Editors' ChoiceNeuroscience

Facilitating Fusion and Release

Science Signaling  20 Mar 2012:
Vol. 5, Issue 216, pp. ec87
DOI: 10.1126/scisignal.2003049

For neurotransmitters to be released from a neuron, a synaptic vesicle must fuse with the plasma membrane and form a fusion pore. Soluble N-ethylmaleimide–sensitive factor attachment protein receptor (SNARE) complexes are the core protein machinery involved in fusion; however, there has been debate regarding the mechanism. Whereas in vitro studies have found that a single SNARE can cause fusion of two bilayers, in vivo studies have shown that a minimum of three SNAREs are required for neurotransmitter release. The apparently contradictory results are explained by Shi et al., who monitored fusion of vesicles to membrane nanodiscs. While a single SNARE complex was sufficient to fuse bilayers, a minimum of three SNARE complexes were required to open a pore large enough for neurotransmitter release.

L. Shi, Q.-T. Shen, A. Kiel, J. Wang, H.-W. Wang, T. J. Melia, J. E. Rothman, F. Pincet, SNARE proteins: One to fuse and three to keep the nascent fusion pore open. Science 335, 1355–1359 (2012). [Abstract] [Full Text]