Histone modifications play critical roles in regulating both global and stage-specific gene expression. Methylation on histones H3K4, H3K36 and H3K79 is generally associated with gene activation, whereas methylation on histones H3K9 and H3K27 is generally associated with gene repression. Histone lysine methylation is dynamically regulated by site-specific methyltransferases and demethylases. EZH2 (the catalytic subunit of PRC2) is responsible for the methylation of H3K27 in cells.
DOT1L is a histone H3 lysine 79 methyltransferase whose inhibition increases the yield of induced pluripotent stem cells (iPSCs). EPZ-5676 is a potent and selective DOT1L inhibitor.
Crucial to PRC2 activity, the histone methyltransferase enhancer of zeste homolog 2 (EZH2) tri-methylates lysine 27 of histone 3 (H3K27me3), leading to chromatin condensation and transcriptional repression.