Functional roles of GRP78 in hepatitis B virus infectivity and antigen secretion

Viruses utilize cellular proteins to mediate their life cycle. However, the hepatitis B virus (HBV) cycle is still mysterious and remains be elucidated. Here, GRP78/BiP/HSPA5, a 78 kDa glucose-regulated protein, was identified as preS2 interacting protein. Pulldown assay showed interaction of protein (GRP78) with both domain-containing large S middle expressed in human hepatocellular cell line. The immunofluorescence studies revealed that colocalized GRP78. Interestingly, it found specifically bound ATPase domain To understand how GRP78 plays role HBV infection, stably GRP78-expressing cells were established, which promoted infectivity replication. In contrast, knockdown changed antigen secretion but not viral DNA amplification. Taken together, these results suggest should interact via modulate secretion.