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Caron-Godon CA, Collington E, Wolf JL, Coletta G, Glerum DM. More than Just Bread and Wine: Using Yeast to Understand Inherited Cytochrome Oxidase Deficiencies in Humans. Int J Mol Sci 2024; 25:3814. [PMID: 38612624 PMCID: PMC11011759 DOI: 10.3390/ijms25073814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 03/26/2024] [Accepted: 03/28/2024] [Indexed: 04/14/2024] Open
Abstract
Inherited defects in cytochrome c oxidase (COX) are associated with a substantial subset of diseases adversely affecting the structure and function of the mitochondrial respiratory chain. This multi-subunit enzyme consists of 14 subunits and numerous cofactors, and it requires the function of some 30 proteins to assemble. COX assembly was first shown to be the primary defect in the majority of COX deficiencies 36 years ago. Over the last three decades, most COX assembly genes have been identified in the yeast Saccharomyces cerevisiae, and studies in yeast have proven instrumental in testing the impact of mutations identified in patients with a specific COX deficiency. The advent of accessible genome-wide sequencing capabilities has led to more patient mutations being identified, with the subsequent identification of several new COX assembly factors. However, the lack of genotype-phenotype correlations and the large number of genes involved in generating a functional COX mean that functional studies must be undertaken to assign a genetic variant as being causal. In this review, we provide a brief overview of the use of yeast as a model system and briefly compare the COX assembly process in yeast and humans. We focus primarily on the studies in yeast that have allowed us to both identify new COX assembly factors and to demonstrate the pathogenicity of a subset of the mutations that have been identified in patients with inherited defects in COX. We conclude with an overview of the areas in which studies in yeast are likely to continue to contribute to progress in understanding disease arising from inherited COX deficiencies.
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Affiliation(s)
- Chenelle A. Caron-Godon
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada; (C.A.C.-G.); (E.C.); (J.L.W.); (G.C.)
| | - Emma Collington
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada; (C.A.C.-G.); (E.C.); (J.L.W.); (G.C.)
| | - Jessica L. Wolf
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada; (C.A.C.-G.); (E.C.); (J.L.W.); (G.C.)
| | - Genna Coletta
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada; (C.A.C.-G.); (E.C.); (J.L.W.); (G.C.)
| | - D. Moira Glerum
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada; (C.A.C.-G.); (E.C.); (J.L.W.); (G.C.)
- Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
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Medlock AE, Hixon JC, Bhuiyan T, Cobine PA. Prime Real Estate: Metals, Cofactors and MICOS. Front Cell Dev Biol 2022; 10:892325. [PMID: 35669513 PMCID: PMC9163361 DOI: 10.3389/fcell.2022.892325] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 05/02/2022] [Indexed: 12/23/2022] Open
Abstract
Metals are key elements for the survival and normal development of humans but can also be toxic to cells when mishandled. In fact, even mild disruption of metal homeostasis causes a wide array of disorders. Many of the metals essential to normal physiology are required in mitochondria for enzymatic activities and for the formation of essential cofactors. Copper is required as a cofactor in the terminal electron transport chain complex cytochrome c oxidase, iron is required for the for the formation of iron-sulfur (Fe-S) clusters and heme, manganese is required for the prevention of oxidative stress production, and these are only a few examples of the critical roles that mitochondrial metals play. Even though the targets of these metals are known, we are still identifying transporters, investigating the roles of known transporters, and defining regulators of the transport process. Mitochondria are dynamic organelles whose content, structure and localization within the cell vary in different tissues and organisms. Our knowledge of the impact that alterations in mitochondrial physiology have on metal content and utilization in these organelles is very limited. The rates of fission and fusion, the ultrastructure of the organelle, and rates of mitophagy can all affect metal homeostasis and cofactor assembly. This review will focus of the emerging areas of overlap between metal homeostasis, cofactor assembly and the mitochondrial contact site and cristae organizing system (MICOS) that mediates multiple aspects of mitochondrial physiology. Importantly the MICOS complexes may allow for localization and organization of complexes not only involved in cristae formation and contact between the inner and outer mitochondrial membranes but also acts as hub for metal-related proteins to work in concert in cofactor assembly and homeostasis.
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Affiliation(s)
- Amy E. Medlock
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States
- Augusta University/University of Georgia Medical Partnership, University of Georgia, Athens, GA, United States
| | - J. Catrice Hixon
- Department of Biological Sciences, Auburn University, Auburn, AL, United States
| | - Tawhid Bhuiyan
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States
| | - Paul A. Cobine
- Department of Biological Sciences, Auburn University, Auburn, AL, United States
- *Correspondence: Paul A. Cobine,
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Wu L, Yu Y, Hu H, Tao Y, Song P, Li D, Guan Y, Gao H, Sui X, Volodymyr T, Volodymyr V, Zhatova H, Li C. New SFT2-like Vesicle Transport Protein (SFT2L) Enhances Cadmium Tolerance and Reduces Cadmium Accumulation in Common Wheat Grains. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:5526-5540. [PMID: 35484643 DOI: 10.1021/acs.jafc.1c08021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Cadmium (Cd) is one of the most toxic heavy metal elements to the environment, which seriously threatens the safe production of food crops. In this study, we identified a novel function of the cytomembrane TaSFT2L protein in wheat (Triticum aestivum). Expression of the TaSFT2L gene in yeast showed no transport activities for Cd, which could explain the role of TaSFT2L in metal tolerance. It was observed that increased autophagic activity in roots caused by silencing of TaSFT2L enhanced Cd tolerance. Transgenic wheat revealed that RNA interference (RNAi) lines enhanced the wheat growth concerning the increased shoot or root elongation, dry weight, and chlorophyll accumulation. Furthermore, RNAi lines decreased root-to-grain Cd translocation in wheat by nearly 68% and Cd accumulation in wheat grains by 53%. Meanwhile, the overexpression lines displayed a compromised growth response and increased Cd accumulation in wheat tissues, compared to wild type. These findings show that TaSFT2L is a key gene involved in regulation of Cd translocation in wheat, and its silencing to form transgenic wheat can inhibit Cd accumulation. This has the ability to alleviate the food chain-associated impact of environmental pollution on human health.
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Affiliation(s)
- Liuliu Wu
- College of Life Science and Technology/Henan Engineering Research Center of Crop Genome Editing/Henan International Joint Laboratory of Plant Genetic Improvement and Soil Remediation/Collaborative Innovation Center of Modern Biological Breeding of Henan Province, Henan Institute of Science and Technology, Xinxiang 453003, China
- Sumy National Agrarian University, Sumy 40021, Ukraine
| | - Yongang Yu
- College of Life Science and Technology/Henan Engineering Research Center of Crop Genome Editing/Henan International Joint Laboratory of Plant Genetic Improvement and Soil Remediation/Collaborative Innovation Center of Modern Biological Breeding of Henan Province, Henan Institute of Science and Technology, Xinxiang 453003, China
| | - Haiyan Hu
- College of Life Science and Technology/Henan Engineering Research Center of Crop Genome Editing/Henan International Joint Laboratory of Plant Genetic Improvement and Soil Remediation/Collaborative Innovation Center of Modern Biological Breeding of Henan Province, Henan Institute of Science and Technology, Xinxiang 453003, China
| | - Ye Tao
- College of Life Science and Technology/Henan Engineering Research Center of Crop Genome Editing/Henan International Joint Laboratory of Plant Genetic Improvement and Soil Remediation/Collaborative Innovation Center of Modern Biological Breeding of Henan Province, Henan Institute of Science and Technology, Xinxiang 453003, China
- Sumy National Agrarian University, Sumy 40021, Ukraine
| | - Puwen Song
- College of Life Science and Technology/Henan Engineering Research Center of Crop Genome Editing/Henan International Joint Laboratory of Plant Genetic Improvement and Soil Remediation/Collaborative Innovation Center of Modern Biological Breeding of Henan Province, Henan Institute of Science and Technology, Xinxiang 453003, China
| | - Dongxiao Li
- College of Life Science and Technology/Henan Engineering Research Center of Crop Genome Editing/Henan International Joint Laboratory of Plant Genetic Improvement and Soil Remediation/Collaborative Innovation Center of Modern Biological Breeding of Henan Province, Henan Institute of Science and Technology, Xinxiang 453003, China
| | - Yuanyuan Guan
- College of Life Science and Technology/Henan Engineering Research Center of Crop Genome Editing/Henan International Joint Laboratory of Plant Genetic Improvement and Soil Remediation/Collaborative Innovation Center of Modern Biological Breeding of Henan Province, Henan Institute of Science and Technology, Xinxiang 453003, China
| | - Huanting Gao
- College of Life Science and Technology/Henan Engineering Research Center of Crop Genome Editing/Henan International Joint Laboratory of Plant Genetic Improvement and Soil Remediation/Collaborative Innovation Center of Modern Biological Breeding of Henan Province, Henan Institute of Science and Technology, Xinxiang 453003, China
| | - Xiaotian Sui
- College of Life Science and Technology/Henan Engineering Research Center of Crop Genome Editing/Henan International Joint Laboratory of Plant Genetic Improvement and Soil Remediation/Collaborative Innovation Center of Modern Biological Breeding of Henan Province, Henan Institute of Science and Technology, Xinxiang 453003, China
| | | | | | | | - Chengwei Li
- College of Life Science and Technology/Henan Engineering Research Center of Crop Genome Editing/Henan International Joint Laboratory of Plant Genetic Improvement and Soil Remediation/Collaborative Innovation Center of Modern Biological Breeding of Henan Province, Henan Institute of Science and Technology, Xinxiang 453003, China
- College of Biological Engineering, Henan University of Technology, Zhengzhou 450000, China
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4
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Feng SJ, Liu XS, Cao HW, Yang ZM. Identification of a rice metallochaperone for cadmium tolerance by an epigenetic mechanism and potential use for clean up in wetland. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 288:117837. [PMID: 34329044 DOI: 10.1016/j.envpol.2021.117837] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 07/09/2021] [Accepted: 07/21/2021] [Indexed: 06/13/2023]
Abstract
Cadmium (Cd) is a toxic heavy metal that initiates diverse chronic diseases through food chains. Developing a biotechnology for manipulating Cd uptake in plants is beneficial to reduce environmental and health risks. Here, we identified a novel epigenetic mechanism underlying Cd accumulation regulated by an uncharacterized metallochaperone namely Heavy Metal Responsive Protein (HMP) in rice plants. OsHMP resides in cytoplasm and nucleus, dominantly induced by Cd stress and binds directly to Cd ions. OsHMP overexpression enhanced the rice growth under Cd stress but accumulated more Cd, whereas knockout or knockdown of OsHMP showed a contrasting effect. The enhanced Cd accumulation in the transgenic lines was confirmed by a long-term experiment with rice growing at the environmentally realistic Cd concentration in soil. The bisulfite sequencing and chromatin immunoprecipitation assessments revealed that Cd stress reduced significantly the DNA methylation at CpG (Cytosine-Guanine) and histone H3K9me2 marks in the upstream of OsHMP. By identifying a couple of mutants defective in DNA methylation and histone modification (H3K9me2) such as Osmet1 (methylatransfease1) and Ossdg714 (kryptonite), we found that the Cd-induced epigenetic hypomethylation at the region was associated with OsHMP overexpression, which consequently led to Cd detoxification in rice. The causal relationship was confirmed by the GUS reporter gene coupled with OsHMP and OsMET1 whereby OsMET1 repressed directly the OsHMP expression. Our work signifies that expression of OsHMP is required for Cd detoxification in rice plants, and the Cd-induced hypomethylation in the specific region is responsible for the enhanced OsHMP expression. In summary, this study gained an insight into the epigenetic mechanism for additional OsHMP expression which consequently ensures rice adaptation to the Cd-contaminated environment.
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Affiliation(s)
- Sheng Jun Feng
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, 210095, China; The State Key Laboratory of Subtropical Silviculture, Laboratory of Plant Molecular and Developmental Biology, Zhejiang A&F University, Hangzhou, 311300, China
| | - Xue Song Liu
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, 210095, China
| | - Hong Wei Cao
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, 210095, China
| | - Zhi Min Yang
- Department of Biochemistry and Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing, 210095, China.
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5
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Soma S, Morgada MN, Naik MT, Boulet A, Roesler AA, Dziuba N, Ghosh A, Yu Q, Lindahl PA, Ames JB, Leary SC, Vila AJ, Gohil VM. COA6 Is Structurally Tuned to Function as a Thiol-Disulfide Oxidoreductase in Copper Delivery to Mitochondrial Cytochrome c Oxidase. Cell Rep 2020; 29:4114-4126.e5. [PMID: 31851937 PMCID: PMC6946597 DOI: 10.1016/j.celrep.2019.11.054] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 10/07/2019] [Accepted: 11/13/2019] [Indexed: 12/31/2022] Open
Abstract
In eukaryotes, cellular respiration is driven by mitochondrial cytochrome c oxidase (CcO), an enzyme complex that requires copper cofactors for its catalytic activity. Insertion of copper into its catalytically active subunits, including COX2, is a complex process that requires metallochaperones and redox proteins including SCO1, SCO2, and COA6, a recently discovered protein whose molecular function is unknown. To uncover the molecular mechanism by which COA6 and SCO proteins mediate copper delivery to COX2, we have solved the solution structure of COA6, which reveals a coiled-coil-helix-coiled-coil-helix domain typical of redox-active proteins found in the mitochondrial inter-membrane space. Accordingly, we demonstrate that COA6 can reduce the copper-coordinating disulfides of its client proteins, SCO1 and COX2, allowing for copper binding. Finally, our determination of the interaction surfaces and reduction potentials of COA6 and its client proteins provides a mechanism of how metallochaperone and disulfide reductase activities are coordinated to deliver copper to CcO. Soma et al. reports the solution structure of cytochrome c oxidase assembly factor COA6 and establishes that it functions as a thiol-disulfide oxidoreductase in a relay system that delivers copper to COX2, a copper-containing subunit of the mitochondrial cytochrome c oxidase.
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Affiliation(s)
- Shivatheja Soma
- Department of Biochemistry and Biophysics, MS 3474, Texas A&M University, College Station, TX 77843, USA
| | - Marcos N Morgada
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Área Biofísica, Departamento de Química Biológica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario (2000), Argentina
| | - Mandar T Naik
- Department of Biochemistry and Biophysics, MS 3474, Texas A&M University, College Station, TX 77843, USA
| | - Aren Boulet
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
| | - Anna A Roesler
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
| | - Nathaniel Dziuba
- Department of Biochemistry and Biophysics, MS 3474, Texas A&M University, College Station, TX 77843, USA
| | - Alok Ghosh
- Department of Biochemistry and Biophysics, MS 3474, Texas A&M University, College Station, TX 77843, USA
| | - Qinhong Yu
- Department of Chemistry, University of California, Davis, Davis, CA 95616, USA
| | - Paul A Lindahl
- Department of Biochemistry and Biophysics, MS 3474, Texas A&M University, College Station, TX 77843, USA; Department of Chemistry, Texas A&M University, College Station, TX 77843, USA
| | - James B Ames
- Department of Chemistry, University of California, Davis, Davis, CA 95616, USA
| | - Scot C Leary
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
| | - Alejandro J Vila
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Área Biofísica, Departamento de Química Biológica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario (2000), Argentina
| | - Vishal M Gohil
- Department of Biochemistry and Biophysics, MS 3474, Texas A&M University, College Station, TX 77843, USA.
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6
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Aich A, Wang C, Chowdhury A, Ronsör C, Pacheu-Grau D, Richter-Dennerlein R, Dennerlein S, Rehling P. COX16 promotes COX2 metallation and assembly during respiratory complex IV biogenesis. eLife 2018; 7:32572. [PMID: 29381136 PMCID: PMC5809144 DOI: 10.7554/elife.32572] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 01/14/2018] [Indexed: 12/25/2022] Open
Abstract
Cytochrome c oxidase of the mitochondrial oxidative phosphorylation system reduces molecular oxygen with redox equivalent-derived electrons. The conserved mitochondrial-encoded COX1- and COX2-subunits are the heme- and copper-center containing core subunits that catalyze water formation. COX1 and COX2 initially follow independent biogenesis pathways creating assembly modules with subunit-specific, chaperone-like assembly factors that assist in redox centers formation. Here, we find that COX16, a protein required for cytochrome c oxidase assembly, interacts specifically with newly synthesized COX2 and its copper center-forming metallochaperones SCO1, SCO2, and COA6. The recruitment of SCO1 to the COX2-module is COX16- dependent and patient-mimicking mutations in SCO1 affect interaction with COX16. These findings implicate COX16 in CuA-site formation. Surprisingly, COX16 is also found in COX1-containing assembly intermediates and COX2 recruitment to COX1. We conclude that COX16 participates in merging the COX1 and COX2 assembly lines.
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Affiliation(s)
- Abhishek Aich
- Department of Cellular Biochemistry, University Medical Centre Göttingen, Göttingen, Germany
| | - Cong Wang
- Department of Cellular Biochemistry, University Medical Centre Göttingen, Göttingen, Germany
| | - Arpita Chowdhury
- Department of Cellular Biochemistry, University Medical Centre Göttingen, Göttingen, Germany
| | - Christin Ronsör
- Department of Cellular Biochemistry, University Medical Centre Göttingen, Göttingen, Germany
| | - David Pacheu-Grau
- Department of Cellular Biochemistry, University Medical Centre Göttingen, Göttingen, Germany
| | | | - Sven Dennerlein
- Department of Cellular Biochemistry, University Medical Centre Göttingen, Göttingen, Germany
| | - Peter Rehling
- Department of Cellular Biochemistry, University Medical Centre Göttingen, Göttingen, Germany.,Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
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7
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Abstract
All known eukaryotes require copper for their development and survival. The essentiality of copper reflects its widespread use as a co-factor in conserved enzymes that catalyze biochemical reactions critical to energy production, free radical detoxification, collagen deposition, neurotransmitter biosynthesis and iron homeostasis. However, the prioritized use of copper poses an organism with a considerable challenge because, in its unbound form, copper can potentiate free radical production and displace iron-sulphur clusters to disrupt protein function. Protective mechanisms therefore evolved to mitigate this challenge and tightly regulate the acquisition, trafficking and storage of copper such that the metal ion is rarely found in its free form in the cell. Findings by a number of groups over the last ten years emphasize that this regulatory framework forms the foundation of a system that is capable of monitoring copper status and reprioritizing copper usage at both the cellular and systemic levels of organization. While the identification of relevant molecular mechanisms and signaling pathways has proven to be difficult and remains a barrier to our full understanding of the regulation of copper homeostasis, mounting evidence points to the mitochondrion as a pivotal hub in this regard in both healthy and diseased states. Here, we review our current understanding of copper handling pathways contained within the organelle and consider plausible mechanisms that may serve to functionally couple their activity to that of other cellular copper handling machinery to maintain copper homeostasis.
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Affiliation(s)
- Zakery N. Baker
- Department of Biochemistry, University of Saskatchewan, Saskatoon, SK Canada S7N 5E5
| | - Paul A. Cobine
- Department of Biological Sciences, Auburn University, Auburn, Alabama 36849, USA
| | - Scot C. Leary
- Department of Biochemistry, University of Saskatchewan, Saskatoon, SK Canada S7N 5E5
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Jett KA, Leary SC. Building the Cu A site of cytochrome c oxidase: A complicated, redox-dependent process driven by a surprisingly large complement of accessory proteins. J Biol Chem 2017; 293:4644-4652. [PMID: 28972150 DOI: 10.1074/jbc.r117.816132] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cytochrome c oxidase (COX) was initially purified more than 70 years ago. A tremendous amount of insight into its structure and function has since been gleaned from biochemical, biophysical, genetic, and molecular studies. As a result, we now appreciate that COX relies on its redox-active metal centers (heme a and a3, CuA and CuB) to reduce oxygen and pump protons in a reaction essential for most eukaryotic life. Questions persist, however, about how individual structural subunits are assembled into a functional holoenzyme. Here, we focus on what is known and what remains to be learned about the accessory proteins that facilitate CuA site maturation.
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Affiliation(s)
- Kimberly A Jett
- Department of Biochemistry, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Scot C Leary
- Department of Biochemistry, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada.
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9
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Synthetic fluorescent probes to map metallostasis and intracellular fate of zinc and copper. Coord Chem Rev 2016. [DOI: 10.1016/j.ccr.2015.11.012] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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10
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Urso E, Maffia M. Behind the Link between Copper and Angiogenesis: Established Mechanisms and an Overview on the Role of Vascular Copper Transport Systems. J Vasc Res 2015; 52:172-96. [PMID: 26484858 DOI: 10.1159/000438485] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 07/07/2015] [Indexed: 11/19/2022] Open
Abstract
Angiogenesis critically sustains the progression of both physiological and pathological processes. Copper behaves as an obligatory co-factor throughout the angiogenic signalling cascades, so much so that a deficiency causes neovascularization to abate. Moreover, the progress of several angiogenic pathologies (e.g. diabetes, cardiac hypertrophy and ischaemia) can be tracked by measuring serum copper levels, which are being increasingly investigated as a useful prognostic marker. Accordingly, the therapeutic modulation of body copper has been proven effective in rescuing the pathological angiogenic dysfunctions underlying several disease states. Vascular copper transport systems profoundly influence the activation and execution of angiogenesis, acting as multi-functional regulators of apparently discrete pro-angiogenic pathways. This review concerns the complex relationship among copper-dependent angiogenic factors, copper transporters and common pathological conditions, with an unusual accent on the multi-faceted involvement of the proteins handling vascular copper. Functions regulated by the major copper transport proteins (CTR1 importer, ATP7A efflux pump and metallo-chaperones) include the modulation of endothelial migration and vascular superoxide, known to activate angiogenesis within a narrow concentration range. The potential contribution of prion protein, a controversial regulator of copper homeostasis, is discussed, even though its angiogenic involvement seems to be mainly associated with the modulation of endothelial motility and permeability.
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Affiliation(s)
- Emanuela Urso
- Department of Biological and Environmental Science and Technologies, University of Salento, Lecce, Italy
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11
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Loop recognition and copper-mediated disulfide reduction underpin metal site assembly of CuA in human cytochrome oxidase. Proc Natl Acad Sci U S A 2015; 112:11771-6. [PMID: 26351686 DOI: 10.1073/pnas.1505056112] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Maturation of cytochrome oxidases is a complex process requiring assembly of several subunits and adequate uptake of the metal cofactors. Two orthologous Sco proteins (Sco1 and Sco2) are essential for the correct assembly of the dicopper CuA site in the human oxidase, but their function is not fully understood. Here, we report an in vitro biochemical study that shows that Sco1 is a metallochaperone that selectively transfers Cu(I) ions based on loop recognition, whereas Sco2 is a copper-dependent thiol reductase of the cysteine ligands in the oxidase. Copper binding to Sco2 is essential to elicit its redox function and as a guardian of the reduced state of its own cysteine residues in the oxidizing environment of the mitochondrial intermembrane space (IMS). These results provide a detailed molecular mechanism for CuA assembly, suggesting that copper and redox homeostasis are intimately linked in the mitochondrion.
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12
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Siciliano G, Pasquali L, Mancuso M, Murri L. Molecular diagnostics and mitochondrial dysfunction: a future perspective. Expert Rev Mol Diagn 2014; 8:531-49. [DOI: 10.1586/14737159.8.4.531] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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13
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Leary SC, Antonicka H, Sasarman F, Weraarpachai W, Cobine PA, Pan M, Brown GK, Brown R, Majewski J, Ha KCH, Rahman S, Shoubridge EA. Novel Mutations inSCO1as a Cause of Fatal Infantile Encephalopathy and Lactic Acidosis. Hum Mutat 2013; 34:1366-70. [DOI: 10.1002/humu.22385] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Accepted: 07/11/2013] [Indexed: 12/12/2022]
Affiliation(s)
- Scot C. Leary
- Department of Biochemistry; University of Saskatchewan; Saskatoon; Canada
| | | | | | | | - Paul A. Cobine
- Department of Biological Sciences; Auburn University; Auburn; Alabama
| | - Min Pan
- Department of Biochemistry; University of Saskatchewan; Saskatoon; Canada
| | - Garry K. Brown
- Department of Biochemistry; University of Oxford; Oxford; UK
| | - Ruth Brown
- Department of Biochemistry; University of Oxford; Oxford; UK
| | - Jacek Majewski
- Department of Human Genetics; McGill University; Montreal; Canada
| | - Kevin C. H. Ha
- Department of Human Genetics; McGill University; Montreal; Canada
| | - Shamima Rahman
- Mitochondrial Research Group; UCL Institute of Child Health; London; UK
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14
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Leary SC, Cobine PA, Nishimura T, Verdijk RM, de Krijger R, de Coo R, Tarnopolsky MA, Winge DR, Shoubridge EA. COX19 mediates the transduction of a mitochondrial redox signal from SCO1 that regulates ATP7A-mediated cellular copper efflux. Mol Biol Cell 2013; 24:683-91. [PMID: 23345593 PMCID: PMC3596241 DOI: 10.1091/mbc.e12-09-0705] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The study of patient tissues and cell lines shows that SCO1 and SCO2 function collaboratively to generate a redox-dependent signal that is transduced from mitochondria to the cytosol by COX19, where it is relayed to ATP7A to regulate the rate of copper efflux from the cell. SCO1 and SCO2 are metallochaperones whose principal function is to add two copper ions to the catalytic core of cytochrome c oxidase (COX). However, affected tissues of SCO1 and SCO2 patients exhibit a combined deficiency in COX activity and total copper content, suggesting additional roles for these proteins in the regulation of cellular copper homeostasis. Here we show that both the redox state of the copper-binding cysteines of SCO1 and the abundance of SCO2 correlate with cellular copper content and that these relationships are perturbed by mutations in SCO1 or SCO2, producing a state of apparent copper overload. The copper deficiency in SCO patient fibroblasts is rescued by knockdown of ATP7A, a trans-Golgi, copper-transporting ATPase that traffics to the plasma membrane during copper overload to promote efflux. To investigate how a signal from SCO1 could be relayed to ATP7A, we examined the abundance and subcellular distribution of several soluble COX assembly factors. We found that COX19 partitions between mitochondria and the cytosol in a copper-dependent manner and that its knockdown partially rescues the copper deficiency in patient cells. These results demonstrate that COX19 is necessary for the transduction of a SCO1-dependent mitochondrial redox signal that regulates ATP7A-mediated cellular copper efflux.
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Affiliation(s)
- Scot C Leary
- Department of Biochemistry, University of Saskatchewan, Saskatoon, SK, Canada.
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15
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Abriata LA. Analysis of copper-ligand bond lengths in X-ray structures of different types of copper sites in proteins. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2012; 68:1223-31. [PMID: 22948924 DOI: 10.1107/s0907444912026054] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Accepted: 06/08/2012] [Indexed: 11/10/2022]
Abstract
An updated picture of the ligand sets and copper-ligand atom bond lengths in proteins is presented which takes advantage of (i) the approximately twofold increase in the number of entries for copper-containing proteins in the PDB since the last study of this kind, especially benefiting from the recent incorporation of the structures of proteins involved in copper homeostasis, and (ii) a preliminary classification of copper sites based on their structural, electronic and functional features. This classification allowed the calculation of reliable target copper-ligand distances for several bonds that were not available in previous work and that are in good agreement with EXAFS data and the known chemistry of these sites. The analysis presented here further disclosed an artifactual dependence of the average of the reported Cu-NHis bond lengths on structure resolution, highlighting the importance of taking this into account when computing target distances even from high-resolution structures. Finally, a relationship between the two Cu-O distances in bidentate carboxylates is disclosed, similar to that reported previously for other metal ions.
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Affiliation(s)
- Luciano A Abriata
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina.
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16
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Dodani SC, Leary SC, Cobine PA, Winge DR, Chang CJ. A targetable fluorescent sensor reveals that copper-deficient SCO1 and SCO2 patient cells prioritize mitochondrial copper homeostasis. J Am Chem Soc 2011; 133:8606-16. [PMID: 21563821 PMCID: PMC3106114 DOI: 10.1021/ja2004158] [Citation(s) in RCA: 223] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We present the design, synthesis, spectroscopy, and biological applications of Mitochondrial Coppersensor-1 (Mito-CS1), a new type of targetable fluorescent sensor for imaging exchangeable mitochondrial copper pools in living cells. Mito-CS1 is a bifunctional reporter that combines a Cu(+)-responsive fluorescent platform with a mitochondrial-targeting triphenylphosphonium moiety for localizing the probe to this organelle. Molecular imaging with Mito-CS1 establishes that this new chemical tool can detect changes in labile mitochondrial Cu(+) in a model HEK 293T cell line as well as in human fibroblasts. Moreover, we utilized Mito-CS1 in a combined imaging and biochemical study in fibroblasts derived from patients with mutations in the two synthesis of cytochrome c oxidase 1 and 2 proteins (SCO1 and SCO2), each of which is required for assembly and metalation of functionally active cytochrome c oxidase (COX). Interestingly, we observe that although defects in these mitochondrial metallochaperones lead to a global copper deficiency at the whole cell level, total copper and exchangeable mitochondrial Cu(+) pools in SCO1 and SCO2 patient fibroblasts are largely unaltered relative to wild-type controls. Our findings reveal that the cell maintains copper homeostasis in mitochondria even in situations of copper deficiency and mitochondrial metallochaperone malfunction, illustrating the importance of regulating copper stores in this energy-producing organelle.
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Affiliation(s)
- Sheel C. Dodani
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Scot C. Leary
- Department of Biochemistry, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
| | - Paul A. Cobine
- Department of Biological Sciences, Auburn University, Auburn, Alabama 36849, United States
| | - Dennis R. Winge
- Department of Medicine and Biochemistry, University of Utah Health Sciences Center, Salt Lake City, Utah 84132, United States
| | - Christopher J. Chang
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Howard Hughes Medical Institute, University of California, Berkeley, California 94720, United States
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17
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Banci L, Bertini I, Cavallaro G, Ciofi-Baffoni S. Seeking the determinants of the elusive functions of Sco proteins. FEBS J 2011; 278:2244-62. [DOI: 10.1111/j.1742-4658.2011.08141.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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18
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Leary SC. Redox regulation of SCO protein function: controlling copper at a mitochondrial crossroad. Antioxid Redox Signal 2010; 13:1403-16. [PMID: 20136502 DOI: 10.1089/ars.2010.3116] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Reversible changes in the redox state of cysteine residues represent an important mechanism with which to regulate protein function. In mitochondria, such redox reactions modulate the localization or activity of a group of proteins, most of which function in poorly defined pathways with essential roles in copper delivery to cytochrome c oxidase (COX) during holoenzyme biogenesis. To date, a total of 8 soluble (COX17, COX19, COX23, PET191, CMC1-4) and 3 integral membrane (COX11, SCO1, SCO2) accessory proteins with cysteine-containing domains that reside within the mitochondrial intermembrane space (IMS) have been identified in yeast, all of which have human orthologues. Compelling evidence from studies of COX17, SCO1, and SCO2 argues that regulation of the redox state of their cysteines is integral to their metallochaperone function. Redox also appears to be crucial to the regulation of a SCO-dependent, mitochondrial signaling pathway that modulates the rate of copper efflux from the cell. Here, I review our understanding of redox-dependent modulation of copper delivery to COX and IMS-localized copper-zinc superoxide dismutase (SOD1) during the maturation of each enzyme, and discuss how this in turn may serve to functionally couple mitochondrial copper handling pathways with those localized elsewhere in the cell to regulate cellular copper homeostasis.
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Affiliation(s)
- Scot C Leary
- Department of Biochemistry, University of Saskatchewan, Saskatoon, Canada.
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19
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Genetic, functional and evolutionary characterization of scox, the Drosophila melanogaster ortholog of the human SCO1 gene. Mitochondrion 2010; 10:433-48. [DOI: 10.1016/j.mito.2010.04.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2009] [Revised: 02/26/2010] [Accepted: 04/02/2010] [Indexed: 12/15/2022]
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20
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Abstract
The current state of knowledge on how copper metallochaperones support the maturation of cuproproteins is reviewed. Copper is needed within mitochondria to supply the Cu(A) and intramembrane Cu(B) sites of cytochrome oxidase, within the trans-Golgi network to supply secreted cuproproteins and within the cytosol to supply superoxide dismutase 1 (Sod1). Subpopulations of copper-zinc superoxide dismutase also localize to mitochondria, the secretory system, the nucleus and, in plants, the chloroplast, which also requires copper for plastocyanin. Prokaryotic cuproproteins are found in the cell membrane and in the periplasm of gram-negative bacteria. Cu(I) and Cu(II) form tight complexes with organic molecules and drive redox chemistry, which unrestrained would be destructive. Copper metallochaperones assist copper in reaching vital destinations without inflicting damage or becoming trapped in adventitious binding sites. Copper ions are specifically released from copper metallochaperones upon contact with their cognate cuproproteins and metal transfer is thought to proceed by ligand substitution.
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Affiliation(s)
- Nigel J Robinson
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, NE2 4HH, United Kingdom.
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21
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Stiburek L, Zeman J. Assembly factors and ATP-dependent proteases in cytochrome c oxidase biogenesis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:1149-58. [PMID: 20398622 DOI: 10.1016/j.bbabio.2010.04.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2009] [Revised: 03/14/2010] [Accepted: 04/07/2010] [Indexed: 12/29/2022]
Abstract
Eukaryotic cytochrome c oxidase (CcO), the terminal enzyme of the energy-transducing mitochondrial electron transport chain is a hetero-oligomeric, heme-copper oxidase complex composed of both mitochondrially and nuclear-encoded subunits. It is embedded in the inner mitochondrial membrane where it couples the transfer of electrons from reduced cytochrome c to molecular oxygen with vectorial proton translocation across the membrane. The biogenesis of CcO is a complicated sequential process that requires numerous specific accessory proteins, so-called assembly factors, which include translational activators, translocases, molecular chaperones, copper metallochaperones and heme a biosynthetic enzymes. Besides these CcO-specific protein factors, the correct biogenesis of CcO requires an even greater number of proteins with much broader substrate specificities. Indeed, growing evidence indicates that mitochondrial ATP-dependent proteases might play an important role in CcO biogenesis. Out of the four identified energy-dependent mitochondrial proteases, three were shown to be directly involved in proteolysis of CcO subunits. In addition to their well-established protein-quality control function these oligomeric proteolytic complexes with chaperone-like activities may function as molecular chaperones promoting productive folding and assembly of subunit proteins. In this review, we summarize the current knowledge of the functional involvement of eukaryotic CcO-specific assembly factors and highlight the possible significance for CcO biogenesis of mitochondrial ATP-dependent proteases.
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Affiliation(s)
- Lukas Stiburek
- Charles University in Prague, First Faculty of Medicine, Department of Pediatrics, Prague, Czech Republic.
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22
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Robinson NJ, Winge DR. Copper metallochaperones. Annu Rev Biochem 2010. [PMID: 20205585 DOI: 10.1146/annurev-biochem-030409-143539]+[] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The current state of knowledge on how copper metallochaperones support the maturation of cuproproteins is reviewed. Copper is needed within mitochondria to supply the Cu(A) and intramembrane Cu(B) sites of cytochrome oxidase, within the trans-Golgi network to supply secreted cuproproteins and within the cytosol to supply superoxide dismutase 1 (Sod1). Subpopulations of copper-zinc superoxide dismutase also localize to mitochondria, the secretory system, the nucleus and, in plants, the chloroplast, which also requires copper for plastocyanin. Prokaryotic cuproproteins are found in the cell membrane and in the periplasm of gram-negative bacteria. Cu(I) and Cu(II) form tight complexes with organic molecules and drive redox chemistry, which unrestrained would be destructive. Copper metallochaperones assist copper in reaching vital destinations without inflicting damage or becoming trapped in adventitious binding sites. Copper ions are specifically released from copper metallochaperones upon contact with their cognate cuproproteins and metal transfer is thought to proceed by ligand substitution.
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Affiliation(s)
- Nigel J Robinson
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, NE2 4HH, United Kingdom.
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23
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Abstract
The current state of knowledge on how copper metallochaperones support the maturation of cuproproteins is reviewed. Copper is needed within mitochondria to supply the Cu(A) and intramembrane Cu(B) sites of cytochrome oxidase, within the trans-Golgi network to supply secreted cuproproteins and within the cytosol to supply superoxide dismutase 1 (Sod1). Subpopulations of copper-zinc superoxide dismutase also localize to mitochondria, the secretory system, the nucleus and, in plants, the chloroplast, which also requires copper for plastocyanin. Prokaryotic cuproproteins are found in the cell membrane and in the periplasm of gram-negative bacteria. Cu(I) and Cu(II) form tight complexes with organic molecules and drive redox chemistry, which unrestrained would be destructive. Copper metallochaperones assist copper in reaching vital destinations without inflicting damage or becoming trapped in adventitious binding sites. Copper ions are specifically released from copper metallochaperones upon contact with their cognate cuproproteins and metal transfer is thought to proceed by ligand substitution.
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Affiliation(s)
- Nigel J Robinson
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, NE2 4HH, United Kingdom.
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24
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Siluvai GS, Nakano MM, Mayfield M, Nilges MJ, Blackburn NJ. H135A controls the redox activity of the Sco copper center. Kinetic and spectroscopic studies of the His135Ala variant of Bacillus subtilis Sco. Biochemistry 2010; 48:12133-44. [PMID: 19921776 DOI: 10.1021/bi901480g] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Sco-like proteins contain copper bound by two cysteines and a histidine residue. Although their function is still incompletely understood, there is a clear involvement with the assembly of cytochrome oxidases that contain the Cu(A) center in subunit 2, possibly mediating the transfer of copper into the Cu(A) binuclear site. We are investigating the reaction chemistry of BSco, the homologue from Bacillus subtilis. Our studies have revealed that BSco behaves more like a redox protein than a metallochaperone. The essential H135 residue that coordinates copper plays a role in stabilizing the Cu(II) rather than the Cu(I) form. When H135 is mutated to alanine, the oxidation rate of both hydrogen peroxide and one-electron outer-sphere reductants increases by 3 orders of magnitude, suggestive of a redox switch mechanism between the His-on and His-off conformational states of the protein. Imidazole binds to the H135A protein, restoring the N superhyperfine coupling in the EPR, but is unable to rescue the redox properties of wild-type Sco. These findings reveal a unique role for H135 in Sco function. We propose a hypothesis that electron transfer from Sco to the maturing oxidase may be essential for proper maturation and/or protection from oxidative damage during the assembly process. The findings also suggest that interaction of Sco with its protein partner(s) may perturb the Cu(II)-H135 interaction and thus induce a sensitive redox activity to the protein.
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Affiliation(s)
- Gnana S Siluvai
- Department of Science and Engineering, Oregon Health and Science University, Beaverton, Oregon 97006, USA
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25
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Leary SC, Sasarman F, Nishimura T, Shoubridge EA. Human SCO2 is required for the synthesis of CO II and as a thiol-disulphide oxidoreductase for SCO1. Hum Mol Genet 2009; 18:2230-40. [DOI: 10.1093/hmg/ddp158] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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26
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Stiburek L, Vesela K, Hansikova H, Hulkova H, Zeman J. Loss of function of Sco1 and its interaction with cytochrome c oxidase. Am J Physiol Cell Physiol 2009; 296:C1218-26. [PMID: 19295170 DOI: 10.1152/ajpcell.00564.2008] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Sco1 and Sco2 are mitochondrial copper-binding proteins involved in the biogenesis of the Cu(A) site in the cytochrome c oxidase (CcO) subunit Cox2 and in the maintenance of cellular copper homeostasis. Human Surf1 is a CcO assembly factor with an important but poorly characterized role in CcO biogenesis. Here, we analyzed the impact on CcO assembly and tissue copper levels of a G132S mutation in the juxtamembrane region of SCO1 metallochaperone associated with early onset hypertrophic cardiomyopathy, encephalopathy, hypotonia, and hepatopathy, assessed the total copper content of various SURF1 and SCO2-deficient tissues, and investigated the possible physical association between CcO and Sco1. The steady-state level of mutant Sco1 was severely decreased in the muscle mitochondria of the SCO1 patient, indicating compromised stability and thus loss of function of the protein. Unlike the wild-type variant, residual mutant Sco1 appeared to migrate exclusively in the monomeric form on blue native gels. Both the activity and content of CcO were reduced in the patient's muscle to approximately 10-20% of control values. SCO1-deficient mitochondria showed accumulation of two Cox2 subcomplexes, suggesting that Sco1 is very likely responsible for a different posttranslational aspect of Cox2 maturation than Sco2. Intriguingly, the various SURF1-deficient samples analyzed showed a tissue-specific copper deficiency similar to that of SCO-deficient samples, suggesting a role for Surf1 in copper homeostasis regulation. Finally, both blue native immunoblot analysis and coimmunoprecipitation revealed that a fraction of Sco1 physically associates with the CcO complex in human muscle mitochondria, suggesting a possible direct relationship between CcO and the regulation of cellular copper homeostasis.
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27
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Rigby K, Cobine PA, Khalimonchuk O, Winge DR. Mapping the functional interaction of Sco1 and Cox2 in cytochrome oxidase biogenesis. J Biol Chem 2008; 283:15015-22. [PMID: 18390903 PMCID: PMC2397465 DOI: 10.1074/jbc.m710072200] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2007] [Revised: 03/19/2008] [Indexed: 11/06/2022] Open
Abstract
Sco1 is implicated in the copper metallation of the Cu(A) site in Cox2 of cytochrome oxidase. The structure of Sco1 in the metallated and apo-conformers revealed structural dynamics primarily in an exposed region designated loop 8. The structural dynamics of loop 8 in Sco1 suggests it may be an interface for interactions with Cox17, the Cu(I) donor and/or Cox2. A series of conserved residues in the sequence motif (217)KKYRVYF(223) on the leading edge of this loop are shown presently to be important for yeast Sco1 function. Cells harboring Y219D, R220D, V221D, and Y222D mutant Sco1 proteins failed to restore respiratory growth or cytochrome oxidase activity in sco1Delta cells. The mutant proteins are stably expressed and are competent to bind Cu(I) and Cu(II) normally. Specific Cu(I) transfer from Cox17 to the mutant apo-Sco1 proteins proceeds normally. In contrast, using two in vivo assays that permit monitoring of the transient Sco1-Cox2 interaction, the mutant Sco1 molecules appear compromised in a function with Cox2. The mutants failed to suppress the respiratory defect of cox17-1 cells unlike wild-type SCO1. In addition, the mutants failed to suppress the hydrogen peroxide sensitivity of sco1Delta cells. These studies implicate different surfaces on Sco1 for interaction or function with Cox17 and Cox2.
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Affiliation(s)
| | | | | | - Dennis R. Winge
- Departments of Medicine and Biochemistry, University of Utah Health Sciences Center, Salt Lake City, Utah 84132
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28
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Leary SC, Winge DR, Cobine PA. "Pulling the plug" on cellular copper: the role of mitochondria in copper export. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2008; 1793:146-53. [PMID: 18522804 DOI: 10.1016/j.bbamcr.2008.05.002] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2008] [Revised: 05/02/2008] [Accepted: 05/05/2008] [Indexed: 10/22/2022]
Abstract
Mitochondria contain two enzymes, Cu,Zn superoxide dismutase (Sod1) and cytochrome c oxidase (CcO), that require copper as a cofactor for their biological activity. The copper used for their metallation originates from a conserved, bioactive pool contained within the mitochondrial matrix, the size of which changes in response to either genetic or pharmacological manipulation of cellular copper status. Its dynamic nature implies molecular mechanisms exist that functionally couple mitochondrial copper handling with other, extramitochondrial copper trafficking pathways. The recent finding that mitochondrial proteins with established roles in CcO assembly can also effect changes in cellular copper levels by modulating copper efflux from the cell supports a mechanistic link between organellar and cellular copper metabolism. However, the proteins and molecular mechanisms that link trafficking of copper to and from the organelle with other cellular copper trafficking pathways are unknown. This review documents our current understanding of copper trafficking to, and within, the mitochondrion for metallation of CcO and Sod1; the pathways by which the two copper centers in CcO are formed; and, the interconnections between mitochondrial function and the regulation of cellular copper homeostasis.
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Affiliation(s)
- Scot C Leary
- Montreal Neurological Institute and McGill University, Montreal, Canada H3A 2B4.
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29
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Khalimonchuk O, Winge DR. Function and redox state of mitochondrial localized cysteine-rich proteins important in the assembly of cytochrome c oxidase. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2007; 1783:618-28. [PMID: 18070608 DOI: 10.1016/j.bbamcr.2007.10.016] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2007] [Revised: 10/22/2007] [Accepted: 10/30/2007] [Indexed: 11/16/2022]
Abstract
The cytochrome c oxidase (CcO) complex of the mitochondrial respiratory chain exists within the mitochondrial inner membrane (IM). The biogenesis of the complex is a multi-faceted process requiring multiple assembly factors that function on both faces of the IM. Formation of the two copper centers of CcO occurs within the intermembrane space (IMS) and is dependent on assembly factors with critical cysteinyl thiolates. Two classes of assembly factors exist, one group being soluble IMS proteins and the second class being proteins tethered to the IM. A common motif in the soluble assembly factors is a duplicated Cx(9)C sequence motif. Since mitochondrial respiration is a major source of reactive oxygen species, control of the redox state of mitochondrial proteins is an important process. This review documents the role of these cysteinyl CcO assembly factors within the IMS and the necessity of redox control in their function.
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Affiliation(s)
- Oleh Khalimonchuk
- University of Utah Health Sciences Center, Department of Medicine, Salt Lake City, Utah 84132, USA
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30
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van Dijk ADJ, Ciofi-Baffoni S, Banci L, Bertini I, Boelens R, Bonvin AMJJ. Modeling protein-protein complexes involved in the cytochrome C oxidase copper-delivery pathway. J Proteome Res 2007; 6:1530-9. [PMID: 17338559 DOI: 10.1021/pr060651f] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Proper assembly and function of cytochrome c oxidase, which catalyzes the reduction of O2 and generates the proton gradient driving ATP synthesis, depend on correct copper delivery and incorporation. Structural details about the protein-protein complexes involved in this process are still missing. We describe here models of four complexes along this pathway obtained by combining bioinformatics interface predictions with information-driven docking and discuss their relevance with respect to known and pathogenic mutations.
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Affiliation(s)
- Aalt D J van Dijk
- Bijvoet Center for Biomolecular Research, Science Faculty, Utrecht University, 3584CH, Utrecht, The Netherlands
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31
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Leary SC, Cobine PA, Kaufman BA, Guercin GH, Mattman A, Palaty J, Lockitch G, Winge DR, Rustin P, Horvath R, Shoubridge EA. The human cytochrome c oxidase assembly factors SCO1 and SCO2 have regulatory roles in the maintenance of cellular copper homeostasis. Cell Metab 2007; 5:9-20. [PMID: 17189203 DOI: 10.1016/j.cmet.2006.12.001] [Citation(s) in RCA: 168] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2006] [Revised: 11/23/2006] [Accepted: 12/07/2006] [Indexed: 10/23/2022]
Abstract
Human SCO1 and SCO2 are metallochaperones that are essential for the assembly of the catalytic core of cytochrome c oxidase (COX). Here we show that they have additional, unexpected roles in cellular copper homeostasis. Mutations in either SCO result in a cellular copper deficiency that is both tissue and allele specific. This phenotype can be dissociated from the defects in COX assembly and is suppressed by overexpression of SCO2, but not SCO1. Overexpression of a SCO1 mutant in control cells in which wild-type SCO1 levels were reduced by shRNA recapitulates the copper-deficiency phenotype in SCO1 patient cells. The copper-deficiency phenotype reflects not a change in high-affinity copper uptake but rather a proportional increase in copper efflux. These results suggest a mitochondrial pathway for the regulation of cellular copper content that involves signaling through SCO1 and SCO2, perhaps by their thiol redox or metal-binding state.
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Affiliation(s)
- Scot C Leary
- Montreal Neurological Institute, McGill University, Montreal, QC H3A 2B4, Canada; Department of Human Genetics, McGill University, Montreal, QC H3A 2B4, Canada
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32
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Banci L, Bertini I, Ciofi-Baffoni S, Leontari I, Martinelli M, Palumaa P, Sillard R, Wang S. Human Sco1 functional studies and pathological implications of the P174L mutant. Proc Natl Acad Sci U S A 2006; 104:15-20. [PMID: 17182746 PMCID: PMC1765425 DOI: 10.1073/pnas.0606189103] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The pathogenic mutant (P174L) of human Sco1 produces respiratory chain deficiency associated with cytochrome c oxidase (CcO) assembly defects. The solution structure of the mutant in its Cu(I) form shows that Leu-174 prevents the formation of a well packed hydrophobic region around the metal-binding site and causes a reduction of the affinity of copper(I) for the protein. K(D) values for Cu(I)WT-HSco1 and Cu(I)P174L-HSco1 are approximately 10(-17) and approximately 10(-13), respectively. The reduction potentials of the two apo proteins are similar, but slower reduction/oxidation rates are found for the mutant with respect to the WT. The mitochondrial metallochaperone in the partially oxidized Cu(1)(I)Cox17(2S-S) form, at variance with the fully reduced Cu(4)(I)Cox17, interacts transiently with both WT-HSco1 and the mutant, forming the Cox17/Cu(I)/HSco1 complex, but copper is efficiently transferred only in the case of WT protein. Cu(1)(I)Cox17(2S-S) indeed has an affinity for copper(I) (K(D) approximately 10(-15)) higher than that of the P174L-HSco1 mutant but lower than that of WT-HSco1. We propose that HSco1 mutation, altering the structure around the metal-binding site, affects both copper(I) binding and redox properties of the protein, thus impairing the efficiency of copper transfer to CcO. The pathogenic mutation therefore could (i) lessen the Sco1 affinity for copper(I) and hence copper supply for CcO or (ii) decrease the efficiency of reduction of CcO thiols involved in copper binding, or both effects could be produced by the mutation.
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Affiliation(s)
- Lucia Banci
- *Magnetic Resonance Center (CERM) and Department of Chemistry, University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Florence, Italy
- FiorGen Foundation, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Florence, Italy
| | - Ivano Bertini
- *Magnetic Resonance Center (CERM) and Department of Chemistry, University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Florence, Italy
- To whom correspondence should be addressed. E-mail:
| | - Simone Ciofi-Baffoni
- *Magnetic Resonance Center (CERM) and Department of Chemistry, University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Florence, Italy
| | - Iliana Leontari
- *Magnetic Resonance Center (CERM) and Department of Chemistry, University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Florence, Italy
| | - Manuele Martinelli
- *Magnetic Resonance Center (CERM) and Department of Chemistry, University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Florence, Italy
| | - Peep Palumaa
- Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
| | - Rannar Sillard
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171 77 Stockholm, Sweden; and
- Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
| | - Shenlin Wang
- *Magnetic Resonance Center (CERM) and Department of Chemistry, University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Florence, Italy
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