RAS signalling pathway is one of the main pathways to transduce intracellular signals in response to mitogens to controls cell growth, survival and anti-apoptotic programs. RAS proteins are GTP-binding proteins and must be bound to GTP to be active. Active RAS binds and activates effector enzymes that control cell proliferation, survival and other cell behaviours. RAS interacts directly with the catalytic subunit of PI3K to activate lipid kinases controlling the activity of downstream enzymes. Some of these kinases have anti-apoptotic activity, playing an important role in the survival signal of RAS. PI3K is also involved in the regulation of the actin cytoskeleton and transcription factor pathways. RAS also effects exchange factors causing inhibition of transcription factors from FoxO family, part of promoting cell cycle arrest and apoptosis. Normal function of these proteins require post-transcriptional modification. Pathway mutations in activation may result in human tumours.

Ras Signaling Pathway References