1. Supplemental materials* *
Phospho-PKA * * * * * no
treatment
10 M
H89
3 M KT
5720
50 M
Rp-
cAMPS
10 M FK
Figure S1.　Effects of PKA inhibitors on phosphorylation state of multiple proteins in hRPE1 cells. In order to evaluate the impact of PKA inhibitors, we used a phospho-PKA substrate antibody to detect the global pattern of phosphorylation state in hRPE1 cells. The cells were grown to ~90% confluency in serum-containing medium, followed by serum starvation for 24 h. Subsequently, the cells were cultured with the indicated drugs for 3 h (H89, KT5720, and Rp-cAMPS) or 30 min (forskolin: FK). Proteins in the cell lysates were separated by SDS-PAGE and analyzed by immunoblotting with an anti-phospho-(Ser/Thr) PKA substrate-selective [K/R][K/R]X[S/T] antibody. The membranes shown are representative results from three independent experiments. Several bands show a less phosphorylated state () in response to individual PKA inhibitor compared to control, which corresponds to increase PKA activity by treatment of forskolin (FK, arrowhead). Each PKA inhibitor did not completely diminish all phosphor-PKA substrates, indicating that phosphorylation state of multiple protein may be controlled by some additional mechanism. Further, individual PKA inhibitor caused a different spectrum for diminishing phosphorylation state. It might be speculated that each PKA inhibitor is responsible for a different functionality of PKA holoenzyme in addition to non-PKA-based effects [37].