Dominant negative CREB inhibited the induction of Egr-1 upon HSV-1 infection. VERO cells were transfected with phMGFP alone and in combination with CREB dominant negative vectors pCREB133 or pKCREB. a.) The transfection efficiency of the three groups is similar as shown by the number of GFP-positive cells. b.) Cells infected with a control vector show induction of Egr-1 protein (red) whereas cells infected with the dominant negative mutants, CREB133(c) or KCREB (d) do not show the induction of the Egr-1 protein.