title: Cytosolic Fe-S Cluster Protein Maturation and Iron Regulation Are Independent of the Mitochondrial Erv1/Mia40 Import System.
abstract: The sulfhydryl oxidase Erv1 partners with the oxidoreductase Mia40 to import cysteine-rich proteins in the mitochondrial intermembrane space. In Saccharomyces cerevisiae, Erv1 has also been implicated in cytosolic Fe-S protein maturation and iron regulation. To investigate the connection between Erv1/Mia40-dependent mitochondrial protein import and cytosolic Fe-S cluster assembly, we measured Mia40 oxidation and Fe-S enzyme activities in several erv1 and mia40 mutants. Although all the erv1 and mia40 mutants exhibited defects in Mia40 oxidation, only one erv1 mutant strain (erv1-1) had significantly decreased activities of cytosolic Fe-S enzymes. Further analysis of erv1-1 revealed that it had strongly decreased glutathione (GSH) levels, caused by an additional mutation in the gene encoding the glutathione biosynthesis enzyme glutamate cysteine ligase (GSH1). To address whether Erv1 or Mia40 plays a role in iron regulation, we measured iron-dependent expression of Aft1/2-regulated genes and mitochondrial iron accumulation in erv1 and mia40 strains. The only strain to exhibit iron misregulation is the GSH-deficient erv1-1 strain, which is rescued with addition of GSH. Together, these results confirm that GSH is critical for cytosolic Fe-S protein biogenesis and iron regulation, whereas ruling out significant roles for Erv1 or Mia40 in these pathways.
authors.affiliation: From the Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208.
authors.forename: Hatice K
authors.initials: HK
authors.lastname: Ozer
authors.affiliation: From the Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208.
authors.forename: Adrienne C
authors.initials: AC
authors.lastname: Dlouhy
authors.affiliation: the John Innes Centre and University of East Anglia, Norwich Research Park, Norwich NR4 7UH, United Kingdom, and.
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Thornton
authors.affiliation: From the Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Hu
authors.affiliation: the Department of Biochemistry and the Redox Biology Center, University of Nebraska, Lincoln, Nebraska 68588.
authors.forename: Yilin
authors.initials: Y
authors.lastname: Liu
authors.affiliation: the Department of Biochemistry and the Redox Biology Center, University of Nebraska, Lincoln, Nebraska 68588.
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Barycki
authors.affiliation: the John Innes Centre and University of East Anglia, Norwich Research Park, Norwich NR4 7UH, United Kingdom, and.
authors.forename: Janneke
authors.initials: J
authors.lastname: Balk
authors.affiliation: From the Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, outten@mailbox.sc.edu.
authors.forename: Caryn E
authors.initials: CE
authors.lastname: Outten
mesh_terms: D000595:Amino Acid Sequence; D003600:Cytosol / Q000378:metabolism*; D005721:Glutamate-Cysteine Ligase / Q000378:metabolism; D005978:Glutathione / Q000172:deficiency / Q000378:metabolism*; D007501:Iron / Q000378:metabolism*; D007506:Iron-Sulfur Proteins / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism*; D033681:Mitochondrial Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000378:metabolism; D050862:Oxidoreductases Acting on Sulfur Group Donors / Q000235:genetics / Q000378:metabolism*; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D005721:Glutamate-Cysteine Ligase; D005978:Glutathione; D007501:Iron; D007506:Iron-Sulfur Proteins; D033681:Mitochondrial Membrane Transport Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D024101:Mitochondrial Proteins; D010088:Oxidoreductases; D050862:Oxidoreductases Acting on Sulfur Group Donors; D029701:Saccharomyces cerevisiae Proteins; C495320:MIA40 protein, S cerevisiae; C073790:ERV1 protein, S cerevisiae; C490862:GSH1 protein, S cerevisiae
keywords: glutathione; iron metabolism; iron-sulfur protein; mitochondrial metabolism; mitochondrial transport; sulfhydryl