Fig. 6: The PDE4DIP-AKAP9 interaction is essential for the Golgi localization and stability of PKA RIIα.

A Western blot analysis of AKAP9 expression in control and PDE4DIP-KD NSCLC cells. B Western blot analysis of PDE4DIP and PKA RIIα (RIIα) expression in control and AKAP9-silenced NSCLC cells. Cells were transfected with control siNC or siRNA targeting AKAP9 (siA1, siA2) for 48 h. C Coimmunoprecipitation of endogenous AKAP9 with PDE4DIP or PKA RIIα in H1299 and A549 cells. Cell lysates were immunoprecipitated with an anti-AKAP9 antibody and subjected to Western blotting with anti-AKAP9, anti-PDE4DIP, and anti-PKA RIIα antibodies. TCL, total cell lysate. D Immunofluorescence analysis of PDE4DIP (green) and PKA RIIα (red) colocalization at the Golgi apparatus in control (siNC) and AKAP9-silenced (siAKAP9/siA1) NSCLC cells. Scale bars, 10 μm. Representative images (left) and colocalization values (Rcoloc) of PDE4DIP and PKA RIIα are shown (right). The data are presented as the means ± SD of three biological replicates, and the P values were determined by Student’s t test. ***P < 0.001 vs. control. E Western blot analysis of PKA RIIα ubiquitination in control (siNC) and AKAP9-silenced (siA1) NSCLC cells.