Figure 1.

Signaling pathways downstream of RAS and potential targets. RAS directly activates the mitogen activated protein kinase (MAPK) cascade, through phosphorylation of Raf (Rapidly accelerated fibro sarcoma) which in turn phosphorylates MEK (Mitogen activated protein kinase kinase), which then phosphorylates MAPK. On the other hand, it also interacts with the PI3K (Phosphatidylinositol-4,5-Bisphosphate 3-Kinase)/AKT (serine/threonine protein kinase) pathway, either by PI3K interaction or through RAC1 which in turn activates p21-activated kinase (PAK), an AKT interacting protein. RAS also activates the RAL (RAS like proto-oncogene) which is involved in various steps of membrane trafficking. The PLCs (Phospholipase C) along with RINI/ABL plays important role in cytoskeletal remodeling. The activation of NORE1/RASSF1 is involved in cell cycle arrest and apoptosis.