Mitochondrial Calcium Transport During Autophagy Initiation

While it has been shown that CA²⁺ dynamics at the ER membrane is essential for the initiation of certain types of Autophagy such as starvation-induced Autophagy, how mitochondrial CA²⁺ transport changes during the first stage of Autophagy is not systemically characterized. An investigation of mitochondrial CA²⁺ dynamics during Autophagy initiation may help us determine the relationship between Autophagy and mitochondrial CA²⁺ fluxes. Here we examine acute mitochondrial and ER calcium responses to a panel of Autophagy inducers in different cell types. Mitochondrial CA²⁺ transport and CA²⁺ transients at the ER membrane are triggered by different Autophagy inducers. The mitophagy-inducer-initiated mitochondrial CA²⁺ uptake relies on mitochondrial calcium uniporter and may decelerate the following Mitophagy. In neurons derived from a Parkinson's patient, mitophagy-inducer-triggered mitochondrial CA²⁺ influx is faster, which may slow the ensuing Mitophagy.