What is the mechanism of RTK signaling?

Receptor tyrosine kinases (RTKs) are activated by ligand-induced oligomerization (normally dimerization), which juxtaposes the tyrosine kinase domains. The RTKs form into dimers when the ligand binds to the extracellular regions. This causes the autophosphorylation of the receptor. The attached ligand can generate all, none, or only a segment of the dimer. The receptors become activated via the stabilization of two distinct receptor molecules. After activation, RTK activation triggers intracellular pathways such as PI3K/AKT/mTOR, and MAP kinase cascade. RTKS are proteins that essentially act as signal transducers. They mediate vital cellular processes including proliferation, metabolism, apoptosis, and differentiation. The dysregulation of RTK signaling may lead to malignancies.