Acute infection of Sindbis virus induces phosphorylation and intracellulartranslocation of small heat shock protein HSP27 and activation of p38 MAP kinase signaling pathway

In general, viral infection is supposed to induce stress responses in the h ost cell. However, very few detailed observations about virus-induced stres s responses have been reported. Here we investigated specific stress respon ses in Vero cells infected with Sindbis virus (SV), a single-stranded RNA v irus, acute infection with which is known to cause apoptotic cell death in the host cells. Prior to the onset of apoptosis, p38 mitogen-activated prot ein kinase (MAPK) and c-Jun NH2-terminal kinases (JNKs) were activated. Sub sequently, a 27-kDa heat shock protein (HSP27) became phosphorylated, and i ntracellular distribution of HSP27 was changed from the cytoplasm to the pe rinuclear region. These results indicate that the cellular signaling cascad es activated by pro-inflammatory cytokines and environmental stresses are a lso activated as a result of lytic infection with SV. These responses may c ontribute to the delayed onset of apoptosis in the host cells and the facil itation of viral replication. (C) 1998 Academic Press.