Oncoproteins & Receptor Signaling
Kinase
The enzyme that switches a protein on–by attaching a phosphate, and changing its shape in the process.
Definition
A kinase is an enzyme that transfers a phosphate group onto a substrate protein, typically switching its activity on and frequently changing its conformation. Tyrosine kinases–EGFRLoading..., HER2/HER3Loading...–phosphorylate tyrosine residues and sit at the head of the growth-signaling pathways most often deregulated in cancer. The conformational change is what makes activation measurable: it moves two epitopes on one protein into proximity, which is the canonical aFRETLoading... application.