Figure 2.

This image shows the physiological regulation and dimerization of BRAF and CRAF in wild-type cells. Class I mutations signal as monomers with autonomous kinase activity. Class II mutations signal constitutively as dimers independently of RAS activity. Class II mutations have low or absent kinase activity and are dependent to RAS and need dimerization to activate the pathway. The slim arrows represent physiological kinase activity. The wide arrows represent kinase activity induced by mutations. The red cross symbolizes absent kinase activity as a monomer in Class III mutants.