Genetic and biochemical analyses of yeast vacuolar protein localization have identified more than 40 gene products that play a role in this process. Included among these components are a sorting receptor, a protein kinase, a phosphatidylinositol kinase, small GTP-binding proteins and a dynamin-like GTPase. Some of these gene products are homologous to proteins required for sorting and transport at other stages of the secretory and endocytic pathways. Others appear to be required for unique functions in the vacuolar protein localization pathway. Recent studies have helped to define the role that each of these components plays in vacuolar protein localization and have offered new insights into the molecular mechanisms of protein sorting.
