Currents through the fusion pore that forms during exocytosis of a secretory vesicle

L. J. Breckenridge, Wolfhard Almers

Research output: Contribution to journalArticle

299 Citations (Scopus)

Abstract

Exocytosis, or the fusion of cytoplasmic vesicles with the cell membrane, occurs in nearly all eukaryotic cells, but its mechanism is not understood. Morphological1,2 and electrophysiological studies3-5 have suggested that membrane fusion begins with the formation of a 'fusion pore', a narrow channel across the closely adjacent membranes of vesicle and cell that forms the first connection of the vesicle lumen with the cell exterior and later dilates to allow release of vesicle contents. We used the patch clamp technique to study exocytosis of single giant secretory vesicles in mast cells of beige mice4,5. The first opening of the fusion pore was found to generate a brief current transient, whose size and direction indicated an initial pore conductance of about 230 pS and a lumen-positive vesicle membrane potential. In time-resolved a.c. admittance measurements, the pore conductance was found to increase to much larger values within milliseconds, as if the pore dilated soon after opening. We conclude that the earliest fusion event may be the formation of a structure similar to an ion channel. Its conductance is of the same order of magnitude as that of a single gap junction channel, the only other known channel that spans two membranes.

Original languageEnglish (US)
Pages (from-to)814-817
Number of pages4
JournalNature
Volume328
Issue number6133
StatePublished - 1988
Externally publishedYes

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Exocytosis
Secretory Vesicles
Cell Membrane
Cytoplasmic Vesicles
Membrane Fusion
Gap Junctions
Eukaryotic Cells
Patch-Clamp Techniques
Ion Channels
Mast Cells
Membrane Potentials
Membranes
Direction compound

ASJC Scopus subject areas

  • General

Cite this

Breckenridge, L. J., & Almers, W. (1988). Currents through the fusion pore that forms during exocytosis of a secretory vesicle. Nature, 328(6133), 814-817.

Currents through the fusion pore that forms during exocytosis of a secretory vesicle. / Breckenridge, L. J.; Almers, Wolfhard.

In: Nature, Vol. 328, No. 6133, 1988, p. 814-817.

Research output: Contribution to journalArticle

Breckenridge, LJ & Almers, W 1988, 'Currents through the fusion pore that forms during exocytosis of a secretory vesicle', Nature, vol. 328, no. 6133, pp. 814-817.
Breckenridge, L. J. ; Almers, Wolfhard. / Currents through the fusion pore that forms during exocytosis of a secretory vesicle. In: Nature. 1988 ; Vol. 328, No. 6133. pp. 814-817.
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