Ubiquitin proteolytic system: focus on SUMO

Expert Rev Proteomics. 2008 Feb;5(1):121-35. doi: 10.1586/14789450.5.1.121.


The small ubiquitin-like modifier proteins (Smt3 in yeast and SUMOs 1-4 in vertebrates) are members of the ubiquitin super family. Like ubiquitin, the SUMOs are protein modifiers that are covalently attached to the epsilon-amino group of lysine residues in the substrates. The application of proteomics to the SUMO field has greatly expanded both the number of known targets and the number of identified target lysines. As new refinements of proteomic techniques are developed and applied to sumoylation, an explosion of novel data is likely in the next 5 years. This ability to examine sumoylated proteins globally, rather than individually, will lead to new insights into both the functions of the individual SUMO types, and how dynamic changes in overall sumoylation occur in response to alterations in cellular environment. In addition, there is a growing appreciation for the existence of cross-talk mechanisms between the sumoylation and ubiquitinylation processes. Rather than being strictly parallel, these two systems have many points of intersection, and it is likely that the coordination of these two systems is a critical contributor to the regulation of many fundamental cellular events.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Animals
  • Caenorhabditis elegans Proteins / metabolism
  • Conserved Sequence
  • Endopeptidases / metabolism
  • Humans
  • Ligases / physiology
  • Lysine / metabolism
  • Mass Spectrometry / methods
  • Mice
  • Models, Molecular
  • Neoplasm Proteins / metabolism
  • Nuclear Proteins / metabolism
  • Proteasome Endopeptidase Complex / metabolism*
  • Protein Array Analysis
  • Protein Processing, Post-Translational / physiology*
  • Proteomics / methods*
  • Saccharomyces cerevisiae Proteins / metabolism
  • Small Ubiquitin-Related Modifier Proteins / physiology*
  • Two-Hybrid System Techniques
  • Ubiquitin / metabolism*
  • Ubiquitin-Protein Ligases / metabolism
  • Ubiquitination*


  • Caenorhabditis elegans Proteins
  • Neoplasm Proteins
  • Nuclear Proteins
  • Saccharomyces cerevisiae Proteins
  • Small Ubiquitin-Related Modifier Proteins
  • Ubiquitin
  • TOPORS protein, human
  • Ubiquitin-Protein Ligases
  • Endopeptidases
  • Proteasome Endopeptidase Complex
  • Ligases
  • Lysine