FIGURE 1.

κB₅→ΙκBα-FLuc bioluminescent reporter system. A, κB₅→ΙκBα-FLuc bioluminescent reporter utilizes the ΙκBα gene fused by a flexible linker to the firefly luciferase (FLuc) gene under the control of a synthetic NF-κB promoter (κB₅), thus recapitulating the endogenous negative feedback loop (1→7). B, HepG2 cells were transiently transfected with κB₅→ΙκBα-FLuc and stimulated continuously with TNFα (170 pm; 3 ng/ml). Lysates were collected at the indicated time points, resolved on a 7.5% SDS-polyacrylamide gel, and blotted for ΙκBα and GAPDH (loading control).