v-SNAREs control exocytosis of vesicles from priming to fusion

EMBO J. 2005 Jun 15;24(12):2114-26. doi: 10.1038/sj.emboj.7600696. Epub 2005 May 26.


SNARE proteins (soluble NSF-attachment protein receptors) are thought to be central components of the exocytotic mechanism in neurosecretory cells, but their precise function remained unclear. Here, we show that each of the vesicle-associated SNARE proteins (v-SNARE) of a chromaffin granule, synaptobrevin II or cellubrevin, is sufficient to support Ca(2+)-dependent exocytosis and to establish a pool of primed, readily releasable vesicles. In the absence of both proteins, secretion is abolished, without affecting biogenesis or docking of granules indicating that v-SNAREs are absolutely required for granule exocytosis. We find that synaptobrevin II and cellubrevin differentially control the pool of readily releasable vesicles and show that the v-SNARE's amino terminus regulates the vesicle's primed state. We demonstrate that dynamics of fusion pore dilation are regulated by v-SNAREs, indicating their action throughout exocytosis from priming to fusion of vesicles.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Calcium / metabolism
  • Cytoplasmic Granules / ultrastructure
  • Cytoplasmic Vesicles / metabolism*
  • Exocytosis / physiology*
  • Membrane Fusion / physiology*
  • Membrane Proteins / biosynthesis
  • Membrane Proteins / deficiency
  • Membrane Proteins / genetics
  • Mice
  • Mice, Inbred C57BL
  • Microscopy, Electron
  • Molecular Sequence Data
  • R-SNARE Proteins
  • SNARE Proteins
  • Time Factors
  • Vesicle-Associated Membrane Protein 3
  • Vesicular Transport Proteins / deficiency
  • Vesicular Transport Proteins / metabolism*


  • Membrane Proteins
  • R-SNARE Proteins
  • SNARE Proteins
  • Vesicle-Associated Membrane Protein 3
  • Vesicular Transport Proteins
  • Calcium