A specific 15-bp TATA box promoter element is required for expression of a herpes simplex virus type 1 late gene

Abstract

The herpes simplex virus type 1 (HSV-1) glycoprotein C (gC) gene is a true late or gamma 2 gene in that its expression shows a strict requirement for viral DNA replication. Elements required for regulated expression of this gene were previously shown to consist of the gC TATA box, transcription start site and a large portion of the leader sequence of the gC gene. In this paper we show that transcription of the gC gene requires a 15-bp sequence, GGGTATAAATTCCGG, which contains the gC TATA box. This sequence contains specific promoter elements because replacement of this sequence with either the TATA box of the HSV-1 early thymidine kinase (tk) gene or two random TATA-like elements results in a transcriptionally inactive gC gene. In addition, we show that temporal expression of HSV beta and gamma genes at early and late times during infection are controlled by separate and distinct regulatory elements; regulatory signals distal to the TATA box are needed for early expression, whereas a gC-like TATA box is needed for late expression. These signals were identified by construction of a chimeric HSV gene that contained the distal control signals of the beta tk gene fused upstream of the TATA sequence of the gamma 2 gC gene. When RNA was isolated at various times postinfection from cells infected with a virus whose genome contained this chimeric tk-gC gene, synthesis of gC mRNA showed both early and late kinetics.