GSE169049
NSD1-mediated HDAC1 recruitment reduces H3K27ac at active enhancers to safeguard associated gene expression
Epigenetics, especially histone marks, functions beyond the DNA sequences to regulate gene expression. Depletion of NSD1, which catalyzes H3K36me2, led to both up- and down-regulation of gene expression, indicating NSD1 is associated with both active and repressed gene expression. It's known that NSD1 regulates the deposition and expansion of H3K27me3, a repressive mark for gene expression, to keep active gene transcription. However, how NSD1 functions to repress gene expression is largely unknown. Here, we found that, when NSD1 was knocked out in mouse embryonic stem cells (mESCs), H3K27ac increased correlatively with the decrease of H3K36me2 at active enhancers, which is associated with mesoderm differentiation genes, leading to elevated gene expression. Mechanistically, NSD1 recruits HDAC1, the deacetylase of H3K27ac, to chromatin. Moreover, HDAC1 knockout (KO) recapitulates the increase of H3K27ac at active enhancers as the NSD1 depletion. Together, we propose that NSD1 deposits H3K36me2 and recruits HDAC1 at active enhancers to serve as a 'safeguard', preventing further activation of active enhancer-associated genes. Overall design: Examination of histone markers in enhancers  in NSD1-/- and HDAC1-/- cells.