Figure 7. The C-Terminal Region of Rac1 Is Required for the Direct Interaction with mTOR.
(A) Fifty to sixty percent confluent 293T cells were treated with PEI (control) or transfected with mTOR, Rictor, or Raptor. Cells were then lysed and biotin-peptides of the Rac1, Rac2, and Cdc42 C-terminal domains and mutated Rac1 peptide: PPP/AAA or RKR/AAA was used to precipitate mTORC proteins for 1 hr at 4°C in the presence of streptavidin beads.
(B and C) 293T cells were transfected with Flag-mTOR. The Flag IPs were eluted by the Flag peptide. The free mTOR protein was precipitated by biotin-Rac1 C-terminal peptide or the biotin-RKR/AAA mutant, followed by streptavidin agarose. Samples were analyzed by SDS-PAGE and western blot (b) or the SDS-PAGE was silver stained (C). MW: molecular weight markers, WL: total proteins from Flag-mTOR transfected cells (1) WT biotin-Rac1 peptide; (2) biotin RKR/AAA mutant; (3) Flag IP. Data are representative of three experiments.
