The endogenous poly(A) site is not required for transactivation of the gC gene by ICP27. (A) Induction of gC protein expression. Vero cells were transfected with pUC19 only (lane 2) or with pgCXTO or pgCpA (lanes 3 to 8, top and bottom panels, respectively). Transfections also included pSG1, which encodes ICP4 and ICP0 (lane 4); pBH27, which encodes ICP27 (lane 5); pSG1 plus pBH27 (lane 6); pUHD15-1, which encodes tet-TA (lane 7); or pUHD15-1 plus pBH27 (lane 8). Expression of gC was assessed by immunoblotting as described for Fig. 2. Lane 1 contains protein extract from HSV-1-infected cells. (B) Induction of gC mRNA expression. Vero cells were transfected with pUC19 only (lane 2) or with pgCPA (lanes 3 to 6). Transactivator plasmids were added as indicated, as in panel A. RNA was prepared at 2 days posttransfection, and equal amounts were subjected to Northern analysis using a gC gene-specific probe. Lane 1 contains RNA from HSV-1-infected Vero cells. A shorter autoradiographic exposure of this lane is shown.