Abstract
A heterotetrameric complex termed AP-3 is involved in signal-mediated protein sorting to endosomal-lysosomal organelles. AP-3 has been proposed to be a component of a nonclathrin coat. In vitro binding assays showed that mammalian AP-3 did associate with clathrin by interaction of the appendage domain of its beta3 subunit with the amino-terminal domain of the clathrin heavy chain. The beta3 appendage domain contained a conserved consensus motif for clathrin binding. AP-3 colocalized with clathrin in cells as observed by immunofluorescence and immunoelectron microscopy. Thus, AP-3 function in protein sorting may depend on clathrin.
MeSH terms
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Adaptor Proteins, Vesicular Transport
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Amino Acid Sequence
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Clathrin / metabolism*
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Endosomes / chemistry
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Fluorescent Antibody Technique
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Humans
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Intracellular Membranes / chemistry
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Jurkat Cells
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Microscopy, Confocal
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Microscopy, Immunoelectron
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Molecular Sequence Data
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Monomeric Clathrin Assembly Proteins*
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Nerve Tissue Proteins / analysis
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Nerve Tissue Proteins / chemistry
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Nerve Tissue Proteins / metabolism*
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Phosphoproteins / analysis
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Phosphoproteins / chemistry
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Phosphoproteins / metabolism*
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Recombinant Fusion Proteins / metabolism
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Sequence Alignment
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Vacuoles / chemistry
Substances
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Adaptor Proteins, Vesicular Transport
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Clathrin
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Monomeric Clathrin Assembly Proteins
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Nerve Tissue Proteins
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Phosphoproteins
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Recombinant Fusion Proteins
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clathrin assembly protein AP180