Recombinant Human HSP40

Background: HSP40 (Heat shock protein 40, also known as DNAJB1) is an essential co-chaperone that cooperates with HSP70 to regulate protein folding, quality control, and degradation pathways. In the ubiquitin–proteasome system (UPS), HSP40 family members help recognize misfolded or damaged proteins and can recruit chaperone-associated E3 ubiquitin ligases such as CHIP (C-terminus of HSC70-Interacting Protein), promoting substrate ubiquitylation and proteasomal clearance. Through these interactions, HSP40 proteins play an important role in substrate triage decisions between protein refolding and degradation, directly influencing cellular proteostasis. HSP40 is also increasingly implicated in targeted protein degradation (TPD) mechanisms, where chaperone networks can affect degrader-induced substrate processing, ubiquitin transfer efficiency, and degradation kinetics. These heat shock proteins are valuable tools for investigating chaperone-mediated ubiquitylation, E3 ligase function, and UPS-driven proteome remodeling in cancer, neurodegeneration, and other protein homeostasis disorders.