GSK3 - A SHAGGY FROG STORY

Glycogen synthase kinase 3 was discovered in mammals several years ago but only recently has it become clear that this enzyme is acutely reg ulated by hormones such as insulin and by growth factors. In mammals, it appears to be controlled by a signalling pathway linked to phosphoi nositide 3-kinase and may regulate a range of biosynthetic processes. Evidence is now accumulating that GSK3 plays a key role in the regulat ion of cell fate and differentiation in many eukaryotic species.