Abstract
ABCA3 is proposed to function as a lung surfactant lipid transporter. Here we report ABCA3-dependent lipid uptake into intracellular vesicles in lung adenocarcinoma A549 cells. A549 cells stably expressing GFP-tagged wild-type ABCA3 (A549/ABCA3(WT)) had larger LAMP3-positive vesicles than their parental cells as well as A549 cells expressing a Walker A motif mutant (A549/ABCA3(N568D)). The choline-phospholipids level in A549/ABCA3(WT) was increased 1.25-fold compared to that in A549 and A549/ABCA3(N568D) cells, while the cholesterol levels were similar. Sucrose gradient fractionation analysis in A549/ABCA3(WT) cells revealed that choline-phospholipids were enriched in low-density and nile red-positive vesicles. Electronmicroscopic analysis showed multilamellar vesicles in A549/ABCA3(WT) cells. These results indicate that ABCA3 mediates ATP-dependent choline-phospholipids uptake into intracellular vesicles.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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ATP-Binding Cassette Transporters / genetics
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ATP-Binding Cassette Transporters / metabolism
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ATP-Binding Cassette Transporters / physiology*
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Adenocarcinoma / metabolism
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Adenocarcinoma / pathology*
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Animals
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Cholesterol / metabolism
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Green Fluorescent Proteins / genetics
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Green Fluorescent Proteins / metabolism
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Humans
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Lung Neoplasms / metabolism
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Lung Neoplasms / pathology*
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Lysosomal Membrane Proteins / metabolism
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Mice
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Neoplasm Proteins / metabolism
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Phosphatidylcholines / metabolism*
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Recombinant Fusion Proteins / genetics
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Recombinant Fusion Proteins / metabolism
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Transfection
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Transport Vesicles / metabolism*
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Transport Vesicles / ultrastructure
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Tumor Cells, Cultured
Substances
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ABCA3 protein, human
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ATP-Binding Cassette Transporters
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LAMP3 protein, human
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Lysosomal Membrane Proteins
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Neoplasm Proteins
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Phosphatidylcholines
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Recombinant Fusion Proteins
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essential 303 forte
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Green Fluorescent Proteins
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Cholesterol