Translational Medical Research Commons^™

Spg7 Targets The M-Aaa Protease Complex To Process Mcu For Uniporter Assembly, Ca2 Influx, And Regulation Of Mitochondrial Permeability Transition Pore Opening, Stephen Hurst, Ariele Baggett, György Csordás, Shey-Shing Sheu

Center for Translational Medicine Faculty Papers

The mitochondrial matrix ATPase associated with diverse cellular activities (m-AAA) protease spastic paraplegia 7 (SPG7) has been recently implicated as either a negative or positive regulatory component of the mitochondrial permeability transition pore (mPTP) by two research groups. To address this controversy, we investigated possible mechanisms that explain the discrepancies between these two studies. We found that loss of the SPG7 gene increased resistance to Ca²-induced mPTP opening. However, this occurs independently of cyclophilin D (cyclosporine A insensitive) rather it is through decreased mitochondrial Ca² concentrations and subsequent adaptations mediated by impaired formation of functional mitochondrial Ca …