Longevity and mitochondrial membrane potential

In Saccharomyces cerevisiae yeast cells a decrease in the mitochondrial membrane potential caused by protonophores or by a loss of mitochondrial DNA leads to an increase in longevity (replicative life span). The loss of mitochondrial DNA also activates retrograde signaling that results in certain changes in transcription. Recently, Miceli and coauthors ((2011) Front. Genet., 2, 102) showed that retrograde response is triggered by a drop in the membrane potential. Independently, it has been shown that retrograde response activates autophagic mitochondrial degradation (mitophagy). Together, it suggests that activation of selective mitophagy increases lifespan by protecting cells from accumulation of damaged mitochondria in cells. Low concentrations of protonophores can be beneficial by increasing the accuracy of the mitophagosomal degradation of mitochondria with deleterious mutations in their DNA.