HTT and Huntington disease: To this end, we used 2 well-established model systems: (i) human embryonic kidney (HEK) cells expressing a polyQ-expanded Huntingtin form (Q74) that causes aggregation and proteotoxicity used as a proxy for the neurodegenerative Huntington's disease (Jimenez-Sanchez et al. 2015) and (ii) yeast expressing a constitutively misfolded carboxypeptidase (ΔssCPY∗) that forms insoluble protein aggregates upon stress (Park et al. 2007).