Oncoproteins & Receptor Signaling
Receptor
The protein that receives the signal–where engagement, not abundance, decides whether anything happens.
Definition
A receptor is a protein that binds a specific ligand and converts that binding into a change inside the cell. Most sit in the plasma membrane with an extracellular binding domain and an intracellular domain that propagates the signal–EGFRLoading... through kinase activity, the checkpointLoading... receptors through inhibitory signaling. Expression says a receptor is present; it does not say it is engaged, which is the gap FRETLoading... measures directly and immunohistochemistry cannot.