mTOR expression affects body and organ weight as well as TORC1 and TORC2 activity. (A-B) Body sizes and weights of KI mice are less than that observed in age-matched WT and HET mice (N = 7 each). (C) KI organ weights are adjusted for body weight and shown as a proportion of the WT organ weight also adjusted for body weight. All data are from 7 mice (age, 57 days). (D) Spleens of KI mice are small and disproportionately reduced compared with other organs. (E) Relative mRNA expression of mTOR in brain, spleen, and fibroblasts of WT, HET, and KI mice (N = 3 each). (F) Protein levels of mTOR (C-terminal antibody) were lower in spleens of KI mice. Basal RAPTOR (G) and RICTOR (H) protein expression was reduced in spleens of HET and KI mice (top left: Western blot; bottom left: protein level relative to WT, normalized with β-actin). In KI splenocytes, lower mTOR levels resulted in less phosphorylation of TORC1 target p-p70SK^Thr389 (G, top right) and TORC2 target p-AKT^Ser473 (H, top right: Western blot; bottom right: protein level relative to WT, normalized with total β-actin).