Fig. 6.

Leucine acts in an additive manner with LPA or insulin to activate mTORC1 signaling. Cells were incubated in medium containing 0.5% serum without leucine for 2 h. Leucine and/or LPA (A) or leucine and/or insulin (B) were added, and, after 2 h, S6K1 phosphorylation was assessed as described in Fig. 3 legend. Values are means ± SE of 3 experiments; in each experiment, 3 samples per condition were independently analyzed. Representative blots are shown. *P < 0.0005 vs. cells incubated in medium containing 0.5% serum without leucine. †P < 0.005 vs. cells treated with leucine alone. ‡P < 0.05 vs. cells treated with LPA alone or insulin alone.