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Reverse Yeast Two-hybrid System to Identify Mammalian Nuclear Receptor Residues that Interact with Ligands and/or Antagonists
Published on: November 15, 2013
Interaction between the aryl hydrocarbon receptor and its antagonists, flavonoids
Itsuko Fukuda1, Rie Mukai, Masaya Kawase
1Research Center for Food Safety and Security, Graduate School of Agricultural Science, Kobe University, Kobe, Hyogo 657-8501, Japan. itsuko@silver.kobe-u.ac.jp
Biochemical and Biophysical Research Communications
|June 15, 2007
Summary
Dietary flavonoids like flavone, flavonol, and flavanone competitively inhibit the aryl hydrocarbon receptor (AhR). Catechin interacts with the AhR complex, indirectly causing antagonism.
Area of Science:
- Biochemistry
- Molecular Biology
- Pharmacology
Background:
- Flavonoids are dietary compounds known to antagonize the aryl hydrocarbon receptor (AhR).
- The precise molecular mechanisms underlying flavonoid antagonism of AhR remain largely unelucidated.
Purpose of the Study:
- To investigate the molecular mechanisms of flavonoid antagonism on the aryl hydrocarbon receptor (AhR).
- To differentiate the effects of various flavonoid subclasses on AhR ligand binding and complex interactions.
Main Methods:
- Investigated inhibitory effects of flavonoids on 3-methylcholanthrene binding to AhR.
- Utilized surface plasmon resonance (SPR) analysis to study direct interactions between flavonoids and the AhR complex (AhRc).
- Assessed the impact of these interactions on AhR DNA binding activity.
Main Results:
- Flavone, flavonol, and flavanone dose-dependently inhibited AhR ligand binding, suggesting competitive antagonism.
- Catechin, along with flavone, flavonol, and flavanone, directly interacted with the AhRc.
- Dissociation constants correlated inversely with suppression of DNA binding, indicating varying antagonistic potencies.
Conclusions:
- Flavone, flavonol, and flavanone function as competitive antagonists of the AhR.
- Catechin associates with the AhRc and exerts antagonistic effects indirectly, distinct from competitive inhibition.
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