Enhancer Decommissioning by LSD1 During Embryonic Stem Cell Differentiation (expression). Mus musculus

Transcription factors and chromatin modifiers play important roles in programming and reprogramming of cellular states during development. Much is known about the role of these regulators in gene activation, but relatively little is known about the critical process of enhancer silencing during differentiation. Here we show that the H3K4/K9 histone demethylase LSD1 plays an essential role in decommissioning enhancers during differentiation of embryonic stem cells (ESCs). LSD1 occupies enhancers of active genes critical for control of ESC state. However, LSD1 is not essential for maintenance of ESC identity. Instead, ESCs lacking LSD1 activity fail to fully differentiate and ESC-specific enhancers fail to undergo the histone demethylation events associated with differentiation. At enhancers, LSD1 is a component of the NuRD complex, which contains additional subunits that are necessary for ESC differentiation. We propose that the LSD1-NuRD complex decommissions enhancers of the pluripotency program upon differentiation, which is essential for complete shutdown of the ESC gene expression program and the transition to new cell states. Overall design: This represents the expression part of the study.