Mitochondrial free radical generation and lifespan control in the fungal aging model Podospora anserina

Exp Gerontol. 2006 Apr;41(4):439-47. doi: 10.1016/j.exger.2006.01.010. Epub 2006 Mar 10.

Abstract

In the filamentous fungus Podospora anserina a central role of mitochondria in the control of aging has been repeatedly demonstrated. Interestingly, impairments in cytochrome c oxidase (COX) activity induce an enhancement in the expression of the quinol-oxygen alternative oxidoreductase (AOX) correlating with an extension of lifespan. This effect is thought to be determined by a reduction of the free radical generation in mitochondria. In the current investigation we have analyzed the electron transport chain composition of P. anserina and the superoxide generation rate in wild type s and in mutant grisea, a long-lived mutant with complex IV deficiency. Here we report that, similarly to other fungi, mitochondrial respiration in P. anserina is a combination of standard and alternative routes. A switch in the COX/AOX respiration balance affects the mitochondrial free radical generation. Lower mitochondrial rates of superoxide generation were found in the long-lived mutant, supporting the central role of mitochondrial free radical generation in the lifespan control of P. anserina. The question of how the activity of the alternative respiratory pathway influences the rate of free radical generation in P. anserina mitochondria is discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aging / metabolism*
  • Blotting, Western / methods
  • Electron Transport Chain Complex Proteins / metabolism
  • Free Radicals / metabolism*
  • Longevity / physiology*
  • Mitochondria / metabolism*
  • Mycology / methods
  • NADH Dehydrogenase / analysis
  • NADH Dehydrogenase / genetics
  • Oxidative Stress
  • Oxygen Consumption
  • Podospora / physiology*
  • RNA, Messenger / analysis
  • Reverse Transcriptase Polymerase Chain Reaction
  • Submitochondrial Particles / metabolism
  • Superoxide Dismutase / metabolism

Substances

  • Electron Transport Chain Complex Proteins
  • Free Radicals
  • RNA, Messenger
  • Superoxide Dismutase
  • NADH Dehydrogenase