DnaJ homolog subfamily B member 12 (DNAJB12) (DNAJB12)

DnaJ homolog subfamily B member 12 (DNAJB12) is an endoplasmic reticulum (ER)-resident co-chaperone belonging to the Hsp40 family [1]. It functions primarily by recruiting Hsp70 chaperones to nascent or misfolded polypeptides, facilitating their proper folding or directing them toward ER-associated degradation (ERAD) [1, 3]. In the context of viral pathogenesis, DNAJB12 has been identified as a critical host factor for the Hepatitis B virus (HBV), where it assists in the assembly and secretion of both infectious virions and non-infectious subviral particles (SVPs) [2]. It specifically interacts with HBV surface proteins (HBsAg) to ensure their correct maturation and exit from the ER [3]. Because the secretion of HBsAg is a hallmark of chronic HBV infection and contributes to immune exhaustion, DNAJB12 is considered a potential host-targeting therapeutic target [2, 3]. Targeting this protein could reduce the viral burden and restore immune responses, although the essential role of DNAJB12 in cellular protein quality control poses a challenge for maintaining a favorable safety profile.

Other names

DNAJ antigen soluble 12DJB12ER-resident Hsp40 co-chaperone

DNAJB12 acts as a co-chaperone that facilitates the proper folding and assembly of Hepatitis B virus (HBV) surface proteins within the endoplasmic reticulum. By inhibiting DNAJB12, the maturation and subsequent secretion of subviral particles (SVPs) and infectious virions are disrupted, leading to a reduction in circulating viral antigens and viral load.