Characterization and susceptibility to antiviral agents of herpes simplex virus type 1 containing a unique thymidine kinase gene with an amber codon between the first and the second initiation codons.
A herpes simplex virus type 1 (HSV-1) containing a thymidine (TK) gene with an amber mutation at the 8th position counted from the first AUG codon was isolated from a child with acute gingivostomatitis. The virus was predicted to express a mutant viral translated from the 2nd AUG codon at the 46th amino acid position and consisting of 331 amino acids. The virus was as sensitive to acyclovir (ACV), 5-bromovinyl-2'-deoxyuridine (BVdU), 1-beta-D-arabinofuranosyl-(E)-5-(2-bromovinyl)uracil (BVaraU), and 1-beta-D-arabinofuranosylthymine (araT) as a wild-type HSV-1. The mutant TK showed the same level of TK activity as the wild-type TK at reaction temperatures of 34 degrees C, 37 degrees C and 39 degrees C. ACV, BVdU, BVaraU, and araT inhibited the replication of the TK-deficient and drug-resistant HSV-1 and HSV-2 in 293T cells in which the mutant TK was expressed to the same extent as in cells in which intact HSV-1-TK was expressed, whereas BVdU and BVaraU inhibited the replication of these viruses less strongly in cells in which HSV-2-TK was expressed. It can be concluded that the mutant HSV-1 exists in nature as a variant and possesses the necessary phosphorylation activities to form ACV-monophosphate from ACV, to form BVdU-diphosphate through BVdU-monophosphate from BVdU, and to form BVaraU-diphosphate through BVaraU-monophosphate from BVaraU. These results indicate that the mutant HSV-1-TK with a deletion of the first 45 amino acid residues is phenotypically the same as that of wild-type HSV-1-TK in terms of the phosphorylation activity of TK-associated anti-herpes virus drugs.
Saijo
M
M
Special Pathogens Laboratory, Department of Virology 1, National Institute of Infectious Diseases, Musahimurayama, Tokyo, Japan. msaijo@nih.go.jp
Suzutani
T
T
Mizuta
K
K
Kurane
I
I
Morikawa
S
S
D000998:Antiviral Agents / Q000494:pharmacology*; D001483:Base Sequence; D002460:Cell Line; D002648:Child; D018388:Codon, Terminator / Q000235:genetics*; D018259:Herpesvirus 1, Human / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D018258:Herpesvirus 2, Human / Q000187:drug effects / Q000235:genetics; D006801:Humans; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D017384:Sequence Deletion; D013283:Stomatitis, Herpetic / Q000821:virology; D013696:Temperature; D013937:Thymidine Kinase / Q000235:genetics* / Q000378:metabolism; D010948:Viral Plaque Assay; D014764:Viral Proteins / Q000235:genetics* / Q000378:metabolism; D014779:Virus Replication / Q000187:drug effects
D000998:Antiviral Agents; D018388:Codon, Terminator; D014764:Viral Proteins; D013937:Thymidine Kinase