The JCI would like to congratulate Dr. Bob Lefkowitz and Dr.
Brian Kobilka on winning the 2012 Nobel Prize in Chemistry for
studies of G-protein coupled receptors (GPCRs). Dr. Lefkowitz,
an investigator at the Howard Hughes Medical Institute and Duke
University Medical Center, is also the Chair of the JCI
Executive Board. GPCRs, also known as seven-transmembrane domain
receptors, are cell surface proteins that sense molecules
outside the cell and activate signal transduction pathways that
allow cells to respond to their environment. The receptors are
activated by a variety of stimuli including light, odors,
hormones, neurotransmitters, and drug compounds. In fact, over
50% of pharmaceuticals act either directly or indirectly through
GPCRs. For many years, scientist were aware that cells were
capable of sensing and responding to environmental stimuli, but
the actual cellular mechanisms that mediated this process were
unknown. In 1968, Lefkowitz began tracing radiolabeled hormone
binding in cells and discovered