Extensive SUMO Modification of Repressive Chromatin Factors Distinguishes Pluripotent from Somatic Cells.

ABSTRACT: Post-translational modification by SUMO is a key regulator of cell identity. In mouse embryonic fibroblasts (MEFs), SUMO impedes reprogramming to pluripotency, while in embryonic stem cells (ESCs), it represses the emergence of totipotent-like cells, suggesting that SUMO targets distinct substrates to preserve somatic and pluripotent states. Using MS-based proteomics, we show that the composition of endogenous SUMOylomes differs dramatically between MEFs and ESCs. In MEFs, SUMO2/3 targets proteins associated with canonical SUMO functions, such as splicing, and transcriptional regulators driving somatic enhancer selection. In contrast, in ESCs, SUMO2/3 primarily modifies highly interconnected repressive chromatin complexes, thereby preventing chromatin opening and transitioning to totipoten

SUBMITTER: Theurillat I 

PROVIDER: S-EPMC7495044 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature