Estrogen-related receptors (NR3B family) and Nurr1, NGFI-B, and Nor1 (NR4A family) are orphan nuclear receptors lacking identified natural ligands. The mechanisms regulating their transcriptional activities have remained elusive. We have previously observed that the members of NR3B and NR4A families are coexpressed in certain cell types such as osteoblasts and that the ability of Nurr1 to transactivate the osteopontin promoter is repressed by ERRs. We have now studied the cross-talk between NR3B and NR4A receptors. We show that NR3B and NR4A receptors mutually repress each others' transcriptional activity. The repression involves intact DNA-binding domains and dimerization interfaces but does not result from competition for DNA binding or from heterodimerization. The activation functions of NR3B and NR4A receptors are dispensable for the cross-talk. In conclusion, we report that cross-talk between NR3B and NR4A receptors is a mechanism modulating the transcriptional activities of these orphan nuclear receptors.
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http://dx.doi.org/10.1016/j.bbrc.2007.05.122 | DOI Listing |
Nucl Receptor Res
January 2017
Biological Sciences, Clemson University, Clemson, SC 29634.
The nuclear receptors (NRs) are ligand-dependent transcription factors that respond to various internal as well as external cues such as nutrients, pheromones, and steroid hormones that play crucial roles in regulation and maintenance of homeostasis and orchestrating the physiological and stress responses of an organism. We annotated the (mummichog; Atlantic killifish) nuclear receptors. Mummichog are a non-migratory, estuarine fish with a limited home range often used in environmental research as a field model for studying ecological and evolutionary responses to variable environmental conditions such as salinity, oxygen, temperature, pH, and toxic compounds because of their hardiness.
View Article and Find Full Text PDFBiochem Biophys Res Commun
July 2007
Institute of Biomedicine, Biomedicum Helsinki, University of Helsinki, Helsinki, Finland.
Estrogen-related receptors (NR3B family) and Nurr1, NGFI-B, and Nor1 (NR4A family) are orphan nuclear receptors lacking identified natural ligands. The mechanisms regulating their transcriptional activities have remained elusive. We have previously observed that the members of NR3B and NR4A families are coexpressed in certain cell types such as osteoblasts and that the ability of Nurr1 to transactivate the osteopontin promoter is repressed by ERRs.
View Article and Find Full Text PDFInt J Dev Biol
February 2003
Department of Zoology and Entomology, University of Queensland, Brisbane, Australia.
Nuclear receptors are a superfamily of metazoan transcription factors that have been shown to be involved in a wide range of developmental and physiological processes. A PCR-based survey of genomic DNA and developmental cDNAs from the ascidian Herdmania identifies eight members of this multigene family. Sequence comparisons and phylogenetic analyses reveal that these ascidian nuclear receptors are representative of five of the six previously defined nuclear receptor subfamilies and are apparent homologues of retinoic acid [NR1B], retinoid X [NR2B], peroxisome proliferator-activated [NR1C], estrogen related [NR3B], neuron-derived orphan (NOR) [NR4A3], nuclear orphan [NR4A], TR2 orphan [NR2C1] and COUP orphan [NR2F3] receptors.
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