Abstract
Class I myosins participate in various interactions between the cell membrane and the cytoskeleton. Several class I myosins preferentially bind to acidic phospholipids, such as phosphatidylserine and phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2], through a tail homology 1 (TH1) domain. Here, we show that the second messenger lipid phosphatidylinositol 3,4,5-trisphosphate (PIP3) binds to the TH1 domain of a subset of Dictyostelium class I myosins (ID, IE, and IF) and recruits them to the plasma membrane. The PIP3-regulated membrane recruitment of myosin I promoted chemotaxis and induced chemoattractant-stimulated actin polymerization. Similarly, PIP3 recruited human myosin IF to the plasma membrane upon chemotactic stimulation in a neutrophil cell line. These data suggest a mechanism through which the PIP3 signal is transmitted through myosin I to the actin cytoskeleton.
Publication types
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Research Support, N.I.H., Extramural
MeSH terms
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Actin Cytoskeleton / genetics
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Actin Cytoskeleton / metabolism*
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Cell Line
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Cell Membrane / genetics
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Cell Membrane / metabolism
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Chemotaxis / physiology*
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Dictyostelium / cytology
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Dictyostelium / genetics
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Dictyostelium / metabolism*
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HL-60 Cells
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Humans
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Myosin Type I / genetics
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Myosin Type I / metabolism*
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Neutrophils / cytology
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Neutrophils / metabolism
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Phosphatidylinositol 4,5-Diphosphate / genetics
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Phosphatidylinositol 4,5-Diphosphate / metabolism
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Phosphatidylinositol Phosphates / genetics
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Phosphatidylinositol Phosphates / metabolism*
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Protein Structure, Tertiary
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Protozoan Proteins / genetics
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Protozoan Proteins / metabolism*
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Signal Transduction / physiology*
Substances
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Phosphatidylinositol 4,5-Diphosphate
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Phosphatidylinositol Phosphates
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Protozoan Proteins
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phosphatidylinositol 3,4,5-triphosphate
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Myosin Type I