| The Carboxypeptidase Y (CPY) biosynthetic pathway serves as a model for studying the trafficking of proteins to the vacuole. Our laboratory has generated 5 endosome-to-vacuole (env) mutants, mut72, mut78, mut79-1A, mut165 and mut186, which have defects in trafficking of proteins between the late endosome and vacuole. These env mutants have been previously shown to accumulate the intermediate precursor, p2CPY, in a compartment outside the vacuole and compromised vacuolar integrity. These 5 env mutants displayed a blockage of CPY trafficking to the vacuole. Some of the mutants showed a defect that is less severe in trafficking CPY through the biosynthetic pathways than others. Fractionations by ficoll gradient and differential centrifugation along with morphological studies by E.M. and FM4-64 binding may indicate possible roles in proteins defective in these mutants, thus allowing for further clarification for the mechanisms and roles of proteins involved in the late biosynthetic pathway. (Abstract shortened by UMI.). |
