Structure of the complex between calmodulin and a functional construct of eukaryotic elongation factor 2 kinase bound to an ATP-competitive inhibitor

J Biol Chem. 2023 Jun;299(6):104813. doi: 10.1016/j.jbc.2023.104813. Epub 2023 May 11.


The calmodulin-activated α-kinase, eukaryotic elongation factor 2 kinase (eEF-2K), serves as a master regulator of translational elongation by specifically phosphorylating and reducing the ribosome affinity of the guanosine triphosphatase, eukaryotic elongation factor 2 (eEF-2). Given its critical role in a fundamental cellular process, dysregulation of eEF-2K has been implicated in several human diseases, including those of the cardiovascular system, chronic neuropathies, and many cancers, making it a critical pharmacological target. In the absence of high-resolution structural information, high-throughput screening efforts have yielded small-molecule candidates that show promise as eEF-2K antagonists. Principal among these is the ATP-competitive pyrido-pyrimidinedione inhibitor, A-484954, which shows high specificity toward eEF-2K relative to a panel of "typical" protein kinases. A-484954 has been shown to have some degree of efficacy in animal models of several disease states. It has also been widely deployed as a reagent in eEF-2K-specific biochemical and cell-biological studies. However, given the absence of structural information, the precise mechanism of the A-484954-mediated inhibition of eEF-2K has remained obscure. Leveraging our identification of the calmodulin-activatable catalytic core of eEF-2K, and our recent determination of its long-elusive structure, here we present the structural basis for its specific inhibition by A-484954. This structure, which represents the first for an inhibitor-bound catalytic domain of a member of the α-kinase family, enables rationalization of the existing structure-activity relationship data for A-484954 variants and lays the groundwork for further optimization of this scaffold to attain enhanced specificity/potency against eEF-2K.

Keywords: ATP-competitive kinase inhibitor; alpha-kinase; atypical kinase; calmodulin-dependent kinase; eukaryotic elongation factor 2 kinase; protein translation.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adenosine Triphosphate* / antagonists & inhibitors
  • Adenosine Triphosphate* / metabolism
  • Animals
  • Calmodulin* / chemistry
  • Calmodulin* / metabolism
  • Catalytic Domain
  • Elongation Factor 2 Kinase* / antagonists & inhibitors
  • Elongation Factor 2 Kinase* / chemistry
  • Elongation Factor 2 Kinase* / genetics
  • Elongation Factor 2 Kinase* / metabolism
  • Humans
  • Peptide Chain Elongation, Translational
  • Peptide Elongation Factor 2 / chemistry
  • Peptide Elongation Factor 2 / metabolism
  • Phosphorylation
  • Structure-Activity Relationship


  • Adenosine Triphosphate
  • Calmodulin
  • Elongation Factor 2 Kinase
  • Peptide Elongation Factor 2
  • EEF2K protein, human
  • A-484954