FIG. 7.
Cloning of gene 20, 21, 28, and 29 promoter reporter plasmids and their activation by IE62. (A) The 125-kbp VZV genome is composed of unique long (UL) and unique short (US) DNA segments, each bound by inverted repeat DNA sequences. The opposing ORFs 20 and 21, along with ORFs 28 and 29, are located within the UL segment (open boxes). The ORF 20/21 and ORF 28/29 intergenic regions were inserted into a promoterless luciferase reporter vector such that each region governed transcription of the luciferase reporter gene. (B) The resulting plasmids (p20-luc, p21-luc, p28-luc, and p29-luc) were used in transient transfection assays to determine intrinsic promoter activity and their response to induction by IE62. Data from at least duplicate experiments are presented as relative activity levels (luciferase activity normalized to β-Gal activity) to indicate the magnitude of promoter activity. Compared to the promoterless plasmid (p-luc), gene 20, 21, 28, and 29 promoters have no intrinsic activity but are induced by IE62. SD, standard deviation.