Rheb1 is Essential for Growth Factor Stimulated mTORC1 Signaling.
(A) Western blots show the failure of serum-starved primary Rheb1−/− MEFs to activate mTORC1 as indicated by pS6K and pS6 in response to insulin stimulation (200nM, 15min).
(B) Western blots reveal normal response of serum-starved Rheb1−/− MEFs to insulin stimulation (200nM, 15min) to activate mTORC2 (pAKT S473) and ERK kinase. IRS1 and 2 are not upregulated in the Rheb1−/− MEFs.
(C) Western blots show the failure of Rheb1−/− primary MEFs to activate mTORC1 activity with AA stimulation (see Supplemental Information).
(D) Immunostaining shows the restoration of the mTORC1 activity in the Rheb1−/− MEFs by myc-Rheb1. DAPI staining (blue) reveals Rheb1−/− MEFs not transfected with Rheb1 transgene.