The half-lives of endogenous LAMTOR3 and Myc6LAMTOR3 are reduced in the absence of LAMTOR2. Cell lysates were separated by SDS-PAGE, analyzed by Western blotting, and probed with the indicated antibodies. A and B, quantifications of the according Western blot are shown in A and B representing the averages of three independent experiments (means ± S.E., n = 3). C, 80% confluent LAMTOR2−/− and LAMTOR2f/−MEF were treated with 50 μg/ml cycloheximide for the corresponding time points. The cell lysates were separated by SDS-PAGE, analyzed by Western blotting, and probed with the indicated antibodies. D, Myc6LAMTOR3LAMTOR2−/− and Myc6LAMTOR3LAMTOR2f/− stable clones were treated with 50 μg/ml cycloheximide for the corresponding time points.