Abnormal protein homeostasis (proteostasis), dysfunctional mitochondria, and aberrant redox signalling are often associated in neurodegenerative disorders, such as Huntington's (HD), Alzheimer's and Parkinson's diseases. It remains incompletely understood, however, how changes in redox signalling affect proteostasis mechanisms, including protein degradation pathways and unfolded protein responses (UPR). This article addresses this open question by investigating the interplay between redox signalling and proteostasis in a mouse model of HD, and by examining the in vivo effects of the mitochondria-targeted antioxidant MitoQ.