Fig. 5.

Mutation of the nuclear factor (NF)-κB binding site in the Na⁺ channel promoter eliminates the effects of ANG II and H₂O₂. A: relationship of the promoter-reporter fragment used to the mouse scn5a promoter (GenBank AY769981). Top line shows the structural organization of this region of the scn5a promoter (3.0 kb). The wild-type and mutant NF-κB binding sites are labeled NF-κB WT and NF-κBm, respectively. Note the presence of untranslated exon 1C and part of exon 2, which contains the translation start site. Nucleotide numbering starts with µ1 corresponding to the protein translation start site. The construct APS3 containing the NF-κB site (♦) showed reduced activity after 48 h of exposure to 100 nmol/l ANG II or 20 µmol/l H₂O₂. Mutating the NF-κB binding site prevented the ANG II or H₂O₂ effects (B). Data are presented as means ± SE and are based on 4 separate experiments in both groups.