The downstream activation sequence of the strict late Herpes Simplex Virus Type 1 U(L)38 promoter interacts with hTAF(II)70, a component of TFIID.

A class of strict late Herpes Simplex Virus Type 1 (HSV-1) promoters contains a conserved sequence element (termed the downstream activation sequence, DAS) located downstream of the transcription start site. These DAS-containing promoters also require both a TATA box and an initiator element for maximal levels of transcription. In this communication, we demonstrate that the downstream promoter element (DPE) found on a class of Drosophila TATA-less promoters and known to bind the homologue of human TAF(II)70 (a component of TFIID), can functionally substitute for DAS in the context of the strict late UL38 promoter in spite of no obvious sequence similarity. Although Drosophila DPE-containing promoters do not require a TATA box, the element does not remove the requirement for a TATA box when functioning in the HSV promoter. Next, we demonstrate that hTAF(II)70, interacts in a sequence specific manner with DAS as predicted from the fact that DPE binds Drosophila TBP. These results suggest that multiple TFIID/promoter interactions are important in the activation of HSV-1 late gene expression upon viral DNA replication. We propose that such interactions could be favored upon viral DNA replication since TFIID concentrates to viral transcription foci that form during the later stages of infection.