Abstract
The homotypic fusion of yeast vacuoles requires Sec18p (NSF)-driven priming to allow vacuole docking, but the mechanism that links priming and docking is unknown. We find that a large multisubunit protein called the Vam2/6p complex is bound to cis-paired SNAP receptors (SNAREs) on isolated vacuoles. This association of the Vam2/6p complex with the cis-SNARE complex is disrupted during priming. The Vam2/6p complex then binds to Ypt7p, a guanosine triphosphate binding protein of the Rab family, to initiate productive contact between vacuoles. Thus, cis-SNARE complexes can contain Rab/Ypt effectors, and these effectors can be mobilized by NSF/Sec18p-driven priming, allowing their direct association with a Rab/Ypt protein to activate docking.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Adaptor Proteins, Vesicular Transport
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Adenosine Triphosphatases*
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Carrier Proteins / isolation & purification
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Carrier Proteins / physiology
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Fungal Proteins / physiology
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Membrane Fusion / physiology*
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Membrane Proteins / isolation & purification
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Membrane Proteins / physiology*
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Models, Biological
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Nuclear Proteins*
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RNA-Binding Proteins / isolation & purification
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RNA-Binding Proteins / physiology
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SNARE Proteins
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Saccharomyces cerevisiae / physiology*
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Saccharomyces cerevisiae / ultrastructure
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Saccharomyces cerevisiae Proteins*
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Vacuoles / physiology*
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Vacuoles / ultrastructure
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Vesicular Transport Proteins*
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rab GTP-Binding Proteins / physiology*
Substances
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Adaptor Proteins, Vesicular Transport
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Carrier Proteins
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Fungal Proteins
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Membrane Proteins
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NPL3 protein, S cerevisiae
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Nuclear Proteins
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RNA-Binding Proteins
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SNARE Proteins
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Saccharomyces cerevisiae Proteins
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VAM6 protein, S cerevisiae
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VPS41 protein, S cerevisiae
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Vesicular Transport Proteins
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Adenosine Triphosphatases
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SEC18 protein, S cerevisiae
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YPT7 protein, S cerevisiae
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rab GTP-Binding Proteins