The exocytotic fusion pore interface

a model of the site of neurotransmitter release.

J. R. Monck, Andres Oberhauser, J. M. Fernandez

Research output: Contribution to journalArticle

36 Citations (Scopus)

Abstract

Ultrastructural techniques have shown that an early event in the exocytotic fusion of a secretory vesicle is the formation of a narrow, water-filled pore spanning both the vesicle and plasma membranes and connecting the lumen of the secretory vesicle to the extracellular environment. Smaller precursors of the exocytotic fusion pore have been detected using electrophysiological techniques, which reveal a dynamic fusion pore that quickly expands to the size of the pores seen with electron microscopy. While it is clear that in the latter stages of expansion, when the size of the fusion pore is several orders of magnitude bigger than any known macromolecule, the fusion pore must be mainly made of lipids, the structure of the smaller precursors is unknown. Patch-clamp measurements of the activity of individual fusion pores in mast cells have shown that the fusion pore has some unusual and unexpected properties, namely that there is a large flux of lipid through the pore and the rate of pore closure has a discontinuous temperature dependency, suggesting a purely lipidic fusion pore. Moreover, comparisons of experimental data with theoretical fusion pores and with breakdown pores support the view that the fusion pore is initially a pore through a single bilayer, as would be expected for membrane fusion proceeding through a hemifusion mechanism. Based on these observations we present a model where the fusion pore is initially a pore through a single bilayer.(ABSTRACT TRUNCATED AT 250 WORDS)

Original languageEnglish (US)
Pages (from-to)151-156
Number of pages6
JournalMolecular Membrane Biology
Volume12
Issue number1
StatePublished - Jan 1995
Externally publishedYes

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Secretory Vesicles
Neurotransmitter Agents
Lipids
Membrane Fusion
Mast Cells
Electron Microscopy
Cell Membrane
Temperature
Water

ASJC Scopus subject areas

  • Cell Biology
  • Molecular Biology

Cite this

The exocytotic fusion pore interface : a model of the site of neurotransmitter release. / Monck, J. R.; Oberhauser, Andres; Fernandez, J. M.

In: Molecular Membrane Biology, Vol. 12, No. 1, 01.1995, p. 151-156.

Research output: Contribution to journalArticle

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