Schematic of p85 regulation of either catalytic subunit of PI3K or PTEN on Akt phosphorylation and cardiomyocyte survival after exposure to I/R.

<p>p85 binding to p110 increase Akt phosphorylation and results in decreased cell death after exposure to I/R, while p85 binding to PTEN decreases Akt phosphorylation and results in increased cell death. By modulating p85 binding to its cognitive binding partners, cell survival is modulated by TAT fusion proteins with p85 mutants lacking either p110 or PTEN binding site. PTEN inhibition by VO-OHpic has a similar cardioprotective effect as for TAT-ΔPTEN p85.