Fusion complex formation protects synaptobrevin against proteolysis by tetanus toxin light chain.
The clostridial neurotoxin, tetanus toxin, is a Zn(2+)-dependent protease which inhibits neurotransmitter exocytosis by selective cleavage of the synaptic vesicle protein, synaptobrevin. Synaptobrevin is thought to serve as a receptor for two neuronal plasma membrane proteins, syntaxin and SNAP-25, which in the presence of non-hydrolyzable ATP analogs form a 20 S fusion complex with the soluble fusion proteins NSF and alpha-SNAP. Here we show that synaptobrevin, when in this 20 S complex, or its 7 S precursor, is protected against proteolysis by the enzymatically active tetanus toxin light chain. Our data define distinct pools of synaptobrevin, which provide markers of different steps of vesicle/plasma membrane interaction.
Abteilung Neurochemie, Max-Planck-Institut für Hirnforschung, Frankfurt/Main, Germany.
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Pellegrini
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O'Connor
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Betz
D000818:Animals; D000954:Antigens, Surface / Q000378:metabolism; D001921:Brain / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D052066:N-Ethylmaleimide-Sensitive Proteins; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D011498:Protein Precursors / Q000378:metabolism; D050683:R-SNARE Proteins; D051381:Rats; D011994:Recombinant Proteins / Q000378:metabolism; D052067:Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins; D050825:Synaptosomal-Associated Protein 25; D050827:Syntaxin 1; D013744:Tetanus Toxin / Q000737:chemistry / Q000494:pharmacology*; D033921:Vesicular Transport Proteins
D000954:Antigens, Surface; D002352:Carrier Proteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D011498:Protein Precursors; D050683:R-SNARE Proteins; D011994:Recombinant Proteins; C494210:Snap25 protein, rat; D052067:Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins; D050825:Synaptosomal-Associated Protein 25; D050827:Syntaxin 1; D013744:Tetanus Toxin; D033921:Vesicular Transport Proteins; D052066:N-Ethylmaleimide-Sensitive Proteins; C498737:Nsf protein, rat