SUMO Weighs In on Polycomb-Dependent Gene Repression

In this issue of Molecular Cell, Kang et al. (2010) report that their studies to characterize the biological activity of a SUMO-specific protease, SENP2, have revealed an important role for reversible SUMO modification in regulating promoter occupancy and gene-specific repression by polycomb repressive complex 1 (PRC1).