Glycogen synthase kinase-3 alpha is an enzyme that in humans is encoded by the GSK3A gene. Glycogen synthase kinase 3-alpha EC 2.7.1.37 is a multifunctional protein serine kinase, homologous to Drosophila 'shaggy' (zeste-white3) and implicated in the control of several regulatory proteins including glycogen synthase and various transcription factors (e.g., JUN). It also plays a role in the WNT and phosphoinositide 3-kinase (especially PIK3CG) signaling pathways.