Brz220 interacts with DWF4, a cytochrome P450 monooxygenase in brassinosteroid biosynthesis, and exerts biological activity

• Published in: Bioscience, biotechnology, and biochemistry Vol. 72; no. 1; pp. 7 - 12
• Main Authors: Sekimata, K.(RIKEN, Wako, Saitama (Japan)), Ohnishi, T, Mizutani, M, Todoroki, Y, Han, S.Y, Uzawa, J, Fujioka, S, Yoneyama, K, Takeuchi, Y, Takatsuto, S, Sakata, K, Yoshida, S, Asami, T
• Format: Journal Article
• Language: English
• Published: Tokyo Japan Society for Bioscience, Biotechnology, and Agrochemistry 01.01.2008; Japan Society for Bioscience Biotechnology and Agrochemistry; Oxford University Press
• Subjects: Arabidopsis - drug effects; Arabidopsis - enzymology; Arabidopsis - growth & development; Arabidopsis - metabolism; Arabidopsis Proteins - metabolism; Arabidopsis Proteins - pharmacology; ARABIDOPSIS THALIANA; AZOLE; AZOLES; Biological and medical sciences; BRASINOSTEROIDES; brassinosteroid; BRASSINOSTEROIDE; BRASSINOSTEROIDS; Cholestanols - metabolism; CITOCROMO P450; Cytochrome P-450 Enzyme System - metabolism; Cytochrome P-450 Enzyme System - pharmacology; CYTOCHROME P450; Dioxoles - metabolism; Dioxoles - pharmacology; DWARFISM; ENANISMO; Escherichia coli; Fundamental and applied biological sciences. Psychology; HYDROXYLATION; Hypocotyl - growth & development; IDROXILACION; NANISME; P450 inhibitor; Phytosterols - metabolism; Plant Growth Regulators - metabolism; Steroids, Heterocyclic - metabolism; Triazoles - metabolism; Triazoles - pharmacology; Brassinosteroid; Cytochrome P450; P450 inhibitor; Biosynthesis; Inhibitor; Biological activity; azole
• ISSN: 0916-8451; 1347-6947
• DOI: 10.1271/bbb.70141

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.