Ubiquitination plays a key role in protein degradation and signal transduction. Ubiquitin is a
small protein modifier that is adducted to lysine residues by the combined function of E1, E2,
and E3 enzymes and is removed by deubiquitinating enzymes. Characterization of
ubiquitination sites is important for understanding the role of this modification in cellular
processes and disease. However, until recently, large-scale characterization of endogenous
ubiquitination sites has been hampered by the lack of efficient enrichment techniques. The …