Figure 8. Nope and Ppk25 interact specifically in cultured cells.
A, HEK293 cells were transfected with plasmids encoding Nope-HA, Arm-HA and, where indicated, Ppk25-Flag and immunoprecipitated using anti-Flag antibody. Extracts, supernatants (S), and precipitates (P) were analyzed on western blots with anti-HA antibody.
B, Same as in A, except that Nope was tagged with Flag and Ppk25 with HA.
C, Extracts of cells expressing Nope-Flag, Ppk25-HA and human β-ENaC-HA were immunoprecipitated with anti-Flag, and both supernatant and pellet were immunoblotted with anti-HA. The increased ratio of Ppk25-HA to β-ENaC-HA in the pellet compared to the supernatant indicates that Nope-Flag interacts preferentially with Ppk25-HA.
D, Same as in C, except that Ppk25 was tagged with Flag and Nope with HA. Here also, the ratio of Nope-HA to β-ENaC-HA is higher in the pellet than in the supernatant.