Quantitative Profiling of Combinational K27/K36 Modifications on Histone H3 Variants in Mouse Organs.

The coexisting post-translational modifications (PTMs) on histone H3N-terminal tails were known to crosstalkbetween each other, indicating their interdependency in the epigenetic regulation pathways. H3K36 methylation, an important activating mark, was recently reported to antagonize with PRC2-mediated H3K27 methylation with possible crosstalkmechanism during transcription regulation process.1 On the basis of our previous studies, we further integrated RP/HILIC liquid chromatography with MRM mass spectrometry to quantify histonePTMs from various mouse organs, especially the combinatorial K27/K36 marks for all three major histone H3variants. Despite their subtle difference in physicochemical properties, we successfully obtained decent separation and high detection sensitivity for both histoneH3.3 specific peptides and histoneH3.1/3.2 specific peptides. In addition, the overall abundance of H3.3 can be quantified simultaneously. We applied this method to investigate the pattern of the combinatorial K...