Fig. 3.

Stress proteins participate in diverse steps of the virus life cycle. Five major steps of the virus life cycle are labeled as steps 1–5: virus entry and uncoating, virus replication, gene expression, assembly and release. Most viruses only undergo these steps in cytoplasm especially RNA viruses like EV-A71, DENV, JEV etc. While some viruses (such as influenza, SV40, HBV etc) also enter into nucleus of host cells. They may undergo other steps in their life cycle which are labelled as a–c: virus nucleus import, nucleus export, and virus RNA processing. During the process of virus infection, Hsp90, Hsp70, Hsp60, Hsp40, Hsp27, and PDIs participate in the virus entry and uncoating steps. Hsp90, Hsp70, Hsp60, Hsp40, Hsp27 and RNA chaperones take part in the virus replication step. Hsp70, Hsp40 and RNA chaperones are required in virus gene expression step. Hsp90, Hsp70 and Hsp40 assist virus assembly. Hsp70 and RNA chaperones contribute to the virus release. While Hsp90 is also important in virus nucleus import and export. Hsp70 plays a role in the virus nucleus import. And RNA chaperones play a major role in virus RNA processing, including replication, initiation of translation, stabilization and decay