Distinct responses of the herpes simplex virus and varicella zoster virus immediate early promoters to the cellular transcription factors Brn-3a and Brn-3b

The related viruses herpes simplex virus (HSV) and varicella tester virus ( VZV) show distinct but related patterns of latent infection and reactivatio n in human sensory ganglia. The cellular POU family transcription factors B rn-3a and Brn-3b are expressed in sensory ganglia and bind to the TAATGARAT (R stands for purine) regulatory motifs in the immediate-early gene promot ers of these viruses. We show that Brn-3a activates the full length HSV IE1 promoter whereas Brn-3b represses its activity. In contrast both Brn-3a an d Brn-3b activate the full length VZV IE promoter. The response of the full length VZV promoter to Brn-3b is not observed with a minimal VZV immediate -early promoter lacking any TAATGARAT elements and cannot be restored by ad dition of either the upstream TAATGARAT-containing region of the HSV IE pro moter or a VZV TAATGARAT-like element to this minimal promoter. The unique effect of Brn-3b on the full length VZV immediate early gene promoter may p lay a key role in the distinct pattern of latent infection and reactivation observed with this virus in vivo. (C) 1999 Elsevier Science Ltd. All right s reserved.