Tax transactivation of the hiNOS promoter is independent of NF-κB element. (A) Reporter luciferase plasmids with κB (κB-LUC), CRE element (WT-LUC), or CArG box (pCArG-LUC) were used as control promoters for Tax mutants. Luciferase activity was determined after incubation for 24 hours and normalized for protein content. The activity of Tax mutants, M22 and Tax703, relative to that of the wild-type Tax, was calculated by comparing luciferase activity in the presence of M22 or Tax703 with that in the presence of wild-type Tax. (B) Jurkat cells were transfected with pGLNOSa together with expression plasmids encoding Tax, its indicated mutants, or the parental expression vector with no insert (Control). Data represent the mean ± SEM of three experiments.