The Intrinsically Disordered C-terminal F Domain of the Ecdysteroid Receptor from Aedes aegypti Exhibits Metal Ion-binding Ability

Publication date: Available online 20 September 2018Source: The Journal of Steroid Biochemistry and Molecular BiologyAuthor(s): Anna Więch, Magdalena Rowińska-Żyrek, Joanna Wątły, Aleksandra Czarnota, Rafał Hołubowicz, Zbigniew Szewczuk, Andrzej Ożyhar, Marek OrłowskiAbstractThe dominant vector of dengue and Zika diseases is a female Aedes aegypti mosquito. Its reproduction is controlled by the formation of an active heterodimer complex of the 20-hydroxyecdysone receptor (EcR) and Ultraspiracle protein (Usp). Although EcR exhibits a structural and functional organization typical of nuclear receptors (NRs), the EcR C-terminus has an additional F domain (AaFEcR) that is rarely present in the NRs superfamily. The presence of F domains is evolutionarily not well conserved in the NRs. The structure-function relationship of EcR F domains in arthropods is unclear and enigmatic. To date, there have been no data concerning the structure and function of AaFEcR.Our results showed that AaFEcR belongs to a family of intrinsically disordered proteins (IDPs) and possesses putative pre-molten globule (PMG) characteristics. Unexpectedly, additional amino acid composition in silico analyses revealed the presence of short unique repeated Pro-His clusters forming an HGPHPHPHG motif, which is similar to those responsible for Zn2+ and Cu2+ binding in histidine-proline-rich glycoproteins (HPRGs). Using SEC, SV-AUC and ESI-TOF MS, we showed that the intrinsically disordered AaFEcR is able t...
Source: The Journal of Steroid Biochemistry and Molecular Biology - Category: Biochemistry Source Type: research