DNAJB5 (DnaJ Heat Shock Protein Family (Hsp40) Member B5) is a Protein Coding gene. DNAJB5 encodes a member of the DNAJ heat shock protein 40 family of co-chaperone proteins. The encoded protein contains an N-terminal DNAJ domain and a C-terminal substrate binding domain but lacks the cysteine-rich domain found in other DNAJ family members. In mice, a multi-protein complex containing this protein, thioredoxin 1, and histone deacetylase 4, serves as a master negative regulator of cardiac hypertrophy.