title: The demographics of the ubiquitin system.
abstract: The ubiquitin system is a major coordinator of cellular physiology through regulation of both protein degradation and signalling pathways. A key building block of a systems-level understanding has been generated by global proteomic studies, which provide copy number estimates for each component. The aggregate of ubiquitin, conjugating enzymes (E1, E2, and E3s), and deubiquitylases (DUBs) represents ∼1.3% of total cellular protein. Complementary approaches have generated quantitative measurements of various ubiquitin pools and further subdivision into different ubiquitin chain topologies. Systematic studies aimed at associating specific enzymes (E2s and DUBs) with the dynamics of these different pools have also made significant progress. Here, we delineate the emerging picture of the most significant determinants of the cellular ubiquitin economy.
authors.affiliation: Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown Street, Liverpool, L69 3BX, UK. Electronic address: clague@liv.ac.uk.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Clague
authors.affiliation: Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown Street, Liverpool, L69 3BX, UK.
authors.forename: Claire
authors.initials: C
authors.lastname: Heride
authors.affiliation: Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown Street, Liverpool, L69 3BX, UK.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Urbé
mesh_terms: D000818:Animals; D001343:Autophagy / Q000235:genetics; D018628:Gene Dosage; D005786:Gene Expression Regulation; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D005810:Multigene Family; D041681:NIH 3T3 Cells; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D059748:Proteolysis; D015398:Signal Transduction; D044763:Ubiquitin-Conjugating Enzymes / Q000235:genetics* / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000235:genetics* / Q000378:metabolism; D064570:Ubiquitin-Specific Proteases / Q000235:genetics* / Q000378:metabolism; D014452:Ubiquitins / Q000235:genetics* / Q000378:metabolism
chemical_list: D014452:Ubiquitins; D044763:Ubiquitin-Conjugating Enzymes; D044767:Ubiquitin-Protein Ligases; D064570:Ubiquitin-Specific Proteases; D046988:Proteasome Endopeptidase Complex
keywords: deubiquitylase; ubiquitin; ubiquitin ligase; ubiquitin system