Fig. 1.

Identification of the compound inhibiting leucine-induced mTORC1 activity. a Schematic summary of the chemical screening for the mTORC1 inhibitor via LRS. b Level of leucine-induced S6K phosphorylation was monitored with 167 synthetic compounds. From the screening, 12 compounds that inhibited leucine-induced S6K phosphorylation more than 90% at 100 μM were selected. c Level of leucine-induced S6K phosphorylation was monitored with 174 additional synthetic compounds. From the screening, 21 compounds that inhibited leucine-induced S6K phosphorylation more than 70% at 20 μM were selected. Finally, two active compounds were selected based on their effects on mTORC1 activity, cell growth and death, as well as chemical solubility. d Chemical structure of BC-LI-0186. e The binding of BC-LI-0186 to LRS WT was determined by SPR as described in Methods. The inset represents the KD value between LRS WT and BC-LI-0186. f Effect of BC-LI-0186 on S6K phosphorylation was determined by Western blotting. AKT phosphorylation (S473) was monitored as a negative control. g Normalized band intensity of S6K phosphorylation in f was quantified and displayed as line graph. The inset represents the IC₅₀ value of BC-LI-0186