Regulation of subcellular localization of the Aryl Hydrocarbon Receptor (AhR)

Archives of Biochemistry and Biophysics
By: , and 

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Abstract

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that mediates the toxicity of dioxin and other xenobiotics. In the absence of exogenous ligand, AhR is cytosolic. We investigated how AhR is retained in the cytosol and how dioxin induces AhR to move to the nucleus. Disruption of nuclear export of AhR by the nuclear export inhibitor leptomycin B (LMB) or by mutation of the AhR nuclear export signal resulted in nuclear accumulation of AhR in the absence of exogenous ligand. Mutation of the AhR nuclear localization signal resulted in defects in nuclear import of AhR in both the presence and the absence of exogenous ligand. Dioxin treatment caused a more rapid accumulation of AhR in the nucleus than LMB treatment. In the presence of both dioxin and LMB, nuclear accumulation of AhR was more rapid than in the presence of dioxin alone. Our results show that AhR shuttles between the nucleus and the cytosol in the absence of exogenous ligand. Binding of ligand induces an increase in the rate of nuclear import of AhR but does not eliminate nuclear export of AhR.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Regulation of subcellular localization of the Aryl Hydrocarbon Receptor (AhR)
Series title Archives of Biochemistry and Biophysics
DOI 10.1006/abbi.2001.2339
Volume 389
Issue 2
Year Published 2001
Language English
Publisher Elsevier
Contributing office(s) Columbia Environmental Research Center
Description 11 p.
First page 207
Last page 217