IDENTIFICATION AND TRANSCRIPTIONAL REGULATION OF THE BACULOVIRUS LEF-6 GENE

We identified an Autographa californica nuclear polyhedrosis virus (Ac MNPV) gene, the late expression factor 6 gene (lef-6), which is involv ed in expression from late and very late AcMNPV gene promoters but not from an early AcMNPV gene promoter in transient expression assays. Th is gene was located within the PstI T fragment of the AcMNPV genome (1 4.7 to 17.9 map units), immediately downstream of Ac-iap, the AcMNPV h omolog of a baculovirus gene family involved in blocking apoptotic pro grammed cell death. The nature and temporal regulation of both Ac-iap and lef-6 transcripts was examined. Ac-iap and lef-6 were cotranscribe d as bicistronic messages at both early and late times postinfection. In addition, lef-6 aas transcribed as a monocistronic mRNA by initiati on from an early promoter within Ac-iap.