MAPK/ERK pathway
The MAPK/ERK pathway is a signaling cascade through a chain of proteins to transduce a signal from the cell surface to the nucleus. Many proteins are included in the signaling pathway, like MAPK, RAF, ERK, which perform signal transduction through transphosphrylation. Kinase activity of MAPK (phosphorylation) acts as on or off switch. The signaling pathway starts with the binding of growth factor to receptor tyrosine kinase and end up with the effect on cell growth. When one of the proteins in the pathway is mutated, it can be stuck in the "on" or "off" position, which may lead to the development of cancer. Drugs that reverse the "on" or "off" switch are being investigated as cancer treatments.
Kinase pathway
Three major proteins are involved in the kinase pathway. RAF, MEK MAPK (ERK), which are all shown to be serine/threonine protein kinase. The first protein to be phosphorylated and activated by upstream Ras G protein is a microtubule-associated protein (MAP). Another name for MAP is RAF. Then, RAF kinase phosphorylates and activates MEK. The activated MEK thus activate mitogen-activated protein kinase MAKP (ERK). Such a protein kinase cascade provides opportunity for feedback regulation and signal amplification. By altering the levels and activities of transcription factors, such as myc, MAPK leads to a significant change in expression of genes that are crucial to the cell cycle.
examples of RAF inhibitors:
