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Garza NM, Swaminathan AB, Maremanda KP, Zulkifli M, Gohil VM. Mitochondrial copper in human genetic disorders. Trends Endocrinol Metab 2023; 34:21-33. [PMID: 36435678 PMCID: PMC9780195 DOI: 10.1016/j.tem.2022.11.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Revised: 10/28/2022] [Accepted: 11/04/2022] [Indexed: 11/24/2022]
Abstract
Copper is an essential micronutrient that serves as a cofactor for enzymes involved in diverse physiological processes, including mitochondrial energy generation. Copper enters cells through a dedicated copper transporter and is distributed to intracellular cuproenzymes by copper chaperones. Mitochondria are critical copper-utilizing organelles that harbor an essential cuproenzyme cytochrome c oxidase, which powers energy production. Mutations in copper transporters and chaperones that perturb mitochondrial copper homeostasis result in fatal genetic disorders. Recent studies have uncovered the therapeutic potential of elesclomol, a copper ionophore, for the treatment of copper deficiency disorders such as Menkes disease. Here we review the role of copper in mitochondrial energy metabolism in the context of human diseases and highlight the recent developments in copper therapeutics.
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Affiliation(s)
- Natalie M Garza
- Department of Biochemistry and Biophysics, MS 3474, Texas A&M University, College Station, TX 77843, USA
| | - Abhinav B Swaminathan
- Department of Biochemistry and Biophysics, MS 3474, Texas A&M University, College Station, TX 77843, USA
| | - Krishna P Maremanda
- Department of Biochemistry and Biophysics, MS 3474, Texas A&M University, College Station, TX 77843, USA
| | - Mohammad Zulkifli
- Department of Biochemistry and Biophysics, MS 3474, Texas A&M University, College Station, TX 77843, USA
| | - Vishal M Gohil
- Department of Biochemistry and Biophysics, MS 3474, Texas A&M University, College Station, TX 77843, USA.
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Garza NM, Zulkifli M, Gohil VM. Elesclomol elevates cellular and mitochondrial iron levels by delivering copper to the iron import machinery. J Biol Chem 2022; 298:102139. [PMID: 35714767 PMCID: PMC9270252 DOI: 10.1016/j.jbc.2022.102139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 06/09/2022] [Accepted: 06/11/2022] [Indexed: 01/16/2023] Open
Abstract
Copper (Cu) and iron (Fe) are redox-active metals that serve as cofactors for many essential cellular enzymes. Disruption in the intracellular homeostasis of these metals results in debilitating and frequently fatal human disorders, such as Menkes disease and Friedreich's ataxia. Recently, we reported that an investigational anticancer drug, elesclomol (ES), can deliver Cu to critical mitochondrial cuproenzymes and has the potential to be repurposed for treatment of Cu deficiency disorders. Here, we sought to determine the specificity of ES and the ES-Cu complex in delivering Cu to cuproenzymes in different intracellular compartments. Using a combination of yeast genetics, subcellular fractionation, and inductively coupled plasma-mass spectrometry-based metal measurements, we showed that ES and ES-Cu treatment results in an increase in cellular and mitochondrial Fe content, along with the expected increase in Cu. Utilizing yeast mutants of Cu and Fe transporters, we demonstrate that ES-based elevation in cellular Fe levels is independent of the major cellular Cu importer, but is dependent on the Fe importer Ftr1 and its partner Fet3, a multicopper-oxidase. As Fet3 is metallated in the Golgi lumen, we sought to uncover the mechanism by which Fet3 receives Cu from ES. Using yeast knockouts of genes involved in Cu delivery to Fet3, we determined that ES can bypass Atx1, a metallochaperone involved in Cu delivery to the Golgi membrane Cu pump, Ccc2, but not Ccc2 itself. Taken together, our study provides a mechanism by which ES distributes Cu in cells and impacts cellular and mitochondrial Fe homeostasis.
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Affiliation(s)
- Natalie M Garza
- Department of Biochemistry and Biophysics, MS 3474, Texas A&M University, College Station, TX 77843, USA
| | - Mohammad Zulkifli
- Department of Biochemistry and Biophysics, MS 3474, Texas A&M University, College Station, TX 77843, USA
| | - Vishal M Gohil
- Department of Biochemistry and Biophysics, MS 3474, Texas A&M University, College Station, TX 77843, USA.
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Garza NM, Griffin AT, Zulkifli M, Qiu C, Kaplan CD, Gohil VM. A genome-wide copper-sensitized screen identifies novel regulators of mitochondrial cytochrome c oxidase activity. J Biol Chem 2021; 296:100485. [PMID: 33662401 PMCID: PMC8027276 DOI: 10.1016/j.jbc.2021.100485] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 02/22/2021] [Accepted: 02/25/2021] [Indexed: 11/30/2022] Open
Abstract
Copper is essential for the activity and stability of cytochrome c oxidase (CcO), the terminal enzyme of the mitochondrial respiratory chain. Loss-of-function mutations in genes required for copper transport to CcO result in fatal human disorders. Despite the fundamental importance of copper in mitochondrial and organismal physiology, systematic identification of genes that regulate mitochondrial copper homeostasis is lacking. To discover these genes, we performed a genome-wide screen using a library of DNA-barcoded yeast deletion mutants grown in copper-supplemented media. Our screen recovered a number of genes known to be involved in cellular copper homeostasis as well as genes previously not linked to mitochondrial copper biology. These newly identified genes include the subunits of the adaptor protein 3 complex (AP-3) and components of the cellular pH-sensing pathway Rim20 and Rim21, both of which are known to affect vacuolar function. We find that AP-3 and Rim mutants exhibit decreased vacuolar acidity, which in turn perturbs mitochondrial copper homeostasis and CcO function. CcO activity of these mutants could be rescued by either restoring vacuolar pH or supplementing growth media with additional copper. Consistent with these genetic data, pharmacological inhibition of the vacuolar proton pump leads to decreased mitochondrial copper content and a concomitant decrease in CcO abundance and activity. Taken together, our study uncovered novel genetic regulators of mitochondrial copper homeostasis and provided a mechanism by which vacuolar pH impacts mitochondrial respiration through copper homeostasis.
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Affiliation(s)
- Natalie M Garza
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA
| | - Aaron T Griffin
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA
| | - Mohammad Zulkifli
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA
| | - Chenxi Qiu
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA
| | - Craig D Kaplan
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA
| | - Vishal M Gohil
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA.
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Zulkifli M, Neff JK, Timbalia SA, Garza NM, Chen Y, Watrous JD, Murgia M, Trivedi PP, Anderson SK, Tomar D, Nilsson R, Madesh M, Jain M, Gohil VM. Yeast homologs of human MCUR1 regulate mitochondrial proline metabolism. Nat Commun 2020; 11:4866. [PMID: 32978391 PMCID: PMC7519068 DOI: 10.1038/s41467-020-18704-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Accepted: 09/02/2020] [Indexed: 12/15/2022] Open
Abstract
Mitochondria house evolutionarily conserved pathways of carbon and nitrogen metabolism that drive cellular energy production. Mitochondrial bioenergetics is regulated by calcium uptake through the mitochondrial calcium uniporter (MCU), a multi-protein complex whose assembly in the inner mitochondrial membrane is facilitated by the scaffold factor MCUR1. Intriguingly, many fungi that lack MCU contain MCUR1 homologs, suggesting alternate functions. Herein, we characterize Saccharomyces cerevisiae homologs Put6 and Put7 of MCUR1 as regulators of mitochondrial proline metabolism. Put6 and Put7 are tethered to the inner mitochondrial membrane in a large hetero-oligomeric complex, whose abundance is regulated by proline. Loss of this complex perturbs mitochondrial proline homeostasis and cellular redox balance. Yeast cells lacking either Put6 or Put7 exhibit a pronounced defect in proline utilization, which can be corrected by the heterologous expression of human MCUR1. Our work uncovers an unexpected role of MCUR1 homologs in mitochondrial proline metabolism.
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Affiliation(s)
- Mohammad Zulkifli
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77843, USA
| | - John K Neff
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77843, USA
| | - Shrishiv A Timbalia
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77843, USA
| | - Natalie M Garza
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77843, USA
| | - Yingqi Chen
- Departments of Medicine and Pharmacology, University of California, San Diego, 9500 Gilman Avenue, La Jolla, CA, 92093, USA
| | - Jeramie D Watrous
- Departments of Medicine and Pharmacology, University of California, San Diego, 9500 Gilman Avenue, La Jolla, CA, 92093, USA
| | - Marta Murgia
- Department of Biomedical Sciences, University of Padova, 35121, Padua, Italy
- Max-Planck-Institute of Biochemistry, Martinsried, 82152, Germany
| | - Prachi P Trivedi
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77843, USA
| | - Steven K Anderson
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77843, USA
| | - Dhanendra Tomar
- Department of Medical Genetics and Molecular Biochemistry, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, 19140, USA
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, 19140, USA
| | - Roland Nilsson
- Cardiovascular Medicine Unit, Department of Medicine, Karolinska Institutet, SE-171 76, Stockholm, Sweden
- Division of Cardiovascular Medicine, Karolinska University Hospital, SE-171 76, Stockholm, Sweden
- Center for Molecular Medicine, Karolinska Institutet, SE-171 76, Stockholm, Sweden
| | - Muniswamy Madesh
- Department of Medicine, Cardiology Division, Center for Precision Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Mohit Jain
- Departments of Medicine and Pharmacology, University of California, San Diego, 9500 Gilman Avenue, La Jolla, CA, 92093, USA
| | - Vishal M Gohil
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77843, USA.
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