title: A major transcriptional regulatory protein (ICP4) of herpes simplex virus type 1 is associated with purified virions.
abstract: Herpes simplex virus type 1 was purified by density gradient centrifugation, and the virion-associated proteins were resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. By Western blot (immunoblot) analysis with an anti-ICP4 monospecific serum, the results indicated that ICP4, one of the five immediate-early proteins of herpes simplex virus type 1, was associated with the purified virions. To define the location of ICP4 within the virion, trypsin digestion experiments were performed. Purified virions were treated with trypsin in the presence or absence of detergent. The virus envelope appeared to protect ICP4 from the trypsin, since virus-associated ICP4 was sensitive to digestion only after detergent treatment. In addition, ICP4 remained associated with the virus particle when the virion-specific glycoproteins were removed after detergent treatment. Finally, ICP4 was not detected in purified preparations of type A and B capsids isolated from the nuclear fraction of virus-infected cells. The above-mentioned data suggest that detectable amounts of ICP4 are present within the tegument region of the virion.
authors.affiliation: Department of Biochemistry and Molecular Biology, Louisiana State University Medical Center, Shreveport 71130-3932.
authors.forename: F
authors.initials: F
authors.lastname: Yao
authors.forename: R J
authors.initials: RJ
authors.lastname: Courtney
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002213:Capsid / Q000032:analysis; D002460:Cell Line; D002499:Centrifugation, Density Gradient; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D017874:Immediate-Early Proteins; D018139:Simplexvirus / Q000032:analysis* / Q000187:drug effects; D014357:Trypsin / Q000494:pharmacology; D014709:Vero Cells; D014764:Viral Proteins / Q000032:analysis*; D014771:Virion / Q000032:analysis* / Q000187:drug effects
chemical_list: D017874:Immediate-Early Proteins; D014764:Viral Proteins; C048925:herpes simplex virus, type 1 protein ICP4; D014357:Trypsin