The N-terminal peptide of the syntaxin Tlg2p modulates binding of its closed conformation to Vps45p.
Proc Natl Acad Sci U S A
; 106(34): 14303-8, 2009 Aug 25.
Article
em En
| MEDLINE
| ID: mdl-19667197
ABSTRACT
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.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Saccharomyces cerevisiae
/
Proteínas de Transporte Vesicular
/
Proteínas Qa-SNARE
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Estados Unidos