Sequential SNARE Assembly Underlies Priming and Triggering of Exocytosis
Changes in SNARE conformations during MgATP-dependent priming of cracked PC12 cells were probed by their altered accessibility to various inhibitors. Dominant negative soluble syntaxin and, to a much lesser extent, VAMP coil domains inhibited exocytosis more efficiently after priming. Neurotoxins an...
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Published in | Neuron (Cambridge, Mass.) Vol. 30; no. 1; pp. 161 - 170 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
United States
Elsevier Inc
01.04.2001
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Subjects | |
Online Access | Get full text |
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Summary: | Changes in SNARE conformations during MgATP-dependent priming of cracked PC12 cells were probed by their altered accessibility to various inhibitors. Dominant negative soluble syntaxin and, to a much lesser extent, VAMP coil domains inhibited exocytosis more efficiently after priming. Neurotoxins and an anti-SNAP25 antibody inhibited exocytosis less effectively after priming. We propose that SNAREs partially and reversibly assemble during priming, and that the syntaxin H3 domain is prevented from fully joining the complex until the arrival of the Ca
2+ trigger. Furthermore, we find that mutation of hydrophobic residues of the SNAP25 C-terminal coil that contribute to SNARE core interactions affects the maximal rate of exocytosis, while mutation of charged residues on the surface of the complex affects the apparent affinity of the coil domain for the partially assembled complex. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0896-6273 1097-4199 |
DOI: | 10.1016/S0896-6273(01)00270-7 |