Abstract
Phospholipase D (PLD) has been proposed to mediate cytoskeletal remodeling and vesicular trafficking along the secretory pathway. We recently described the activation of an ADP ribosylation factor-regulated PLD at the plasma membrane of chromaffin cells undergoing secretagogue-stimulated exocytosis. We show here that the isoform involved is PLD1b, and, using a real-time assay for individual cells, that PLD activation and exocytosis are closely correlated. Moreover, overexpressed PLD1, but not PLD2, increases stimulated exocytosis in a phosphatidylinositol 4,5-bisphosphate-dependent manner, whereas catalytically inactive PLD1 inhibits it. These results provide the first direct evidence that PLD1 is an important component of the exocytotic machinery in neuroendocrine cells.
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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Actins / metabolism
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Animals
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Catalysis
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Cattle
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Cells, Cultured
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Chromaffin Cells / cytology
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Chromaffin Cells / enzymology*
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Chromaffin Cells / physiology
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Enzyme Inhibitors / pharmacology
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Exocytosis / physiology*
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Intracellular Fluid / enzymology
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Isoenzymes / antagonists & inhibitors
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Isoenzymes / metabolism
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Neurosecretory Systems / cytology
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PC12 Cells
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Phosphatidylinositol 4,5-Diphosphate / metabolism
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Phospholipase D / antagonists & inhibitors
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Phospholipase D / metabolism*
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Protein Kinase C / metabolism
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Rats
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Sphingosine / analogs & derivatives
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Sphingosine / pharmacology
Substances
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Actins
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Enzyme Inhibitors
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Isoenzymes
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N-acetylsphingosine
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Phosphatidylinositol 4,5-Diphosphate
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Protein Kinase C
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Phospholipase D
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phospholipase D1
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Sphingosine