Figure 6: A proposed model of free Raptor-mediated regulation of hepatic lipogenesis.
From: mTORC1-independent Raptor prevents hepatic steatosis by stabilizing PHLPP2
Akt represents the common molecular hub of insulin regulation of hepatic glucose production and lipogenesis. In the post-prandial state, Akt-mediated FoxO nuclear exclusion occurs rapidly, after which Akt is dephosphorylated by PHLPP2 at Ser473 to terminate insulin action. In aging or obesity, loss of free Raptor destabilizes PHLPP2, leading to prolonged Akt activity and Srebp1c-dependent lipogenesis.
