Membrane fusion is one of the most important cellular processes by which two initially distinct lipid bilayers merge their hydrophobic cores, resulting in one interconnected structure. The so-called SNARE proteins play a central role in many fusion processes and they regulated by several accessory proteins. In order to study SNARE-mediated membrane fusion, in vitro protein reconstitution assays involving ensemble FRET have been used over a decade. Recently, we have developed single-vesicle-based FRET approaches to overcome shortcomings of ensemble assays for studying the dynamics and kinetics of SNARE-mediated membrane fusion. Moreover, we also created an optogenetic tool to control the conformation of SNAREs and studied the role of protein clusters in membrane fusion.
