Abstract
Transport of a subset of membrane proteins to the yeast vacuole requires the function of the AP-3 adaptor protein complex. To define the molecular requirements of vesicular transport in this pathway, we used a biochemical approach to analyse the formation and content of the AP-3 transport intermediate. A vam3tsf (vacuolar t-SNARE) mutant blocks vesicle docking and fusion with the vacuole and causes the accumulation of 50-130-nanometre membrane vesicles, which we isolated and showed by biochemical analysis and immunocytochemistry to contain both AP-3 adaptors and alkaline phosphatase (ALP) pathway cargoes. Inactivation of AP-3 or the protein Vps41 blocks formation of this vesicular intermediate. Vps41 binds to the AP-3 delta-adaptin subunit, suggesting that they function together in the formation of ALP pathway transport intermediates at the late Golgi.
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 Protein Complex alpha Subunits
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Adaptor Proteins, Vesicular Transport
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Alkaline Phosphatase / genetics
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Alkaline Phosphatase / metabolism
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Binding Sites
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Biological Transport
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Carrier Proteins / genetics
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Carrier Proteins / metabolism*
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Carrier Proteins / physiology
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Cell Compartmentation
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Cell Membrane / metabolism
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Fungal Proteins / genetics
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Fungal Proteins / metabolism*
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Fungal Proteins / physiology
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Membrane Proteins / genetics
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Membrane Proteins / metabolism*
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Monomeric Clathrin Assembly Proteins*
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Mutagenesis
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Nuclear Proteins*
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Qa-SNARE Proteins
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RNA-Binding Proteins / genetics
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RNA-Binding Proteins / metabolism*
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RNA-Binding Proteins / physiology
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Saccharomyces cerevisiae Proteins*
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Vacuoles / metabolism
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Vesicular Transport Proteins*
Substances
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Adaptor Protein Complex alpha Subunits
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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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Monomeric Clathrin Assembly Proteins
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NPL3 protein, S cerevisiae
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Nuclear Proteins
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Qa-SNARE Proteins
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RNA-Binding Proteins
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Saccharomyces cerevisiae Proteins
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VAM3 protein, S cerevisiae
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VPS41 protein, S cerevisiae
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Vesicular Transport Proteins
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clathrin assembly protein AP180
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Alkaline Phosphatase