SIGNAL ACCOMPLISHMENT WINS CHEMISTRY NOBEL
• Robert Lefkowitz (Duke University; left) and his former postdoctoral fellow Brian Kobilka (Stanford; right) take home the 2012 Nobel prize in Chemistry for their discoveries in the field of cell signaling by G Protein Coupled Receptors (GPCR). Considered the Holy Grail in the membrane protein field, these are major targets of modern drugs.
• More than 800 human genes comprise the GPCR family, making it the largest group of membrane protein receptors. Together, they detect hormones, growth factors, odorants, neurotransmitters and thousands of different ligands. The visual protein of the eye, rhodopsin, is a GPCR. They share a common structure of 7 helices that twist through the membrane, attaching to molecular switches (G proteins) on the inside. The whole structure acts as an on/off switch that sets off a signaling cascade that can be amplified and tuned. Lefkowitz cloned the first GPCR and Kobilka solved the structure of the adrenergic receptor, β2AR, that controls the flight or fight response.
Image of β2AR: http://en.wikipedia.org/wiki/File:Beta2Receptor-with-Gs.png