The DNA-Binding Properties of the Major Regulatory Protein α4 of Herpes Simplex Viruses

Abstract

The transition from the expression of alpha, the first set of five herpes simplex virus genes expressed after infection, to beta and gamma genes, expressed later in infection, requires the participation of infected cell protein 4 (alpha 4), the major viral regulatory protein. The alpha 4 protein is present in complexes formed by proteins extracted from infected cells and viral DNA fragments derived from promoter domains. This report shows that the alpha 4 protein forms specific complexes with DNA fragments derived from 5' transcribed noncoding domains of late (gamma 2) genes whose expression requires viral DNA synthesis as well as functional alpha 4 protein. Some of the DNA fragments to which alpha 4 binds do not contain homologs of the previously reported DNA binding site consensus sequence, suggesting that alpha 4 may recognize and interact with more than one type of DNA binding site. The alpha 4 proteins can bind to DNA directly. A posttranslationally modified form of the alpha 4 protein designated alpha 4c differs from the alpha 4a and alpha 4b forms with respect to its affinity for DNA fragments differing in the nucleotide sequences of the binding sites.

A Prominent Serine-rich Region in Vmw175, the Major Transcriptional Regulator Protein of Herpes Simplex Virus Type 1, is not Essential for Virus Growth in Tissue Culture

“…Vmw175 is a sequence-specific D N A -b i n d i n g protein which recognizes a number of different sequences of which m a n y contain the consensus A T C G T C (Faber & Wilcox, 1986b;Beard et al, 1986;Michael et al, 1988). The sequence at the cap site of the IE-3 promoter is strongly bound by Vmw175 (Mfiller, 1987).…”

The Product of Varicella-zoster Virus Gene 62 Autoregulates Its Own Promoter

“…This binding site includes a consensus sequence (ATCGTC) common to many, but not all, sequences with which Vmw175 can associate (Muller, 1987;Faber & Wilcox, 1986;Michael et al, 1988). We attempted to determine whether analogous sequences in the region of the gene 62 cap site were required for repression by the VZV 140K protein by constructing deletion variants of pl40CAT in which promoter sequences upstream of the TATA box remained intact but leader or cap site-leader sequences were deleted.…”

A mutant of herpes simplex virus type 1 immediate early polypeptide Vmw175 binds to the cap site of its own promoter in vitro but fails to autoregulate in vivo

“…How can these apparently contradictory observations be reconciled? The crux of the question is whether DNA binding to the IE-3 cap site probe in vitro is a reliable measure of DNA binding in vivo, either to ATCGTC sequences or to other apparently unrelated binding sequences, such as those defined by Michael et al (1988). This question can only be answered by further detailed studies.…”

“…An important step forward in the understanding of the mechanism of action of Vmw175 has been the demonstration that it can bind specifically to certain DNA sequences containing the consensus sequence ATCGTC Beard et al, 1986;Muller, 1987;Tedder et al, 1989;Kattar-Cooley & Wilcox, 1989) and also (perhaps less strongly) to other sequences that have been less well characterized (Michael et al, 1988). Although ATCGTC sequences occur throughout the HSV-1 genome they are not commonly found in the regions of early and late promoters.…”