SB216763 #13621

The maleimide derivative SB216763 is a potent and selective cell permeable inhibitor of glycogen synthase kinase 3 (GSK-3). Research studies using peptide-based protein kinase assays show that SB216763 inhibits GSK-3α in an ATP competitive manner with an IC₅₀ of 34 nM, and is an equally effective GSK3-β inhibitor. Similar assays demonstrate that SB216763 (at concentrations up to 10 µM) does not inhibit as many as 24 other serine/threonine and tyrosine protein kinases (1). As a consequence of inhibiting GSK-3, SB216763 stimulates glycogen synthesis in human liver cells (EC₅₀ 3.6 µM) via glycogen synthase activation and induces expression of a β-catenin regulated reporter gene in HEK293 cells (1). Furthermore, SB216763 induces accumulation of β-catenin, a key downstream effector in the Wnt signaling pathway, in many cell types (2-5). Additional research indicates that SB216763 can prevent neuronal cell death induced by PI3 kinase pathway inhibition (2). Glycogen synthase kinase 3 inhibitors such as SB216763 can be important research tools in studying the functional role of GSK-3 in cell signaling pathways.