NMDAR‐dependent Argonaute 2 phosphorylation regulates miRNA activity and dendritic spine plasticity

• Dipen Rajgor ^[1] ; Thomas M Sanderson ^[1] ; Mascia Amici ^[1] ; Graham L Collingridge ^[2] ; Jonathan G Hanley ^[1]
  1. [1] University of Bristol

     University of Bristol

     Reino Unido

     
  2. [2] 2 Centre for Synaptic Plasticity and School of Physiology, Pharmacology & Neuroscience University of Bristol Bristol UK; 3 Department of Physiology Faculty of Medicine University of Toronto Toronto ON Canada; 4 Lunenfeld‐Tanenbaum Research Institute Mount Sinai Hospital Toronto ON Canada
• Localización: EMBO journal: European Molecular Biology Organization, ISSN 0261-4189, Vol. 37, Nº. 11, 2018, págs. 7-7
• Idioma: inglés
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• Resumen

  • MicroRNAs (miRNAs) repress translation of target mRNAs by associating with Argonaute (Ago) proteins to form the RNA‐induced silencing complex (RISC), underpinning a powerful mechanism for fine‐tuning protein expression. Specific miRNAs are required for NMDA receptor (NMDAR)‐dependent synaptic plasticity by modulating the translation of proteins involved in dendritic spine morphogenesis or synaptic transmission. However, it is unknown how NMDAR stimulation stimulates RISC activity to rapidly repress translation of synaptic proteins. We show that NMDAR stimulation transiently increases Akt‐dependent phosphorylation of Ago2 at S387, which causes an increase in binding to GW182 and a rapid increase in translational repression of LIMK1 via miR‐134. Furthermore, NMDAR‐dependent down‐regulation of endogenous LIMK1 translation in dendrites and dendritic spine shrinkage requires phospho‐regulation of Ago2 at S387. AMPAR trafficking and hippocampal LTD do not involve S387 phosphorylation, defining this mechanism as a specific pathway for structural plasticity. This work defines a novel mechanism for the rapid transduction of NMDAR stimulation into miRNA‐mediated translational repression to control dendritic spine morphology.