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Updated: May 9, 2026

Quantification of Monocyte Chemotactic Activity In Vivo and Characterization of Blood Monocyte Derived Macrophages
Published on: August 12, 2019
MsrB1 and MICALs regulate actin assembly and macrophage function via reversible stereoselective methionine oxidation
Byung Cheon Lee1, Zalán Péterfi, Fukun W Hoffmann
1Division of Genetics, Department of Medicine, Brigham & Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
Abstract:
Redox control of protein function involves oxidation and reduction of amino acid residues, but the mechanisms and regulators involved are insufficiently understood. Here, we report that in conjunction with Mical proteins, methionine-R-sulfoxide reductase B1 (MsrB1) regulates mammalian actin assembly via stereoselective methionine oxidation and reduction in a reversible, site-specific manner. Two methionine residues in actin are specifically converted to methionine-R-sulfoxide by Mical1 and Mical2 and reduced back to methionine by selenoprotein MsrB1, supporting actin disassembly and assembly, respectively. Macrophages utilize this redox control during cellular activation by stimulating MsrB1 expression and activity as a part of innate immunity. We identified the regulatory role of MsrB1 as a Mical antagonist in orchestrating actin dynamics and macrophage function. More generally, our study shows that proteins can be regulated by reversible site-specific methionine-R-sulfoxidation.
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