Iba1 Is an Actin-Cross-Linking Protein in Macrophages/Microglia

doi:10.1006/bbrc.2001.5388

Biochemical and Biophysical Research Communications

Volume 286, Issue 2, 17 August 2001, Pages 292-297

https://doi.org/10.1006/bbrc.2001.5388 Get rights and content

Abstract

Iba1 is a 17-kDa EF hand protein that is specifically expressed in macrophages/microglia and is upregulated during the activation of these cells. When exposed to macrophage colony-stimulating factor (M-CSF), microglia cell line MG5 immediately produces intense membrane ruffles in which Iba1 accumulates together with filamentous actin. In this study, we investigated the physical interaction between Iba1 and actin by centrifugation assay and electron microscopic examination and showed that Iba1 possesses actin-binding and -cross-linking activities. Inhibitory mutant Iba1 that suppresses M-CSF-induced membrane ruffling had lost the actin-cross-linking activity, and it inhibited the cross-linking activity of intact Iba1. These results indicate that Iba1 is a macrophage/microglia-specific actin-cross-linking protein essential for M-CSF-induced membrane ruffling.

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^☆: Abbreviations used: F-actin, filamentous actin; GST, glutathione S-transferase; M-CSF, macrophage colony-stimulating factor; PBS, phosphate-buffered saline; SDS–PAGE, sodium dodecyl sulfate–polyacrylamide gel electrophoresis.

¹: Japan Science and Technology Corporation Domestic Research Fellow.

²: To whom correspondence should be addressed. Fax: 81-42-346-1751. E-mail: [email protected].

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Regular ArticleIba1 Is an Actin-Cross-Linking Protein in Macrophages/Microglia☆

Abstract

Biochem. Biophys. Res. Commun.

Brain Res. Mol. Brain Res.

J. Biol. Chem.

J. Mol. Biol.

J. Biol. Chem.

Trends Neurosci.

Neurosci. Res.

J. Biol. Chem.

Biochem. Biophys. Res. Commun.

Involvement of Iba1 in membrane ruffling and phagocytosis of macrophages/microglia

J. Cell Sci.

On the crawling of animal cells

Science

Inhibition by drebrin of the actin-bundling activity of brain fascin, a protein localized in filopodia of growth cones

J. Neurochem.

Regular Article
Iba1 Is an Actin-Cross-Linking Protein in Macrophages/Microglia☆