Abstract
Rapid neurotransmitter release depends on the Ca 2+ sensor Synaptotagmin-1 (Syt1) and the SNARE complex formed by synaptobrevin, syntaxin-1 and SNAP-25. How Syt1 triggers release has been unclear, partly because elucidating high-resolution structures of Syt1-SNARE complexes has been challenging. An NMR approach based on lanthanide-induced pseudocontact shifts now reveals a dynamic binding mode in which basic residues in the concave side of the Syt1 C 2 B-domain β-sandwich interact with a polyacidic region of the SNARE complex formed by syntaxin-1 and SNAP-25. The physiological relevance of this dynamic structural model is supported by mutations in basic residues of Syt1 that markedly impair SNARE-complex binding in vitro and Syt1 function in neurons. Mutations with milder effects on binding have correspondingly milder effects on Syt1 function. Our results support a model whereby dynamic interaction facilitates cooperation between Syt1 and the SNAREs in inducing membrane fusion.
Original language | English (US) |
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Pages (from-to) | 555-564 |
Number of pages | 10 |
Journal | Nature Structural and Molecular Biology |
Volume | 22 |
Issue number | 7 |
DOIs | |
State | Published - Jul 9 2015 |
ASJC Scopus subject areas
- Structural Biology
- Molecular Biology