Brz220与油菜素类固醇生物合成中的细胞色素P450单加氧酶DWF4相互作用，并发挥生物活性。

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

作者信息

Sekimata Katsuhiko, Ohnishi Toshiyuki, Mizutani Masaharu, Todoroki Yasushi, Han Sun-Young, Uzawa Jun, Fujioka Shozo, Yoneyama Koichi, Takeuchi Yasutomo, Takatsuto Suguru, Sakata Kanzo, Yoshida Shigeo, Asami Tadao

机构信息

Discovery Research Institute, RIKEN, Wako, Saitama, Japan.

出版信息

Biosci Biotechnol Biochem. 2008 Jan;72(1):7-12. doi: 10.1271/bbb.70141. Epub 2008 Jan 7.

DOI:10.1271/bbb.70141

PMID:18175930

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.

摘要

用Brz220（2RS，4RS-1-[4-丙基-2-(4-三氟甲基苯基)-1,3-二氧杂环己烷-2-基甲基]-1H-1,2,4-三唑）的四种立体异构体处理拟南芥后，其表现出与油菜素甾醇（BR）生物合成突变体相似的矮化表型，而BR处理可挽救这种表型。通过在黑暗中用BR处理拟南芥，研究了每种Brz220立体异构体的作用靶点。结果表明，这些立体异构体阻断了BR生物合成中的22-羟基化步骤。这一步骤由DWF4催化，DWF4是一种被鉴定为类固醇22-羟化酶的拟南芥细胞色素P450。该酶在大肠杆菌中表达，并分析了这些立体异构体与重组DWF4的结合亲和力。结果表明，在这些立体异构体中，与DWF4的结合亲和力与对拟南芥下胚轴生长的抑制之间存在正相关。在此背景下，我们得出结论，DWF4是拟南芥中Brz220的作用靶点。