Hsp70 negatively controls rotavirus protein bioavailability in caco-2 cells infected by the rotavirus RF strain

Broquet AH, Lenoir C, Gardet A, Sapin C, Chwetzoff S, Jouniaux AM, Lopez S, Trugnan G, Bachelet M, Thomas G
Source: J Virol
Publication Date: (2007)
Issue: 81(3): 1297-304
Research Area:
Cancer Research/Cell Biology
Cells used in publication:
Species: human
Tissue Origin: colon
Nucleofector® I/II/2b
Previous studies demonstrated that the induction of the heat shock protein Hsp70 in response to viral infection is highly specific and differs from one cell to another and for a given virus type. However, no clear consensus exists so far to explain the likely reasons for Hsp70 induction within host cells during viral infection. We show here that upon rotavirus infection of intestinal cells, Hsp70 is indeed rapidly, specifically, and transiently induced. Using small interfering RNA-Hsp70-transfected Caco-2 cells, we observed that Hsp70 silencing was associated with an increased virus protein level and enhanced progeny virus production. Upon Hsp70 silencing, we observed that the ubiquitination of the main rotavirus structural proteins was strongly reduced. In addition, the use of proteasome inhibitors in infected Caco-2 cells was shown to induce an accumulation of structural viral proteins. Together, these results are consistent with a role of Hsp70 in the control of the bioavailability of viral proteins within cells for virus morphogenesis.