A function for monoubiquitination in the internalization of a G protein-coupled receptor

Mol Cell. 1998 Jan;1(2):193-202. doi: 10.1016/s1097-2765(00)80020-9.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Division / physiology
  • Cytoplasm / metabolism
  • Endocytosis / physiology*
  • GTP-Binding Proteins / metabolism*
  • Humans
  • Lysine / metabolism
  • Mutagenesis / physiology
  • Receptors, Mating Factor
  • Receptors, Peptide / genetics
  • Receptors, Peptide / metabolism*
  • Saccharomyces cerevisiae / chemistry
  • Saccharomyces cerevisiae / cytology
  • Saccharomyces cerevisiae / metabolism*
  • Signal Transduction / physiology
  • Transcription Factors*
  • Transcription, Genetic / physiology
  • Ubiquitins / genetics
  • Ubiquitins / metabolism*


  • Receptors, Mating Factor
  • Receptors, Peptide
  • Transcription Factors
  • Ubiquitins
  • GTP-Binding Proteins
  • Lysine