Abstract Virus proliferation depends on the successful recruitment of host cellular components
for their own replication, protein synthesis, and virion assembly. In the course of
virus particle production a large number of proteins are synthesized in a relatively short
time, whereby protein folding can become a limiting step. Most viruses therefore need cellular
chaperones during their life cycle. In addition to their own protein folding problems
viruses need to interfere with cellular processes such as signal transduction, cell cycle regulation
and induction of apoptosis in order to create a favorable environment for their proliferation
and to avoid premature cell death. Chaperones are involved in the control of
these cellular processes and some viruses reprogram their host cell by interacting with
them. Hsp70 chaperones, as central components of the cellular chaperone network, are
frequently recruited by viruses. This review focuses on the function of Hsp70 chaperones
at the different stages of the viral life cycle emphasizing mechanistic aspects.