SUMO engages multiple corepressors to regulate chromatin structure and transcription

Post-translational modification of many transcription factors and cofactors by the small ubiquitin-related modifier SUMO has been correlated with transcriptional repression. Recent investigations of the molecular mechanisms underlying SUMO-dependent repression have identified diverse chromatin modifying enzymes and chromatin associated proteins as effectors of SUMO-dependent changes in chromatin structure and gene expression. A surprising diversity of proteins has been identified to be recruited to promoters in a SUMO-dependent manner, including the histone deacetylase HDAC2, the histone demethylase LSD1, the histone methyltransferase SETDB1, the nucleosome remodeling ATPase Mi-2, and chromatin-associated proteins HP1 and L3MBTL1 and L3MBTL2. These findings suggest that SUMOylation plays a central role in coordinating histone modifications and chromatin structure important for regulation of gene expression.