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SelR reverses Mical-mediated oxidation of actin to regulate F-actin dynamics

Ruei-Jiun Hung1, Christopher S Spaeth, Hunkar Gizem Yesilyurt

  • 1Departments of Neuroscience and Pharmacology and Neuroscience Graduate Program, The University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.

Nature Cell Biology
|November 12, 2013
PubMed

Insights

Oxidation of actin by the Mical enzyme alters its polymerization. A newly identified enzyme, SelR, reverses this process, revealing a reversible redox system controlling actin dynamics and cell behavior.

Area of Science:

  • Cell Biology
  • Biochemistry
  • Developmental Biology

Background:

  • Actin polymerization is crucial for cellular functions.
  • Oxidation of methionine 44 (Met44) in actin by the Mical enzyme alters its polymerization properties.
  • Mical functions with Semaphorin cues to regulate cellular behavior.

Purpose of the Study:

  • To investigate the reversibility of Mical-mediated actin oxidation.
  • To identify the enzyme responsible for reversing actin oxidation.
  • To understand the role of this reversible system in cellular processes.

Main Methods:

  • Genetic screening to identify enzymes opposing Mical activity.
  • Biochemical assays to confirm enzyme specificity and function.
  • In vivo studies to observe cellular behaviors.

Main Results:

  • Identified SelR, a methionine sulfoxide reductase (MsrB) enzyme, that reverses Mical's oxidation of actin.
  • SelR specifically reduces the R-isomer of methionine sulfoxide, restoring actin's polymerization.
  • Mical oxidizes actin stereospecifically to actin Met-44-R-sulfoxide (actin(Met(R)O-44)).

Conclusions:

  • A reversible redox system regulates actin polymerization via specific methionine residue interconversion.
  • This Mical-SelR system controls actin-dependent cellular behaviors and development.
  • The findings reveal a novel mechanism for modulating protein function through reversible oxidation.

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