Dual function of Sdh3 in the respiratory chain and TIM22 protein translocase of the mitochondrial inner membrane

Mol Cell. 2011 Dec 9;44(5):811-8. doi: 10.1016/j.molcel.2011.09.025.

Abstract

The mitochondrial inner membrane harbors the complexes of the respiratory chain and translocase complexes for precursor proteins. We have identified a further subunit of the carrier translocase (TIM22 complex) that surprisingly is identical to subunit 3 of respiratory complex II, succinate dehydrogenase (Sdh3). The membrane-integral protein Sdh3 plays specific functions in electron transfer in complex II. We show by genetic and biochemical approaches that Sdh3 also plays specific functions in the TIM22 complex. Sdh3 forms a subcomplex with Tim18 and is involved in biogenesis and assembly of the membrane-integral subunits of the TIM22 complex. We conclude that the assembly of Sdh3 with different partner proteins, Sdh4 and Tim18, recruits it to two different mitochondrial membrane complexes with functions in bioenergetics and protein biogenesis, respectively.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Electron Transport Complex II / metabolism
  • Electron Transport*
  • Mitochondrial Membrane Transport Proteins / metabolism*
  • Mitochondrial Membranes / enzymology
  • Mitochondrial Membranes / metabolism*
  • Mitochondrial Precursor Protein Import Complex Proteins
  • Saccharomyces cerevisiae / cytology
  • Saccharomyces cerevisiae / enzymology
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Succinate Dehydrogenase / metabolism*

Substances

  • Mitochondrial Membrane Transport Proteins
  • Mitochondrial Precursor Protein Import Complex Proteins
  • Saccharomyces cerevisiae Proteins
  • TIM22 protein, S cerevisiae
  • Electron Transport Complex II
  • Succinate Dehydrogenase