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A Stimulation Function of Synaptotagmin-1 in Ternary SNARE Complex Formation Dependent on Munc18 and Munc13
- Source :
- Frontiers in Molecular Neuroscience, Vol 10 (2017)
- Publication Year :
- 2017
- Publisher :
- Frontiers Media S.A., 2017.
-
Abstract
- The Ca2+ sensor synaptotagmin-1 (Syt1) plays an essential function in synaptic exocytosis. Recently, Syt1 has been implicated in synaptic vesicle priming, a maturation step prior to Ca2+-triggered membrane fusion that is believed to involve formation of the ternary SNARE complex and require priming proteins Munc18-1 and Munc13-1. However, the mechanisms of Syt1 in synaptic vesicle priming are still unclear. In this study, we found that Syt1 stimulates the transition from the Munc18-1/syntaxin-1 complex to the ternary SNARE complex catalyzed by Munc13-1. This stimulation can be further enhanced in a membrane-containing environment. Further, we showed that Syt1, together with Munc18-1 and Munc13-1, stimulates trans ternary SNARE complex formation on membranes in a manner resistant to disassembly factors NSF and α-SNAP. Disruption of a proposed Syt1/SNARE binding interface strongly abrogated the stimulation function of Syt1. Our results suggest that binding of Syt1 to an intermediate SNARE assembly with Munc18-1 and Munc13-1 is critical for the stimulation function of Syt1 in ternary SNARE complex formation, and this stimulation may underlie the priming function of Syt1 in synaptic exocytosis.
Details
- Language :
- English
- ISSN :
- 16625099
- Volume :
- 10
- Database :
- Directory of Open Access Journals
- Journal :
- Frontiers in Molecular Neuroscience
- Publication Type :
- Academic Journal
- Accession number :
- edsdoj.54974eb325244b18b9269da1562b9255
- Document Type :
- article
- Full Text :
- https://doi.org/10.3389/fnmol.2017.00256