| First Author | Zilly FE | Year | 2006 |
| Journal | PLoS Biol | Volume | 4 |
| Issue | 10 | Pages | e330 |
| PubMed ID | 17002520 | Mgi Jnum | J:115928 |
| Mgi Id | MGI:3692474 | Doi | 10.1371/journal.pbio.0040330 |
| Citation | Zilly FE, et al. (2006) Munc18-bound syntaxin readily forms SNARE complexes with synaptobrevin in native plasma membranes. PLoS Biol 4(10):e330 |
| abstractText | Munc18-1, a protein essential for regulated exocytosis in neurons and neuroendocrine cells, belongs to the family of Sec1/Munc18-like (SM) proteins. In vitro, Munc18-1 forms a tight complex with the SNARE syntaxin 1, in which syntaxin is stabilized in a closed conformation. Since closed syntaxin is unable to interact with its partner SNAREs SNAP-25 and synaptobrevin as required for membrane fusion, it has hitherto not been possible to reconcile binding of Munc18-1 to syntaxin 1 with its biological function. We now show that in intact and exocytosis-competent lawns of plasma membrane, Munc18-1 forms a complex with syntaxin that allows formation of SNARE complexes. Munc18-1 associated with membrane-bound syntaxin 1 can be effectively displaced by adding recombinant synaptobrevin but not syntaxin 1 or SNAP-25. Displacement requires the presence of endogenous SNAP-25 since no displacement is observed when chromaffin cell membranes from SNAP-25-deficient mice are used. We conclude that Munc18-1 allows for the formation of a complex between syntaxin and SNAP-25 that serves as an acceptor for vesicle-bound synaptobrevin and that thus represents an intermediate in the pathway towards exocytosis. |
