Effects of Botulinum Neurotoxin a on Protein Phosphorylation in Synaptosomes

  • Dennis L. Leatherman
  • John L. Middlebrook


The phosphorylation of presynaptic proteins was examined in the presence of chlorpromazine using synaptic lysates derived from rat brain synaptosomes that had been preincubated with or without botulinum neurotoxin A. Chlorpromazine increased the phosphorylated state of a number of phosphoproteins with apparent molecular weights (Mrs) between 40 and 60 kilodaltons. The drug’s most prominent effect was a 2.5–3.5-fold increase in the incorporation of phosphate into a peptide of Mr~43 kilodaltons (pp43), as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis. After preincubation with toxin, the chlorpromazine-promoted increase in the phosphorylated state of pp43 was inhibited in a concentration- and temperature-dependent manner.


Botulinum Toxin Botulinum Neurotoxin Synaptic Plasma Membrane Krebs Ringer Buffer Botulinum Neurotoxin Type 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Dolly JO, Black JD, Williams RS, Melling J. Acceptors for botulinum neurotoxin reside on motor nerve terminals and mediate its internalization. Nature 1984; 307: 457–460.PubMedCrossRefGoogle Scholar
  2. 2.
    Simpson LL. Kinetic studies on the interaction between botulinum toxin type A and the cholinergic neuromuscular junction. J Pharmacol Exp Ther 1980; 212: 16–21.PubMedGoogle Scholar
  3. 3.
    Poulain B, Tauc L, Mohan PM, Maisey EA, Wadsworth JDF, Dolly JO. Intracellular toxicity of botulinum neurotoxins A and B and their purified subunits studied at central synapses of Aplysia. Neuroscience 1987; 22:Suppl 1215p.Google Scholar
  4. 4.
    McInnes C, Dolly JO. Cat+-dependent noradrenaline release from permeabilized PC12 cells is blocked by botulinum neurotoxin A or its light chain. FEBS Lett 1990; 261: 323–326.PubMedCrossRefGoogle Scholar
  5. 5.
    Ashton AC, Dolly JO. Characterization of the inhibitory action of botulinum neurotoxin type A on the release of several neurotransmitters from rat cerebrocortical synaptosomes. J Neurochem 1988; 50: 1808–1816.PubMedCrossRefGoogle Scholar
  6. 6.
    Bitther MA, Dasgupta BR, Holz RW. Isolated light chains of botulinum neurotoxins inhibit exocytosis. Studies in digitonin-permeabilized chromaffin cells. J Biol Chem 1989; 264: 10354–10360.Google Scholar
  7. 7.
    Walass SI, Greengard P. Protein phosphorylation and neuronal function. Pharmacol Rev 1991; 43: 299349.Google Scholar
  8. 8.
    Lowry OH, Rosebrough NJ, Farr AL, Randall RJ. Protein measurement with the Folin phenol reagent. J Biol Chem 1951; 193: 265–275.PubMedGoogle Scholar
  9. 9.
    Cotman CW. Isolation of synaptosomal and synaptic plasma membrane fractions. In: Fleischer S, and Packer L, eds. Meth Enzymol 31. New York: Academic Press, 1974: 445.Google Scholar
  10. 10.
    Simpson LL. The origin, structure and pharmacological activity of botulinum toxin. Pharmacol Rev 1981; 33: 155–188.PubMedGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1993

Authors and Affiliations

  • Dennis L. Leatherman
    • 1
  • John L. Middlebrook
    • 1
  1. 1.Department of Immunology and Molecular Biology Toxinology DivisionUnited States Army Medical Research Institute of Infectious DiseasesFrederickUSA

Personalised recommendations