A conserved retinoid X receptor (RXR) from the mollusk Biomphalaria glabrata transactivates transcription in the presence of retinoids.

Détails

ID Serval
serval:BIB_41B0E841AA18
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
A conserved retinoid X receptor (RXR) from the mollusk Biomphalaria glabrata transactivates transcription in the presence of retinoids.
Périodique
Journal of Molecular Endocrinology
Auteur(s)
Bouton D., Escriva H., de Mendonça R.L., Glineur C., Bertin B., Noël C., Robinson-Rechavi M., de Groot A., Cornette J., Laudet V., Pierce R.J.
ISSN
0952-5041 (Print)
ISSN-L
0952-5041
Statut éditorial
Publié
Date de publication
2005
Peer-reviewed
Oui
Volume
34
Numéro
2
Pages
567-582
Langue
anglais
Résumé
Retinoid X receptors (RXR) are members of the nuclear receptor superfamily of ligand-activated transcription factors that have been characterized in a wide variety of metazoan phyla. They act as heterodimer partners of other nuclear receptors, and in vertebrates also activate transcription as homodimers in the presence of a ligand, 9-cis retinoic acid. In order to test the hypothesis that retinoic acid signaling pathways involving RXRs are present in the Lophotrochozoa, we have sought to isolate conserved members of this family from the platyhelminth parasite Schistosoma mansoni and its intermediate host, the mollusk Biomphalaria glabrata. Here we report that an RXR ortholog from B. glabrata (BgRXR) is better conserved, compared with mouse RXRalpha, both in the DNA-binding domain (89% identity) and in the ligand-binding domain (LBD) (81% identity), than are arthropod homologs. In EMSA, BgRXR binds to the direct repeat response element DR1 as a homodimer or as a heterodimer with mammalian RARalpha, LXR, FXR or PPARalpha. When transfected alone into mammalian cell lines, BgRXR transactivated transcription of a reporter gene from the Apo-A1 promoter in the presence of 9-cis retinoic acid or DHA. Constructs with the Gal4 DNA binding domain fused to the hinge and LBDs of BgRXR were used to show that ligand-dependent activation of transcription by BgRXR required its intact AF-2 activation domain, and that the LBD can form homodimers. Finally, the binding of 9-cis retinoic acid preferentially protected the LBD of BgRXR from degradation by trypsin in a proteolysis protection assay. Our results show that BgRXR binds and is activated by retinoids and suggest that retinoid signaling pathways are conserved in the Lophotrochozoa. The nucleotide sequence reported in this paper has been submitted to the GenBank/EBI Data Bank with accession no. AY048663.
Mots-clé
Amino Acid Sequence, Animals, Biomphalaria/genetics, Biomphalaria/metabolism, Dimerization, Genes, Reporter, Mice, Molecular Sequence Data, Phylogeny, Protein Binding, Protein Structure, Quaternary, Recombinant Fusion Proteins/genetics, Recombinant Fusion Proteins/metabolism, Retinoid X Receptors/chemistry, Retinoid X Receptors/classification, Retinoids/metabolism, Sequence Alignment, Signal Transduction/physiology, Transcription, Genetic, Transcriptional Activation, Two-Hybrid System Techniques
Pubmed
Web of science
Création de la notice
24/01/2008 18:46
Dernière modification de la notice
03/03/2018 16:34
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