DnaJ heat shock protein family (Hsp40) member B8 (DNAJB8)

DnaJ heat shock protein family (Hsp40) member B8 (DNAJB8) is a protein chaperone encoded by the DNAJB8 gene, belonging to the Hsp40/DNAJ family. Its canonical function is to suppress the aggregation and toxicity of misfolded and disease-associated polyglutamine proteins, especially in neurodegenerative contexts. DNAJB8 exerts chaperone activity by interacting with Hsp70, using a unique C-terminal tail critical for binding pathogenic substrates and regulating activity. In cancer, DNAJB8 is selectively expressed in stem-like subpopulations and as a cancer/testis antigen, enhancing tumor initiation, maintenance of stem-like cell traits, and resistance to therapies such as docetaxel and oxaliplatin. Mechanistically, its oligomeric assembly is regulated by aromatic-rich motifs and domain interactions that control Hsp70 recruitment. DNAJB8 is considered a promising candidate for cancer immunotherapy and as a functional biomarker for aggressive and therapy-resistant cancers, though clinical targeting remains challenging due to tissue specificity and essential roles in proteostasis.

Other names

DnaJ homolog subfamily B member 8DNAJB8MGC33884CT156DJ6dnaJ homolog subfamily B member 8testicular tissue protein Li 56DnaJ (Hsp40) homolog, subfamily B, member 8

Promotes resistance to chemotherapeutic drugs (e.g., docetaxel, oxaliplatin) by enhancing the proportion of stem-like cancer cells and inhibiting tumor suppressor (TP53) degradation. Acts as an immunogenic antigen (cancer/testis antigen) - potential target for immunotherapy.