Mitochondrial Dynamics and Autophagy

Abstract

Efficient mitochondrial quality control is critical for maintenance of a healthy mitochondrial population. Both mitochondrial dynamics and selective mitochondrial autophagy, termed mitophagy, contribute to mitochondrial turnover and quality control. Mitochondrial fusion and fission allow for complementation of mitochondrial solutes, proteins, and DNA but also for generation of unequal daughter organelles. Selective fusion is utilized for incorporation of polarized mitochondria back into the network, while a depolarized mitochondrion will not fuse, but instead will be targeted for elimination by mitophagy. Mitophagy is dependent on mitochondrial dysfunction, such as depolarization, and a number of proteins are required for core autophagic machinery, signaling, and mitochondrial segregation and targeting. The relationship between mitochondrial dynamics and autophagy and how they may contribute to both mitochondrial and cellular quality control is beginning to be elucidated. Even with the questions that remain in regards to the regulation and interdependence of mitochondrial dynamics and mitophagy, it is clear that alterations in these processes lead to mitochondrial dysfunction and pathological states such as neurodegeneration.