Phosphorylation of the Epstein-Barr virus (EBV) DNA polymerase processivity factor EA-D by the EBV-encoded protein kinase and effects of the L-riboside benzimidazole 1263W94.
A member of the family of L-riboside benzimidazole compounds, 1263W94, was shown recently to inhibit replication of Epstein-Barr virus (EBV) (V. L. Zacny, E. Gershburg, M. G. Davis, K. K. Biron, and J. S. Pagano, J. Virol. 73:7271-7277, 1999). In the present report the effect of 1263W94 on the phosphorylation pattern of the EBV DNA polymerase processivity factor, EA-D, during viral reactivation in latently EBV-infected Akata cells is analyzed. This pattern specifically changes with progression of cytolytic infection. In the presence of 1263W94 the appearance of the hyperphosphorylated form of EA-D is mainly affected. Next, coexpression of the cloned EBV-encoded protein kinase (EBV PK), BGLF4, with EA-D demonstrated the ability of EBV PK to phosphorylate EA-D to its hyperphosphorylated form in transient assays. However, the phosphorylation of EA-D was not directly inhibited by 1263W94 in these coexpression assays. The results indicate that the EBV PK appears to be responsible for the hyperphosphorylation of EA-D, imply that the phosphorylation status of EA-D is important for viral replication, and suggest that 1263W94 acts at a level other than direct inhibition of EA-D phosphorylation by EBV PK.
Gershburg
Edward
E
Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA.
Pagano
Joseph S
JS
D000956:Antigens, Viral / Q000378:metabolism*; D000998:Antiviral Agents / Q000494:pharmacology*; D001562:Benzimidazoles / Q000494:pharmacology*; D002461:Cell Line, Transformed; D004268:DNA-Binding Proteins; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D004854:Herpesvirus 4, Human / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D006801:Humans; D010766:Phosphorylation / Q000187:drug effects; D011499:Protein Processing, Post-Translational; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D012263:Ribonucleosides / Q000494:pharmacology*; D014407:Tumor Cells, Cultured; D014764:Viral Proteins; D014775:Virus Activation; D004004:Dichlororibofuranosylbenzimidazole / Q000031:analogs & derivatives
D000956:Antigens, Viral; D000998:Antiviral Agents; D001562:Benzimidazoles; D004268:DNA-Binding Proteins; D004259:DNA-Directed DNA Polymerase; D017346:Protein Serine-Threonine Kinases; D012263:Ribonucleosides; D014764:Viral Proteins; C033305:Epstein-Barr virus early antigen; C406063:BGLF4 protein, Epstein-Barr virus; C083202:BALF5 protein, Epstein-barr virus; C400401:maribavir; D004004:Dichlororibofuranosylbenzimidazole