Fig. 7.

Activation of Akt by H₂O₂ regulates the activity of the pro-apoptotic Protein Bax. H₂O₂, that produces a mild oxidative environment, activates the PI3K/Akt survival pathway (blue arrows). When Akt is activated by H₂O₂, Bax is located in the cytoplasm in its phosphorylated (inactive) form and the cell survives (blue arrows). Inhibition of the PI3K pathway results in dephosphorylation of Bax and its translocation to the mitochondria (red arrows). Insertion of Bax into the mitochondria leads to cytochrome c release (possibly through Bax pore formation), caspase-3 activation, and apoptosis (red arrows). Abbreviations: MOM, mitochondrial outer membrane; MIM: mitochondrial inner membrane; MIS, mitochondrial intermembrane space.