DNAJC12 also known as JDP1 is a member of a subclass of the HSP40/DnaJ protein family. DNAJC12 is a J-domain co-chaperone that partners with HSP70 machinery to regulate protein folding and proteostasis within the cytosol and endoplasmic reticulum. By stimulating HSP70 ATPase activity, DnaJC12 supports maturation and stability of client proteins and helps coordinate cellular responses to proteotoxic stress. This chaperone network interfaces with ubiquitin–proteasome and ER-associated degradation pathways to maintain protein quality control. Altered DNAJC12 function has been linked to disrupted enzyme homeostasis and neuro-metabolic phenotypes, making it relevant for studying stress adaptation and protein maturation pathways.