Research in my laboratory is focused on characterization of the assembly, processing and membrane trafficking of apically expressed glycoproteins in polarized kidney epithelial cells. We use biochemistry and electrophysiology techniques in cultured cells and Xenopus oocytes, as well as transgenic mice, to study the function of glycosylation, palmitoylation and proteolytic processing of model proteins such as the epithelial sodium channel (ENaC), gamma-glutamyltranspeptidase and the cell surface sensor MUC1. Our recent studies have revealed that ENaC is activated by a very novel mechanism of proteolytic release of inhibitory peptides both in the biosynthetic pathway and post-Golgi compartments, and in pathological states such as proteinuria (kidney) and Cystic Fibrosis (lung). Our current studies of MUC1 function in normal kidney epithelia are focused on its role in epithelial survival and recovery from acute kidney injury using both a model of polarized kidney epithelial cells cultured under hypoxic conditions, and a proven mouse model of kidney ischemia-reperfusion injury.