Presynaptic protein synthesis required for NT-3-induced long-term synaptic modulation

Mol Brain. 2011 Jan 7:4:1. doi: 10.1186/1756-6606-4-1.

Abstract

Background: Neurotrophins elicit both acute and long-term modulation of synaptic transmission and plasticity. Previously, we demonstrated that the long-term synaptic modulation requires the endocytosis of neurotrophin-receptor complex, the activation of PI3K and Akt, and mTOR mediated protein synthesis. However, it is unclear whether the long-term synaptic modulation by neurotrophins depends on protein synthesis in pre- or post-synaptic cells.

Results: Here we have developed an inducible protein translation blocker, in which the kinase domain of protein kinase R (PKR) is fused with bacterial gyrase B domain (GyrB-PKR), which could be dimerized upon treatment with a cell permeable drug, coumermycin. By genetically targeting GyrB-PKR to specific cell types, we show that NT-3 induced long-term synaptic modulation requires presynaptic, but not postsynaptic protein synthesis.

Conclusions: Our results provide mechanistic insights into the cell-specific requirement for protein synthesis in the long-term synaptic modulation by neurotrophins. The GyrB-PKR system may be useful tool to study protein synthesis in a cell-specific manner.

MeSH terms

  • Aminocoumarins / metabolism
  • Animals
  • DNA Gyrase / chemistry
  • DNA Gyrase / genetics
  • DNA Gyrase / metabolism
  • Dimerization
  • Long-Term Potentiation / physiology
  • Neuromuscular Junction / anatomy & histology
  • Neuromuscular Junction / physiology
  • Neuronal Plasticity / physiology*
  • Neurons / cytology
  • Neurons / metabolism
  • Neurotrophin 3 / genetics
  • Neurotrophin 3 / metabolism*
  • Patch-Clamp Techniques
  • Presynaptic Terminals / physiology*
  • Protein Biosynthesis*
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Synaptic Transmission / physiology*
  • Tissue Culture Techniques
  • Topoisomerase II Inhibitors
  • Xenopus laevis / embryology
  • eIF-2 Kinase / chemistry*
  • eIF-2 Kinase / genetics
  • eIF-2 Kinase / metabolism

Substances

  • Aminocoumarins
  • Neurotrophin 3
  • Recombinant Fusion Proteins
  • Topoisomerase II Inhibitors
  • eIF-2 Kinase
  • DNA Gyrase
  • coumermycin