SNAREs constitute the core machinery of intracellular membrane fusion, but vesicular SNAREs localize to specific compartments via largely unknown mechanisms. Here, we identified an interaction between VAMP7 and SNAP-47 using a proteomics approach. We found that SNAP-47 mainly localized to cytoplasm, the endoplasmic reticulum (ER), and ERGIC and could also shuttle between the cytoplasm and the nucleus.
View Article and Find Full Text PDFThe brain is particularly vulnerable to ischaemia; however, neurons can become tolerant to ischaemic insult. This tolerance has been shown to involve activation of NMDA receptors, but its mechanisms have not yet been fully elucidated. Using a preconditioning protocol, we show that neurons surviving to a transient NMDA exposure become resistant to the glutamatergic agonist.
View Article and Find Full Text PDFCerebral ischaemia is associated with brain damage and inhibition of neuronal protein synthesis. A deficit in neuronal metabolism and altered excitatory amino acid release may both contribute to those phenomena. In the present study, we demonstrate that both NMDA and metabolic impairment by 2-deoxyglucose or inhibitors of mitochondrial respiration inhibit protein synthesis in cortical neurons through the phosphorylation of eukaryotic elongation factor (eEF-2), without any change in phosphorylation of initiation factor eIF-2alpha.
View Article and Find Full Text PDFCRMP1, CRMP2, and CRMP5 have been identified as cytosolic proteins relaying semaphorin 3A signalling, one of the molecular cues conducting axon and dendrite growth and guidance. They are highly expressed during brain ontogenesis, but, because of their lower levels in the adult, their distribution in the mature brain is poorly documented. By using specific antibodies, we investigated the cellular distribution of these CRMPs in different adult brain structures and in neural cell cultures with a special focus on the splice variants CRMP2A and CRMP2B.
View Article and Find Full Text PDFTransient cerebral ischemia, which is accompanied by a sustained release of glutamate, strongly depresses protein synthesis. We have previously demonstrated in cortical neurons that a glutamate-induced increase in intracellular Ca(2+) is likely responsible for the blockade of the elongation step of protein synthesis. In this study, we provide evidence indicating that NMDA mobilizes a thapsigargin-sensitive pool of intracellular Ca(2+).
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