title: The Activity of Menkes Disease Protein ATP7A Is Essential for Redox Balance in Mitochondria.
abstract: Copper-transporting ATPase ATP7A is essential for mammalian copper homeostasis. Loss of ATP7A activity is associated with fatal Menkes disease and various other pathologies. In cells, ATP7A inactivation disrupts copper transport from the cytosol into the secretory pathway. Using fibroblasts from Menkes disease patients and mouse 3T3-L1 cells with a CRISPR/Cas9-inactivated ATP7A, we demonstrate that ATP7A dysfunction is also damaging to mitochondrial redox balance. In these cells, copper accumulates in nuclei, cytosol, and mitochondria, causing distinct changes in their redox environment. Quantitative imaging of live cells using GRX1-roGFP2 and HyPer sensors reveals highest glutathione oxidation and elevation of H2O2 in mitochondria, whereas the redox environment of nuclei and the cytosol is much less affected. Decreasing the H2O2 levels in mitochondria with MitoQ does not prevent glutathione oxidation; i.e. elevated copper and not H2O2 is a primary cause of glutathione oxidation. Redox misbalance does not significantly affect mitochondrion morphology or the activity of respiratory complex IV but markedly increases cell sensitivity to even mild glutathione depletion, resulting in loss of cell viability. Thus, ATP7A activity protects mitochondria from excessive copper entry, which is deleterious to redox buffers. Mitochondrial redox misbalance could significantly contribute to pathologies associated with ATP7A inactivation in tissues with paradoxical accumulation of copper (i.e. renal epithelia).
authors.affiliation: From the Departments of Physiology.
authors.forename: Ashima
authors.initials: A
authors.lastname: Bhattacharjee
authors.affiliation: From the Departments of Physiology.
authors.forename: Haojun
authors.initials: H
authors.lastname: Yang
authors.affiliation: the Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, Oregon 97239.
authors.forename: Megan
authors.initials: M
authors.lastname: Duffy
authors.affiliation: the Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, Oregon 97239.
authors.forename: Emily
authors.initials: E
authors.lastname: Robinson
authors.affiliation: the Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, Oregon 97239.
authors.forename: Arianrhod
authors.initials: A
authors.lastname: Conrad-Antoville
authors.affiliation: From the Departments of Physiology.
authors.forename: Ya-Wen
authors.initials: YW
authors.lastname: Lu
authors.affiliation: the Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, Oregon 97239.
authors.forename: Tony
authors.initials: T
authors.lastname: Capps
authors.affiliation: Biological Chemistry, and.
authors.forename: Lelita
authors.initials: L
authors.lastname: Braiterman
authors.affiliation: Cell Biology Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.
authors.forename: Michael
authors.initials: M
authors.lastname: Wolfgang
authors.affiliation: the Medical Research Council Mitochondrial Biology Unit, Cambridge CB2 0XY, United Kingdom, and.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Murphy
authors.affiliation: the Section on Translational Neuroscience, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892.
authors.forename: Ling
authors.initials: L
authors.lastname: Yi
authors.affiliation: the Section on Translational Neuroscience, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892.
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Kaler
authors.affiliation: From the Departments of Physiology, Lutsenko@jhmi.edu.
authors.forename: Svetlana
authors.initials: S
authors.lastname: Lutsenko
authors.affiliation: the Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, Oregon 97239, rallem@ohsu.edu.
authors.forename: Martina
authors.initials: M
authors.lastname: Ralle
mesh_terms: D041721:3T3-L1 Cells; D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001693:Biological Transport, Active / Q000235:genetics; D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism*; D002461:Cell Line, Transformed; D003300:Copper / Q000378:metabolism; D000073840:Copper-Transporting ATPases; D005347:Fibroblasts / Q000201:enzymology* / Q000473:pathology; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D007706:Menkes Kinky Hair Syndrome / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D051379:Mice; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D010084:Oxidation-Reduction
chemical_list: C486201:Atp7a protein, mouse; D027682:Cation Transport Proteins; D003300:Copper; D006861:Hydrogen Peroxide; D000251:Adenosine Triphosphatases; C081184:ATP7A protein, human; D000073840:Copper-Transporting ATPases
keywords: ATP7A; Menkes disease; biosensor; copper transport; glutathione; mitochondria; neurological disease; oxidation-reduction (redox)