Protein homeostasis (i.e. maintenance of an optimal balance between biogenesis, folding, trafficking, assembly, disassembly and degradation of proteins) is required for cell health. Hsp70 chaperones, which are present in all cellular compartments, play critical roles in protein homeostasis. Hsp70 systems are increasingly being tied to human diseases, ranging from cancer to neurological disorders to metabolic dysfunctions and are targets for disease interventions. The overarching goal of this proposal is to gain a better understanding of molecular characteristics of Hsp70, and its J-protein co-chaperones, that drive their specific functions in cellular processes, by employing a well-established J-protein/Hsp70 system in Saccharomyces cerevisiae. J-proteins are considered exploitable targets for disease intervention, because their specificity increases the likelihood Hsp70 activity can be specifically manipulated in a therapeutically beneficial way.