Glucagon-like peptide-I (GLP-1), a member of the glucagon-secretin peptide family, is secreted from L-cells of the small intestine and binds to a class B (class 2) G protein-coupled receptor. The GLP-1 receptor is expressed in pancreatic beta cells and upon binding to GLP-1, it couples to Gs to increase cAMP levels and insulin secretion. In addition, GLP-1 has been shown to delay gastric emptying and regulate appetite. Therefore, the GLP-1 receptor represents an important therapeutic target for type II diabetes. In addition, the degradation-resistant analog of GLP-1, exanatide, is used clinically in combination with other glucose-lowering drugs to control type II diabetes.