Mitochondrial quality control

Mitochondria Mitochondria contain proteins encoded by the nucleus and by their own mitochondrial genome. Sometimes protein synthesis within the mitochondria goes wrong, which can damage both mitochondrial and cellular fitness. Richter et al. interfered with intramitochondrial protein synthesis by means of an antibiotic and found that misfolded proteins accumulated at the inner mitochondrial membrane. This compromised the mitochondrial membrane potential, kicking into gear a mechanism to put the brakes on mitochondrial protein synthesis. The reduction in mitochondrial protein synthesis protected the mitochondria from further damage. This quality-control mechanism would be expected to protect mitochondria in the event of short-term perturbations of mitochondrial translation. J. Cell Biol. 211 , 373 (2015).