More than a third of FDA-approved drugs work by targeting a G protein-coupled receptor, or GPCR. The human body has more than 800 types of GPCRs that provide cells with information about the external environment to calibrate responses. Drugs that either block or activate GPCRs are used to treat a wide range of diseases including hypertension, pain, and inflammation. Most drugs bind to the outside of the receptor, but this can result in adverse side effects because receptors often resemble one another. In a new study published in Nature, Sivaraj Sivaramakrishnan, PhD, a Professor in the College of Biological Sciences, along with graduate student Fred Sadler and co-authors Michael Ritt and Yatharth Sharma, uncovered the role of the third intracellular loop in the GPCR’s signaling mechanism, suggesting the possibility of a more targeted approach to drug discovery and a paradigm shift for new therapeutics. The open-access article is titled Autoregulation of GPCR Signalling Through the Third Intracellular Loop.”