Dr. Baranski's research has provided important mechanistic insights into how G protein-coupled receptors, a superfamily of heptahelical transmembrane proteins, act as elegantly engineered switches to turn on specific signaling cascades within cells. Using novel biochemical and genetic analyses, he has focused on a single receptor, the human C5a receptor, and identified essential components of the receptor switch mechanism. These studies have broad impact and clinical significance, since the majority of pharmaceuticals target these receptors.