Fig. 7. Effect of NIK variants on NF-B activation in reporter gene assays. 293 cells were transfected with a NF-B-dependent luciferase reporter (containing 5 NF-B binding sites) and a constitutively expressed ß-galactosidase construct for normalization together with NIK variants exhibiting distinct intracellular localizations. The fold induction over the vector control is given for nuclear/non-nucleolar NIK (NES mutant, 143-146A), nuclear/nucleolar NIK (NES mutant), for cytoplasmic NIK that shuttles between cytosol and nucleus (cyt./shuttling; YFP-NIK wild type) and for cytoplasmic NIK that has both NES and NLS mutated (NES mutant, 143-149 A; cyt./non-shuttling).