Membrane fusion between liposomes containing SNARE proteins involved in mast cell exocytosis.

OBJECTIVE AND DESIGN

We monitored the membrane fusion of liposomes to determine if the minimal components of soluble N-ethyl maleimide-sensitive factor attachment protein receptor (SNARE), which is involved in mast cell exocytosis, have fusogenic activity.

METHODS

Three core components of SNARE were reconstituted into liposomes. Membrane fusion between liposomes containing vesicle associated membrane protein (VAMP) -7 or -8 and liposomes containing synaptosomal-associated protein 23 kDa (SNAP23) and syntaxin-3 or -4 was monitored by fluorescence resonance energy transfer.

RESULTS

The combination of SNAP23/syntaxin-3/VAMP-8 showed the most efficient liposome-liposome fusogenic activity. Liposomes with VAMP-7 exhibited poor fusogenic activity regardless of the syntaxin isoform.

CONCLUSION

The core components of SNAP23, syntaxin-3, and VAMP-8 appear to be minimal machinery to induce membrane fusion, while VAMP-7 appears to be unessential for membrane fusion.