USP 14 inhibition corrects an in vivo model of impaired mitophagy

Mitochondrial autophagy or mitophagy is a key process that allows selective sequestration and degradation of dysfunctional mitochondria to prevent excessive reactive oxygen species, and activation of cell death. Recent studies revealed that ubiquitin–proteasome complex activity and mitochondrial membrane rupture are key steps preceding mitophagy, in combination with the ubiquitination of specific outer mitochondrial membrane (OMM) proteins. The deubiquitinating enzyme ubiquitin‐specific peptidase 14 ( USP 14) has been shown to modulate both proteasome activity and autophagy. Here, we report that genetic and pharmacological inhibition of USP 14 promotes mitophagy, which occurs in the absence of the well‐characterised mediators of mitophagy, PINK 1 and Parkin. Critical to USP 14‐induced mitophagy is the exposure of the LC 3 receptor Prohibitin 2 by mitochondrial fragmentation and mitochondrial membrane rupture. Genetic or pharmacological inhibition of USP 14 in vivo corrected mitochondrial dysfunction and locomotion behaviour of PINK 1/Parkin mutant Drosophila model of Parkinson's disease, an age‐related progressive neurodegenerative disorder that is correlated with diminished mitochondrial quality control. Our study identifies a novel therapeutic target that ameliorates mitochondrial dysfunction and in vivo PD ‐related symptoms.