| RRC ID |
45206
|
| 著者 |
Sugatani J, Hattori Y, Noguchi Y, Yamaguchi M, Yamazaki Y, Ikari A.
|
| タイトル |
Threonine-290 regulates nuclear translocation of the human pregnane X receptor through its phosphorylation/dephosphorylation by Ca2+/calmodulin-dependent protein kinase II and protein phosphatase 1.
|
| ジャーナル |
Drug Metab Dispos
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| Abstract |
The human pregnane X receptor (hPXR) is recognized as a xenobiotic-sensing nuclear receptor that transcriptionally regulates the gene expression of drug-metabolizing enzymes and transporters. Our study elucidates the mechanism by which the localization of hPXR is regulated through threonine-290. A phosphomimetic mutation at threonine-290 (T290D) retained hPXR in the cytoplasm of HepG2, HuH6, and SW480 cells in vitro and the mouse liver in vivo even after treatment with rifampicin, and a phosphodeficient mutation (T290A) translocated from the cytoplasm to the nucleus as the wild-type hPXR. The amount of the unphosphorylated wild-type yellow fluorescent protein-hPXR fusion protein but not the T290A mutant increased on Phos-tag gels in response to stimulations with rifampicin and cyclin-dependent kinase 2 inhibitor roscovitine, and a marked increase was observed in the unphosphorylated levels of the T290A mutant in nontreated cells. The Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) inhibitor KN93 [2-[N-(2-hydroxyethyl)]-N-(4-methoxybenzenesulfonyl)]amino-N-(4-chlorocinnamyl)-N-methylbenzylamine)] and transfection with anti-CaMKII small-interfering RNA (siRNA) enhanced the unphosphorylated levels of the wild-type protein. CaMKII directly phosphorylated the threonine-290 of hPXR, and the T290A mutant conferred resistance to CaMKII. The protein phosphatase (PP) inhibitor okadaic acid (100 nM) and transfection with anti-PP1 siRNA but not anti-PP2A siRNA led to reduced expression of CYP3A4 mRNA. After the rifampicin and roscovitine stimulations, PP1 was recruited to the wild-type hPXR but not the T290A mutant. These results suggest that phosphorylation at threonine-290 by CaMKII may impair the function of hPXR by repressing its translocation to the nucleus, and dephosphorylation by PP1 is necessary for the xenobiotic-dependent nuclear translocation of hPXR.
|
| 巻・号 |
42(10)
|
| ページ |
1708-18
|
| 公開日 |
2014-10-1
|
| DOI |
10.1124/dmd.114.059139
|
| PII |
dmd.114.059139
|
| PMID |
25074870
|
| MeSH |
Animals
Benzylamines / pharmacology
Calcium-Calmodulin-Dependent Protein Kinase Type 2 / metabolism*
Cell Line
Cell Nucleus / metabolism*
Gene Expression Regulation, Enzymologic / drug effects
Glucuronosyltransferase / biosynthesis
HSP90 Heat-Shock Proteins / metabolism
Humans
Liver / drug effects
Liver / metabolism
Mice
Mutation
Okadaic Acid / pharmacology
Phosphorylation / drug effects
Pregnane X Receptor
Protein Phosphatase 1 / metabolism*
Protein Transport
Purines / pharmacology
RNA, Small Interfering / pharmacology
Receptors, Steroid / chemistry*
Receptors, Steroid / metabolism*
Rifampin / pharmacology
Roscovitine
Sulfonamides / pharmacology
Threonine / genetics
Threonine / metabolism*
|
| IF |
3.231
|
| 引用数 |
12
|
|
WOS 分野
|
PHARMACOLOGY & PHARMACY
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| リソース情報 |
| ヒト・動物細胞 |
|
