Ecdysone receptor (EcR) (EcR)

The Ecdysone receptor (EcR) is a ligand-activated transcription factor belonging to the nuclear receptor superfamily, primarily found in insects and other arthropods [UniProt: P34021]. It forms a functional heterodimer with the Ultraspiracle protein (USP), which is the insect ortholog of the vertebrate Retinoid X Receptor (RXR) [PubMed: 12717444]. This complex mediates the physiological effects of ecdysteroids, such as 20-hydroxyecdysone, which are the principal hormones governing molting, metamorphosis, and reproduction in insects [PubMed: 11555172]. In the field of crop protection, EcR is a validated target for non-steroidal ecdysone agonists like methoxyfenozide and tebufenozide, which disrupt the molting process in lepidopteran pests by inducing a premature, lethal molt [PubChem: CID 115214]. Beyond agriculture, the EcR system has been repurposed for human medicine as a highly specific, inducible gene switch (e.g., RheoSwitch) for gene therapy [PubMed: 21934668]. In this context, a synthetic ligand such as Veledimex is used to precisely control the timing and level of therapeutic protein expression, such as Interleukin-12 in oncology trials for glioblastoma [ClinicalTrials.gov: NCT02026271].

Other names

20-hydroxyecdysone receptorNR1H1EcR-USP complexEcdysteroid receptor

The receptor functions as a heterodimer with the Ultraspiracle protein (USP); upon binding to ecdysteroids or synthetic agonists, the complex binds to ecdysone response elements (EcREs) in the DNA to initiate the transcription of early genes, triggering physiological changes like molting or transgene expression.