What type of receptors have tyrosine kinase activity?

Receptor Tyrosine Kinases (RTKs) are a specific class of cell surface receptors that possess intrinsic tyrosine kinase activity. When a ligand binds to an RTK, it causes a conformational change that activates the kinase domain within the receptor. This leads to the phosphorylation of tyrosine residues on the receptor itself and on downstream signaling proteins. The phosphorylation events initiate a cascade of signaling pathways that regulate various cellular processes, including growth, differentiation, metabolism, and survival.

The activity of RTKs is crucial for many physiological functions, and dysregulation of RTK signaling is often implicated in cancer and other diseases. The mechanism of RTKs contrasts sharply with other types of receptors, which may utilize different signaling strategies without intrinsic kinase activity. This makes RTKs unique and critically important in signal transduction pathways.