Phosphorylation of the VP16 transcriptional activator protein during herpes simplex virus infection and mutational analysis of putative phosphorylation sites.
VP16 is a virion phosphoprotein of herpes simplex virus and a transcriptional activator of the viral immediate-early (IE) genes. We identified four novel VP16 phosphorylation sites (Ser18, Ser353, Ser411, and Ser452) at late times in infection but found no evidence of phosphorylation of Ser375, a residue reportedly phosphorylated when VP16 is expressed from a transfected plasmid. A virus carrying a Ser375Ala mutation of VP16 was viable in cell culture but with a slow growth rate. The association of the mutant VP16 protein with IE gene promoters and subsequent IE gene expression was markedly reduced during infection, consistent with prior transfection and in vitro results. Surprisingly, the association of Oct-1 with IE promoters was also diminished during infection by the mutant strain. We propose that Ser375 is important for the interaction of VP16 with Oct-1, and that the interaction is required to enable both proteins to bind to IE promoters.
Ottosen
Søren
S
Department of Biochemistry and Molecular Biology, Michigan State University, 510 Biochemistry Building, East Lansing, 48824-1319, USA.
Herrera
Francisco J
FJ
Doroghazi
James R
JR
Hull
Angela
A
Mittal
Sheenu
S
Lane
William S
WS
Triezenberg
Steven J
SJ
D000595:Amino Acid Sequence; D000818:Animals; D002522:Chlorocebus aethiops; D047369:Chromatin Immunoprecipitation; D006367:HeLa Cells; D006561:Herpes Simplex / Q000821:virology; D017405:Herpes Simplex Virus Protein Vmw65 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D017874:Immediate-Early Proteins / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D050811:Octamer Transcription Factor-1 / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D018139:Simplexvirus / Q000235:genetics / Q000254:growth & development / Q000378:metabolism / Q000472:pathogenicity*; D015533:Transcriptional Activation; D014709:Vero Cells
D017405:Herpes Simplex Virus Protein Vmw65; D017874:Immediate-Early Proteins; D050811:Octamer Transcription Factor-1