Expression of baculovirus late and very late genes depends on LEF-4, a component of the viral RNA polymerase whose guanyltransferase function is essential.
Baculovirus lef-4 encodes one subunit of the viral RNA polymerase. Here, we demonstrate the essential nature of LEF-4 by RNA interference and bacmid knockout technology. Silencing of LEF-4 in wild-type virus-infected cells suppressed expression of structural genes, while early expression was unaffected, demonstrating its essential role in late gene expression. After transfection of insect cells with lef-4 mutant bacmid, no viral progeny was produced, further defining its central role in infection. Cotransfection with wild-type lef-4 plasmid restored normal replication, but plasmid encoding a guanyltransferase-deficient version failed to rescue. These results emphasize the importance of the mRNA capping function of LEF-4.
Department of Biochemistry, Texas A&M University, 2128 TAMU, College Station, Texas 77843-2128, USA.
Dagmar
D
Knebel-Mörsdorf
Ilja
I
Quadt
Yi
Y
Li
Laura
L
Montier
Linda A
LA
Guarino
D000818:Animals; D012321:DNA-Directed RNA Polymerases / Q000502:physiology*; D015870:Gene Expression; D017924:Nucleopolyhedroviruses / Q000235:genetics*; D009713:Nucleotidyltransferases / Q000502:physiology*; D012315:RNA Caps / Q000502:physiology; D018411:Spodoptera; D014158:Transcription, Genetic; D014764:Viral Proteins / Q000235:genetics / Q000502:physiology*; D000098556:mRNA Guanylyltransferases
D012315:RNA Caps; D014764:Viral Proteins; C084398:late expression factor 4, baculovirus; D009713:Nucleotidyltransferases; D000098556:mRNA Guanylyltransferases; D012321:DNA-Directed RNA Polymerases