The activation mechanism of the aryl hydrocarbon receptor (AhR) by molecular chaperone HSP90
| Autor: | Tomoya Okamoto, Hideaki Itoh, Yuhtaroh Nagata, Soh Yamamoto, Ewa Grave, Hirotaka Okada, Kei Ohtaka, Miki Hosaka, Kana Fukuda, Noriko Tsuji, Shiho Yoshida, Michiro Otaka, Kazuhiro Sekine, Shiori Hatakeyama, Asami Haga |
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| Jazyk: | angličtina |
| Předmět: |
CYP1A1
cytochrome P450 1A1 Aryl hydrocarbon receptor nuclear translocator RT-PCR reverse transcription-polymerase chain reaction 3-MC 3-methylcholanthrene TCDD 2 3 7 8-tetrachlorodibenzo-p-dioxin β-NF β-naphthoflavone GST glutathione glutathione S-transferase HSP90 90-kDa of heat shock protein General Biochemistry Genetics and Molecular Biology Article IPTG isopropyl-1-thio-β-d-galactopyranoside bHLH basic helix-loop-helix PAS domain XAP2 hepatitis B virus X-associated protein polycyclic compounds PAS per-arnt-sim HSP90 Transcription factor lcsh:QH301-705.5 Aryl hydrocarbon receptor Dioxin receptor DEPC dihydrochloride diethylpyrocarbonated biology Basic helix-loop-helix Arnt AhR nuclear translocator PLA proximity ligation assay 17-DMAG 17-(dimethylaminoethylamino)-17-demethoxygeldanamycin dimethylsulfoxide AhR respiratory system Ligand (biochemistry) Molecular biology respiratory tract diseases Nuclear receptor lcsh:Biology (General) Cytoplasm NLS nuclear localization signal AhR aryl hydrocarbon receptor biology.protein Molecular chaperone XRE xenobiotic responsible element DAPI 4′ 6-diamidino-2-phenylindole |
| Zdroj: | FEBS Open Bio FEBS Open Bio, Vol 4, Iss C, Pp 796-803 (2014) |
| ISSN: | 2211-5463 |
| DOI: | 10.1016/j.fob.2014.09.003 |
| Popis: | Highlights • We showed the direct interaction of AhR and HSP90 using purified protein. • The ligand 17-DMAG induces a dissociation of HSP90 from AhR. • The AhR–HSP90 complex is not affected by the timing of β-naphthoflavone binding to AhR. • The AhR–HSP90 complex was translocated to the nucleus after treatment with β-naphthoflavone. The aryl hydrocarbon receptor is a member of the nuclear receptor superfamily that associates with the molecular chaperone HSP90 in the cytoplasm. The activation mechanism of the AhR is not yet fully understood. It has been proposed that after binding of ligands such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 3methylcholanthrene (3-MC), or β-naphthoflavone (β-NF), the AhR dissociates from HSP90 and translocates to the nucleus. It has also been hypothesized that the AhR translocates to the nucleus and forms a complex with HSP90 and other co-chaperones. There are a few reports about the direct association or dissociation of AhR and HSP90 due to difficulties in purifying AhR. We constructed and purified the PAS domain from AhR. Binding of the AhR-PAS domain to β-NF affinity resin suggested that it possesses ligand-binding affinity. We demonstrated that the AhR-PAS domain binds to HSP90 and the association is not affected by ligand binding. The ligand 17-DMAG inhibited binding of HSP90 to GST-PAS. In an immunoprecipitation assay, HSP90 was co-immunoprecipitated with AhR both in the presence or absence of ligand. Endogenous AhR decreased in the cytoplasm and increased in the nucleus of HeLa cells 15 min after treatment with ligand. These results suggested that the ligand-bound AhR is translocated to nucleus while in complex with HSP90. We used an in situ proximity ligation assay to confirm whether AhR was translocated to the nucleus alone or together with HSP90. HSP90 was co-localized with AhR after the nuclear translocation. It has been suggested that the ligand-bound AhR was translocated to the nucleus with HSP90. Activated AhR acts as a transcription factor, as shown by the transcription induction of the gene CYP1A1 8 h after treatment with β-NF. |
| Databáze: | OpenAIRE |
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