Selective sorting and destruction of mitochondrial membrane proteins in aged yeast

Elife. 2016 Apr 20:5:e13943. doi: 10.7554/eLife.13943.


Mitochondrial dysfunction is a hallmark of aging, and underlies the development of many diseases. Cells maintain mitochondrial homeostasis through a number of pathways that remodel the mitochondrial proteome or alter mitochondrial content during times of stress or metabolic adaptation. Here, using yeast as a model system, we identify a new mitochondrial degradation system that remodels the mitochondrial proteome of aged cells. Unlike many common mitochondrial degradation pathways, this system selectively removes a subset of membrane proteins from the mitochondrial inner and outer membranes, while leaving the remainder of the organelle intact. Selective removal of preexisting proteins is achieved by sorting into a mitochondrial-derived compartment, or MDC, followed by release through mitochondrial fission and elimination by autophagy. Formation of MDCs requires the import receptors Tom70/71, and failure to form these structures exacerbates preexisting mitochondrial dysfunction, suggesting that the MDC pathway provides protection to mitochondria in times of stress.

Keywords: MDC; S. cerevisiae; aging; autophagy; cell biology; lysosome; mitochondria; protein degradation; vacuole; yeast.

MeSH terms

  • Aged
  • Humans
  • Mitochondrial Membranes / chemistry*
  • Mitochondrial Proteins / metabolism*
  • Protein Transport
  • Proteolysis
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae / physiology*


  • Mitochondrial Proteins