Plays an indispensable role in the organization of KRT8/KRT18 filaments. Acts as an endogenous molecular chaperone for neuronal proteins including huntingtin. Suppresses aggregation and toxicity of polyglutamine-containing, aggregation-prone proteins. Isoform B but not isoform A inhibits huntingtin aggregation. Has a stimulatory effect on the ATPase activity of HSP70 in a dose-dependent and time-dependent manner and hence acts as a co-chaperone of HSP70. Also reduces cellular toxicity and caspase-3 activity. Defects in DNAJB6 are the cause of limb-girdle muscular dystrophy type 1E (LGMD1E). An autosomal dominant myopathy characterized by adult onset of proximal muscle weakness, beginning in the hip girdle region and later progressing to the shoulder girdle region. There is evidence that LGMD1E is caused by dysfunction of isoform B (PubMed:22366786). 3 isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.