7TM Receptors

Seven transmembrane (7TM)-spanning receptors, also known as G protein-coupled receptors (GPCRs), are a large superfamily of signaling proteins expressed on the plasma membrane that function as receivers for extracellular stimuli. About 330 7TM receptors GPCRs have been identified in the human genome (exclusive the olfactory receptors). Since their signaling is involved in numerous physiological functions and pathological conditions, 7TM receptors constitute the molecular target of a significant percentage of the currently marketed drugs  (~ 25%). Moreover, many additional members of the superfamily have been identified as potential targets for the treatment of a variety of diseases and are the object of substantial drug discovery efforts.