G Protein Coupled Receptors

G protein coupled receptors involve this protein called a G protein. The receptor itself contains a series of seven transmembrane domains so these are helices that extend across the membrane. For basically every type of receptor there'll be one or maybe a small number but generally one specific signal molecule that they respond to. There's lots of different types of signals that need to be detected and for a given receptor it'll have its given signal molecule which will bind to a specific region in the extracellular matrix. This will elicit a conformational change so the protein will rearrange slightly and this will have an effect on the G protein.