L-OPA1 regulates mitoflash biogenesis independently from membrane fusion.

ABSTRACT: Mitochondrial flashes mediated by optic atrophy 1 (OPA1) fusion protein are bioenergetic responses to stochastic drops in mitochondrial membrane potential (Δψ_m) whose origin is unclear. Using structurally distinct genetically encoded pH-sensitive probes, we confirm that flashes are matrix alkalinization transients, thereby establishing the pH nature of these events, which we renamed "mitopHlashes". Probes located in cristae or intermembrane space as verified by electron microscopy do not report pH changes during Δψ_m drops or respiratory chain inhibition. Opa1 ablation does not alter Δψ_m fluctuations but drastically decreases the efficiency of mitopHlash/Δψ_m coupling, which is restored by re-expressing fusion-deficient OPA1^K301A

SUBMITTER: Rosselin M 

PROVIDER: S-EPMC5331265 | biostudies-literature | 2017 Mar

REPOSITORIES: biostudies-literature