Increase in synaptic vesicle proteins in synapsin-transfected NG108-15 cells: a subcellular fractionation study.
We have examined the subcellular distribution of synapsins and synaptophysin in density gradients from synapsin- and vector-transfected NG108-15 cells, since we recently found that transfection of synapsin IIb cDNA into neuroblastoma x glioma hybrid cells (NG108-15) resulted in cell lines that had a more neuronal phenotype than controls. The increase in synapsins and synaptophysin in the transfected cells was maximal in the region of the gradient containing small synaptic vesicles. The transferrin receptor, a marker for early endosomes, did not increase in the synapsin-containing fractions in the transfected cells. Secretogranin I, a soluble protein stored in and secreted from large dense cored vesicles, showed a very pronounced increase in the dense regions of gradients from transfected cells. These subcellular fractionation data suggest a possible role for the synapsins in the regulation of synaptic vesicle function.
Fried
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Department of Molecular and Cellular Neuroscience, Rockefeller University, New York, New York 10021, USA.
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D000818:Animals; D001345:Autoradiography; D002499:Centrifugation, Density Gradient; D004247:DNA / Q000096:biosynthesis; D004591:Electrophoresis, Polyacrylamide Gel; D015151:Immunoblotting; D007150:Immunohistochemistry; D016253:Microscopy, Immunoelectron; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009447:Neuroblastoma / Q000378:metabolism; D051381:Rats; D013347:Subcellular Fractions / Q000378:metabolism; D016704:Synapsins / Q000378:metabolism*; D013572:Synaptic Vesicles / Q000378:metabolism* / Q000648:ultrastructure; D014162:Transfection; D014407:Tumor Cells, Cultured
D009419:Nerve Tissue Proteins; D016704:Synapsins; D004247:DNA