Subcellular localization of neural-specific NPDC-1 protein.
NPDC-1 is a gene specifically expressed in neural cells when they stop to divide and begin to differentiate. Immunocytochemical study analysis of differentiated PC12 cells transfected with NPDC-tag vectors showed that NPDC-1 is transported in vesicles from the Golgi apparatus to the cell membrane and is then likely internalized into endosomes. The protein colocalized, at least partially, with synaptic vesicle proteins: synaptophysin, synaptobrevin 2, and Rab3 GEP (Rab3 GTP/GDP exchange protein). Moreover, subcellular fractionation of rat brain showed that crude synaptic membrane and crude synaptic vesicle fractions were enriched in NPDC-1. Although NPDC-1 bound Rab3 GEP in vitro, it seems unlikely to be involved in Ca2+-dependent exocytosis and, thus, in synaptic vesicle trafficking.
Evrard
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Laboratoire Biologie Moléculaire et Différenciation, Unité de Génétique Oncologique, CNRS-URA 8125, Institut Gustave Roussy, Villejuif, France. clevrard@free.fr
Rouget
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D000818:Animals; D015153:Blotting, Western / Q000379:methods; D001921:Brain / Q000166:cytology / Q000378:metabolism; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology*; D018834:Chaperonin 60 / Q000378:metabolism; D003001:Cloning, Molecular / Q000379:methods; D004622:Embryo, Mammalian; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008565:Membrane Proteins / Q000378:metabolism; D016296:Mutagenesis / Q000502:physiology; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D009474:Neurons / Q000166:cytology*; D016716:PC12 Cells; D050683:R-SNARE Proteins; D051381:Rats; D017208:Rats, Wistar; D013347:Subcellular Fractions / Q000378:metabolism*; D014162:Transfection / Q000379:methods; D020692:rab3 GTP-Binding Proteins / Q000378:metabolism
D018834:Chaperonin 60; D008565:Membrane Proteins; C484270:NPDC1 protein, human; C502007:NPDC1 protein, rat; D009419:Nerve Tissue Proteins; D050683:R-SNARE Proteins; D049452:Green Fluorescent Proteins; D020692:rab3 GTP-Binding Proteins