Peroxisome proliferator-activated receptor alpha (PPARα) is a well-characterized nuclear receptor widely recognized as a master regulator of metabolic responses to nutrient deprivation. Under nutrient-deprived conditions, free fatty acids released from adipose tissue lipolysis are delivered to the liver, where they act as endogenous ligands for PPARα. Upon activation, PPARα promotes lipid catabolism and gluconeogenesis, thereby conserving energy and maintaining metabolic homeostasis during energy-limiting states. While most studies have focused on PPARα's roles in glucose and lipid metabolism, its relationship with protein metabolism remains less well understood. Recently, our group identified a novel role for PPARα in directly activating autophagy, independent of the mTOR pathway. In addition, we demonstrated that PPARα activation represses the transcriptional activity of coagulation factor genes Fga and F11 through direct interaction with promoter-proximal Inverted Repeat-1 (IR-1) Farnesoid X Receptor (FXR) response elements. Other studies have also reported that PPARα reduces the expression of secreted proteins, including apolipoprotein B, complement components, and coagulation factors, suggesting a broader role for PPARα in protein metabolism. Beyond its known roles in regulating autophagy-related protein degradation and the expression of certain secreted proteins, we identified a novel function of PPARα in orchestrating proteostasis from protein synthesis to degradation in the liver, a central organ for maintaining systemic proteostasis.