9628802 Gharakhanian This is a Career Advancement Award for Women Scientists and Engineers. The project focuses on the selective recognition, sorting and transport of proteins to the lysosome (vacuole) of the yeast, Saccharomyces cerevisiae. As in higher eukaryotes, the lysosomal vacuole of the yeast is its degradative organelle, and several hydrolytic enzymes are localized there via the secretory pathway. Various mutant screening strategies in different laboratories have resulted in the isolation of a large collection of yeast mutants that exhibit severe defects in protein delivery to the vacuole, called vacuolar protein sorting mutants (vps mutants). The defective genes in these mutants are likely to encode components of the cell's protein sorting apparatus. Using a modified screening method, this laboratory isolated a new vps mutant, vps47, which represents a unique genetic defect: it is the only severe temperature sensitive vps mutant to date that shows no defects in the integrity, structure, or function of the vacuole. This represents a very interesting gene within the vacuolar localization machinery. This project, which will be carried out during a sabbatical year, entails the cloning and characterization of the VPS 47 gene. Insight into the function of this and other vps gene products will be gained from these characterizations. ***
