Tankyrases (TNKS) are poly-ADP-ribosyltransferases, which cleave NAD+ to produce nicotinamide and ADP-ribose, which is then covalently attached to an acceptor protein in a process known as poly(ADP-ribosyl)ation. MN-64 is a potent inhibitor of TNKS1 and TNKS2 (IC50s = 6 and 72 nM, respectively). It is ineffective against several poly(ADP-ribosyl) polymerases (IC50 > 19 μM). Through its effects on TNKS, MN-64 inhibits signaling along the Wnt/β-catenin pathway in a cell-based reporter assay.
