FIGURE 3.

SARS-CoV PLpro inhibits activation of IRF-3-dependent promoters by acting at a level downstream of the IRF-3 kinases and proximal to IRF-3.A, activation of p55C1B, an IRF-3-dependent synthetic promoter, by medium poly(I-C) (hatched bars) or SeV infection (solid bars) in HEK293-TLR3 cells with expression of SARS-CoV PLpro-TM (TM) or a control vector (Vect). B and C, activation of IFN-β (B) and p55C1B (C) promoters by ectopic expression of various signaling molecules within TLR3 and RIG-I/MDA5 pathways at or above the level of IRF-3 in HEK293 cells with (solid bars) or without (empty bars) expression of SARS-CoV PLpro-TM. N-RIG and N-MDA5 denote the caspase recruitment domain of RIG-I and MDA5, respectively.