Crystal structure of glycogen synthase kinase 3 beta: structural basis for phosphate-primed substrate specificity and autoinhibition

Cell. 2001 Jun 15;105(6):721-32. doi: 10.1016/s0092-8674(01)00374-9.


Glycogen synthase kinase 3 beta (GSK3 beta) plays a key role in insulin and Wnt signaling, phosphorylating downstream targets by default, and becoming inhibited following the extracellular signaling event. The crystal structure of human GSK3 beta shows a catalytically active conformation in the absence of activation-segment phosphorylation, with the sulphonate of a buffer molecule bridging the activation-segment and N-terminal domain in the same way as the phosphate group of the activation-segment phospho-Ser/Thr in other kinases. The location of this oxyanion binding site in the substrate binding cleft indicates direct coupling of P+4 phosphate-primed substrate binding and catalytic activation, explains the ability of GSK3 beta to processively hyperphosphorylate substrates with Ser/Thr pentad-repeats, and suggests a mechanism for autoinhibition in which the phosphorylated N terminus binds as a competitive pseudosubstrate with phospho-Ser 9 occupying the P+4 site.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Binding Sites
  • Calcium-Calmodulin-Dependent Protein Kinases / antagonists & inhibitors
  • Calcium-Calmodulin-Dependent Protein Kinases / chemistry*
  • Calcium-Calmodulin-Dependent Protein Kinases / genetics
  • Calcium-Calmodulin-Dependent Protein Kinases / metabolism
  • Catalysis
  • Crystallography, X-Ray
  • Dimerization
  • Enzyme Activation
  • Glycogen Synthase Kinase 3
  • Glycogen Synthase Kinases
  • Humans
  • Insulin / metabolism*
  • Models, Molecular
  • Phosphorylation
  • Phosphoserine / metabolism
  • Phosphotyrosine / metabolism
  • Protein Binding
  • Protein Conformation*
  • Protein Structure, Secondary
  • Signal Transduction
  • Substrate Specificity


  • Insulin
  • Phosphoserine
  • Phosphotyrosine
  • Glycogen Synthase Kinases
  • Calcium-Calmodulin-Dependent Protein Kinases
  • Glycogen Synthase Kinase 3

Associated data

  • PDB/1H8F