N-terminal peptide of the syntaxin Tlg2p modulates binding of its closed conformation to Vps45p

The Sec1/Munc18 (SM) protein family regulates intracellular trafficking through interactions with individual SNARE proteins and assembled SNARE complexes. Revealing a common mechanism of this regulation has been challenging, largely because of the multiple modes of interaction observed between SM pr...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Proceedings of the National Academy of Sciences - PNAS 2009-08, Vol.106 (34), p.14303-14308
Hauptverfasser: Furgason, Melonnie L.M, MacDonald, Chris, Shanks, Scott G, Ryder, Sean P, Bryant, Nia J, Munson, Mary
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:The Sec1/Munc18 (SM) protein family regulates intracellular trafficking through interactions with individual SNARE proteins and assembled SNARE complexes. Revealing a common mechanism of this regulation has been challenging, largely because of the multiple modes of interaction observed between SM proteins and their cognate syntaxin-type SNAREs. These modes include binding of the SM to a closed conformation of syntaxin, binding to the N-terminal peptide of syntaxin, binding to assembled SNARE complexes, and/or binding to nonsyntaxin SNAREs. The SM protein Vps45p, which regulates endosomal trafficking in yeast, binds the conserved N-terminal peptide of the syntaxin Tlg2p. We used size exclusion chromatography and a quantitative fluorescent gel mobility shift assay to reveal an additional binding site that does not require the Tlg2p N-peptide. Characterization of Tlg2p mutants and truncations indicate that this binding site corresponds to a closed conformation of Tlg2p. Furthermore, the Tlg2p N-peptide competes with the closed conformation for binding, suggesting a fundamental regulatory mechanism for SM-syntaxin interactions in SNARE assembly and membrane fusion.
ISSN:0027-8424
1091-6490
DOI:10.1073/pnas.0902976106