FIG 4.

Protease activity is required for SVV 3C^pro-mediated cleavage of MAVS, TRIF, and TANK. Plasmids expressing Flag-MAVS (A), Flag-TRIF (B), and Flag-TANK (C) were cotransfected with plasmids expressing SVV 3C^pro or empty vector into 293T cells. The inhibitors MG132 (10 μM), NH₄CL (10 mM), and z-VAD-FMK (50 μM) were added as indicated at 12 h posttransfection and for another 12 h. The protein patterns were assessed by immunoblotting. (D) Amino acid sequence alignment of 3C^pro derived from SVV (APA28975), FMDV (NP_74046), EMCV (NP_740410), HAV (AKI05745), and EV71 (AFP66570). (E to G) Plasmids expressing Flag-MAVS (E), Flag-TRIF (F), and Flag-TANK (G) were cotransfected with plasmids expressing wild-type SVV 3C^pro and indicated 3C^pro mutations for 24 h. The protein patterns were assessed by immunoblotting.