Effects of phospholipids on the membrane interaction and phosphorylation of Akt. (a) Representative SPR sensorgrams of the binding of full-length Akt to liposomes with various phospholipid compositions (x:y:50:[50 − x − y] PIP₃/PS/PE/PC). 200 nM Akt was injected onto the L1 chip coated with liposomes. The response of the control liposomes containing PE/PC (50:50), which was insignificant, was subtracted from each sensorgram to correct for background drift. The sensorgram was obtained using PBS as the running buffer. (b) The effect of salt concentration on the binding of Akt to liposomes containing PIP₃ and/or PS. (c–e) Representative SPR sensorgrams showing insignificant effects of PIP₂, PIP (c), PI (d), and PE/PC on Akt-membrane interaction. (f) Western blot data showing PS- or PIP₃-dependent Akt phosphorylation of T308 and S473 by PDK1 and mTORC2, respectively. The band intensity of pT308 or pS473 were normalized to the Akt level (data are mean ± SD [error bars], n ≥ 3). Statistical significance was tested against liposomes containing 0% PS and 0% PIP₃. *, P < 0.05; **, P < 0.01; ***, P < 0.001.