Our group is interested in SNARE proteins, which play a major role during exocytosis. SNAREs are capable of forming coiled-coil complexes, whose formation produces energy sufficient for inducing fusion of vesicles and target membranes. After fusion, the SNARE complexes are disassembled to its constituent SNAREs by NSF and SNAPs, and are recycled for another round of fusion. We are applying various single-molecule techniques to decipher the mechanisms of proteins and molecules that are involved in this process [1][2].
Recently we have developed an in vitro assay for observing the disassembly of single SNARE complexes by NSF. Using this assay, we were able to show that NSF hydrolyzes ATPs it carried prior to SNARE complex binding, and releases the resulting energy at once to disassemble a SNARE complex – akin to a spring [3]. We are currently working on how the individual domains of NSF, SNAPs, and SNAREs interact to couple the energy produced from ATP hydrolysis to SNARE unwinding.
[1] Lee et al., Science, 2010
[2] Lee et al., PNAS, 2016
[3] Ryu et al., Science, 2015