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Specific interaction between Sam68 and neuronal mRNAs: implication for the activity-dependent biosynthesis of
Julien Grange1, Agnès Belly, Stéphane Dupas
1Université Joseph Fourier, Grenoble Institute of Neuroscience, Grenoble, France.
Journal of Neuroscience Research
|August 20, 2008
Summary
The splicing protein Sam68 moves to neuron dendrites and binds to plasticity-related mRNAs like Eef1a1. Sam68 enhances the translation of Eef1a1 mRNA, crucial for long-term synaptic changes.
Area of Science:
- Neuroscience
- Molecular Biology
- Cell Biology
Background:
- The splicing regulatory protein Sam68 is found in the adult brain and cultured neurons.
- Sam68 relocates to neuronal somatodendritic domains and associates with dendritic polysomes in an activity-dependent manner.
Purpose of the Study:
- To investigate the neuronal mRNAs bound by Sam68 in vivo.
- To explore the role of Sam68 in the utilization of plasticity-related mRNAs, specifically Eef1a1.
Main Methods:
- Coimmunoprecipitation and microarray screening to identify Sam68-associated mRNAs.
- Neuronal depolarization in cortical cultures to study Eef1a1 mRNA translation.
- Expression of a dominant-negative Sam68 mutant (GFP-Sam68DeltaC) in hippocampal neurons.
Main Results:
- Sam68 associates with plasticity-related mRNAs, including Eef1a1.
- Neuronal depolarization induces Eef1a1 mRNA translation and increases Sam68 association with polysomal mRNAs.
- Inhibition of Sam68 function reduces eEF1A protein levels, suggesting Sam68 promotes Eef1a1 mRNA translation.
Conclusions:
- Sam68 plays a role in enhancing the translational efficiency of Eef1a1 mRNA.
- These findings highlight the complex regulation of eEF1A biosynthesis during long-term synaptic plasticity.
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