The mitochondrial respiratory chain is a modulator of apoptosis Academic Article uri icon


MeSH Major

  • Apoptosis
  • Electron Transport
  • Mitochondria


  • Mitochondrial dysfunction and dysregulation of apoptosis are implicated in many diseases such as cancer and neurodegeneration. We investigate here the role of respiratory chain (RC) dysfunction in apoptosis, using mitochondrial DNA mutations as genetic models. Although some mutations eliminate the entire RC, others target specific complexes, resulting in either decreased or complete loss of electron flux, which leads to impaired respiration and adenosine triphosphate (ATP) synthesis. Despite these similarities, significant differences in responses to apoptotic stimuli emerge. Cells lacking RC are protected against both mitochondrial- and endoplasmic reticulum (ER) stress-induced apoptosis. Cells with RC, but unable to generate electron flux, are protected against mitochondrial apoptosis, although they have increased sensitivity to ER stress. Finally, cells with a partial reduction in electron flux have increased apoptosis under both conditions. Our results show that the RC modulates apoptosis in a context-dependent manner independent of ATP production and that apoptotic responses are the result of the interplay between mitochondrial functional state and environmental cues.

publication date

  • December 17, 2007



  • Academic Article



  • eng

PubMed Central ID

  • PMC2140029

Digital Object Identifier (DOI)

  • 10.1083/jcb.200704059

PubMed ID

  • 18086914

Additional Document Info

start page

  • 1163

end page

  • 77


  • 179


  • 6