Affordable Access

A pathogenic cytochrome b mutation reveals new interactions between subunits of the mitochondrial bc1 complex.

Authors
  • Saint-Georges, Yann
  • Bonnefoy, Nathalie
  • di Rago, Jean Paul
  • Chiron, Stephane
  • Dujardin, Geneviève
Type
Published Article
Journal
Journal of Biological Chemistry
Publisher
American Society for Biochemistry & Molecular Biology (ASBMB)
Publication Date
Dec 20, 2002
Volume
277
Issue
51
Pages
49397–49402
Identifiers
PMID: 12384503
Source
Medline
License
Unknown

Abstract

Energy transduction in mitochondria involves five oligomeric complexes embedded within the inner membrane. They are composed of catalytic and noncatalytic subunits, the role of these latter proteins often being difficult to assign. One of these complexes, the bc1 complex, is composed of three catalytic subunits including cytochrome b and seven or eight noncatalytic subunits. Recently, several mutations in the human cytochrome b gene have been linked to various diseases. We have studied in detail the effects of a cardiomyopathy generating mutation G252D in yeast. This mutation disturbs the biogenesis of the bc1 complex at 36 degrees C and decreases the steady-state level of the noncatalytic subunit Qcr9p. In addition, the G252D mutation and the deletion of QCR9 show synergetic defects that can be partially bypassed by suppressor mutations at position 252 and by a new cytochrome b mutation, P174T. Altogether, our results suggest that the supernumerary subunit Qcr9p enhances or stabilizes the interactions between the catalytic subunits, this role being essential at high temperature.

Report this publication

Statistics

Seen <100 times