Perilous journey: a tour of the ubiquitin-proteasome system.
Eukaryotic cells are equipped to degrade proteins via the ubiquitin-proteasome system (UPS). Proteins become degraded upon their conjugation to chains of ubiquitin where they are then directed to the 26S proteasome, a macromolecular protease. The transfer of ubiquitin to proteins and their subsequent degradation are highly complex processes, and new research is beginning to uncover the molecular details of how ubiquitination and degradation take place in the cell. We review some of the new data providing insights into how these processes occur. Although distinct mechanisms are often observed, some common themes are emerging for how the UPS guides protein substrates through their final journey.
Department of Chemistry, University of Nevada, Las Vegas, 4505 South Maryland Parkway, Las Vegas, NV 89154-4003, USA. Electronic address: gary.kleiger@unlv.edu.
Gary
G
Kleiger
Department of Biochemistry and Molecular Biology, Centre of High-Throughput Biology, University of British Columbia, 2125 East Mall, Vancouver, BC V6T1Z4, Canada. Electronic address: mayor@mail.ubc.ca.
Thibault
T
Mayor
D000818:Animals; D006801:Humans; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D059748:Proteolysis; D025801:Ubiquitin / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism*
D025801:Ubiquitin; D044767:Ubiquitin-Protein Ligases; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease
E1-activating; E2-conjugating; E3-ligase; proteolysis; ubiquitin proteasome system