Structural highlights
Function
[EF2K_HUMAN] Threonine kinase that regulates protein synthesis by controlling the rate of peptide chain elongation. Upon activation by a variety of upstream kinases including AMPK or TRPM7, phosphorylates the elongation factor EEF2 at a single site, renders it unable to bind ribosomes and thus inactive. In turn, the rate of protein synthesis is reduced.[1] [2]
Publication Abstract from PubMed
Binding of Ca2+-loaded calmodulin (CaM) activates eukaryotic elongation factor 2 kinase (eEF-2K) that phosphorylates eEF-2, its only known cellular target, leading to a decrease in global protein synthesis. Here, using an eEF-2K-derived peptide (eEF-2KCBD) that encodes the region necessary for its CaM-mediated activation, we provide a structural basis for their interaction. The striking feature of this association is the absence of Ca2+ from the CaM C-lobe sites, even under high Ca2+ conditions. eEF-2KCBD engages CaM largely through the C lobe of the latter in an anti-parallel 1-5-8 hydrophobic mode reinforced by a pair of unique electrostatic contacts. Sparse interactions of eEF-2KCBD with the CaM N lobe results in persisting inter-lobe mobility. A conserved eEF-2K residue (W85) anchors it to CaM by inserting into a deep hydrophobic cavity within the CaM C lobe. Mutation of this residue (W85S) substantially weakens interactions between full-length eEF-2K and CaM in vitro and reduces eEF-2 phosphorylation in cells.
Structural Basis for the Recognition of Eukaryotic Elongation Factor 2 Kinase by Calmodulin.,Lee K, Alphonse S, Piserchio A, Tavares CD, Giles DH, Wellmann RM, Dalby KN, Ghose R Structure. 2016 Sep 6;24(9):1441-1451. doi: 10.1016/j.str.2016.06.015. Epub 2016 , Aug 4. PMID:27499441[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Browne GJ, Finn SG, Proud CG. Stimulation of the AMP-activated protein kinase leads to activation of eukaryotic elongation factor 2 kinase and to its phosphorylation at a novel site, serine 398. J Biol Chem. 2004 Mar 26;279(13):12220-31. Epub 2004 Jan 5. PMID:14709557 doi:10.1074/jbc.M309773200
- ↑ Ryazanov AG, Ward MD, Mendola CE, Pavur KS, Dorovkov MV, Wiedmann M, Erdjument-Bromage H, Tempst P, Parmer TG, Prostko CR, Germino FJ, Hait WN. Identification of a new class of protein kinases represented by eukaryotic elongation factor-2 kinase. Proc Natl Acad Sci U S A. 1997 May 13;94(10):4884-9. PMID:9144159
- ↑ Lee K, Alphonse S, Piserchio A, Tavares CD, Giles DH, Wellmann RM, Dalby KN, Ghose R. Structural Basis for the Recognition of Eukaryotic Elongation Factor 2 Kinase by Calmodulin. Structure. 2016 Sep 6;24(9):1441-1451. doi: 10.1016/j.str.2016.06.015. Epub 2016 , Aug 4. PMID:27499441 doi:http://dx.doi.org/10.1016/j.str.2016.06.015
