Source:http://linkedlifedata.com/resource/pubmed/id/10954430
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rdf:type | |
lifeskim:mentions | |
pubmed:dateCreated |
2000-11-29
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pubmed:abstractText |
We have applied fluorescence ratio imaging to the analysis of an actin-binding protein concentration relative to F-actin in macrophages, in order to explore the role of a novel (alpha)-actinin isoform, actinin-4, relative to that of the classical isoform, actinin-1. Conventional immunofluorescence images showed that both isoforms were enriched in F-actin-rich regions such as cell surface ruffles. However, ratio images further demonstrated that actinin-4 concentrations relative to F-actin were higher in peripheral inward curved ruffles and dorsal circular ruffles, presumed precursor forms of macropinosomes, than in straight linear ruffles, while actinin-1 concentrations were uniform among the different types of ruffles. Macropinosome pulse-labeling and chase experiments indicated that actinin-4 was also closely associated with newly formed macropinosomes and gradually dissociated with their maturation. Consistent with ratio imaging data, macrophages scrape-loaded with anti-actinin-4 showed a more reduced rate of macropinocytosis than those loaded with anti-actinin-1. Altogether, these results indicate that actinin-4 and actinin-1 contribute differently to F-actin dynamics, that actinin-4 is more preferentially involved in early stages of macropinocytosis than actinin-1. A similar redistribution of actinin-4 was also observed during phagocytosis, suggesting that actinin-4 may play the same role in the two mechanistically analogous types of endocytosis, i.e. macropinocytosis and phagocytosis.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/ACTN4 protein, human,
http://linkedlifedata.com/resource/pubmed/chemical/Actinin,
http://linkedlifedata.com/resource/pubmed/chemical/Actn4 protein, mouse,
http://linkedlifedata.com/resource/pubmed/chemical/Microfilament Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Protein Isoforms
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pubmed:status |
MEDLINE
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pubmed:month |
Sep
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pubmed:issn |
0021-9533
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
113 ( Pt 18)
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
3329-40
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pubmed:dateRevised |
2008-11-21
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pubmed:meshHeading |
pubmed-meshheading:10954430-Actinin,
pubmed-meshheading:10954430-Animals,
pubmed-meshheading:10954430-Antibody Specificity,
pubmed-meshheading:10954430-Cell Physiological Phenomena,
pubmed-meshheading:10954430-Cells, Cultured,
pubmed-meshheading:10954430-HL-60 Cells,
pubmed-meshheading:10954430-Humans,
pubmed-meshheading:10954430-Macrophages,
pubmed-meshheading:10954430-Mice,
pubmed-meshheading:10954430-Mice, Inbred C3H,
pubmed-meshheading:10954430-Microfilament Proteins,
pubmed-meshheading:10954430-Microscopy, Confocal,
pubmed-meshheading:10954430-Microscopy, Fluorescence,
pubmed-meshheading:10954430-Phagocytosis,
pubmed-meshheading:10954430-Pinocytosis,
pubmed-meshheading:10954430-Protein Isoforms,
pubmed-meshheading:10954430-U937 Cells
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pubmed:year |
2000
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pubmed:articleTitle |
Actinin-4 is preferentially involved in circular ruffling and macropinocytosis in mouse macrophages: analysis by fluorescence ratio imaging.
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pubmed:affiliation |
Department of Anatomy, Kagawa Medical University, Miki, Kagawa 761-0793, Japan. naraki@kms.ac.jp
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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