FUS interacts with ATP synthase beta subunit and induces mitochondrial unfolded protein response in cellular and animal models

Significance In this study, we used an inducible cellular model for FUS proteinopathy to demonstrate that mitochondrial dysfunction occurs as the earliest detectable change induced by FUS. In cellular and fly models, FUS interacts with the mitochondrial ATP synthase β-subunit (ATP5B), disrupts ATP synthase complex assembly, suppresses the activity of mitochondrial ATP synthase, and activates the mitochondrial unfolded protein response (UPR mt ). ATP5B expression is increased in cells and flies expressing FUS. Down-regulating expression of ATP5B or UPR mt genes ameliorates FUS-induced neurodegeneration. Our data uncover a previously unknown role of FUS in targeting mitochondrial ATP synthesis and activating UPR mt .