Abstract
Specific recognition of phosphoinositides is crucial for protein sorting and membrane trafficking. Protein transport to the yeast vacuole depends on the Vam7 t-SNARE and its phox homology (PX) domain. Here, we show that the PX domain of Vam7 targets to vacuoles in vivo in a manner dependent on phosphatidylinositol 3-phosphate generation. A novel phosphatidylinositol-3-phosphate-binding motif and an exposed loop that interacts with the lipid bilayer are identified by nuclear magnetic resonance spectroscopy. Conservation of key structural and binding site residues across the diverse PX family indicates a shared fold and phosphoinositide recognition function.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Sequence
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Binding Sites
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Fungal Proteins / chemistry
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Fungal Proteins / metabolism*
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Intracellular Membranes / chemistry
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Intracellular Membranes / metabolism
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Membrane Proteins / chemistry
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Membrane Proteins / metabolism*
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Membranes, Artificial
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Microscopy, Fluorescence
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Molecular Sequence Data
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Nerve Tissue Proteins / metabolism*
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Nuclear Magnetic Resonance, Biomolecular
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Phosphatidylinositol Phosphates / chemistry
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Phosphatidylinositol Phosphates / metabolism*
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Phosphatidylinositol Phosphates / physiology
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Protein Binding
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Protein Structure, Tertiary
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Protein Transport / physiology
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Qc-SNARE Proteins
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SNARE Proteins
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Saccharomyces cerevisiae
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Saccharomyces cerevisiae Proteins
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Sequence Alignment
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Synaptosomal-Associated Protein 25
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Vacuoles / physiology
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Vacuoles / ultrastructure
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Vesicular Transport Proteins*
Substances
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Fungal Proteins
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Membrane Proteins
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Membranes, Artificial
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Nerve Tissue Proteins
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Phosphatidylinositol Phosphates
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Qc-SNARE Proteins
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SNARE Proteins
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Saccharomyces cerevisiae Proteins
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Synaptosomal-Associated Protein 25
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VAM7 protein, S cerevisiae
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Vesicular Transport Proteins
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phosphatidylinositol 3-phosphate