Research in the lab is directed to elucidate the structure-function relationships of G protein-coupled receptors, especially the neural melanocortin receptors, melanocortin-3 and -4 receptors. These receptors are critically involved in the regulation of energy homeostasis. Naturally occurring mutations in the genes for these receptors have been identified from obese patients. Our current focus is two fold: 1. The molecular defects of the naturally occurring mutations identified from obese patients in these receptors; 2. The molecular mechanisms of ligand binding and receptor activation. A multi-disciplinary approach, including pharmacological, molecular biological, and cell biological techniques, as well as computer modeling, is used for these studies.