Heat shock protein 90 facilitates formation of the HBV capsid via interacting with the HBV core protein dimers.

The mechanism by which host factors contribute to hepatitis B virus (HBV) capsid formation during the viral life cycle remains unclear. This study analyzed the interaction between heat shock protein 90 (Hsp90), a host factor, and the HBV core protein. Hsp90 was found to bind to HBV core protein dimers, which was then encapsidated into the HBV capsid. Furthermore, activated Hsp90 may facilitate the formation of the human HBV capsid by catalyzing core assembly and reducing the degree of capsid dissociation at various temperatures, both in vitro and in vivo, and when subjected to detergent treatments in vitro. In addition, inhibition or downregulation of Hsp90 reduced HBV production in HepG2.2.15 cells. These results showed that Hsp90 plays an important role in HBV capsid stabilization and HBV formation.