Substitution of a TATA box from a herpes simplex virus late gene in the viral thymidine kinase promoter alters ICP4 inducibility but not temporal expression

Abstract

The role of cis-acting promoter elements associated with herpes simplex virus type 1 (HSV-1) early and late genes was evaluated during productive infection with regard to activation of gene expression by the HSV-1 transactivator ICP4 and control of temporal regulation. A set of recombinant viruses was constructed such that expression of an HSV-1 early gene, thymidine kinase (tk), was placed under the control of either the tk TATA box or the TATA box from the late gene, glycoprotein C (gC), in the presence or absence of the upstream Spl and CCAAT sites normally found in the tk promoter. The presence of Spl sites in the promoter or replacement of the tk TATA box with the gC TATA box resulted in a decreased activation of tk mRNA expression by ICP4. Substitution of the A+T-rich region from the gC TATA box in the context of the remainder of the surrounding tk sequences resulted in a promoter that bound recombinant TATA-binding protein (TBP) better at lower concentrations than the wild-type tk promoter did. These results indicate that tk promoters that are better able to utilize TBP are less responsive to ICP4 activation and suggest that activation by ICP4 involves the general transcription factors that interact with TBP or TBP itself. Additionally, all of the viruses expressed tk at early times postinfection, indicating that cis-acting promoter elements that control the level of expression of HSV-1 early and late genes do not determine temporal regulation.

Quantification of transcripts from the ICP4 and thymidine kinase genes in mouse ganglia latently infected with herpes simplex virus

“…We chose to assay for tk because tk transcription is dependent upon ICP4 activation. ICP4 induces a 30-fold increase in tk RNA expression in the context of productive infection (29,30). There was a strong positive correlation (r ϭ 0.79) between the amounts of ICP4specific and tk-specific RNAs.…”

Transcriptional activation of the herpes simplex virus type 1 UL38 promoter conferred by the cis-acting downstream activation sequence is mediated by a cellular transcription factor

“…A characteristic which distinguishes the ry promoters from promoters of the oa, i, and 13y classes is the lack of functional upstream cis-acting sites, and analyses of the UL38, US11, and gC (UL44) promoters indicate that a TATA box at approximately position -30 defines their 5' extents (9, 12, 17, 23). While a TATA box is critical for efficient late gene expression, other cis-acting elements must define the differential kinetic behavior of early and late promoters, since specific TATA homologies are interchangeable between promoters of different kinetic classes (21,40).…”

A Functionally Distinct TATA Box Required for Late Progression through the Epstein-Barr Virus Life Cycle

“…While both viruses have targeted regulatory elements near late core promoters, the specific targets are unique. HSV late gene expression requires specific sequences within the vicinity of the transcriptional start site (9,11,15,16,18,23), but in contrast to EBV, the TATA boxes of early and late genes are interchangeable in HSV (17,42). Identification of the cis regulators of late gene expression in both HSV and EBV are important initial steps in ultimately understanding the complex link to lytic DNA replication, but a complete understanding requires iden-tification of trans factors, basal or promoter specific, interacting with these elements.…”