Department of Biological Chemistry, School of Medicine, University of California, Irvine, CA 92697-1700, USA. pkaiser@uci.edu
Ubiquitination--the linkage of one or more molecules of the protein ubiquitin to another protein--regulates a wide range of biological processes in all eukaryotes. We review the proteome-wide strategies that are being used to study aspects of ubiquitin biology, including substrates, components of the proteasome and ubiquitin ligases, and deubiquitination.