the maintenance of protein homeostasis (proteostasis) is essential for all functions of cells and the organism and results from a tightly controlled balance between synthesis, folding, and selective degradation of damaged and aggregated proteins. Multiple physiological situations challenge the proteome, including developmental changes or adaptation to environmental stress conditions, as well as the accumulation of misfolded or damaged proteins. In the past few years, characterization of the molecular machinery involved in the maintenance of cellular proteostasis has led to a better understanding of how this process controls physiological and pathological situations, hence allowing the design of novel therapeutic tools.