SNARE proteins are the main molecular constituents of the synaptic vesicle fusion machinery. The release of molecules contained inside synaptic vesicles is mediated by the assembly of the SNARE complex. It is formed by the coil-coiling of three proteins: the v-SNARE VAMP/Synaptobrevin and the t-SNAREs, Syntaxin and SNAP25.

A cooperative interaction between SNARE complexes has been suggested to be necessary for the fusion of a synaptic vesicle with the presynaptic membrane to occur. Previous experiments, made with botulinum neurotoxins type A and E on mouse neuromuscular junction, led to predict a central role of the SNAP25 C-terminus in protein-protein contacts between SNARE complexes. A computational model, based on such interactions, proposes that the formation of the vesicle/presynaptic membrane fusion pore is catalyzed by a SNARE supercomplex consisting in a "ten petal" rosette. This prediction was tested in D. melanogaster by altering the putative key amino acids, thought to be involved in rosette formation, by site-directed mutagenesis. Transgenic lines (harboring the mutation-bearing constructs in a SNAP25 wild-type background) were thus generated. Using the UAS/GAL4 system the expression of these constructs was directed specifically in the nervous system. Electrophysiological recordings as well as behavioural experiments in mutants showed alterations supporting the model entailing the involvement of a rosette of SNARE complexes in the process of neuroexocytosis.