(A) N549 forms two hydrogen bonds with the backbone of T504 within the helicase 2i domain of the RIG-I structure (PDB ID: 4A36).
(B) HEK293/Flag-RIG-I-WT or HEK293/Flag-RIG-I-QQ cells were transfected with an empty or UL37-containing plasmid. Whole cell lysates (WCLs) were analyzed by two-dimensional gel electrophoresis.
(C) HEK293/Flag-RIG-I-QQ cells were mock-infected or infected with HSV-1 (MOI=5) or Sendai virus (SeV, 100 HAU/ml) for 4 h. Purified RIG-I was resolved by gel filtration and analyzed by immunoblotting.
(D–F) Control HEK293 (Vec) or HEK293 cells stably expressing RIG-I-WT, RIG-I-DD or RIG-I-QQ were were infected with HSV-1 (MOI=5) for 4h and WCLs were analyzed by immunoblotting with the indicated antibodies (D). Total RNA was analyzed by real-time PCR (E). Supernatant was collected at 16 hpi and cytokines (IFN-β and RANTES) were quantified by ELISA (F). M, mock-infected; numbers on the top indicate hours post-infection in (D).
(G) Stable HEK293 cell lines as above were infected with HSV-1 at MOI=0.5 and viral titer was determined by plaque assay.
For E, F and G, data are presented as mean ± SD.