G-protein-linked receptor
G-protein-linked receptor
[¦jē ‚prō‚tēn ‚liŋkt ri′sep·tər] (cell and molecular biology)
A cell surface receptor that consists of a polypeptide chain threaded across the membrane seven times and that, when activated by the binding of a ligand, in turn activates a cytosolic G-protein molecule, which then initiates a cascade of reactions effecting the intracellular response to the extracellular signal (the ligand).