DUB-le vision: snapshots of the proteasome during substrate processing

Covalent modification by the small protein ubiquitin can target proteins for destruction by the proteasome, but the ubiquitin signal itself is recycled. Surprisingly, proteasomes contain three different deubiquitinating enzymes (DUBs). Recent work by Zhang and Zou et al. reveals how one of these enzymes, Usp14, regulates, and is regulated by, the proteasome. Covalent modification by the small protein ubiquitin can target proteins for destruction by the proteasome, but the ubiquitin signal itself is recycled. Surprisingly, proteasomes contain three different deubiquitinating enzymes (DUBs). Recent work by Zhang and Zou et al. reveals how one of these enzymes, Usp14, regulates, and is regulated by, the proteasome.