Figure 2.

Oncogenic RAS activation of MAPK and PI3K/AKT signaling. Figure 2 illustrates oncogenic RAS-mediated activation of MAPK and PI3K/AKT signaling. Mutant RAS proteins are prevalent in their active, GTP-bound states in tumor cells, resulting in elevated activation of downstream signaling cascades. Active RAS interacts with the RAS binding domain (RBD) of RAF to activate MAPK signaling, which is typically associated with tumor cell proliferation. RAS can also interact with the RBD of PI3K in order to activate PI3K/AKT signaling and promote tumor cell survival. Red arrows indicate elevations of phosphorylated protein levels in the presence of mutant RAS (outlined in the red box).