title: Dynamics of elongation factor 2 kinase regulation in cortical neurons in response to synaptic activity.
abstract: The rapid regulation of cell signaling in response to calcium in neurons is essential for real-time processing of large amounts of information in the brain. A vital regulatory component, and one of the most energy-intensive biochemical processes in cells, is the elongation phase of mRNA translation, which is controlled by the Ca(2+)/CaM-dependent elongation factor 2 kinase (eEF2K). However, little is known about the dynamics of eEF2K regulation in neurons despite its established role in learning and synaptic plasticity. To explore eEF2K dynamics in depth, we stimulated synaptic activity in mouse primary cortical neurons. We find that synaptic activity results in a rapid, but transient, increase in eEF2K activity that is regulated by a combination of AMPA and NMDA-type glutamate receptors and the mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK) and mammalian target of rapamycin complex 1 (mTORC1) pathways. We then used computational modeling to test the hypothesis that considering Ca(2+)-coordinated MEK/ERK, mTORC1, and eEF2k activation is sufficient to describe the observed eEF2K dynamics. Although such a model could partially fit the empirical findings, it also suggested that a crucial positive regulator of eEF2K was also necessary. Through additional modeling and empirical evidence, we demonstrate that AMP kinase (AMPK) is also an important regulator of synaptic activity-driven eEF2K dynamics in neurons. Our combined modeling and experimental findings provide the first evidence that it is necessary to consider the combined interactions of Ca(2+) with MEK/ERK, mTORC1, and AMPK to adequately explain eEF2K regulation in neurons.
authors.affiliation: University of Southampton, Centre for Biological Sciences, Southampton, SO17 1BJ, United Kingdom.
authors.forename: Justin W
authors.initials: JW
authors.lastname: Kenney
authors.affiliation: University of Edinburgh, School of Informatics, Edinburgh, EH8 9AB, United Kingdom, and.
authors.forename: Oksana
authors.initials: O
authors.lastname: Sorokina
authors.affiliation: University of Southampton, Centre for Biological Sciences, Southampton, SO17 1BJ, United Kingdom.
authors.forename: Maja
authors.initials: M
authors.lastname: Genheden
authors.affiliation: Institute of Cell Biophysics, Pushchino, 142290, Russia.
authors.forename: Anatoly
authors.initials: A
authors.lastname: Sorokin
authors.affiliation: University of Edinburgh, School of Informatics, Edinburgh, EH8 9AB, United Kingdom, and C.G.Proud@soton.ac.uk douglas.armstrong@ed.ac.uk.
authors.forename: J Douglas
authors.initials: JD
authors.lastname: Armstrong
authors.affiliation: University of Southampton, Centre for Biological Sciences, Southampton, SO17 1BJ, United Kingdom, C.G.Proud@soton.ac.uk douglas.armstrong@ed.ac.uk.
authors.forename: Christopher G
authors.identifier: http://orcid.org/0000-0003-0704-6442
authors.initials: CG
authors.lastname: Proud
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001640:Bicuculline / Q000494:pharmacology; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology*; D003198:Computer Simulation; D054736:Elongation Factor 2 Kinase / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018683:Excitatory Amino Acid Agents / Q000494:pharmacology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D058787:GABA-A Receptor Antagonists / Q000494:pharmacology; D000076222:Mechanistic Target of Rapamycin Complex 1; D051379:Mice; D008810:Mice, Inbred C57BL; D008959:Models, Neurological; D046912:Multiprotein Complexes / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D017711:Nonlinear Dynamics; D010766:Phosphorylation / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects; D013569:Synapses / Q000187:drug effects / Q000502:physiology*; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism
chemical_list: D004791:Enzyme Inhibitors; D018683:Excitatory Amino Acid Agents; D058787:GABA-A Receptor Antagonists; D046912:Multiprotein Complexes; D000076222:Mechanistic Target of Rapamycin Complex 1; D058570:TOR Serine-Threonine Kinases; D054736:Elongation Factor 2 Kinase; D048049:Extracellular Signal-Regulated MAP Kinases; D001640:Bicuculline
keywords: AMPK; ERK; bicuculline; dynamical systems; mTORC1; translation elongation