Mitochondrial disulfide bond formation is driven by intersubunit electron transfer in Erv1 and proofread by glutathione.
The disulfide relay system in the intermembrane space of mitochondria is of crucial importance for mitochondrial biogenesis. Major players in this pathway are the oxidoreductase Mia40 that oxidizes substrates and the sulfhydryl oxidase Erv1 that reoxidizes Mia40. To analyze in detail the mechanism of this oxidative pathway and the interplay of its components, we reconstituted the complete process in vitro using purified cytochrome c, Erv1, Mia40, and Cox19. Here, we demonstrate that Erv1 dimerizes noncovalently and that the subunits of this homodimer cooperate in intersubunit electron exchange. Moreover, we show that Mia40 promotes complete oxidation of the substrate Cox19. The efficient formation of disulfide bonds is hampered by the formation of long-lived, partially oxidized intermediates. The generation of these side products is efficiently counteracted by reduced glutathione. Thus, our findings suggest a role for a glutathione-dependent proofreading during oxidative protein folding by the mitochondrial disulfide relay.
Bien
Melanie
M
Institut für Zellbiologie, Universität Kaiserslautern, Erwin-Schrödinger-Strasse 13, 67663 Kaiserslautern, Germany.
Longen
Sebastian
S
Wagener
Nikola
N
Chwalla
Ilona
I
Herrmann
Johannes M
JM
Riemer
Jan
J
D000595:Amino Acid Sequence; D017124:Conserved Sequence; D004220:Disulfides / Q000378:metabolism*; D004579:Electron Transport; D005978:Glutathione / 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 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D050862:Oxidoreductases Acting on Sulfur Group Donors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D017510:Protein Folding; D055503:Protein Multimerization; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment
C520018:Cox19 protein, S cerevisiae; D004220:Disulfides; C495320:MIA40 protein, S cerevisiae; D033681:Mitochondrial Membrane Transport Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D024101:Mitochondrial Proteins; D018832:Molecular Chaperones; D021122:Protein Subunits; D029701:Saccharomyces cerevisiae Proteins; D050862:Oxidoreductases Acting on Sulfur Group Donors; C073790:ERV1 protein, S cerevisiae; D005978:Glutathione