The interaction of white spot syndrome virus envelope protein VP28 with shrimp Hsc70 is specific and ATP-dependent.

White spot syndrome virus (WSSV) is one of the most devastating pathogens of shrimps and other crustaceans. In a previous study, we demonstrated that the major envelope protein VP28 of WSSV was involved in the attachment and penetration into shrimp cells. Here we showed that heat-shock cognate protein 70 (Hsc70) of shrimp was a binding partner of VP28 during virus infection. Hsc70 expression was enhanced by WSSV infection at the early stage and peaked at 12h post-infection and decreased drastically at the late stage. In shrimp haemocytes, both VP28 and Hsc70 proteins localized in the cytoplasm and their association was specific, ATP-dependent and Hsc70 concentration dependent. Moreover, direct VP28-Hsc70 association required both ATPase domain and peptide binding domain of Hsc70. The data obtained will help elucidate the role of VP28 protein in the process of virus infection.