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One SNARE complex is sufficient for membrane fusion

Nature Structural & Molecular Biology volume 17, pages 358–364 (2010)Cite this article

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Abstract

In eukaryotes, most intracellular membrane fusion reactions are mediated by the interaction of SNARE proteins that are present in both fusing membranes. However, the minimal number of SNARE complexes needed for membrane fusion is not known. Here we show unambiguously that one SNARE complex is sufficient for membrane fusion. We performed controlled in vitro Förster resonance energy transfer (FRET) experiments and found that liposomes bearing only a single SNARE molecule are still capable of fusion with other liposomes or with purified synaptic vesicles. Furthermore, we demonstrated that multiple SNARE complexes do not act cooperatively, showing that synergy between several SNARE complexes is not needed for membrane fusion. Our findings shed new light on the mechanism of SNARE-mediated membrane fusion and call for a revision of current views of fusion events such as the fast release of neurotransmitters.

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Figure 1: Characterization of the SNARE-containing liposomes.
Figure 2: SNARE distribution over the liposomes.
Figure 3: Bulk lipid mixing as a function of SNARE density.
Figure 4: Liposomes containing a single SNARE participate in membrane fusion.
Figure 5: Fusion with purified synaptic vesicles, content mixing and lipid mixing as a function of liposome concentration.
Figure 6: Formation of SNARE complexes, monitored using C-terminal FRET.

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Acknowledgements

We thank M. Druminski, A. Stein and U. Ries for technical support and L.K. Tamm and coworkers for critical comments. This work was supported by grants from the US National Institutes of Health (P01 GM072694) and the Deutsche Forschungsgemeinschaft (SFB803). G.v.d.B. is financed by the Human Frontier Science Program. G.B. is financed by the Deutsche Forschungsgemeinschaft (EXC171).

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Authors and Affiliations

  1. Department of Neurobiology, Max-Planck Institute for Biophysical Chemistry, Göttingen, Germany

    Geert van den Bogaart, Matthew G Holt, Dietmar Riedel & Reinhard Jahn

  2. Department of Neuro- and Sensory Physiology, Laboratory for Molecular and Cellular Systems, University Medicine Göttingen, Göttingen, Germany

    Gertrude Bunt & Fred S Wouters

  3. Deutsche Forschungsgemeinschaft Research Center for Molecular Physiology of the Brain, University Medicine Göttingen, Göttingen, Germany

    Gertrude Bunt & Fred S Wouters

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  1. Geert van den Bogaart
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Contributions

G.v.d.B. purified the proteins, designed, performed and analyzed the FRET and sequential photobleaching experiments, and programmed the software for the data analysis. M.G.H. purified the synaptic vesicles and performed the partial proteolysis and flotation experiments. G.B. and F.S.W. assisted with the microscopy. D.R. performed the electron microscopy. G.v.d.B. and R.J. designed the study and wrote the paper. All authors discussed the results and commented on the manuscript.

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Correspondence to Reinhard Jahn.

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The authors declare no competing financial interests.

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van den Bogaart, G., Holt, M., Bunt, G. et al. One SNARE complex is sufficient for membrane fusion. Nat Struct Mol Biol 17, 358–364 (2010). https://doi.org/10.1038/nsmb.1748

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