Comparative characterization of the seven H3K4 methyltransferase in Arabidopsis thaliana

Methylation of H3 lysine 4 (H3K4me) marks transcribed elements of the eukaryotic genome, and their distribution alters dynamically through developmental stages and environmental change. These dynamic regulations are likely achieved by the combinatorial work of H3K4me writers, which multi-cellular organisms carry multiple copies of. To better understand the chromatin targeting mechanisms of H3K4 methyltransferase in plants, here we comparatively characterized the seven H3K4 methyltransferases (ATX(R)s) in model plants Arabidopsis. This MS dataset, complemented with the ChIP-seq and AlphaScreen, provides a characterization of ATX(R)s protein. This work clarified, in combination with previous results, ATX1-5 (TRX/TRR-type methyltransferase) localizes on loci with specific sets of chromatin modifications and DNA motifs. Notably, ATXR3, the major H3K4me3 methyltransferase in Arabidopsis, was not associated with COMPASS, which suggests H3K4me3 regulation in plants and animals is divergent. Our work provides a foundation for understanding the regulation of H3K4 methyltransferases in plants.