A function for monoubiquitination in the internalization of a G protein-coupled receptor.
Modification of an S. cerevisiae G protein-coupled receptor with ubiquitin is required for its ligand-stimulated internalization. We now demonstrate that monoubiquitination on a single lysine residue is sufficient to signal receptor internalization, a modification distinct from that required for proteasome recognition. Formation of a polyubiquitin chain is not necessary, as demonstrated by the ability of mutant ubiquitins that lack lysine residues to serve as efficient internalization signals. Fusion of ubiquitin in-frame to a receptor that lacks cytoplasmic tail lysines also promotes rapid receptor internalization, indicating that ubiquitin itself and not a specific type of linkage to the receptor acts as an internalization signal. Thus, we have defined a cellular function for monoubiquitination in alpha-factor receptor endocytosis.
Pubmed ID: 9659916 RIS Download
Animals | Cell Division | Cytoplasm | Endocytosis | GTP-Binding Proteins | Humans | Lysine | Mutagenesis | Receptors, Mating Factor | Receptors, Peptide | Saccharomyces cerevisiae | Signal Transduction | Transcription Factors | Transcription, Genetic | Ubiquitins