Hemifusion arrest by complexin is relieved by Ca2+-synaptotagmin I

Nat Struct Mol Biol. 2006 Aug;13(8):748-50. doi: 10.1038/nsmb1124. Epub 2006 Jul 16.

Abstract

Synaptic transmission relies on an exquisitely orchestrated series of protein-protein interactions. Here we show that fusion driven by neuronal SNAREs is inhibited by the regulatory protein complexin. Furthermore, inner-leaflet mixing is strongly impaired relative to total lipid mixing, indicating that inhibition by complexin arrests fusion at hemifusion. When the calcium sensor synaptotagmin is added in the presence of calcium, inhibition by complexin is relieved and full fusion rapidly proceeds.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adaptor Proteins, Vesicular Transport
  • Animals
  • Calcium / metabolism
  • Drosophila Proteins / genetics
  • Drosophila Proteins / metabolism
  • Escherichia coli / genetics
  • Immunoprecipitation
  • Liposomes / metabolism
  • Membrane Fusion / physiology
  • Mice
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • SNARE Proteins / genetics
  • SNARE Proteins / metabolism
  • Synaptic Transmission
  • Synaptotagmin I / genetics
  • Synaptotagmin I / metabolism*

Substances

  • Adaptor Proteins, Vesicular Transport
  • Drosophila Proteins
  • Liposomes
  • Nerve Tissue Proteins
  • SNARE Proteins
  • Synaptotagmin I
  • complexin I
  • Calcium