ABSTRACT
G protein-coupled receptors (GPCRs) form the largest membrane-bound receptor family expressed by humans (encompassing ca. 4% of the proteincoding genome) (Schoneberg et al. 2004). They are of paramount importance for pharmaceutical intervention (ca. 40% of currently marketed drugs target GPCRs) (Overington et al. 2006). GPCRs are located in the plasma membrane and transduce signals through their interactions with both extracellular ligands (or light in the case of rhodopsin) and intracellular heterotrimeric guanine nucleotide-binding proteins (G proteins) to initiate signaling cascades that allow cells to react to changes within their environment (Audet and Bouvier 2012). The resulting response regulates a broad range of cellular processes engaged in the control of cell proliferation, differentiation, motility, as well as apoptosis. Chemicals and light sensing also rely on GPCRs signaling. These proteins are also involved in a plethora of inammatory diseases (Sun and Ye 2012), cardiovascular diseases, neurological disorders, and cancer (Dorsam and Gutkind 2007).
