Source:http://linkedlifedata.com/resource/pubmed/id/12482911
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
Pt 2
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| pubmed:dateCreated |
2002-12-16
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| pubmed:abstractText |
Previous studies have shown that Fcgamma receptor (FcR)-mediated phagocytosis and macropinocytosis in macrophages consist of two dissociable activities: a phosphoinositide 3-kinase (PI3K)-independent extension of phagocytic cups and a PI3K-dependent contractile mechanism that closes phagosomes and ruffles into intracellular organelles. Here, we identify an additional contractile activity that persists in the presence of the PI3K inhibitor wortmannin. ML-7, an inhibitor of myosin-light-chain kinase (MLCK), inhibited FcR-mediated phagocytosis, macropinocytosis and cell movements associated with ruffling. Scanning electron microscopy demonstrated a striking difference in morphology between phagocytic cups in the different inhibitors: whereas phagocytic cups of control cells and wortmannin-treated cells conformed closely to particles and appeared to have constricted them, the phagocytic cups in cells treated with ML-7 were more open. Video microscopy of macrophages expressing green-fluorescent-protein (GFP)-actin fusions revealed that bound IgG-opsonized erythrocytes were squeezed during phagosome formation and closure. In ML-7, GFP-actin-rich protrusions extended outward but failed to squeeze particles. Moreover, in contrast to the effects of PI3K inhibitors, ML-7 markedly reduced ruffle movement, and perturbed circular ruffle formation. These PI3K-independent myosin-II-based contractile activities that squeeze phagocytic cups and curve ruffles therefore represent a third component activity of the actin cytoskeleton during phagocytosis and macropinocytosis.
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| pubmed:grant | |
| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:citationSubset |
IM
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| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Androstadienes,
http://linkedlifedata.com/resource/pubmed/chemical/Azepines,
http://linkedlifedata.com/resource/pubmed/chemical/Contractile Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Enzyme Inhibitors,
http://linkedlifedata.com/resource/pubmed/chemical/ML 7,
http://linkedlifedata.com/resource/pubmed/chemical/Myosin-Light-Chain Kinase,
http://linkedlifedata.com/resource/pubmed/chemical/Myosins,
http://linkedlifedata.com/resource/pubmed/chemical/Naphthalenes,
http://linkedlifedata.com/resource/pubmed/chemical/Phosphatidylinositol 3-Kinases,
http://linkedlifedata.com/resource/pubmed/chemical/Receptors, IgG,
http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Fusion Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/wortmannin
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| pubmed:status |
MEDLINE
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| pubmed:month |
Jan
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| pubmed:issn |
0021-9533
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:day |
15
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| pubmed:volume |
116
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
247-57
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| pubmed:dateRevised |
2011-11-17
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| pubmed:meshHeading |
pubmed-meshheading:12482911-Actin Cytoskeleton,
pubmed-meshheading:12482911-Androstadienes,
pubmed-meshheading:12482911-Animals,
pubmed-meshheading:12482911-Azepines,
pubmed-meshheading:12482911-Cell Surface Extensions,
pubmed-meshheading:12482911-Cells, Cultured,
pubmed-meshheading:12482911-Contractile Proteins,
pubmed-meshheading:12482911-Enzyme Inhibitors,
pubmed-meshheading:12482911-Erythrocytes,
pubmed-meshheading:12482911-Macrophages,
pubmed-meshheading:12482911-Mice,
pubmed-meshheading:12482911-Microscopy, Electron, Scanning,
pubmed-meshheading:12482911-Myosin-Light-Chain Kinase,
pubmed-meshheading:12482911-Myosins,
pubmed-meshheading:12482911-Naphthalenes,
pubmed-meshheading:12482911-Phagocytosis,
pubmed-meshheading:12482911-Phosphatidylinositol 3-Kinases,
pubmed-meshheading:12482911-Pinocytosis,
pubmed-meshheading:12482911-Receptors, IgG,
pubmed-meshheading:12482911-Recombinant Fusion Proteins
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| pubmed:year |
2003
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| pubmed:articleTitle |
Phosphoinositide-3-kinase-independent contractile activities associated with Fcgamma-receptor-mediated phagocytosis and macropinocytosis in macrophages.
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| pubmed:affiliation |
Department of Histology and Cell Biology, Kagawa Medical University, Miki, Kagawa 761-0793, Japan. naraki@kms.ac.jp
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| pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
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