Inhibition of Nuclear Translocation of Transcription Factor NF-κB by a Synthetic Peptide Containing a Cell Membrane-permeable Motif and Nuclear Localization Sequence

Abstract

To control agonist-induced nuclear translocation of transcription factor κB (NF-κB) in intact cells, cell-permeable synthetic peptides were devised. Their import into intact cells was dependent on a hydrophobic region selected from the signal peptide sequences and was verified by their inaccessibility to extracellular proteases and by confocal laser scanning microscopy. When a cell-permeable peptide carried a functional cargo representing the nuclear localization sequence of NF-κB p50, it inhibited in a concentration-dependent manner nuclear translocation of NF-κB in cultured endothelial and monocytic cells stimulated with lipopolysaccharide or tumor necrosis factor-α. Synthetic peptide analogues with deleted hydrophobic cell membrane-permeable motif or with a mutated nuclear localization sequence were inactive. Cell membrane-permeable peptides were not cytotoxic within the concentration range used in these experiments. These results suggest that cell-permeable synthetic peptides carrying a functional cargo can be applied to control signal transduction-dependent subcellular traffic of transcription factors mediating the cellular responses to different agonists. Moreover, this approach can be used to study other intracellular processes involving proteins with functionally distinct domains. To control agonist-induced nuclear translocation of transcription factor κB (NF-κB) in intact cells, cell-permeable synthetic peptides were devised. Their import into intact cells was dependent on a hydrophobic region selected from the signal peptide sequences and was verified by their inaccessibility to extracellular proteases and by confocal laser scanning microscopy. When a cell-permeable peptide carried a functional cargo representing the nuclear localization sequence of NF-κB p50, it inhibited in a concentration-dependent manner nuclear translocation of NF-κB in cultured endothelial and monocytic cells stimulated with lipopolysaccharide or tumor necrosis factor-α. Synthetic peptide analogues with deleted hydrophobic cell membrane-permeable motif or with a mutated nuclear localization sequence were inactive. Cell membrane-permeable peptides were not cytotoxic within the concentration range used in these experiments. These results suggest that cell-permeable synthetic peptides carrying a functional cargo can be applied to control signal transduction-dependent subcellular traffic of transcription factors mediating the cellular responses to different agonists. Moreover, this approach can be used to study other intracellular processes involving proteins with functionally distinct domains.