Intraneuronal distribution of a synaptic vesicle membrane protein: antibody binding sites at axonal membrane compartments and trans-Golgi network and accumulation at nodes of Ranvier.
The distribution of a cholinergic synaptic vesicle-specific transmembrane glycoprotein (Buckley and Kelly, 1985, J. Cell Biol. 100, 1284-1294) was investigated in the entire electromotor neuron of Torpedo marmorata using a monoclonal antibody and immunocytochemistry at the light- and electron-microscopical level (immunoperoxidase, colloidal gold). In the nerve, terminal binding of immunogold particles is restricted to synaptic vesicles. In the axon a number of additional membrane compartments like multivesicular bodies, vesiculotubular structures, lamellar bodies and electron-dense granules share the surface located synaptic vesicle-specific transmembrane glycoprotein-epitope. Membranous structures likely to represent the axoplasmic reticulum inside axons and nerve terminals are not labelled. Antibody-binding membrane compartments are accumulated at nodes of Ranvier. In the perikaryon the tubules of the trans-Golgi network as well as multivesicular bodies, lamellar bodies, electron-lucent vesicles, granules with electron-dense core and peroxisomes are labelled. Immunotransfer blots of isolated synaptic vesicles and tissue extracts of electric organ display a 100,000 mol. wt band of broad electrophoretic mobility typical of the synaptic vesicle-specific transmembrane glycoprotein. Extracts of electromotor nerve and electric lobe contain in addition a strong band at 85,000 mol. wt and a few lower molecular weight bands. We suggest that the synaptic vesicle originates directly from the trans-Golgi network. The endoplasmic reticulum is not involved in vesicle formation or retrieval. On retrograde transport the vesicle membrane compartment is likely to fuse with other intra-axonal (endosomal?) organelles.
Janetzko
A
A
AK Neurochemie, Zoologisches Institut der J. W. Goethe-Universität, Frankfurt am Main, F.R.G.
Zimmermann
H
H
Volknandt
W
W
D000818:Animals; D000954:Antigens, Surface / Q000378:metabolism*; D001369:Axons / Q000378:metabolism*; D004557:Electric Organ / Q000378:metabolism* / Q000648:ultrastructure; D006056:Golgi Apparatus / Q000378:metabolism*; D007150:Immunohistochemistry; D008970:Molecular Weight; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D011901:Ranvier's Nodes / Q000378:metabolism*; D013572:Synaptic Vesicles / Q000378:metabolism*; D014101:Torpedo
D000954:Antigens, Surface; D009419:Nerve Tissue Proteins