Acetylcholine exocytosis in PC12 cells deficient in SNAP-25

Neuroreport. 1997 Jul 7;8(9-10):2271-4. doi: 10.1097/00001756-199707070-00035.


Stimulus-induced acetylcholine (ACh) exocytosis from presynaptic nerve terminals involves two important steps: fusion of ACh loaded vesicles at presynaptic release sites, followed by release into the synaptic cleft. We studied the role of the putative vesicle fusion protein SNAP-25 in this process. The nerve growth factor-differentiated PC12 cell line was used as an experimental model. A bee venom tetradecapeptide (INLKALAALAKKIL-NH2) phospholipase A2 (PLA2) activator, mastoparan, was used to induce ACh release. Treatment of PC12 cells with appropriate antisense oligonucleotides blocked SNAP-25 expression, as judged by Western blot protein analysis with a specific monoclonal antibody. Despite apparent elimination of SNAP-25, treatment of differentiated PC12 cells with mastoparan and high (80 mM) K+ induced ACh exocytosis. The results indicate that in PC12 cells, ACh exocytosis due to mastoparan plus K+ can occur in the absence of SNAP-25.

MeSH terms

  • Acetylcholine / metabolism*
  • Animals
  • Blotting, Western
  • Exocytosis / drug effects
  • Exocytosis / physiology*
  • Intercellular Signaling Peptides and Proteins
  • Membrane Proteins*
  • Nerve Tissue Proteins / metabolism*
  • Neurotoxins / pharmacology
  • PC12 Cells / metabolism*
  • Peptides
  • Potassium Chloride / pharmacology
  • Rats
  • Synaptosomal-Associated Protein 25
  • Wasp Venoms / pharmacology


  • Intercellular Signaling Peptides and Proteins
  • Membrane Proteins
  • Nerve Tissue Proteins
  • Neurotoxins
  • Peptides
  • Snap25 protein, rat
  • Synaptosomal-Associated Protein 25
  • Wasp Venoms
  • Potassium Chloride
  • mastoparan
  • Acetylcholine