In higher metazoans, the nuclear hormone receptors activate transcription trough their specific adaptors, nuclear hormone receptor adaptors NCoA, which are absent in lower metazoans. The Nine amino acid TransActivation Domain, 9aaTAD, was reported for a large number of the transcription activators that recruit general mediators of transcription. In this study, we demonstrated that the 9aaTAD from NHR-49 receptor of nematode C.elegans activates transcription as a small peptide. We showed that the ancient 9aaTAD domains are conserved in the nuclear hormone receptors including human HNF4, RARa, VDR and PPARg. Also their small 9aaTAD peptides effectively activated transcription in absence of the NCoA adaptors. We also showed that adjacent H11 domains in ancient and modern hormone receptors have an inhibitory effect on their 9aaTAD function.

• MeSH
• aktivace transkripce * MeSH
• alfa receptor kyseliny retinové chemie   metabolismus   MeSH
• Caenorhabditis elegans chemie   metabolismus   MeSH
• hepatocytární jaderný faktor 4 chemie   metabolismus   MeSH
• lidé MeSH
• molekulární modely MeSH
• peptidy chemie   metabolismus   MeSH
• PPAR gama chemie   metabolismus   MeSH
• proteinové domény MeSH
• proteiny Caenorhabditis elegans chemie   metabolismus   MeSH
• receptory cytoplazmatické a nukleární chemie   metabolismus   MeSH
• receptory kalcitriolu chemie   metabolismus   MeSH
• sekvence aminokyselin MeSH
• sekvenční seřazení MeSH
• signální transdukce MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The Pregnane X (PXR), Vitamin D (VDR) and Farnesoid X (FXR) nuclear receptors have been shown to be receptors of bile acids controlling their detoxification or synthesis. Chenodeoxycholic (CDCA) and lithocholic (LCA) acids are ligands of FXR and VDR, respectively, whereas 3-keto and acetylated derivates of LCA have been described as ligands for all three receptors. In this study, we hypothesized that oxidation or acetylation at position 3, 7 and 12 of bile acids DCA (deoxycholic acid), LCA, CA (cholic acid), and CDCA by detoxification enzymes or microbiome may have an effect on the interactions with bile acid nuclear receptors. We employed reporter gene assays in HepG2 cells, the TR-FRET assay with recombinant PXR and RT-PCR to study the effects of acetylated and keto bile acids on the nuclear receptors activation and their target gene expression in differentiated hepatic HepaRG cells. We demonstrate that the DCA 3,12-diacetate and CA 3,7,12-triacetate derivatives are ligands of PXR and DCA 3,12-diacetate induces PXR target genes such as CYP3A4, CYP2B6 and ABCB1/MDR1. In conclusion, we found that acetylated DCA and CA are potent ligands of PXR. Whether the acetylated bile acid derivatives are novel endogenous ligands of PXR with detoxification or physiological functions should be further studied in ongoing experiments.

• MeSH
• acetylace MeSH
• buněčné kultury MeSH
• buňky Hep G2 MeSH
• cytochrom P-450 CYP3A genetika   MeSH
• cytochrom P450 CYP2B6 genetika   MeSH
• hepatocyty účinky léků   enzymologie   metabolismus   MeSH
• kyselina cholová chemie   metabolismus   farmakologie   MeSH
• kyselina deoxycholová chemie   metabolismus   farmakologie   MeSH
• lidé MeSH
• ligandy MeSH
• myši MeSH
• oxidace-redukce MeSH
• P-glykoprotein genetika   MeSH
• plazmidy MeSH
• receptory cytoplazmatické a nukleární chemie   genetika   metabolismus   MeSH
• receptory kalcitriolu chemie   genetika   metabolismus   MeSH
• reportérové geny MeSH
• simulace molekulového dockingu MeSH
• steroidní receptory chemie   genetika   metabolismus   MeSH
• techniky dvojhybridového systému MeSH
• transfekce MeSH
• vazba proteinů MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH