کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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2200988 | 1099990 | 2010 | 9 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Glutamate regulates eEF1A phosphorylation and ribosomal transit time in Bergmann glial cells Glutamate regulates eEF1A phosphorylation and ribosomal transit time in Bergmann glial cells](/preview/png/2200988.png)
Glutamate, the major excitatory transmitter in the vertebrate brain, is involved in neuronal development and synaptic plasticity. Glutamatergic stimulation leads to differential gene expression patterns in neuronal and glial cells. A glutamate-dependent transcriptional control has been established for several genes. However, much less is known about the molecular events that modify the translational machinery upon exposure to this neurotransmitter. In a glial model of cerebellar cultured Bergmann cells, glutamate induces a biphasic effect on [35S]-methionine incorporation into proteins that suggests that the elongation phase of protein biosynthesis is the target for regulation. Indeed, after a 15 min exposure to glutamate a transient increase in elongation factor 2 phosphorylation has been reported, an effect mediated through the activation of the elongation factor 2 kinase.In this contribution, we sought to characterize the phosphorylation status of the eukaryotic elongation factor 1A (eEF1A) and the ribosomal transit time under glutamate exposure. A dose-dependent increase in eEF1A phosphorylation was found after a 60 min glutamate treatment; this phenomenon is Ca2+/CaM dependent, blocked with Src and phosphatidyl-inositol 3-kinase inhibitors and with rapamicyn. Concomitantly, the ribosomal transit time was increased with a 15 min glutamate exposure. After 60 more minutes, the average time used by the ribosomes to complete a polypeptide chain had almost returned to its initial level. These results strongly suggest that glutamate exerts an exquisite time-dependent translational control in glial cells, a process that might be critical for glia–neuron interactions.
Figure optionsDownload as PowerPoint slideResearch highlights▶ Glutamate augments eEF1A phosphorylation through a Ca2+/CaMKII dependent pathway. ▶ Glutamate increases ribosomal transit time in Bergmann glia cells. ▶ Glutamate regulates translation elongation in Bergmann glia cells.
Journal: Neurochemistry International - Volume 57, Issue 7, December 2010, Pages 795–803