Regulation of mitochondrial proteostasis by the proton gradient

Maria Patron, Daryna Tarasenko, Hendrik Nolte, Lara Kroczek, Mausumi Ghosh, Yohsuke Ohba, Yvonne Lasarzewski, Zeinab Alsadat Ahmadi, Alfredo Cabrera-Orefice, Akinori Eyiama, Tim Kellermann, Elena I. Rugarli, Ulrich Brandt, Michael Meinecke, Thomas Langer

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)

Abstract

Mitochondria adapt to different energetic demands reshaping their proteome. Mitochondrial proteases are emerging as key regulators of these adaptive processes. Here, we use a multiproteomic approach to demonstrate the regulation of the m-AAA protease AFG3L2 by the mitochondrial proton gradient, coupling mitochondrial protein turnover to the energetic status of mitochondria. We identify TMBIM5 (previously also known as GHITM or MICS1) as a Ca2+/H+ exchanger in the mitochondrial inner membrane, which binds to and inhibits the m-AAA protease. TMBIM5 ensures cell survival and respiration, allowing Ca2+ efflux from mitochondria and limiting mitochondrial hyperpolarization. Persistent hyperpolarization, however, triggers degradation of TMBIM5 and activation of the m-AAA protease. The m-AAA protease broadly remodels the mitochondrial proteome and mediates the proteolytic breakdown of respiratory complex I to confine ROS production and oxidative damage in hyperpolarized mitochondria. TMBIM5 thus integrates mitochondrial Ca2+ signaling and the energetic status of mitochondria with protein turnover rates to reshape the mitochondrial proteome and adjust the cellular metabolism.

Original languageEnglish
Article numbere110476
JournalEMBO Journal
Volume41
Issue number16
DOIs
Publication statusPublished - 2022 Aug 16
Externally publishedYes

Keywords

  • AFG3L2
  • mitochondrial calcium
  • proton gradient
  • respiratory chain
  • TMBIM5

ASJC Scopus subject areas

  • Neuroscience(all)
  • Molecular Biology
  • Biochemistry, Genetics and Molecular Biology(all)
  • Immunology and Microbiology(all)

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