SNARE Proteins : One to Fuse and Three to Keep the Nascent Fusion Pore Open

Neurotransmission is a process in which neurotransmitters are released in the synapse to transmit information. This process is finely regulated spatially as well as temporally. It requires a complex protein machinery. The latter is based on SNARE proteins that are responsible for the fusion of the pre-synaptic membrane with that of the synaptic vesicle. One SNARE protein is located on the vesicle (v-SNARE), and another one is on the membrane (a heterodimer, the t- SNARE). t- and v-SNAREs pair to form a structure, the “SNAREpin”, and force the membrane contact and this leads to fusion. By using suspended nanometric membranes called “nanodiscs”, Frédéric Pincet from the LPS-ENS and a team from Yale University have demonstrated that only one SNAREpin is sufficient for fusion, but at least three SNAREpins are required to engage the release of neurotransmitters.

They have also shown that presence of native transmembrane SNARE domains are mandatory for a rapid and efficient release. These results put to an end a many years long controversy and allow to explain recentl data that appeared contradictory. They have been published in Science on the 16th march 2012.

press release of the CNRS