A key signaling pathway involved in chemotactic
PF00299804 is the one involving phosphatidylinositol-3-phosphate-dependent phosphorylation and activation of the protein kinase Akt/PKB [26]. NO and Akt signaling are tightly interlinked, as Akt activates eNOS by phosphorylating it on Ser 1177 [9] and [10] and NO, in turn, increases Akt phosphorylation [27]. To gain insight into the mechanism of eNOS-induced attenuation of migration, we therefore compared activation of the PI3K/Akt pathway in response to serum in induced or non-induced eNOS-HeLa TetOff cells. After incubation overnight in serum-free medium,
cells were either lysed or exposed to 10% FBS for a further 10 min before lysis and immunoblotting analysis for Akt, phospho-Akt (pAkt), and eNOS. As shown in Fig. 3, exposure of the serum-starved non-induced cells to FBS caused a nearly 3-fold increase in Akt phosphorylation. In contrast, and in agreement with their reduced migratory capacity, Akt phosphorylation in response to serum was lower in the eNOS-expressing cells.
