Together we are stronger: fusion protects mitochondria from autophagosomal degradation

Autophagy. 2011 Dec;7(12):1568-9. doi: 10.4161/auto.7.12.17992.


Starvation induces a protective process of self-cannibalization called autophagy that is thought to mediate nonselective degradation of cytoplasmic material. We recently reported that mitochondria escape autophagosomal degradation through extensive fusion into mitochondrial networks upon certain starvation conditions. The extent of mitochondrial elongation is dependent on the type of nutrient deprivation, with amino acid depletion having a particularly strong effect. Downregulation of the mitochondrial fission protein Drp1 was determined to be important in bringing about starvation-induced mitochondrial fusion. The formation of mitochondrial networks during nutrient depletion selectively blocked their autophagic degradation, presumably allowing cells to sustain efficient ATP production and thereby survive starvation.

MeSH terms

  • Animals
  • Autophagy*
  • Cyclic AMP-Dependent Protein Kinases
  • Membrane Fusion*
  • Mice
  • Mitochondria / metabolism*
  • Phagosomes / metabolism*
  • Signal Transduction
  • TOR Serine-Threonine Kinases / metabolism


  • TOR Serine-Threonine Kinases
  • Cyclic AMP-Dependent Protein Kinases