Baculovirus lef-12 is not required for viral replication.
The baculovirus lef-12 (orf41) gene is required for transient expression of baculovirus late genes. To analyze the role of LEF-12 in the context of infected cells, two mutant viruses were constructed. Both mutants were viable in Trichoplusia ni High 5 and Spodoptera frugiperda Sf9 cells. Single-step growth curves, however, indicated that virus yields were reduced approximately fivefold in the absence of LEF-12. Pulse-labeling of infected cells revealed that LEF-12 mutant viruses entered the late phase and synthesized late proteins at levels equivalent to or only twofold lower than those of wild-type virus-infected cells. Western blot analyses confirmed that LEF-12 was not synthesized in cells infected with mutant virus. In wild-type virus-infected cells, LEF-12 was not detected until 18 h postinfection, and accumulation of LEF-12 peaked at 24 to 36 h postinfection. Primer extension mapping revealed that lef-12 mRNA was synthesized by 12 h postinfection and peaked between 18 and 24 h postinfection. Furthermore, synthesis of lef-12 mRNA and LEF-12 protein were inhibited by the addition of aphidicolin, indicating that lef-12 is expressed after DNA replication.
Guarino
Linda A
LA
Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843-2128, USA. lguarino@tamu.edu
Mistretta
Toni-Ann
TA
Dong
Wen
W
D000595:Amino Acid Sequence; D000818:Animals; D016590:Aphidicolin / Q000494:pharmacology; D001483:Base Sequence; D002460:Cell Line; D004261:DNA Replication / Q000187:drug effects; D015870:Gene Expression / Q000187:drug effects; D005814:Genes, Viral; D008969:Molecular Sequence Data; D009036:Moths; D009154:Mutation; D017924:Nucleopolyhedroviruses / Q000187:drug effects / Q000235:genetics* / Q000502:physiology*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D012367:RNA, Viral / Q000096:biosynthesis / Q000235:genetics; D018411:Spodoptera; D014764:Viral Proteins / Q000235:genetics; D014779:Virus Replication / Q000187:drug effects / Q000235:genetics* / Q000502:physiology
D012333:RNA, Messenger; D012367:RNA, Viral; D014764:Viral Proteins; D016590:Aphidicolin