We are investigating mechanisms that underlie the transport of ER-derived vesicles to the Golgi complex in the yeast Saccharomyces cerevisiae. Our focus is on a set of proteins contained on purified ER-derived vesicles that are found to catalyze distinct steps in this trasnport processs. Several of the genes involved in this process have been identified through genetic analyses and we are able to assay this transport event in a cell-free reaction. Through a combinded genetic and biochemical approach, we are characterizing the proteins and protein-protein interactions required to reproduce this transport reaction.