Dynamic binding mode of a Synaptotagmin-1-SNARE complex in solution

Kyle D Brewer; Taulant Bacaj; Andrea Cavalli; Carlo Camilloni; James D Swarbrick; Jin Liu; Amy Zhou; Peng Zhou; Nicholas Barlow; Junjie Xu; Alpay B Seven; Eric A Prinslow; Rashmi Voleti; Daniel Häussinger; Alexandre M J J Bonvin; Diana R Tomchick; Michele Vendruscolo; Bim Graham; Thomas C Südhof; Josep Rizo

doi:10.1038/nsmb.3035

Dynamic binding mode of a Synaptotagmin-1-SNARE complex in solution

Nat Struct Mol Biol. 2015 Jul;22(7):555-64. doi: 10.1038/nsmb.3035. Epub 2015 Jun 1.

Authors

Kyle D Brewer¹, Taulant Bacaj², Andrea Cavalli³, Carlo Camilloni⁴, James D Swarbrick⁵, Jin Liu⁶, Amy Zhou¹, Peng Zhou², Nicholas Barlow⁵, Junjie Xu¹, Alpay B Seven¹, Eric A Prinslow¹, Rashmi Voleti¹, Daniel Häussinger⁷, Alexandre M J J Bonvin⁸, Diana R Tomchick⁹, Michele Vendruscolo⁴, Bim Graham⁵, Thomas C Südhof², Josep Rizo¹

Affiliations

¹ 1] Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas, USA. [2] Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, USA. [3] Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
² 1] Department of Molecular and Cellular Physiology, Stanford University Medical School, Stanford, California, USA. [2] Howard Hughes Medical Institute, Stanford University Medical School, Stanford, California, USA.
³ 1] Institute for Research in Biomedicine, Bellinzona, Switzerland. [2] Department of Chemistry, University of Cambridge, Cambridge, UK.
⁴ Department of Chemistry, University of Cambridge, Cambridge, UK.
⁵ Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia.
⁶ 1] Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas, USA. [2] Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, USA. [3] Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, USA. [4] Department of Chemistry, Southern Methodist University, Dallas, Texas, USA.
⁷ Department of Chemistry, University of Basel, Basel, Switzerland.
⁸ Bijvoet Center for Biomolecular Research, Faculty of Science, Utrecht University, Utrecht, the Netherlands.
⁹ 1] Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas, USA. [2] Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, USA.

Abstract

Rapid neurotransmitter release depends on the Ca2+ 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 C2B-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.

Publication types

Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

MeSH terms

Animals
Cells, Cultured
Humans
Mice, Inbred C57BL
Models, Molecular
Neurons / metabolism
Nuclear Magnetic Resonance, Biomolecular
Protein Binding
Protein Structure, Tertiary
Rats
SNARE Proteins / chemistry
SNARE Proteins / metabolism*
Synaptotagmin I / chemistry
Synaptotagmin I / metabolism*

Substances

SNARE Proteins
Synaptotagmin I

Abstract

Publication types

MeSH terms

Substances

Grants and funding