| Recognition, sorting, and localization of lysosomal proteases to the degradative lysosome are vital for the operation of eukaryotic cells. In order to elucidate the steps involved in endosome-to-v&barbelow;acuole (env) delivery of soluble hydrolases to the vacuole, our lab had previously isolated several env mutants of the yeast Saccharomyces cerevisiae that internally accumulate p2CPY but have intact secretion. Mutants of the env1 strains internally accumulate p2CPY whereas in the vps35 deletion mutant p2CPY is secreted. It appears that the dysfunction of Vps35p in env1 mutants results in a more severe trafficking defect affecting vacuolar function, suggesting that this protein may play a crucial role in the sorting and delivery of vacuolar proteins. Complementation studies show that the vps35-10 allele complements the env1 allele, suggesting that env1 may present a novel allele of VPS35, whose dysfunction defines a new and yet to be described function for Vps35p, possibly in post-endosomal trafficking to the vacuole. (Abstract shortened by UMI.)... |
