Syntaxin1a variants lacking an N-peptide or bearing the LE mutation bind to Munc18a in a closed conformation.

Détails

Ressource 1Télécharger: Colbert PNAS 2013.pdf (1395.13 [Ko])
Etat: Serval
Version: Final published version
ID Serval
serval:BIB_0C4B820E84E4
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Syntaxin1a variants lacking an N-peptide or bearing the LE mutation bind to Munc18a in a closed conformation.
Périodique
Proceedings of the National Academy of Sciences of the United States of America
Auteur(s)
Colbert K.N., Hattendorf D.A., Weiss T.M., Burkhardt P., Fasshauer D., Weis W.I.
ISSN
1091-6490 (Electronic)
ISSN-L
0027-8424
Statut éditorial
Publié
Date de publication
2013
Peer-reviewed
Oui
Volume
110
Numéro
31
Pages
12637-12642
Langue
anglais
Résumé
In neurons, soluble N-ethylmaleimide-sensitive factor attachment receptor (SNARE) proteins drive the fusion of synaptic vesicles to the plasma membrane through the formation of a four-helix SNARE complex. Members of the Sec1/Munc18 protein family regulate membrane fusion through interactions with the syntaxin family of SNARE proteins. The neuronal protein Munc18a interacts with a closed conformation of the SNARE protein syntaxin1a (Syx1a) and with an assembled SNARE complex containing Syx1a in an open conformation. The N-peptide of Syx1a (amino acids 1-24) has been implicated in the transition of Munc18a-bound Syx1a to Munc18a-bound SNARE complex, but the underlying mechanism is not understood. Here we report the X-ray crystal structures of Munc18a bound to Syx1a with and without its native N-peptide (Syx1aΔN), along with small-angle X-ray scattering (SAXS) data for Munc18a bound to Syx1a, Syx1aΔN, and Syx1a L165A/E166A (LE), a mutation thought to render Syx1a in a constitutively open conformation. We show that all three complexes adopt the same global structure, in which Munc18a binds a closed conformation of Syx1a. We also identify a possible structural connection between the Syx1a N-peptide and SNARE domain that might be important for the transition of closed-to-open Syx1a in SNARE complex assembly. Although the role of the N-peptide in Munc18a-mediated SNARE complex assembly remains unclear, our results demonstrate that the N-peptide and LE mutation have no effect on the global conformation of the Munc18a-Syx1a complex.
Mots-clé
Amino Acid Substitution, Humans, Munc18 Proteins/chemistry, Munc18 Proteins/genetics, Peptides, Protein Binding, Protein Structure, Quaternary, Protein Structure, Secondary, SNARE Proteins/chemistry, SNARE Proteins/genetics, Sequence Deletion, Syntaxin 1/chemistry, Syntaxin 1/genetics
Pubmed
Web of science
Open Access
Oui
Création de la notice
20/12/2013 12:53
Dernière modification de la notice
08/05/2019 14:19
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