The Autographa californica multiple nucleopolyhedrovirus lef-5 gene is required for productive infection

To examine the role of the AcMNPV lef-5 gene in the context of the infection cycle, we generated an AcMNPV lef-5 knockout virus (vAclef5ko) and a complementing cell line that supports viral replication. We examined AcMNPV DNA replication, early and late gene expression, and production of infectious viral progeny in the absence of lef-5. While early gene expression and DNA replication were not reduced by the lef-5 knockout, expression of a late reporter was disrupted and representative late transcripts were dramatically reduced. Progeny virus production was not detected after transfection of Sf9 cells with the lef-5 knockout bacmid, but was rescued by insertion of an egfp- or myc-tagged lef-5 gene into the vAclef5ko genome. An egfp-tagged lef-5 gene from SeMNPV was used to generate a stable Sf9 cell line that supported replication of the vAclef5ko virus. The LEF-5 protein was also found to co-localize with IE-1 in infected cell nuclei.