The receptors, which snake in and out of the cell membrane, serve as one of the main methods of communication within the body — conveying chemical messages into the cell's interior from outside through the membrane. Over the course of the last three decades, Kobilka and his colleague Robert Lefkowitz, MD, with whom Kobilka shares the prize, have played an important role in discovering and understanding GPCRs. Last year, Kobilka was the first to crystallize and analyze one of the receptors bound to its signaling molecule, which is a critical step toward understanding how to control them.
Roughly 800 different GPCRs have been identified to date, making them one of the largest families of human proteins. These proteins regulate the beating of our hearts, the workings of our brains and nearly every other physiological process. About 40 percent of all medications target these receptors, including Zyprexa, which is used to treat schizophrenia; the antihistamine Clarinex; and Zantac, which is used for stomach ulcers and gastro-esophageal reflux disease. GPCRs are also involved in some kinds of drug addictions, such as addiction to morphine and other opiates.