title: Eukaryotic elongation factor 2 kinase regulates the cold stress response by slowing translation elongation.
abstract: Cells respond to external stress conditions by controlling gene expression, a process which occurs rapidly via post-transcriptional regulation at the level of protein synthesis. Global control of translation is mediated by modification of translation factors to allow reprogramming of the translatome and synthesis of specific proteins that are required for stress protection or initiation of apoptosis. In the present study, we have investigated how global protein synthesis rates are regulated upon mild cooling. We demonstrate that although there are changes to the factors that control initiation, including phosphorylation of eukaryotic translation initiation factor 2 (eIF2) on the α-subunit, the reduction in the global translation rate is mediated by regulation of elongation via phosphorylation of eukaryotic elongation factor 2 (eEF2) by its specific kinase, eEF2K (eukaryotic elongation factor 2 kinase). The AMP/ATP ratio increases following cooling, consistent with a reduction in metabolic rates, giving rise to activation of AMPK (5'-AMP-activated protein kinase), which is upstream of eEF2K. However, our data show that the major trigger for activation of eEF2K upon mild cooling is the release of Ca2+ ions from the endoplasmic reticulum (ER) and, importantly, that it is possible to restore protein synthesis rates in cooled cells by inhibition of this pathway at multiple points. As cooling has both therapeutic and industrial applications, our data provide important new insights into how the cellular responses to this stress are regulated, opening up new possibilities to modulate these responses for medical or industrial use at physiological or cooler temperatures.
authors.affiliation: *Medical Research Council Toxicology Unit, Lancaster Road, Leicester LE1 9HN, U.K.
authors.forename: John R P
authors.initials: JR
authors.lastname: Knight
authors.affiliation: *Medical Research Council Toxicology Unit, Lancaster Road, Leicester LE1 9HN, U.K.
authors.forename: Amandine
authors.initials: A
authors.lastname: Bastide
authors.affiliation: †School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, U.K.
authors.forename: Anne
authors.initials: A
authors.lastname: Roobol
authors.affiliation: †School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, U.K.
authors.forename: Jo
authors.initials: J
authors.lastname: Roobol
authors.affiliation: *Medical Research Council Toxicology Unit, Lancaster Road, Leicester LE1 9HN, U.K.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Jackson
authors.affiliation: ‡Centre for Analytical Bioscience, School of Pharmacy, University Park, University of Nottingham, Nottingham NG7 2RD, U.K.
authors.forename: Wahyu
authors.initials: W
authors.lastname: Utami
authors.affiliation: ‡Centre for Analytical Bioscience, School of Pharmacy, University Park, University of Nottingham, Nottingham NG7 2RD, U.K.
authors.forename: David A
authors.initials: DA
authors.lastname: Barrett
authors.affiliation: †School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, U.K.
authors.forename: C Mark
authors.initials: CM
authors.lastname: Smales
authors.affiliation: *Medical Research Council Toxicology Unit, Lancaster Road, Leicester LE1 9HN, U.K.
authors.forename: Anne E
authors.initials: AE
authors.lastname: Willis
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism; D000249:Adenosine Monophosphate / Q000235:genetics / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000235:genetics / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D058639:Cold-Shock Response / Q000502:physiology*; D054736:Elongation Factor 2 Kinase / Q000235:genetics / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000235:genetics / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D010441:Peptide Chain Elongation, Translational / Q000502:physiology*; D010766:Phosphorylation / Q000502:physiology
chemical_list: D000249:Adenosine Monophosphate; D000255:Adenosine Triphosphate; C517689:EEF2K protein, human; D054736:Elongation Factor 2 Kinase; D055372:AMP-Activated Protein Kinases; D002118:Calcium