The N-terminal domain of NS2 is essential for the interaction with IRF7. (A) GFP-tagged NS2, NS2-N (amino acids (aa) 1 to 53), NS2-C (aa 54 to 121) were constructed and cloned into pEGFP-C1 by using standard molecular biology techniques. (B,C) The N-terminal domain of NS2 influences the interaction between NS2 and IRF7. HEK293 cells were transfected with HA-IRF7 along with GFP-NS2, GFP-NS2-N, and GFP-NS2-C expression plasmid, followed by IP with anti-GFP or anti-HA. (D) The effects of overexpression of the N-terminal domain of NS2 on RIG-IN and SeV-induced IFN-β secretion. HEK293 cells were transfected with GFP-NS2-N or GFP, and subsequently treated with RIG-IN or infected with SeV. The concentration of IFN-β in the supernatants was assessed by using human IFN-β DuoSet ELISA kit. The data shown represent three independent experiments (p < 0.05 (*), p < 0.01 (**)).