Figure 7.

γ-ENaC constructs generated by site-directed mutagenesis to identify TMPRSS2 cleavage sites distal and proximal to the γ-inhibitory tract. Comparison of the primary sequence of wildtype γ-ENaC with those of γ-ENaC mutants generated and experimentally tested in the current study. The γ-inhibitory tract is labeled as described in Figure 6A. The putative TMPRSS2 cleavage sites (arginine and lysine residues) are marked in bold black. Putative cleavage sites eliminated by alanine substitutions are marked in bold red. Results from corresponding functional experiments are shown in Figure 8, Figure 9, Figure 10. ENaC, epithelial sodium channel; TMPRSS2, transmembrane serine protease 2.