Munc13 mediates the transition from the closed syntaxin-Munc18 complex to the SNARE complex

Cong Ma, Wei Li, Yibin Xu, Jose Rizo-Rey

Research output: Contribution to journalArticlepeer-review

235 Scopus citations


During the priming step that leaves synaptic vesicles ready for neurotransmitter release, the SNARE syntaxin-1 transitions from a closed conformation that binds Munc18-1 tightly to an open conformation within the highly stable SNARE complex. Control of this conformational transition is important for brain function, but the underlying mechanism is unknown. NMR and fluorescence experiments now show that the Munc13-1 MUN domain, which plays a central role in vesicle priming, markedly accelerates the transition from the syntaxin-1-Munc18-1 complex to the SNARE complex. This activity depends on weak interactions of the MUN domain with the syntaxin-1 SNARE motif, and probably with Munc18-1. Together with available physiological data, these results provide a defined molecular basis for synaptic vesicle priming, and they illustrate how weak protein-protein interactions can play crucial biological roles by promoting transitions between high-affinity macromolecular assemblies.

Original languageEnglish (US)
Pages (from-to)542-549
Number of pages8
JournalNature Structural and Molecular Biology
Issue number5
StatePublished - May 2011

ASJC Scopus subject areas

  • Structural Biology
  • Molecular Biology


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