HSP40/DNAJ Chaperones

Members of the HSP40/DNAJ family comprise one of the largest groups of molecular chaperones, and are present in all living organisms from bacteria to humans. The hallmark of DNAJs is the presence of a J-domain, which is crucial for interaction with HSP70. DNAJs can be seen as the workforce that steers HSP70 machines, regulating client input and specificity. The different DNAJs are involved in processes such as (re)folding, intracellular transport across membranes, protein modifications, remodelling of protein complexes and protein degradation. In particular, different DNAJs are able to suppress aggregate formation of several amyloidogenic proteins linked to human diseases. On the other hand, mutations in many DNAJs give rise to a wide range of pathologies, attesting to their fundamental role in cellular homeostasis and general protein quality control.