Structure of plasmid constructs. (A) The plasmid constructs containing the full-length clones of IRF9, Stat1 and Stat2 fused with GFP either at the N-terminal or C-terminal ends. (B) Full length IRF9 clone fused with the TAD of either Stat1 or Stat2. IRF9-S1C contains the full length IRF9 molecule fused in frame with the 38 C-terminal amino acids of Stat1. IRF9-S2C also contains the full length IRF9 molecule fused in frame with the 104 C-terminal amino acids of Stat2. (C) The ISRE reporter plasmid containing four copies of ISRE sequences positioned upstream of the HSV thymidine kinase (TK) promoter TATA box that drives the expression of FL. The bottom construct, used as a transfection control contains RL downstream of a HSV TK promoter.