title: Mia40-dependent oxidation of cysteines in domain I of Ccs1 controls its distribution between mitochondria and the cytosol.
abstract: Superoxide dismutase 1 (Sod1) is an important antioxidative enzyme that converts superoxide anions to hydrogen peroxide and water. Active Sod1 is a homodimer containing one zinc ion, one copper ion, and one disulfide bond per subunit. Maturation of Sod1 depends on its copper chaperone (Ccs1). Sod1 and Ccs1 are dually localized proteins that reside in the cytosol and in the intermembrane space of mitochondria. The import of Ccs1 into mitochondria depends on the mitochondrial disulfide relay system. However, the exact mechanism of this import process has been unclear. In this study we detail the import and folding pathway of Ccs1 and characterize its interaction with the oxidoreductase of the mitochondrial disulfide relay Mia40. We identify cysteines at positions 27 and 64 in domain I of Ccs1 as critical for mitochondrial import and interaction with Mia40. On interaction with Mia40, these cysteines form a structural disulfide bond that stabilizes the overall fold of domain I. Although the cysteines are essential for the accumulation of functional Ccs1 in mitochondria, they are dispensable for the enzymatic activity of cytosolic Ccs1. We propose a model in which the Mia40-mediated oxidative folding of domain I controls the cellular distribution of Ccs1 and, consequently, active Sod1.
authors.affiliation: Cell Biology and University of Kaiserslautern, 67663 Kaiserslautern, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Klöppel
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Kerstin
authors.initials: K
authors.lastname: Kojer
authors.forename: Carmelina
authors.initials: C
authors.lastname: Petrungaro
authors.forename: Sebastian
authors.initials: S
authors.lastname: Longen
authors.forename: Sebastian
authors.initials: S
authors.lastname: Fiedler
authors.forename: Sandro
authors.initials: S
authors.lastname: Keller
authors.forename: Jan
authors.initials: J
authors.lastname: Riemer
mesh_terms: D003001:Cloning, Molecular; D003545:Cysteine / Q000737:chemistry / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism*; D004220:Disulfides / Q000378:metabolism; D004926:Escherichia coli; D015966:Gene Expression Regulation, Fungal; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism*; D033681:Mitochondrial Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D051336:Mitochondrial Membranes / Q000378:metabolism*; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D018832:Molecular Chaperones / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D010084:Oxidation-Reduction; D010957:Plasmids; D017510:Protein Folding; D021381:Protein Transport / Q000235:genetics*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics*; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism; D000072105:Superoxide Dismutase-1; D014161:Transduction, Genetic; D014169:Transformation, Bacterial
chemical_list: C491960:CCS1 protein, S cerevisiae; D004220:Disulfides; C495320:MIA40 protein, S cerevisiae; D033681:Mitochondrial Membrane Transport Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D018832:Molecular Chaperones; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1; D003545:Cysteine