A role for mitochondria in autophagy regulation.

Understanding the functional relationship between mitochondria and autophagy is critical for understanding the molecular mechanisms underlying aging and neurodegeneration. Autophagy functions in both cellular homeostasis and in quality control in the selective removal of dysfunctional mitochondria. A current working model in the field is that impaired autophagy results in a cell-damaging accumulation of dysfunctional mitochondria over time. We described our findings that respiratory-deficient mitochondria can inhibit general (macro) autophagy in Saccharomyces cerevisiae by conserved signaling pathways during amino acid starvation. These data point to an interdependence of mitochondrial function and autophagy and raise the possibility that negative regulation of autophagy by dysfunctional mitochondria is a critical contributing factor in many diseases.