Figure 5.

Inhibition of NF-κB activation and down stream events by stable expression of dominant-negative IκB-kinase β (dnIkkβ). (A Upper) dnIkkβ-Expressing transfectant cells by light microscopy (i), 4′,6-diamidino-2-phenylindole (DAPI)-stained nuclei (ii), and immunofluorescence with anti-FLAG antibody in the presence of the secondary antibody (iii). The positive signals show dnIkkβ-conjugated FLAG protein in the cytoplasm. (Lower) Processed vector-control plasmid-transfected CSMLO cells in which no FLAG protein could be detected (vi). (B Upper) Active NF-κB was determined by its [γ-³²P]DNA binding activity by EMSA, in three dnIkkβ-expressing stable transfectants (dnIkkβ1-1, dnIkkβ1-3, and dnIkk-β1-5) and (Lower) in parent CSMLO cells and vector control plasmid expressing transfectant (vect1-5). (C Upper) The level of ccD1 in the same three-dnIkkβ-expressing CSMLO and vector control transfected cells, as measured by Western blot analysis. (Lower) Actin analyzed similarly by immunodetection with anti-β-actin antibody that serves as a loading control.