Induction of RNA polymerase II activity in Junin virus-infected cells.

Nuclear involvement of the host cell in Junin virus (JV) replication was studied. alpha-Amanitin was shown to inhibit JV yield, and RNA synthesis in cell nuclei was found to be augmented during the eclipse period. JV infection exerted a selective effect on cellular RNA polymerase activities, when measured in purified infected nuclei. RNA polymerase I was inhibited, but RNA polymerase II was stimulated. These data support the hypothesis that RNA polymerase II is involved in arenavirus replication.