Menin is a 'reader' of histone H3 lysine 79 methylation (RNA-Seq)

Methylation of histone H3 lysine-79 is an epigenetic mark for gene regulation in development, cellular differentiation and disease progression. However, it remains poorly understood how this histone mark is translated into downstream effects due to the lack of knowledge of H3K79 methylation 'readers'. Here, we develop a nucleosome-based photoaffinity probe to capture proteins that recognize H3K79 dimethylation (H3K79me2) in nucleosomal context. In combination with a quantitative proteomics approach, this probe identifies menin as a bona fide “reader” for H3K79me2. Menin directly and selectively binds to the nucleosome with H3K79me2 mark in vitro. In cells, menin is tightly associated with this histone mark on chromatin, particularly in gene bodies. Reading H3K79me2 at intragenic enhancers, menin promotes gene transcription, likely by mediating enhancer–promoter interactions. Overall design: MCF7 cells were treated with EPZ5676 or DMSO control. RNA-seq was performed in triplicates for each condition.