Mutational dissection of the HSV-1 immediate-early protein Vmw175 involved in transcriptional transactivation and repression

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

“…lb). The effect of the mutation is essentially to eliminate repression of the IE-3 promoter by Vmw175 (Paterson & Everett, 1988). The same effect was observed in cotransfections of p 140CAT and pI13 (Fig.…”

“…Titration of p175 led to a greater reduction in activity, fourfold in the presence of 8 ~tg p175. Although this was less efficient than in previous assays (Paterson & Everett, 1988), it does confirm repression of the IE3 promoter by Vmw175. In marked contrast, titration of pl40SV resulted in an increase in IE3 promoter activity of two-to fourfold.…”

“…1 b) has been shown to be of crucial importance for repression of the IE-3 promoter (Paterson & Everett, 1988;DeLuca & Schaffer, 1988;Shepard et al, 1989). To determine whether region 2 of Vmw175 was also involved in the repression of the gene 62 promoter, plasmid pI13 (Paterson & Everett, 1988) was cotransfected in increasing amounts with p140CAT. Plasmid pI13 contains an in-frame insertion of four amino acids in the proline codon at position 324 of Vmw175 (region 2; see Fig.…”

“…It was derived from p 140 (McKee et al, 1990) by the method of Paterson & Everett (1988) and contains a mutation resulting in the insertion of four amino acids into the glycine codon at position 471 of the 140K protein, which lies within region 2 (amino acid residues 467 to 641; see Fig. 1 b).…”

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

“…The functional importance of region 4 has been demonstrated by the isolation of ts and deletion mutants with defects that map in its vicinity (DeLuca et al, 1984;DeLuca & Schaffer, 1988). In addition, the construction of insertion mutations in a plasmid-encoded copy of IE gene 3 has shown that mutations in both regions 2 and 4 can affect the ability of Vmw175 to regulate gene expression in transfection assays (Paterson & Everett, 1988a). In contrast to tsK, which fails both to activate early and late gene transcription and to autoregulate IE expression, the ts mutants described by DeLuca et al (1984) are at least partially permissive for early gene transcription, although they are unable to autoregulate IE gene expression at the NPT.…”