Research Interests The focus of our lab is to characterize the mechanisms by which the sorting of membrane proteins is regulated in epithelial cells. We are primarily interested in the role of clathrin and clathrin adaptors in the regulation of membrane traffic and of sorting of membrane proteins in epithelial cells. By using a combination of cellular, biochemical, and molecular techniques, we are trying to characterize the interaction of clathrin adaptors with cargo proteins and to identify and characterize novel adaptor proteins associated with specific membrane trafficking pathways. Two organ-based cellular systems are being investigated, gastric acid secretory (oxyntic) cells and lacrimal gland acinar cells. Oxyntic cells possess a well-regulated apical recycling pathway along which the H,K-ATPase is sorted and are therefore being used as a model system for investigation into this particular membrane trafficking pathway in epithelial cells. Lacrimal acinar cells possess a vigorous basal-to-apical transcytotic pathway along which the polymeric immunoglobulin receptor is sorted. We are studying the regulation of its sorting in collaboration with the lab of Dr. Austin Mircheff (Physiology-Biophysics). We also use cultured epithelial cell lines, such as the Madin-Darby canine kidney and Caco-2 cell lines, to study these trafficking pathways. The knowledge gained from these studies may ultimately provide insight into the trafficking and processing of exogenously admininstered therapeutic macromolecules in epithelial cells in vivo.