Medical College of Wisconsin
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Botulinum neurotoxin Light Chain/A1 uses fast synaptic vesicle cycling to cleave plasma membrane bound SNAP-25. Commun Biol 2025 Sep 29;8(1):1383

Date

09/30/2025

Pubmed ID

41023315

Pubmed Central ID

PMC12480579

DOI

10.1038/s42003-025-08633-4

Scopus ID

2-s2.0-105017790990 (requires institutional sign-in at Scopus site)   1 Citation

Abstract

Botulinum neurotoxins (BoNT) are the most potent protein toxins for humans, yet how BoNT-Light Chain/A1 (LC/A1) journeys to cleave intracellular SNAP-25 is understudied. Here we use a cell-based assay to measure cytosolic EGFP-LC/A1 intracellular trafficking and SNAP-25 cleavage in Neuro-2A cells. Intracellular LC/A1 associated on microtubules and co-localized with Rab GTPases involved in fast synaptic vesicles and endosome recycling. Multiple Dominant Negative (DN) Rabs GTPases involved in fast synaptic vesicles or endosome recycling inhibited LC/A1 trafficking to the intracellular plasma membrane and SNAP-25 cleavage. A cytosolic LC/A1 variant that bound the plasma membrane from the cytosol was insensitive to DNRab GTPases involved in fast synaptic vesicle recycling. LC/A1 traffics on fast synaptic vesicles to the intracellular plasma membrane to cleave SNAP-25. Our data suggest, like Heavy Chain host cell entry and LC catalysis, LC intracellular trafficking to target host substrates can contribute to bacterial toxin potency.

Author List

Gardner A, Sneller M, Tepp WH, Barbieri JT, Pellett S

Author

Joseph T. Barbieri PhD Professor in the Microbiology and Immunology department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Animals
Botulinum Toxins
Botulinum Toxins, Type A
Cell Membrane
Humans
Mice
Protein Transport
Synaptic Vesicles
Synaptosomal-Associated Protein 25