FIG. 5.

K1 is an inhibitor of NF-κB activation. Luciferase assays of NF-κB promoter activation in HEK 293T cells. (A to C) NF-κB-Luc (0.5 μg) was cotransfected with different activators of NF-κB (K13, ORF75, and p65) and K1 or K10.5 in the indicated amounts. (D) In an additional control experiment, a reporter plasmid (EF-1α-Luc; 0.5 μg) expressing luciferase under the control of the constitutively active promoter of EF-1α was used in the absence or presence of K1 and K10.5 under identical conditions. (A to D) In all studies, the total amount of plasmid in each transfection mix was adjusted to 3.0 μg by the addition of pcDNA. NF-κB promoter activation was analyzed by measurement of luciferase 48 h after transfection. Values obtained were normalized according to protein content, and the results are expressed in terms of the fc in comparison to the results for the negative control (pcDNA only, left bar in each panel; set to 1). The luciferase assays were performed at least three times; mean values and standard deviations of relative light units (RLU) are shown. −, absent; *, P ≤ 0.05; n.s., not significant.