Figure 3. The N proteins of MHV and SARS-CoV inhibit PACT-mediated activation of RIG-I/MDA5.

HEK-293T cells grown in 24-well plates were transfected with expression plasmids for RIG-I (A, C) or MDA5 (B, D), PACT, and N proteins from MHV (A, B) or SARS-CoV (C, D) as well as IFN-β–Luc and pRL–TK reporter plasmids. The dual-luciferase assays were carried out at 28 h post-transfection. The results represent the means and standard deviations of three independent experiments. *P < 0.05; ***P < 0.001.