The role of selective transport in neuronal protein sorting.
To assess whether selective microtubule-based vesicle transport underlies the polarized distribution of neuronal proteins, we expressed green fluorescent protein- (GFP-) tagged chimeras of representative axonal and dendritic membrane proteins in cultured hippocampal neurons and visualized the transport of carrier vesicles containing these proteins in living cells. Vesicles containing a dendritic protein, transferrin receptor (TfR), were preferentially transported into dendrites and excluded from axons. In contrast, vesicles containing the axonal protein NgCAM (neuron-glia cell adhesion molecule) were transported into both dendrites and axons. These data demonstrate that neurons utilize two distinct mechanisms for the targeting of polarized membrane proteins, one (for dendritic proteins) based on selective transport, the other (for axonal proteins) based on a selectivity "filter" that occurs downstream of transport.
Burack
M A
MA
Center for Research on Occupational and Environmental Toxicology, Oregon Health Sciences University, Portland 97201, USA.
Silverman
M A
MA
Banker
G
G
D000818:Animals; D001369:Axons / Q000378:metabolism; D001692:Biological Transport / Q000502:physiology; D019062:Cell Adhesion Molecules, Neuron-Glia / Q000378:metabolism; D002462:Cell Membrane / Q000502:physiology; D016764:Cell Polarity / Q000502:physiology; D002478:Cells, Cultured; D002678:Chimera / Q000502:physiology; D003712:Dendrites / Q000378:metabolism; D005089:Exocytosis / Q000502:physiology; D049452:Green Fluorescent Proteins; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism; D007202:Indicators and Reagents; D008164:Luminescent Proteins / Q000235:genetics; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009474:Neurons / Q000502:physiology; D051381:Rats; D011990:Receptors, Transferrin / Q000378:metabolism
D019062:Cell Adhesion Molecules, Neuron-Glia; D007202:Indicators and Reagents; D008164:Luminescent Proteins; D009419:Nerve Tissue Proteins; D011990:Receptors, Transferrin; D049452:Green Fluorescent Proteins