Vespucio 49, E-41092, Sevilla, Spain
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31
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Chaplin AK, Tan BG, Vijgenboom E, Worrall JAR. Copper trafficking in the CsoR regulon of Streptomyces lividans. Metallomics 2014; 7:145-55. [PMID: 25409712 DOI: 10.1039/c4mt00250d] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
In the actinobacterium Streptomyces lividans copper homeostasis is controlled through the action of the metalloregulator CsoR. Under copper stress, cuprous ions bind to apo-CsoR resulting in the transcriptional derepression of genes encoding for copper efflux systems involving CopZ-like copper chaperones and CopA-like P-type ATPases. Whether CsoR obtains copper via a protein-protein mediated trafficking mechanism is unknown. In this study we have characterised the copper trafficking properties of two S. lividans CopZ proteins (SLI_1317 and SLI_3079) under the transcriptional control of a CsoR (SLI_4375). Our findings indicate that both CopZ-proteins have cysteine residues in the Cu(i) binding MX1CX2X3C motif with acid-base properties that are modulated for a high cuprous ion affinity and favourable Cu(i)-exchange with a target. Using electrophoretic mobility shift assays transfer of Cu(i) is shown to occur in a unidirectional manner from the CopZ to the CsoR. This transfer proceeds via a shallow thermodynamic affinity gradient and is also kinetically favoured through the modulation of the acid-base properties of the cysteine residues in the Cys2His cuprous ion binding motif of CsoR. Using RNA-seq coupled with the mechanistic insights of Cu(i) transfer between CopZ and CsoR in vitro, we propose a copper trafficking pathway for the CsoR regulon that initially involves the buffering of cytosolic copper by three CopZ chaperones followed by transfer of Cu(i) to CsoR to illicit a transcriptional response.
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Affiliation(s)
- Amanda K Chaplin
- School of Biological Science, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UK.
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32
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Structural and mechanistic insights into an extracytoplasmic copper trafficking pathway in Streptomyces lividans. Biochem J 2014; 459:525-38. [PMID: 24548299 DOI: 10.1042/bj20140017] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In Streptomyces lividans an extracytoplasmic copper-binding Sco protein plays a role in two unlinked processes: (i) initiating a morphological development switch and (ii) facilitating the co-factoring of the CuA domain of CcO (cytochrome c oxidase). How Sco obtains copper once secreted to the extracytoplasmic environment is unknown. In the present paper we report on a protein possessing an HX₆MX₂₁HXM motif that binds a single cuprous ion with subfemtomolar affinity. High-resolution X-ray structures of this extracytoplasmic copper chaperone-like protein (ECuC) in the apo- and Cu(I)-bound states reveal that the latter possesses a surface-accessible cuprous-ion-binding site located in a dish-shaped region of β-sheet structure. A cuprous ion is transferred under a favourable thermodynamic gradient from ECuC to Sco with no back transfer occurring. The ionization properties of the cysteine residues in the Cys⁸⁶xxxCys⁹⁰ copper-binding motif of Sco, together with their positional locations identified from an X-ray structure of Sco, suggests a role for Cys⁸⁶ in initiating an inter-complex ligand-exchange reaction with Cu(I)-ECuC. Generation of the genetic knockouts, Δsco, Δecuc and Δsco/ecuc, and subsequent in vivo assays lend support to the existence of a branched extracytoplasmic copper-trafficking pathway in S. lividans. One branch requires both Sco and to a certain extent ECuC to cofactor the CuA domain, whereas the other uses only Sco to deliver copper to a cuproenzyme to initiate morphological development.
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Abstract
The measurement of reliable Cu(I) protein binding affinities requires competing reference ligands with similar binding strengths; however, the literature on such reference ligands is not only sparse but often conflicting. To address this deficiency, we have created and characterized a series of water-soluble monovalent copper ligands, MCL-1, MCL-2, and MCL-3, that form well-defined, air-stable, and colorless complexes with Cu(I) in aqueous solution. X-ray structural data, electrochemical measurements, and an extensive network of equilibrium titrations showed that all three ligands form discrete Cu(I) complexes with 1:1 stoichiometry and are capable of buffering Cu(I) concentrations between 10(-10) and 10(-17) M. As most Cu(I) protein affinities have been obtained from competition experiments with bathocuproine disulfonate or 2,2'-bicinchoninic acid, we further calibrated their Cu(I) stability constants against the MCL series. To demonstrate the application of these reagents, we determined the Cu(I) binding affinity of CusF (log K = 14.3 ± 0.1), a periplasmic metalloprotein required for the detoxification of elevated copper levels in Escherichia coli . Altogether, this interconnected set of affinity standards establishes a reliable foundation that will facilitate the precise determination of Cu(I) binding affinities of proteins and small-molecule ligands.
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Affiliation(s)
- Pritha Bagchi
- School of Chemistry and Biochemistry, Petit Institute for
Bioengineering and Bioscience, Georgia Institute of Technology, 901 Atlantic Drive,
Atlanta, GA 30332, U.S.A
| | - M. Thomas Morgan
- School of Chemistry and Biochemistry, Petit Institute for
Bioengineering and Bioscience, Georgia Institute of Technology, 901 Atlantic Drive,
Atlanta, GA 30332, U.S.A
| | - John Bacsa
- X-ray Crystallography Center, Department of Chemistry, Emory
University, 1515 Dieckey Drive, Atlanta, GA 30322, U.S.A
| | - Christoph J. Fahrni
- School of Chemistry and Biochemistry, Petit Institute for
Bioengineering and Bioscience, Georgia Institute of Technology, 901 Atlantic Drive,
Atlanta, GA 30332, U.S.A
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Badarau A, Baslé A, Firbank SJ, Dennison C. Investigating the role of zinc and copper binding motifs of trafficking sites in the cyanobacterium Synechocystis PCC 6803. Biochemistry 2013; 52:6816-23. [PMID: 24050657 PMCID: PMC3793899 DOI: 10.1021/bi400492t] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Although zinc and copper are required by proteins with very different functions, these metals can be delivered to cellular locations by homologous metal transporters within the same organism, as demonstrated by the cyanobacterial ( Synechocystis PCC 6803) zinc exporter ZiaA and thylakoidal copper importer PacS. The N-terminal metal-binding domains of these transporters (ZiaAN and PacSN, respectively) have related ferredoxin folds also found in the metallochaperone Atx1, which delivers copper to PacS, but differ in the residues found in their M/IXCXXC metal-binding motifs. To investigate the role of the nonconserved residues in this region on metal binding, the sequence from ZiaAN has been introduced into Atx1 and PacSN, and the motifs of Atx1 and PacSN swapped. The motif sequence can tune Cu(I) affinity only approximately 3-fold. However, the introduction of the ZiaAN motif (MDCTSC) dramatically increases the Zn(II) affinity of both Atx1 and PacSN by up to 2 orders of magnitude. The Atx1 mutant with the ZiaAN motif crystallizes as a side-to-side homodimer very similar to that found for [Cu(I)2-Atx1]2 ( Badarau et al. Biochemistry 2010 , 49 , 7798 ). In a crystal structure of the PacSN mutant possessing the ZiaAN motif (PacSN(ZiaAN)), the Asp residue from the metal-binding motif coordinates Zn(II). This demonstrates that the increased Zn(II) affinity of this variant and the high Zn(II) affinity of ZiaAN are due to the ability of the carboxylate to ligate this metal ion. Comparison of the Zn(II) sites in PacSN(ZiaAN) structures provides additional insight into Zn(II) trafficking in cyanobacteria.
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Affiliation(s)
- Adriana Badarau
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University , Newcastle upon Tyne, NE2 4HH, United Kingdom
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35
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Badarau A, Baslé A, Firbank SJ, Dennison C. Crosstalk between Cu(I) and Zn(II) homeostasis via Atx1 and cognate domains. Chem Commun (Camb) 2013; 49:8000-2. [PMID: 23926594 PMCID: PMC3763678 DOI: 10.1039/c3cc42709a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The copper metallochaperone Atx1 and the N-terminal metal-binding domain of a copper-transporting ATP-ase can form tight Zn(II)-mediated hetero-complexes in both cyanobacteria and humans. Copper and zinc homeostasis could be linked by metal binding to these CXXC-containing proteins.
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Affiliation(s)
- Adriana Badarau
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
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36
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Spectroscopic characterization of copper(I) binding to apo and metal-reconstituted zinc finger peptides. J Biol Inorg Chem 2013; 18:669-78. [DOI: 10.1007/s00775-013-1012-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Accepted: 05/29/2013] [Indexed: 01/10/2023]
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37
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A new structural paradigm in copper resistance in Streptococcus pneumoniae. Nat Chem Biol 2013; 9:177-83. [PMID: 23354287 PMCID: PMC3578076 DOI: 10.1038/nchembio.1168] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 12/18/2012] [Indexed: 12/11/2022]
Abstract
Copper resistance has emerged as an important virulence determinant of microbial pathogens. In Streptococcus pneumoniae, copper resistance is mediated by the copper-responsive repressor CopY, CupA and the copper-effluxing P(1B)-type ATPase CopA. We show here that CupA is a previously uncharacterized cell membrane-anchored Cu(I) chaperone and that a Cu(I) binding-competent, membrane-localized CupA is obligatory for copper resistance. The crystal structures of the soluble domain of CupA and the N-terminal metal-binding domain (MBD) of CopA (CopA(MBD)) reveal isostructural cupredoxin-like folds that each harbor a binuclear Cu(I) cluster unprecedented in bacterial copper trafficking. NMR studies reveal unidirectional Cu(I) transfer from the low-affinity site on the soluble domain of CupA to the high-affinity site of CopA(MBD). However, copper binding by CopA(MBD) is not essential for cellular copper resistance, consistent with a primary role of CupA in cytoplasmic Cu(I) sequestration and/or direct delivery to the transmembrane site of CopA for cellular efflux.
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38
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Allen S, Badarau A, Dennison C. The influence of protein folding on the copper affinities of trafficking and target sites. Dalton Trans 2012; 42:3233-9. [PMID: 23169585 DOI: 10.1039/c2dt32166a] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The relative influence of protein unfolding on the Cu(I) affinity of trafficking and target sites for copper has been determined. For the copper metallochaperone Atx1 from Synechocystis PCC 6803 (a cyanobacterium), Saccharomyces cerevisiae and humans unfolding in urea results in a decrease in the Cu(I) affinity from (4-5) × 10(17) M(-1) to (1-3) × 10(16) M(-1) at pH 7. The affinities of the unfolded Atx1s are similar to those for CXXC-containing peptides. Partial unfolding, due to the loop 5 His61Lys mutation in Synechocystis Atx1, gives rise to a more limited decrease in Cu(I) affinity. For the copper target protein plastocyanin from Synechocystis, chemical unfolding results in the Cu(I) affinity decreasing by 5-orders of magnitude. This differential influence of protein unfolding on Cu(I) affinity is due to a more complex copper site structure in the target protein, including numerous interactions of non-coordinating residues with ligating amino acids. This second-coordination sphere is much simpler in the Atx1s with the main interaction provided by the loop 5 residue that tunes the Cu(I) affinity by altering the pK(a) of the C-terminal Cys ligand of the CXXC motif. This interaction and others are absent in the unfolded Atx1s and the two Cys ligands have pK(a) values reminiscent of free thiols (>8) resulting in lowered Cu(I) affinities at pH 7. Residues close to the active site of the thiol-disulfide oxidoreductase thioredoxin appear to lower the Cu(I) affinity of its CXXC motif to 3.1 × 10(15) M(-1) at pH 7, presumably to prevent copper binding in vivo. The structure of a copper site, including the number and relative position of ligands in the primary structure and the complexity of the second-coordination sphere, results in dramatically different effects of unfolding on Cu(I) affinity that has important implications for copper homeostasis.
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Affiliation(s)
- Stephen Allen
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
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39
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Tamasi G, Mangani S, Cini R. Copper(I)-alkyl sulfide and -cysteine tri-nuclear clusters as models for metallo proteins: a structural density functional analysis. J Biomol Struct Dyn 2012; 30:728-51. [DOI: 10.1080/07391102.2012.689703] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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40
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Kachalova GS, Shosheva AC, Bourenkov GP, Donchev AA, Dimitrov MI, Bartunik HD. Structural comparison of the poplar plastocyanin isoforms PCa and PCb sheds new light on the role of the copper site geometry in interactions with redox partners in oxygenic photosynthesis. J Inorg Biochem 2012; 115:174-81. [PMID: 22883960 DOI: 10.1016/j.jinorgbio.2012.07.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Revised: 07/09/2012] [Accepted: 07/12/2012] [Indexed: 01/06/2023]
Abstract
Plastocyanin (PC) from poplar leaves is present in two isoforms, PCa and PCb, which differ in sequence by amino acid replacements at locations remote from the copper center and simultaneously act in the photosynthetic electron-transport chain. We describe ultra-high resolution structures of PCa and high-resolution structures of PCb, both under oxidizing and reducing conditions at pH 4, 6 and 8. The docking on cytochrome f and photosystem I, respectively, has been modeled for both isoforms. PCa and PCb exhibit closely similar overall and active-site structures, except for a difference in the relative orientation of the acidic patches. The isoforms exhibit substantial differences in the dependence of the reduced (Cu(I)) geometry on pH. In PCa, the decrease in pH causes a gradual dissociation of His87 from Cu(I) at low pH, probably adopting a neutral tautomeric state. In PCb, the histidine remains covalently bound to Cu(I) and may adopt a doubly protonated state at low pH. The fact that both isoforms have similar although not identical functions in photosynthetic electron flows suggests that the His87 imidazole does not play a crucial role for the pathway of electron transport from cytochrome f to oxidized PC.
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Affiliation(s)
- Galina S Kachalova
- A.N.Bach Institute of Biochemistry, Russian Academy of Sciences, Leninsky pr., Moscow 119071, Russia
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41
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Shin LJ, Lo JC, Yeh KC. Copper chaperone antioxidant protein1 is essential for copper homeostasis. PLANT PHYSIOLOGY 2012; 159:1099-110. [PMID: 22555879 PMCID: PMC3387697 DOI: 10.1104/pp.112.195974] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 05/01/2012] [Indexed: 05/05/2023]
Abstract
Copper (Cu) is essential for plant growth but toxic in excess. Specific molecular mechanisms maintain Cu homeostasis to facilitate its use and avoid the toxicity. Cu chaperones, proteins containing a Cu-binding domain(s), are thought to assist Cu intracellular homeostasis by their Cu-chelating ability. In Arabidopsis (Arabidopsis thaliana), two Cu chaperones, Antioxidant Protein1 (ATX1) and ATX1-Like Copper Chaperone (CCH), share high sequence homology. Previously, their Cu-binding capabilities were demonstrated and interacting molecules were identified. To understand the physiological functions of these two chaperones, we characterized the phenotype of atx1 and cch mutants and the cchatx1 double mutant in Arabidopsis. The shoot and root growth of atx1 and cchatx1 but not cch was specifically hypersensitive to excess Cu but not excess iron, zinc, or cadmium. The activities of antioxidant enzymes in atx1 and cchatx1 were markedly regulated in response to excess Cu, which confirms the phenotype of Cu hypersensitivity. Interestingly, atx1 and cchatx1 were sensitive to Cu deficiency. Overexpression of ATX1 not only enhanced Cu tolerance and accumulation in excess Cu conditions but also tolerance to Cu deficiency. In addition, the Cu-binding motif MXCXXC of ATX1 was required for these physiological functions. ATX1 was previously proposed to be involved in Cu homeostasis by its Cu-binding activity and interaction with the Cu transporter Heavy metal-transporting P-type ATPase5. In this study, we demonstrate that ATX1 plays an essential role in Cu homeostasis in conferring tolerance to excess Cu and Cu deficiency. The possible mechanism is discussed.
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Affiliation(s)
- Lung-Jiun Shin
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei 114, Taiwan (L.-J.S.)
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei 11529, Taiwan (L.-J.S., J.-C.L., K.-C.Y.)
- Institute of Plant Biology, National Taiwan University, Taipei 10617, Taiwan (J.-C.L.)
| | - Jing-Chi Lo
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei 114, Taiwan (L.-J.S.)
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei 11529, Taiwan (L.-J.S., J.-C.L., K.-C.Y.)
- Institute of Plant Biology, National Taiwan University, Taipei 10617, Taiwan (J.-C.L.)
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42
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Keller AM, Benítez JJ, Klarin D, Zhong L, Goldfogel M, Yang F, Chen TY, Chen P. Dynamic multibody protein interactions suggest versatile pathways for copper trafficking. J Am Chem Soc 2012; 134:8934-43. [PMID: 22578168 DOI: 10.1021/ja3018835] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
As part of intracellular copper trafficking pathways, the human copper chaperone Hah1 delivers Cu(+) to the Wilson's Disease Protein (WDP) via weak and dynamic protein-protein interactions. WDP contains six homologous metal binding domains (MBDs) connected by flexible linkers, and these MBDs all can receive Cu(+) from Hah1. The functional roles of the MBD multiplicity in Cu(+) trafficking are not well understood. Building on our previous study of the dynamic interactions between Hah1 and the isolated fourth MBD of WDP, here we study how Hah1 interacts with MBD34, a double-domain WDP construct, using single-molecule fluorescence resonance energy transfer (smFRET) combined with vesicle trapping. By alternating the positions of the smFRET donor and acceptor, we systematically probed Hah1-MBD3, Hah1-MBD4, and MBD3-MBD4 interaction dynamics within the multidomain system. We found that the two interconverting interaction geometries were conserved in both intermolecular Hah1-MBD and intramolecular MBD-MBD interactions. The Hah1-MBD interactions within MBD34 are stabilized by an order of magnitude relative to the isolated single-MBDs, and thermodynamic and kinetic evidence suggest that Hah1 can interact with both MBDs simultaneously. The enhanced interaction stability of Hah1 with the multi-MBD system, the dynamic intramolecular MBD-MBD interactions, and the ability of Hah1 to interact with multiple MBDs simultaneously suggest an efficient and versatile mechanism for the Hah1-to-WDP pathway to transport Cu(+).
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Affiliation(s)
- Aaron M Keller
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, USA
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43
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Variations in methanobactin structure influences copper utilization by methane-oxidizing bacteria. Proc Natl Acad Sci U S A 2012; 109:8400-4. [PMID: 22582172 DOI: 10.1073/pnas.1112921109] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Methane-oxidizing bacteria are nature's primary biological mechanism for suppressing atmospheric levels of the second-most important greenhouse gas via methane monooxygenases (MMOs). The copper-containing particulate enzyme is the most widespread and efficient MMO. Under low-copper conditions methane-oxidizing bacteria secrete the small copper-binding peptide methanobactin (mbtin) to acquire copper, but how variations in the structures of mbtins influence copper metabolism and species selection are unknown. Methanobactins have been isolated from Methylocystis strains M and hirsuta CSC1, organisms that can switch to using an iron-containing soluble MMO when copper is limiting, and the nonswitchover Methylocystis rosea. These mbtins are shorter, and have different amino acid compositions, than the characterized mbtin from Methylosinus trichosporium OB3b. A coordinating pyrazinedione ring in the Methylocystis mbtins has little influence on the Cu(I) site structure. The Methylocystis mbtins have a sulfate group that helps stabilize the Cu(I) forms, resulting in affinities of approximately 10(21) M(-1). The Cu(II) affinities vary over three orders of magnitude with reduction potentials covering approximately 250 mV, which may dictate the mechanism of intracellular copper release. Copper uptake and the switchover from using the iron-containing soluble MMO to the copper-containing particulate enzyme is faster when mediated by the native mbtin, suggesting that the amino acid sequence is important for the interaction of mbtins with receptors. The differences in structures and properties of mbtins, and their influence on copper utilization by methane-oxidizing bacteria, have important implications for the ecology and global function of these environmentally vital organisms.
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Allen S, Badarau A, Dennison C. Cu(I) affinities of the domain 1 and 3 sites in the human metallochaperone for Cu,Zn-superoxide dismutase. Biochemistry 2012; 51:1439-48. [PMID: 22320662 DOI: 10.1021/bi201370r] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The delivery of copper by the human metallochaperone CCS is a key step in the activation of Cu,Zn-superoxide dismutase (SOD1). CCS is a three-domain protein with Cu(I)-binding CXXC and CXC motifs in domains 1 and 3, respectively. A detailed analysis of the binding of copper to CCS, including variants in which the Cys residues from domains 1 and 3 have been mutated to Ser, and also using separate domain 1 and 3 constructs, demonstrates that CCS is able to bind 1 equiv of Cu(I) in both of these domains. The Cu(I) affinity of domain 1 is approximately 5 × 10(17) M(-1) at pH 7.5, while that of domain 3 is at least 1 order of magnitude weaker. The CXXC site will therefore be preferentially loaded with Cu(I), suggesting that domain 1 plays a role in the acquisition of the metal. The delivery of copper to the target occurs via domain 3 whose structural flexibility and ability to be transiently metalated during copper delivery appear to be more important than the Cu(I) affinity of its CXC motif. The Cu(I) affinity of domain 1 of CCS is comparable to that of HAH1, another cytosolic copper metallochaperone. CCS and HAH1 readily exchange Cu(I), providing a mechanism whereby cross-talk can occur between copper trafficking pathways.
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Affiliation(s)
- Stephen Allen
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, United Kingdom
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Cyanobacterial metallochaperone inhibits deleterious side reactions of copper. Proc Natl Acad Sci U S A 2011; 109:95-100. [PMID: 22198771 DOI: 10.1073/pnas.1117515109] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Copper metallochaperones supply copper to cupro-proteins through copper-mediated protein-protein-interactions and it has been hypothesized that metallochaperones thereby inhibit copper from causing damage en route. Evidence is presented in support of this latter role for cyanobacterial metallochaperone, Atx1. In cyanobacteria Atx1 contributes towards the supply of copper to plastocyanin inside thylakoids but it is shown here that in copper-replete medium, copper can reach plastocyanin without Atx1. Unlike metallochaperone-independent copper-supply to superoxide dismutase in eukaryotes, glutathione is not essential for Atx1-independent supply to plastocyanin: Double mutants missing atx1 and gshB (encoding glutathione synthetase) accumulate the same number of atoms of copper per cell in the plastocyanin pool as wild type. Critically, Δatx1ΔgshB are hypersensitive to elevated copper relative to wild type cells and also relative to ΔgshB single mutants with evidence that hypersensitivity arises due to the mislocation of copper to sites for other metals including iron and zinc. The zinc site on the amino-terminal domain (ZiaA(N)) of the P(1)-type zinc-transporting ATPase is especially similar to the copper site of the Atx1 target PacS(N), and ZiaA(N) will bind Cu(I) more tightly than zinc. An NMR model of a substituted-ZiaA(N)-Cu(I)-Atx1 heterodimer has been generated making it possible to visualize a juxtaposition of residues surrounding the ZiaA(N) zinc site, including Asp(18), which normally repulse Atx1. Equivalent repulsion between bacterial copper metallochaperones and the amino-terminal regions of P(1)-type ATPases for metals other than Cu(I) is conserved, again consistent with a role for copper metallochaperones to withhold copper from binding sites for other metals.
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