Fig 3.

Effects of b-Zip, SP1/KLF, and MEF2 family transcription factors on the BZLF1 promoter. (A) b-Zip family transcription factor activation of the BZLF1 promoter. HEK293T cells were transfected with 10 ng of the reporter plasmid pZp-luc or its derivatives, 1 ng of pCMV-RL, and 100 ng of expression plasmids for the indicated genes. Luciferase assays were carried out as described in Materials and Methods. Luciferase activity is shown as fold activation over that with the control vector (Cont). Each bar represents the mean and SD of three independent transfections. Derivatives of pZp-luc (wt), pZpmZII-luc (mZII), or pZpmZIII-luc (mZIII) contained point mutations in the binding motifs for cellular b-Zip transcription factors or for the viral b-Zip transcription factor BZLF1. The pZpmZII+ZIII-luc vector (mZII,III) contained both mutations. (B) KLF4, SP1, and MEF2B activation of the BZLF1 promoter. HEK293T cells were transfected with 10 ng of the reporter plasmid pZp-luc (wt), 100 ng of pGL4.70(hRluc), and 100 ng of expression plasmid for KLF4, SP1, or MEF2B. pZp-luc reporters with point mutations in SP1-binding sites (mSP1) and MEF2 (mMEF2) binding sites were also used. Luciferase assays were carried out as described in Materials and Methods. Luciferase activity is shown as fold activation over that with control vector and pZp-luc (wt). Each bar represents the mean and SD of three independent transfections. Diagrams below the graphs show constructs of the reporter plasmid pZp-luc and its derivatives.