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Controlling synaptotagmin activity by electrostatic screening.
- Source :
-
Nature Structural & Molecular Biology . Oct2012, Vol. 19 Issue 10, p991-997. 7p. 1 Diagram, 5 Graphs. - Publication Year :
- 2012
-
Abstract
- Exocytosis of neurosecretory vesicles is mediated by the SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins syntaxin-1, synaptobrevin and SNAP-25, with synaptotagmin functioning as the major Ca2+ sensor for triggering membrane fusion. Here we show that bovine chromaffin granules readily fuse with large unilamellar liposomes in a SNARE-dependent manner. Fusion is enhanced by Ca2+, but only when the target liposomes contain phosphatidylinositol-4,5-bisphosphate and when polyphosphate anions, such as nucleotides or pyrophosphate, are present. Ca2+-dependent enhancement is mediated by endogenous synaptotagmin-1. Polyphosphates operate by an electrostatic mechanism that reverses an inactivating cis association of synaptotagmin-1 with its own membrane without affecting trans binding. Hence, the balancing of trans- and cis-membrane interactions of synaptotagmin-1 could be a crucial element in the pathway of Ca2+-dependent exocytosis. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 15459993
- Volume :
- 19
- Issue :
- 10
- Database :
- Academic Search Index
- Journal :
- Nature Structural & Molecular Biology
- Publication Type :
- Academic Journal
- Accession number :
- 82336758
- Full Text :
- https://doi.org/10.1038/nsmb.2375