acyclovir-triphosphate and Cell-Transformation--Viral

Proteins from herpes simplex virus (HSV)-infected cells were used to reconstitute DNA synthesis in vitro on a preformed replication fork. The preformed replication fork consisted of a nicked, double-stranded, circular DNA molecule with a 5' single-strand tail that was noncomplementary to the template. The products of DNA synthesis on this substrate were rolling-circle molecules, as demonstrated by electron microscopy and alkaline agarose gel electrophoresis. The tails contained double-stranded regions, indicating that both leading- and lagging-strand DNA syntheses occurred. Rolling-circle DNA replication was dependent upon HSV DNA polymerase and ATP and was stimulated by a crude fraction containing ICP8 (HSV DNA-binding protein). Similar protein fractions from mock-infected cells were unable to support rolling-circle DNA replication. This in vitro DNA replication system should prove useful in the identification and characterization of the enzymatic activities required at the HSV replication fork.

Topics: Acyclovir; Animals; Antiviral Agents; Cell Nucleus; Cell Transformation, Viral; DNA Replication; DNA-Directed DNA Polymerase; DNA, Viral; Kinetics; Microscopy, Electron; Oligonucleotide Probes; Simplexvirus; Vero Cells

Vaccinia and pseudorabies viruses are resistant to ACV [Acyclovir or 9-(2-hydroxyethoxymethyl)guanine] in normal cells. However, both viruses are sensitive in thymidine kinase (TK)-transformed cells in which the resident HSV-specific TK is able to phosphorylate the drug. This demonstrates the sensitivity of these viruses to phosphorylated ACV and suggests a wider antiviral activity for the phosphorylated drug.

Topics: Acyclovir; Animals; Cell Line; Cell Transformation, Viral; Guanine; Herpesvirus 1, Suid; Mice; Phosphorylation; Thymidine Kinase; Vaccinia virus; Viral Plaque Assay