Abstract
Intracellular membrane fusion is mediated by the SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins that are highly conserved and tightly regulated by a variety of factors. The exocyst complex is one of the multi-subunit tethering complexes and functions in the tethering of the secretory vesicles to the plasma membrane. We have found that the yeast Sec3, a subunit of the exocyst, binds to the t-SNARE protein Sso2 and promotes its interaction with another t-SNARE protein, Sec9. Here, we describe the structural analysis and in vitro membrane fusion assays, by which we found that Sec3 binding leads to a conformational change within Sso2, and facilitates SNARE assembly and the membrane fusion.
Keywords:
Liposome; Membrane fusion; Sec3; Sec9; Soluble N-ethylmaleimide-sensitive factor attachment protein receptor; Sso2; Structure analysis.
Publication types
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Research Support, N.I.H., Extramural
MeSH terms
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Amino Acid Motifs / genetics
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Liposomes / chemistry
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Liposomes / metabolism
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Membrane Fusion*
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Models, Molecular*
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Mutagenesis
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Protein Binding
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Qa-SNARE Proteins / chemistry
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Qa-SNARE Proteins / genetics
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Qa-SNARE Proteins / isolation & purification
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Qa-SNARE Proteins / metabolism*
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Qc-SNARE Proteins / chemistry
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Qc-SNARE Proteins / isolation & purification
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Qc-SNARE Proteins / metabolism
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Recombinant Proteins / chemistry
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Recombinant Proteins / genetics
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Recombinant Proteins / isolation & purification
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Recombinant Proteins / metabolism
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Saccharomyces cerevisiae Proteins / chemistry
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Saccharomyces cerevisiae Proteins / genetics
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Saccharomyces cerevisiae Proteins / isolation & purification
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Saccharomyces cerevisiae Proteins / metabolism*
Substances
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Liposomes
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Qa-SNARE Proteins
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Qc-SNARE Proteins
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Recombinant Proteins
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SEC3 protein, S cerevisiae
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SEC9 protein, S cerevisiae
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SSO2 protein, S cerevisiae
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Saccharomyces cerevisiae Proteins