簡要描述：The RAF family of signaling proteins has three isoforms: A RAF, RAF 1 and B RAF. These proteins are instrumental in forwarding the stimulus generated by mitogens from monomeric G proteins to the MAP kinase pathway. RAF 1 is known to be downstream of Ras and binds to it by an N terminal noncatalytic domain. This domain is conserved in A RAF and B RAF. 14-3-3 is also known to be an activator of RAFs. Activated RAF directly phosphorylates and activates MEK. A RAF is expressed at a very high co