HSPA1A and infection: Hsp70 is translocated from cytoplasm to the nucleus in the late stage of infection, coincident with localization change of the viral capsid proteins.254 In vitro studies show that Hsp70 functions to keep proper assembly of Polyomavirus.255 The prokaryotic Hsp70 chaperone DnaK also interacts with recombinant VP1 at the C-terminal domain where it links pentamers in an assembled capsid.255 When DnaK binds to VP1, it inhibits VP1 assembly, which is induced by calcium in vitro.