Please note that we have stopped the regular imports of Gene Expression Omnibus (GEO) data into ArrayExpress. This may not be the latest version of this experiment.
E-GEOD-50209 - Genome-wide maps of MLL4 during brown preadipocyte differentiation
Released on 17 December 2013, last updated on 3 June 2014
Enhancers play a central role in cell-type-specific gene expression and are marked by H3K4me1/2. Active enhancers are further marked by H3K27ac. However, the methyltransferases responsible for the deposition of H3K4me1/2 on enhancers remain elusive. Furthermore, the functions of these methyltransferases on enhancers and associated cell-type-specific gene expression are poorly understood. Here, we identify MLL4 (KMT2D) as a major H3K4 mono- and di-methyltransferase in mammalian cells. Using adipogenesis and myogenesis as model systems, we show that MLL4 exhibits cell-type- and differentiation-stage-specific genomic binding and is predominantly localized on enhancers. MLL4 co-localizes with lineage-determining transcription factors (TFs) on active enhancers during differentiation. Deletion of MLL4 dramatically decreases H3K4me1/2 and H3K27ac on enhancers and leads to severe defects in cell-type-specific gene expression and cell differentiation. Finally, we provide evidence that lineage-determining TFs recruit and require MLL4 to establish enhancers critical for cell-type-specific gene expression. Together, these results identify MLL4 as an H3K4 mono-/di-methyltransferase required for enhancer activation during cell differentiation. ChIP-Seq analyses of MLL4 binding profiles at D0 (day 0), D2 (day 2), and D7 (day 7) of adipogenesis in WT (MLL3-/-) and MLL4 KO (MLL3-/-;MLL4-/-) brown preadipocytes. D0 and D2 input DNA samples can be found in GSE50417.
Chaochen Wang, Ji-Eun Lee, Kai Ge, Shiliyang Xu, Weiqun Peng