In order to form long-term memories, it is necessary to strengthen existing neural circuits or to form new circuits, which require dendritic local protein synthesis. Previously, I identified eEF1A, a protein translation factor, in postsynaptic membran ...
In order to form long-term memories, it is necessary to strengthen existing neural circuits or to form new circuits, which require dendritic local protein synthesis. Previously, I identified eEF1A, a protein translation factor, in postsynaptic membrane (the postsynaptic density, PSD). Yeast two-hybrid selected N-acetylglucosamine kinase (GlcNAc kinase, NAGK) for eEF1A-binding partner. In this work, the interaction of eEF1A and NAGK was confirmed by co-immunoprecipitation. Whn DIV21 hippocampal neurons were immunostained with NAGK antiboy, NAGK immunopunctae were distributed throughout dendrites. The NAGK punctae did not overlap eEF1A or NR2B, but abut each other. In the early morphological development, both eEF1A and NAGK were highly expressed at the protrusion of cell membranes, such as filopodia and growthcone. Interestingly, the subcellular distribution of NAGK was very similar to that of microtubule. The expression of NAGK overlapped with actin in the early developmental stages but not in mature neurons. When microtubule was dissociated by vincristine, microtubule formed paracrystals which were disposed either randomly to somatodendritic shaft or periphery of the shaft. In either cases, NAGK followed microtubules. When microtubules were partially recovered, NAGK returned to normal distribution. However, there was no significant alteration in subcellular distribution when microfilaments were dissociated by latrunculin, indicating that microtubule regulates the distribution of NAGK. Taken together, these results suggest that eEF1A, in association with NAGK, have a role in changing membrane morphology such as in the formation of filopodia, growthcone, and dendritic spines.