Physiology, Tyrosine Kinase Receptors

Signal transduction is how an electrical, physical, or chemical signal elicits a cellular response by activating a cellular receptor and initiating a chain of biochemical events. Most commonly, signal transduction occurs when an extracellular molecule binds to a transmembrane protein receptor, triggering intracellular protein kinase activation and protein phosphorylation. Receptor tyrosine kinases (RTKs) constitute one class of transmembrane receptors and are characterized by their cytoplasmic regions' intrinsic tyrosine kinase activity.

RTKs are expressed in tissues throughout the body during intrauterine development and adulthood and play a critical role in regulating cell differentiation, proliferation, survival, metabolism, and migration. Unsurprisingly, research has found that RTK dysfunction plays a role in various human diseases, most notably cancers. An in-depth understanding of specific RTKs, their signaling cascades, and their effects on cell function has allowed for the development of many targeted drug therapies with significant improvements in clinical outcomes.