WD-repeat protein 5 (WDR5) is a scaffold protein commonly involved in the formation of nucleosome-modifying protein complexes with histones. For example, WDR5 is a component of a mixed-lineage leukemia (MLL) methyltransferase complex that targets histone 3. WDR5 can also be a component of histone acetyltransferase complexes and can directly bind methylated as well as unmodified histones. WDR5-0103 is a small molecule that binds a peptide-binding pocket on WDR5 (Kd = 450 nM), inhibiting the catalytic activity of the MLL core complex in vitro (IC50 = 39 μM).
3-[(3-Methoxybenzoyl)amino]-4-(4-methyl-1-piperazinyl)benzoic Acid Methyl Ester is an small molecule inhibitor of WDR5, an essential componet of the human trithorax-like famliy of SET1 methyltransferase complexes that carry out trimethylation of histone 3 Lys4.