title: Regulation of the expression of the varicella-zoster virus open reading frame 66 gene.
abstract: The varicella-zoster virus (VZV) open reading frame (ORF) 66 encodes a serine/threonine kinase that phosphorylates the major viral transactivator protein, immediate-early (IE) 62, preventing its nuclear importation. Cytoplasmic sequestration of IE62 may alter viral gene transcription and could serve as a mechanism for maintaining VZV latency. We examined the regulation of expression of the ORF66 gene by mapping the promoter region, which was localized to within 150 bases of the start codon. The ORF66 promoter was activated by two viral regulatory proteins, IE62 and IE63. We evaluated the binding of viral regulatory proteins and cellular transcription factors based on recognized cellular transcription factor binding sites identified within the ORF66 promoter. These included Sp1 and TBP binding sites, several of which were essential for optimal promoter activity. Site-directed mutations in Sp1 and TBP binding sites led to varying degrees of impairment of ORF66 gene expression in the context of VZV infection. We also examined the effect of Sp1 and TBP mutations on IE62, Sp1, and TBP binding. These studies reveal that host cell-derived and viral factors contribute to and cooperate in the expression of this important viral kinase gene.
authors.affiliation: Division of Viral Diseases, Measles, Mumps, Rubella, and Herpesvirus Laboratory Branch, Centers for Disease Control and Prevention, Office of Infectious Diseases, National Center for Immunizations and Respiratory Diseases, Atlanta, GA 30333, USA. apz5@cdc.gov
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Folster
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Jensen
authors.forename: William T
authors.initials: WT
authors.lastname: Ruyechan
authors.forename: Naoki
authors.initials: N
authors.lastname: Inoue
authors.forename: D Scott
authors.initials: DS
authors.lastname: Schmid
mesh_terms: D001665:Binding Sites; D015967:Gene Expression Regulation, Viral; D014645:Herpesvirus 3, Human / Q000201:enzymology* / Q000502:physiology*; D006801:Humans; D017874:Immediate-Early Proteins / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D016366:Open Reading Frames; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000096:biosynthesis*; D015534:Trans-Activators / Q000378:metabolism; D024363:Transcription Initiation Site; D014759:Viral Envelope Proteins / Q000378:metabolism; D014764:Viral Proteins / Q000096:biosynthesis*
chemical_list: C074221:IE62 protein, Human herpesvirus 3; D017874:Immediate-Early Proteins; D015534:Trans-Activators; D014759:Viral Envelope Proteins; D014764:Viral Proteins; C074551:immediate early protein 63, Human herpesvirus 3; D017346:Protein Serine-Threonine Kinases