FIG 6.

mTORC1 contributes to the phosphorylation of Ulk1 at S757 under hyperosmotic stress. Wild-type MEFs and T24 cells cultured for 1 h in DMEM with DMSO (control) or 1 μM torin 1 (+) were further cultured for 1 h in DMEM with 0.8 M sucrose containing the same reagents. The cells were also cultured in amino acid-free DMEM (−AA) for 1 h. The cell lysates were analyzed for Western blotting using antibodies against phosphorylated Ulk1 (S575), Ulk1, phosphorylated Akt (S473), Akt, phosphorylated S6K1 (T389), S6K1, phosphorylated 4E-BP1 (T37/46), 4E-BP1, and GAPDH as a loading control. Molecular weights are indicated on the right.