Fig. 8

Schematic representation of the PP2A switch. In resting cells (a) the PP2Ac-IGBP1 dimer interacts with the p85 subunit of the PI3K, and thereby dephosphorylates it and keeps it active, resulting in the phosphorylation of AKT on both Thr308 and Ser473. The active AKT then phosphorylates MLK3 and thereby blocks the activation of JNK [48]. b Upon PKC activation by GqPCR or TPA, the PP2Ac-IGBP1 dimer is detached from PI3K, thus allowing inactivation through autophosphorylation on Ser608. c The released dimer forms a trimer with PP2Aa and interacts with AKT, dephosphorylating both the activatory residues of the kinase, thus rendering the AKT inactive, and allow activation of the JNK cascade. A more detailed description is provided in the discussion section