title: A conserved mitochondrial ATP-binding cassette transporter exports glutathione polysulfide for cytosolic metal cofactor assembly.
abstract: An ATP-binding cassette transporter located in the inner mitochondrial membrane is involved in iron-sulfur cluster and molybdenum cofactor assembly in the cytosol, but the transported substrate is unknown. ATM3 (ABCB25) from Arabidopsis thaliana and its functional orthologue Atm1 from Saccharomyces cerevisiae were expressed in Lactococcus lactis and studied in inside-out membrane vesicles and in purified form. Both proteins selectively transported glutathione disulfide (GSSG) but not reduced glutathione in agreement with a 3-fold stimulation of ATPase activity by GSSG. By contrast, Fe(2+) alone or in combination with glutathione did not stimulate ATPase activity. Arabidopsis atm3 mutants were hypersensitive to an inhibitor of glutathione biosynthesis and accumulated GSSG in the mitochondria. The growth phenotype of atm3-1 was strongly enhanced by depletion of the mitochondrion-localized, GSH-dependent persulfide oxygenase ETHE1, suggesting that the physiological substrate of ATM3 contains persulfide in addition to glutathione. Consistent with this idea, a transportomics approach using mass spectrometry showed that glutathione trisulfide (GS-S-SG) was transported by Atm1. We propose that mitochondria export glutathione polysulfide, containing glutathione and persulfide, for iron-sulfur cluster assembly in the cytosol.
authors.affiliation: From the John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom, the Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, United Kingdom.
authors.forename: Theresia A
authors.initials: TA
authors.lastname: Schaedler
authors.affiliation: From the John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom.
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Thornton
authors.affiliation: From the John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom, the School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, United Kingdom.
authors.forename: Inga
authors.initials: I
authors.lastname: Kruse
authors.affiliation: the Institute of Crop Science and Resource Conservation, University of Bonn, 53113 Bonn, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Schwarzländer
authors.affiliation: the Institute of Crop Science and Resource Conservation, University of Bonn, 53113 Bonn, Germany.
authors.forename: Andreas J
authors.initials: AJ
authors.lastname: Meyer
authors.affiliation: the Department of Pharmacology, University of Cambridge, Cambridge CB2 1PD, United Kingdom, and hwv20@cam.ac.uk.
authors.forename: Hendrik W
authors.initials: HW
authors.lastname: van Veen
authors.affiliation: From the John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom, the School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, United Kingdom janneke.balk@jic.ac.uk.
authors.forename: Janneke
authors.initials: J
authors.lastname: Balk
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D017124:Conserved Sequence; D003600:Cytosol / Q000378:metabolism*; D005978:Glutathione / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D008670:Metals / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000502:physiology*; D008969:Molecular Sequence Data; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D013440:Sulfides / Q000737:chemistry*
chemical_list: C091561:ATM1 protein, S cerevisiae; C510573:ATM3 protein, Arabidopsis; D018528:ATP-Binding Cassette Transporters; D029681:Arabidopsis Proteins; D008670:Metals; D024101:Mitochondrial Proteins; D029701:Saccharomyces cerevisiae Proteins; D013440:Sulfides; D000251:Adenosine Triphosphatases; D005978:Glutathione
keywords: ABC Transporter; Arabidopsis; Glutathione; Iron-Sulfur Protein; Mitochondria; Transportomics; Yeast