2. Academic Validation
  3. Dynamin inhibition blocks botulinum neurotoxin type A endocytosis in neurons and delays botulism

Dynamin inhibition blocks botulinum neurotoxin type A endocytosis in neurons and delays botulism

  • J Biol Chem. 2011 Oct 14;286(41):35966-35976. doi: 10.1074/jbc.M111.283879.
Callista B Harper 1,  Sally Martin 1,  Tam H Nguyen 1,  Shari J Daniels 1,  Nickolas A Lavidis 2,  Michel R Popoff 3,  Gordana Hadzic 4,  Anna Mariana 5,  Ngoc Chau 5,  Adam McCluskey 4,  Phillip J Robinson 5,  Frederic A Meunier 6
Affiliations

Affiliations

  • 1 Queensland Brain Institute, the University of Queensland, Brisbane, Queensland 4072, Australia.
  • 2 School of Biomedical Sciences, the University of Queensland, Brisbane, Queensland 4072, Australia.
  • 3 Unité des Bactéries anaérobies et Toxines, Institut Pasteur, 28 rue du Dr. Roux, 75724 Paris cedex, France.
  • 4 Centre for Chemical Biology, Chemistry Building, the University of Newcastle, Callaghan, New South Wales 2308, Australia.
  • 5 Children's Medical Research Institute, the University of Sydney, Sydney, New South Wales 2145, Australia.
  • 6 Queensland Brain Institute, the University of Queensland, Brisbane, Queensland 4072, Australia. Electronic address: [email protected].
PMID: 21832053 DOI: 10.1074/jbc.M111.283879
Abstract

The botulinum neurotoxins (BoNTs) are di-chain Bacterial proteins responsible for the paralytic disease botulism. Following binding to the plasma membrane of cholinergic motor nerve terminals, BoNTs are internalized into an endocytic compartment. Although several endocytic pathways have been characterized in neurons, the molecular mechanism underpinning the uptake of BoNTs at the presynaptic nerve terminal is still unclear. Here, a recombinant BoNT/A heavy chain binding domain (Hc) was used to unravel the internalization pathway by fluorescence and electron microscopy. BoNT/A-Hc initially enters cultured hippocampal neurons in an activity-dependent manner into synaptic vesicles and clathrin-coated vesicles before also entering endosomal structures and multivesicular bodies. We found that inhibiting Dynamin with the novel potent Dynasore analog, Dyngo-4a(TM), was sufficient to abolish BoNT/A-Hc internalization and BoNT/A-induced SNAP25 cleavage in hippocampal neurons. Dyngo-4a also interfered with BoNT/A-Hc internalization into motor nerve terminals. Furthermore, Dyngo-4a afforded protection against BoNT/A-induced paralysis at the rat hemidiaphragm. A significant delay of >30% in the onset of botulism was observed in mice injected with Dyngo-4a. Dynamin inhibition therefore provides a therapeutic avenue for the treatment of botulism and Other Diseases caused by pathogens sharing dynamin-dependent uptake mechanisms.

Figures
Products