PSME3 and juvenile Huntington disease: Induction of PA28γ expression by TRPA1 channel and the transcription factor NHR49 at low temperature was required for the extension of lifespan, inhibition of age-related reduction in proteolysis, and suppression of protein aggregation in age-related disease models, such as Huntington's disease, while PA28γ had no effect on lifespan at normal temperature.