a, b and d, Control (sgGFP) or SZT2-deficient (sgSZT2) cells were deprived of amino acids (a, b) or serum (b) for 1 h and stimulated with amino acids (a, b) or serum (b) for 10 min when indicated. Total cell lysates were analyzed by immunoblotting. c, Cells were treated as in (a). The localization of mTOR and Lamp2 was determined by immunostaining. See Extended Data Fig. 1f for statistical analyses. Data (a, b, d) are representatives of three independent experiments.