Brz220 interacts with DWF4, a cytochrome P450 monooxygenase in brassinosteroid biosynthesis, and exerts biological activity.
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.
Sekimata
Katsuhiko
K
Discovery Research Institute, RIKEN, Wako, Saitama, Japan.
Ohnishi
Toshiyuki
T
Mizutani
Masaharu
M
Todoroki
Yasushi
Y
Han
Sun-Young
SY
Uzawa
Jun
J
Fujioka
Shozo
S
Yoneyama
Koichi
K
Takeuchi
Yasutomo
Y
Takatsuto
Suguru
S
Sakata
Kanzo
K
Yoshida
Shigeo
S
Asami
Tadao
T
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
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