A heavyweight joins the fray

摘要

Tagging of DNA-damage-associated proteins by ubiquitin is key to coordinating the DNA-damage response. The ubiquitin-related protein SUMO is revealed as a crucial regulator of ubiquitylation in DNA repair.rnUbiquitylation-the attachment of ubiquitin groups to cellular proteins-was initially characterized by its role in promoting protein destruction. However, we now know that the consequences of ubiquitylation are diverse, and that it affects many cellular systems. The ubiquitin modification comes in many flavours (addition of a single ubiquitin molecule, for example, or of polyubiquitin chains that differ in the position of the linkage between ubiquitin molecules), and the various types of ubiquitylation can alter the fate of target proteins in different ways.