Inhibits NF-kappa-B by complexing with and trapping it in the cytoplasm. However, the unphosphorylated form resynthesized after cell stimulation is able to bind NF-kappa-B allowing its transport to the nucleus and protecting it to further IKBA-dependent inactivation. Association with inhibitor kappa B-interacting NKIRAS1 and NKIRAS2 prevent its phosphorylation rendering it more resistant to degradation, explaining its slower degradation. Shirane, M. et al. (1999) J Biol Chem 274, 28169-28174. DiDonato J, et al. (1996) Mol Cell Biol 16(4): 1295-304
