NF-κB inhibitor is a synthetic peptide corresponding to the nuclear localization sequence of NF-κB p105 subunit (also known as p50) appended to a hydrophobic sequence to facilitate import into living cells.¹It blocks the nuclear import of p105 in cells treated with activators of NF-κB signaling, including LPS and TNF-α.¹In this way, NF-κB inhibitor blocks gene expression that is regulated by NF-κB.^2,3This peptide is commonly used to evaluate the role of NF-κB signaling in cellular responses.^4,5

1.Lin, Y.Z., Tao, S., Veach, R.A., et al.Inhibition of nuclear translocation of transcription factor NF-κB by a synthetic peptide containing a cell membrane-permeable motif and nuclear localization sequenceJ. Biol. Chem.270(24)14255-14258(1995) 2.Torgerson, T.R., Colosia, A.D., Donahue, J.P., et al.Regulation of NF-κB, AP-1, NFAT, and STAT1 nuclear import in T lymphocytes by noninvasive delivery of peptide carrying the nuclear localization sequence of NF-κB p50Journal of Immunology161(11)6084-6092(1998) 3.Kasibhatla, S., Genestier, L., and Green, D.R.Regulation of fas-ligand expression during activation-induced cell death in T lymphocytes via nuclear factor κBThe Journal of Biological Chemisty274(2)987-992(1999) 4.Methot, L., Hermann, R., Tang, Y., et al.Interaction and antagonistic roles of NF-κB and Hes6 in the regulation of cortical neurogenesisMolecular and Cellular Biology33(14)2797-2808(2013) 5.WÄster, P., Rosdahl, I., and Ölinger, K.Cell fate regulated by nuclear factor-κB- and activator protein-1-dependent signalling in human melanocytes exposed to ultraviolet A and ultraviolet BBritish Journal of Dermatology171(6)1336-1346(2014)