MS049 is a potent and selective inhibitor of PRMT4 (IC50 = 34 nM) and PRMT6 (IC50 = 43 nM). It is less active against additional type I PRMTs (IC50s = >130, >220, and 1.6 μM for PRMT1, PRMT3, and PRMT8, respectively) and displays no inhibition against type II or type III PRMTs nor any additional methyltransferases or nonepigenetic targets tested.

PRMT6:43 nM, PRMT4:34 nM

HEK293 cells were grown in 12-well plates in DMEM supplemented with 10% FBS, penicillin (100 units/mL) and streptomycin (100 μg/mL). 30% confluent cells were treated with different concentrations of compounds in triplicates or DMSO control for 72 h. Cells were lysed in 100 μL of total lysis buffer (20 mM Tris-HCl pH 8, 150 mM NaCl, 1 mM EDTA, 10 mM MgCl2, 0.5% TritonX-100, 12.5 U/mL benzonase, complete EDTA-free protease inhibitor cocktail ). After 3 min incubation at RT, SDS was added to final 1% concentration. Lysates were run on SDS-PAGE and immunoblotting was done as outlined below to determine Med12-Rme2a levels in Western blot. They are for reference only.