Substrate-induced ubiquitylation and endocytosis of yeast amino acid permeases.

ABSTRACT: Many plasma membrane transporters are downregulated by ubiquitylation, endocytosis, and delivery to the lysosome in response to various stimuli. We report here that two amino acid transporters of Saccharomyces cerevisiae, the general amino acid permease (Gap1) and the arginine-specific permease (Can1), undergo ubiquitin-dependent downregulation in response to their substrates and that this downregulation is not due to intracellular accumulation of the transported amino acids but to transport catalysis itself. Following an approach based on permease structural modeling, mutagenesis, and kinetic parameter analysis, we obtained evidence that substrate-induced endocytosis requires transition of the permease to a conformational state preceding substrate release into the cell. Furthermore, this

SUBMITTER: Ghaddar K 

PROVIDER: S-EPMC4248734 | biostudies-literature | 2014 Dec

REPOSITORIES: biostudies-literature