Identification and characterization of a Drosophila nuclear receptor with the ability to inhibit the ecdysone response.
In a search for retinoid X receptor-like molecules in Drosophila, we have identified an additional member of the nuclear receptor superfamily, XR78E/F. In the DNA-binding domain, XR78E/F is closely related to the mammalian receptor TR2, as well as to the nuclear receptors Coup-TF and Seven-up. We demonstrate that XR78E/F binds as a homodimer to direct repeats of the sequence AGGTCA. In transient transfection assays, XR78E/F represses ecdysone signaling in a DNA-binding-dependent fashion. XR78E/F has its highest expression in third-instar larvae and prepupae. These experiments suggest that XR78E/F may play a regulatory role in the transcriptional cascade triggered by the hormone ecdysone in Drosophila.
D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D015139:Blotting, Southern; D004330:Drosophila / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D004440:Ecdysone / Q000378:metabolism*; D004441:Ecdysterone / Q000031:analogs & derivatives / Q000494:pharmacology; D017344:Genes, Insect; D015698:Genomic Library; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D011485:Protein Binding; D018168:Receptors, Retinoic Acid / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D047488:Retinoid X Receptors; D017422:Sequence Analysis, DNA; D015398:Signal Transduction; D013997:Time Factors; D014018:Tissue Distribution; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D018168:Receptors, Retinoic Acid; D011994:Recombinant Proteins; D047488:Retinoid X Receptors; D014157:Transcription Factors; D004440:Ecdysone; C055348:muristerone A; D004441:Ecdysterone