Skip to main content
. Author manuscript; available in PMC: 2015 Mar 2.
Published in final edited form as: Cell. 2014 Feb 13;156(4):786–799. doi: 10.1016/j.cell.2014.01.024

Figure 7. TSC2 null cells are impaired in their response to amino acid starvation, leading to their death.

Figure 7

(A-B) Amino acid removal causes cell death in TSC2 null cells. TSC2−/− and the respective TSC2+/+ control MEFs were treated on day 1 with medium +/− amino acids in the presence of dialyzed FBS. On day 4, all samples were given fresh medium containing amino acids. (A) DIC images captured on days 1, 4, and 7. (B) Cell viability determined using the Cell-Titer Glo kit (Promega).

(C) TSC2-null MEFs show defective autophagy induction upon amino acid withdrawal. TSC2−/− and the respective TSC2+/+ control MEFs were treated with medium containing (+) or lacking amino acids in the presence of dialyzed FBS for the indicated times. Activation of autophagy visualized on an immunoblot via increased conversion of LC3A to the faster migrating lipidated form II and degradation of p62 protein.

(D-E) Pharmacological inhibition of TORC1 rescues survival of TSC2-null MEFs upon amino acid withdrawal. TSC2−/− mouse embryonic fibroblasts were treated with medium containing (+aa) or lacking (−aa) amino acids with or without 20nM Rapamycin (−aa/+Rapa) for 3 days in the presence of dialyzed FBS. DIC images (D) and respective cell viability titers determined using the Cell-Titer Glo kit (Promega) (E).

Error bars: std. dev.