FN interacts with the TAK1-TAB1, 2, and 3 complexes.

<p>(A) HEK293 cells were transfected with TAK1, TAB1, TAB2, TAB3, IkBα, or NEMO with indicated tags along with pFN. At 48 h post-transfection, Co-IP and immunoblot analysis was performed with the indicated antibodies. The expression levels of transfected FN, TAK1, TAB1, TAB2, TAB3, IkBα, and NEMO were detected by western blot. (B) Huh7 cells were stimulated with SeV (MOI = 1) at the indicated times. Co-IP and immunoblot analysis was performed with the indicated antibodies. The expression levels of endogenous FN, TAK1, TAB1, TAB2, TAB3, and c-Jun were detected by western blot. (C) A schematic diagram of the functional domains of FN and the five truncated segments. The number shows the amino acid sequence of each segments. (D) HEK293 cells were transfected with empty vector or full length HA-FN or each of five HA-FN-truncated constructs, D1–5 along with Flag-TAK1, Flag-TAB1, Myc-TAB2, or Myc-TAB3. At 48 h post-transfection, Co-IP and immunoblot analysis was performed with the indicated antibodies. (E) Constructs expressing GFP, wild-type FN or each of five truncated FN D1–5 were transfected along with IFN-α2 promoter and cells were stimulated with SeV (MOI = 1) or PBS. At 24 h post-transfection, cells were harvested to measure luciferase activity. (F) NC-KD and FN-KD cells were stimulated with SeV (MOI = 1) or PBS for 48 h and TAK1 and p-TAK1 expression was determined by western blot. All experiments were repeated at least three times with similar results. Data represent means ± SD, n = 3 (*p<0.05).