Protein arginine methyltransferases (PRMTs) are essential epigenetic players in living cells. The dysregulation of PRMTs is closely related to many diseases, including cancer. Based on previously reported PRMT1 inhibitors bearing the diamidine pharmacophore, a combinatorial high throughput screening strategy led to compound K313, which possesses a biochemical IC50 value of 0.84 µM against PRMT1.

Histone code is the post-translational modification patterns appear at histone, which regulates transcription and many other cellular events. H4R3 is one of the important substrates for both PRMT1 and PRMT5. PRMTs are important in establishing histone code. They are also regulated by the histone code. In this study, we explored the mechanism of how the post-translational modifications on H4 tail peptide affect the activity of PRMTs.