Fig. 4.

Effect of BIOGF1K on activation of IRF3 and its upstream signaling. (A) Levels of phospho-IRF3, IRF3, and lamin A/C in nuclear fractions were determined by nuclear fractionation and immunoblotting analysis. (B–D) Phospho-protein or total protein levels of IRF3, TBK1, and β-actin in whole cell lysates were determined by immunoblotting analysis. (E) Inhibition of TBK1-induced IRF3 activation by BIOGF1K was analyzed using a reporter gene assay in HEK293 cells transfected with IRF3-Luc (1 μg/mL) and TBK1 in the presence or absence of BIOGF1K. Luciferase activity was measured using a luminometer. **p < 0.01, compared with the control. IRF3, interferon regulatory factor 3; LPS, lipopolysaccharide; TBK1, TANK-binding kinase 1.