title: Brz220 interacts with DWF4, a cytochrome P450 monooxygenase in brassinosteroid biosynthesis, and exerts biological activity.
abstract: Arabidopsis thaliana (Arabidopsis) treated with the four stereoisomers of Brz220 (2RS, 4RS-1-[4-propyl-2-(4-trifluoromethylphenyl)-1, 3-dioxane-2-ylmethyl]-1H-1, 2, 4-triazole) showed a dwarf phenotype like brassinosteroid (BR) biosynthesis mutants that were rescued by treatment of BRs. The target sites of each Brz220 stereoisomer were investigated by treatment of Arabidopsis with BRs in the dark. The results suggest that the stereoisomers block the 22-hydroxylation step in BR biosynthesis. This step is catalyzed by DWF4, an Arabidopsis cytochrome P450 identified as a steroid 22-hydroxylase. The enzyme was expressed in E. coli, and the binding affinity of the stereoisomers to recombinant DWF4 was analyzed. The results indicate that in these stereoisomers there exists a positive correlation between binding affinity to DWF4 and inhibition of Arabidopsis hypocotyl growth. In this context, we concluded that DWF4 is the target site of Brz220 in Arabidopsis.
authors.affiliation: Discovery Research Institute, RIKEN, Wako, Saitama, Japan.
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Sekimata
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Ohnishi
authors.forename: Masaharu
authors.initials: M
authors.lastname: Mizutani
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Todoroki
authors.forename: Sun-Young
authors.initials: SY
authors.lastname: Han
authors.forename: Jun
authors.initials: J
authors.lastname: Uzawa
authors.forename: Shozo
authors.initials: S
authors.lastname: Fujioka
authors.forename: Koichi
authors.initials: K
authors.lastname: Yoneyama
authors.forename: Yasutomo
authors.initials: Y
authors.lastname: Takeuchi
authors.forename: Suguru
authors.initials: S
authors.lastname: Takatsuto
authors.forename: Kanzo
authors.initials: K
authors.lastname: Sakata
authors.forename: Shigeo
authors.initials: S
authors.lastname: Yoshida
authors.forename: Tadao
authors.initials: T
authors.lastname: Asami
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism* / Q000494:pharmacology*; D060406:Brassinosteroids; D002777:Cholestanols / Q000378:metabolism*; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism* / Q000494:pharmacology; D004149:Dioxoles / Q000378:metabolism* / Q000494:pharmacology; D018546:Hypocotyl / Q000254:growth & development; D010840:Phytosterols / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000378:metabolism*; D013260:Steroids, Heterocyclic / Q000378:metabolism*; D014230:Triazoles / Q000378:metabolism* / Q000494:pharmacology
chemical_list: C459439:1-(2-(4-trifluoromethylphenyl)-4-n-propyl-1,3-dioxolan-2-ylmethyl)-1H-1,2,4-triazole; C111451:AT3G50660 protein, Arabidopsis; D029681:Arabidopsis Proteins; D060406:Brassinosteroids; D002777:Cholestanols; D004149:Dioxoles; D010840:Phytosterols; D010937:Plant Growth Regulators; D013260:Steroids, Heterocyclic; D014230:Triazoles; D003577:Cytochrome P-450 Enzyme System; C023623:brassinolide