Japanese encephalitis virus replication: studies on host cell nuclear involvement.

Replication, as measured by virus production, of both the flavivirus Japanese encephalitis virus (JEV) and the alphavirus Venezuelan encephalitis virus (VEV) was unaffected by short pulses of actinomycin D (act D) at early times postinfection (PI). Replication of JEV was found to be partially inhibited by continuous exposure to act D under conditions where VEV replication was equally sensitive to the drug. JEV replication proceeded normally in the presence of mitomycin C, a DNA synthesis inhibitor. Autoradiographic analysis revealed that virus-specific RNA was present only in the cytoplasm at both early and late times PI. When infected cell membranes were separated on a discontinuous sucrose gradient, most of the virus-specific RNA was associated with the endoplasmic reticulum fraction.