title: HSV1-specific thymidylate kinase activity in infected cells.
abstract: Several 5-methoxymethyldeoxyuridine (MMdU)-resistant mutants of herpes simplex virus type 1 (HSV1) were classified by measuring their sensitivities to the deoxythymidine kinase (dTK)-dependent antiviral drugs 9-(2-hydroxyethoxymethyl)-guanine (acyclovir, ACV), 1-beta-D-arabinofuranosylthymine (araT), and E-(2)-5-bromovinyldeoxyuridine (BVdU) and to the dTK-independent antiviral drug phosphonoacetate (PAA). Compared to wild-type (WT) virus, all five of the dTK- mutants were highly resistant (greater than or equal to 500-fold) to BVdU and MMdU, moderately resistant to ACV (50- to 100-fold) and araT (10- to 20-fold), but not resistant to PAA. The dTK of the mutant MMdUr-20 (dTK+) appeared to phosphorylate dTMP less well than that of the WT virus, while its affinity for deoxythymidine was not altered. Two other drug-resistant HSV mutants-S1 (isolated against ACV) and B3 (isolated against BVdU)--also showed reduced phosphorylation of dTMP. This suggests that alterations in both dTK and thymidylate kinase activities may determine sensitivity to antiviral drugs.
mesh_terms: D000212:Acyclovir / Q000494:pharmacology; D000818:Animals; D001973:Bromodeoxyuridine / Q000031:analogs & derivatives / Q000494:pharmacology; D002478:Cells, Cultured; D006224:Cricetinae; D003857:Deoxyuridine / Q000031:analogs & derivatives / Q000494:pharmacology; D004352:Drug Resistance, Microbial; D006561:Herpes Simplex / Q000201:enzymology*; D007700:Kinetics; D051379:Mice; D009703:Nucleoside-Phosphate Kinase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010746:Phosphonoacetic Acid / Q000494:pharmacology; D010766:Phosphorylation; D010770:Phosphotransferases / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: C020235:brivudine; C024722:5-methoxymethyl-2'-deoxyuridine; D010770:Phosphotransferases; D009703:Nucleoside-Phosphate Kinase; C020093:dTMP kinase; D001973:Bromodeoxyuridine; D010746:Phosphonoacetic Acid; D003857:Deoxyuridine; D000212:Acyclovir