tailieunhanh - Báo cáo khoa học: Arthropod nuclear receptors and their role in molting

The molting process in arthropods is regulated by steroid hormones acting via nuclear receptor proteins. The most common molting hormone is the ecdysteroid, 20-hydroxyecdysone. The receptors of 20-hydroxyecdysone have also been identified in many arthropod species, and the amino acid sequences determined. | iFEBS Journal REVIEW ARTICLE Arthropod nuclear receptors and their role in molting Yoshiaki Nakagawa1 and Vincent C. Henrich2 1 Division of Applied Sciences Graduate Schoolof Agriculture Kyoto University Kyoto Japan 2 Center for Biotechnology Genomics and Health Research University of North Carolina Greensboro UNCG NC USA Keywords ecdsyone receptor ecdysteroids EcR insecticides juvenile hormone transcription factor USP Correspondence Y. Nakagawa Division of Applied Sciences Graduate Schoolof Agriculture Kyoto University Kitashirakawa Sakyo-Ku Kyoto 606-8502 Japan Fax 81 75 753 6123 Tel 81 75 753 6117 E-mail naka@ Received 1 June 2009 revised 18 August 2009 accepted 2 September 2009 doi The molting process in arthropods is regulated by steroid hormones acting via nuclear receptor proteins. The most common molting hormone is the ecdysteroid 20-hydroxyecdysone. The receptors of 20-hydroxyecdysone have also been identified in many arthropod species and the amino acid sequences determined. The functional molting hormone receptors consist of two members of the nuclear receptor superfamily namely the ecdysone receptor and the ultraspiracle although the ecdysone receptor may be functional in some instances without the ultraspiracle. Generally the ecdysone receptor ultraspiracle heterodimer binds to a number of ecdysone response elements sequence motifs that reside in the promoter of various ecdyster-oid-responsive genes. In the ensuing transcriptional induction the ecdysone receptor ultraspiracle complex binds to 20-hydroxyecdysone or to a cognate ligand that in turn leads to the release of a corepressor and the recruitment of coactivators. 3D structures of the ligand-binding domains of the ecdysone receptor and the ultraspiracle have been solved for a few insect species. Ecdysone agonists bind to ecdysone receptors specifically and ligand-ecdysone receptor binding is enhanced in the presence of the ultraspiracle in .