Receptor tyrosine kinase structure and function in health and disease

Receptor tyrosine kinases (RTKs) are membrane proteins that control the flow of information through signal transduction pathways, impacting on different aspects of cell function. RTKs are characterized by a ligand-binding ectodomain, a single transmembrane alpha-helix, a cytosolic region comprising juxtamembrane and kinase domains followed by a flexible C-terminal tail. Somatic and germline RTK mutations can induce aberrant signal transduction to give rise to cardiovascular, developmental and oncogenic abnormalities. RTK overexpression occurs in certain cancers, correlating signal strength and disease incidence. Diverse RTK activation and signal transduction mechanisms are employed by cells during commitment to health or disease. Small molecule inhibitors are one means to target RTK function in disease initiation and progression. This review considers RTK structure, activation, and signal transduction and evaluates biological relevance to therapeutics and clinical outcomes.