mTOR, or Mammalian target of rapamycin, a large protein kinase, is a regulator of cell growth and survival via its mTORC1 (mTOR + GBL + Raptor) and mTORC2 (mTOR + GBL + SIN1 + Rictor) complexes. SIN1 is an essential component of mTORC2, which activates Akt by phosphorylating Ser473. Phosphorylation of SIN1 at Thr86/398 causes its dissociation from the mTORC2 complex, inhibiting mTORC2s kinase activity.
