title: Genotypic and phenotypic characterization of the thymidine kinase of ACV-resistant HSV-1 derived from an acyclovir-sensitive herpes simplex virus type 1 strain.
abstract: Twenty-four strains of acyclovir (ACV)-resistant (ACV(r)) herpes simplex virus type 1 (HSV-1) were generated from the HSV-1 TAS strain by exposure to ACV, and the genotype and phenotype of the thymidine kinase (TK) from these mutants were analyzed. The TK polypeptide of the ACV(r) HSV-1 strains was examined by Western blot using an anti-HSV-1 TK rabbit serum. The sensitivity of each strain to ACV, foscarnet and cidofovir (CDV) was also determined. A single guanine (G) insertion or a single cytosine (C) deletion was detected in 12 of the 24 ACV(r) strains at the G or C homopolymer stretches within the TK gene. Genotypic analysis predicted that two thirds of the ACV(r) HSV-1 strains expressed truncated TK polypeptides, while one third expressed viral TK polypeptide with a single amino acid substitution at various sites. Western blot abnormalities in the viral TK polypeptides were identified in 21 ACV(r) strains. There was an inverse correlation between the susceptibility of the HSV-1 mutant strains to ACV and that to CDV. Nucleotide sequencing of the TK gene and Western blot analysis of the viral TK polypeptides are considered to be one of the methods for predicting virus sensitivity to ACV and CDV.
authors.affiliation: Special Pathogens Laboratory, Department of Virology 1, National Institute of Infectious Diseases, 4-7-1 Gakuen, Musashimurayama, Tokyo 208-0011, Japan. msaijo@nih.go.jp
authors.forename: Masayuki
authors.initials: M
authors.lastname: Saijo
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Suzutani
authors.forename: Erik
authors.initials: E
authors.lastname: De Clercq
authors.forename: Masahiro
authors.initials: M
authors.lastname: Niikura
authors.forename: Akihiko
authors.initials: A
authors.lastname: Maeda
authors.forename: Shigeru
authors.initials: S
authors.lastname: Morikawa
authors.forename: Ichiro
authors.initials: I
authors.lastname: Kurane
mesh_terms: D000212:Acyclovir / Q000494:pharmacology*; D000595:Amino Acid Sequence; D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D001483:Base Sequence; D015153:Blotting, Western; D002522:Chlorocebus aethiops; D000077404:Cidofovir; D003596:Cytosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D024882:Drug Resistance, Viral / Q000235:genetics; D018259:Herpesvirus 1, Human / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D063065:Organophosphonates; D009943:Organophosphorus Compounds / Q000494:pharmacology; D017422:Sequence Analysis, DNA; D013937:Thymidine Kinase / Q000235:genetics* / Q000378:metabolism; D014709:Vero Cells; D010948:Viral Plaque Assay
chemical_list: D000998:Antiviral Agents; D063065:Organophosphonates; D009943:Organophosphorus Compounds; D003596:Cytosine; D013937:Thymidine Kinase; D000077404:Cidofovir; D000212:Acyclovir