Mia40 protein serves as an electron sink in the Mia40-Erv1 import pathway

Sonya E. Neal, Deepa V. Dabir, Heather L. Tienson, Darryl M. Horn, Kathrin Glaeser, Rachel R. Ogozalek Loo, Antonio Barrientos, Carla M. Koehler

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

A redox-regulated import pathway consisting of Mia40 and Erv1 mediates the import of cysteine-rich proteins into the mitochondrial intermembrane space. Mia40 is the oxidoreductase that inserts two disulfide bonds into the substrate simultaneously. However, Mia40 has one redox-active cysteine pair, resulting in ambiguity about how Mia40 accepts numerous electrons during substrate oxidation. In this study, we have addressed the oxidation of Tim13 in vitro and in organello. Reductants such as glutathione and ascorbate inhibited both the oxidation of the substrate Tim13 in vitro and the import of Tim13 and Cmc1 into isolated mitochondria. In addition, a ternary complex consisting of Erv1, Mia40, and substrate, linked by disulfide bonds, was not detected in vitro. Instead, Mia40 accepted six electrons from substrates, and this fully reduced Mia40 was sensitive to protease, indicative of conformational changes in the structure. Mia40 in mitochondria from the erv1-101 mutant was also trapped in a completely reduced state, demonstrating that Mia40 can accept up to six electrons as substrates are imported. Therefore, these studies support that Mia40 functions as an electron sink to facilitate the insertion of two disulfide bonds into substrates.

Original languageEnglish (US)
Pages (from-to)20804-20814
Number of pages11
JournalJournal of Biological Chemistry
Volume290
Issue number34
DOIs
StatePublished - Aug 21 2015

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Disulfides
Electrons
Substrates
Oxidation-Reduction
Cysteine
Mitochondria
Proteins
Mitochondrial Proteins
Reducing Agents
Oxidation
Glutathione
Oxidoreductases
Peptide Hydrolases
In Vitro Techniques

ASJC Scopus subject areas

  • Biochemistry
  • Cell Biology
  • Molecular Biology

Cite this

Neal, S. E., Dabir, D. V., Tienson, H. L., Horn, D. M., Glaeser, K., Ogozalek Loo, R. R., ... Koehler, C. M. (2015). Mia40 protein serves as an electron sink in the Mia40-Erv1 import pathway. Journal of Biological Chemistry, 290(34), 20804-20814. https://doi.org/10.1074/jbc.M115.669440

Mia40 protein serves as an electron sink in the Mia40-Erv1 import pathway. / Neal, Sonya E.; Dabir, Deepa V.; Tienson, Heather L.; Horn, Darryl M.; Glaeser, Kathrin; Ogozalek Loo, Rachel R.; Barrientos, Antonio; Koehler, Carla M.

In: Journal of Biological Chemistry, Vol. 290, No. 34, 21.08.2015, p. 20804-20814.

Research output: Contribution to journalArticle

Neal, SE, Dabir, DV, Tienson, HL, Horn, DM, Glaeser, K, Ogozalek Loo, RR, Barrientos, A & Koehler, CM 2015, 'Mia40 protein serves as an electron sink in the Mia40-Erv1 import pathway', Journal of Biological Chemistry, vol. 290, no. 34, pp. 20804-20814. https://doi.org/10.1074/jbc.M115.669440
Neal SE, Dabir DV, Tienson HL, Horn DM, Glaeser K, Ogozalek Loo RR et al. Mia40 protein serves as an electron sink in the Mia40-Erv1 import pathway. Journal of Biological Chemistry. 2015 Aug 21;290(34):20804-20814. https://doi.org/10.1074/jbc.M115.669440
Neal, Sonya E. ; Dabir, Deepa V. ; Tienson, Heather L. ; Horn, Darryl M. ; Glaeser, Kathrin ; Ogozalek Loo, Rachel R. ; Barrientos, Antonio ; Koehler, Carla M. / Mia40 protein serves as an electron sink in the Mia40-Erv1 import pathway. In: Journal of Biological Chemistry. 2015 ; Vol. 290, No. 34. pp. 20804-20814.
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