The Payne lab studies molecular mechanisms responsible for selective protein transport within cells, with a focus on pathways that involve transport by clathrin-coated vesicles (ccv). These conserved pathways are fundamental to normal cell function and defects in pathway components are associated with a number of diseases including cancer, heart disease, and neurodegenerative disorders.

The lab has developed genetic, biochemical, structural and live cell imaging strategies to study clathrin-mediated transport in yeast, and more recently in animal cells.

Projects in the lab include: 1) Endocytosis and receptor sorting. Efforts are directed at understanding the roles of specific components of the endocytic machinery. For example, the role of a membrane-bending BAR domain protein, RVS167, in endocytosis is being characterized. Novel RVS167 interaction partners have been identified, the molecular basis of interactions are being assessed by in vitro binding and structural analysis, and the role of these interactions in endocytosis are being defined in vivo, in yeast and animals cells. Another project addresses possible roles for amyloid-like interactions during endocytosis. 2) The mechanism of ccv formation at the trans Golgi network (TGN). Clathrin adaptors play central roles in clathrin coat assembly, connecting clathrin, clathrin coat-associated proteins, and cargo. The Payne lab has defined an interaction network of TGN/endosome adaptors with hubs centered on adaptor complex-1 (AP-1) and Gga adaptor proteins, uncovered a novel process of sequential adaptor-specific ccv formation at the TGN that we term adaptor progression, and provided evidence that adaptor progression is regulated by the TGN-enriched phosphoinositide, PI4P. The molecular mechanisms responsible for phosphoinositide-mediated adaptor progression are being defined. Additional projects address the structure and function of adaptor-associated proteins in transport between the TGN and endosomes.

Greg Payne is a cell biologist and geneticist studying mechanisms of intracellular protein transport. He joined the Department of Biological Chemistry in the UCLA School of Medicine in 1987, received tenure in 1994, became full professor in 2000, and was departmental Vice Chair from 2004-2009. Dr. Payne received his B.S. in Cell Biology with Honors in Drama from University of Michigan in 1977 and his Ph.D. in Biochemistry in the lab of Harold Varmus from University of California, San Francisco. He was a postdoctoral with Randy Schekman at University of California, Berkeley. He has served as director of the joint Ph.D. admissions program, ACCESS, since 2008. Dr. Payne research involves cell biological, biochemical,strtuctural, molecular and standard genetic and genomic approaches to understand vesicle mediated traffic in yeast.