Three’s the Charm

Science Signaling  26 Oct 2010:
Vol. 3, Issue 145, pp. ec333
DOI: 10.1126/scisignal.3145ec333

The molecular machinery mediating membrane fusion during secretion from a cell requires a complex of so-called SNARE proteins that forms a coiled bundle of four parallel α-helices. Mohrmann et al. developed an elegant approach to find out how many SNARE complexes are required to promote secretion of individual secretory vesicles in living chromaffin cells by titrating the ratio of wild-type and mutant SNARE proteins expressed. For fast synchronous release, a minimum of three SNARE complexes per vesicle were required. Fewer SNARE complexes resulted in slower release.

R. Mohrmann, H. de Wit, M. Verhage, E. Neher, J. B. Sørensen, Fast vesicle fusion in living cells requires at least three SNARE complexes. Science 330, 502–505 (2010). [Abstract] [Full Text]