Functional ecdysone receptor is the product of EcR and Ultraspiracle genes.

Published

Journal Article

Although the biological activity of the insect moulting hormone ecdysone, is manifested through a hormonally regulated transcriptional cascade associated with chromosomal puffing, a direct association of the receptor with the puff has yet to be established. The cloned ecdysone receptor (EcR) is by itself incapable of high-affinity DNA binding or transcriptional activation. Rather, these activities are dependent on heterodimer formation with Ultraspiracle (USP) the insect homologue of vertebrate retinoid X receptor. Here we report that native EcR and USP are co-localized on ecdysone-responsive loci of polytene chromosomes. Moreover, we show that natural ecdysones selectively promote physical association between EcR and USP, and conversely, that high-affinity hormone binding requires both EcR and USP. Replacement of USP with retinoid X receptor produces heterodimers with distinct pharmacological and functional properties. These results redefine the ecdysone receptor as a dynamic complex whose activity may be altered by combinatorial interactions among subunits and ligand.

Full Text

Duke Authors

Cited Authors

  • Yao, TP; Forman, BM; Jiang, Z; Cherbas, L; Chen, JD; McKeown, M; Cherbas, P; Evans, RM

Published Date

  • December 1993

Published In

Volume / Issue

  • 366 / 6454

Start / End Page

  • 476 - 479

PubMed ID

  • 8247157

Pubmed Central ID

  • 8247157

Electronic International Standard Serial Number (EISSN)

  • 1476-4687

International Standard Serial Number (ISSN)

  • 0028-0836

Digital Object Identifier (DOI)

  • 10.1038/366476a0

Language

  • eng