Ito Takuya, Kondoh Yasumitsu, Yoshida Kazuko, Umezawa Taishi, Shimizu Takeshi, Shinozaki Kazuo, Osada Hiroyuki
Chemical Biology Research Group, RIKEN Center for Sustainable Resource Science, Wako, Saitama, 351-0198, Japan.
Gene Discovery Research Group, RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, 230-0045, Japan.
Chembiochem. 2015 Nov;16(17):2471-8. doi: 10.1002/cbic.201500429. Epub 2015 Oct 23.
Abscisic acid (ABA) signaling is involved in multiple processes in plants, such as water stress control and seed dormancy. Major regulators of ABA signaling are the PYR/PYL/RCAR family receptor proteins, group A protein phosphatases 2C (PP2Cs), and subclass III of SNF1-related protein kinase 2 (SnRK2). Novel ABA agonists and antagonists to modulate the functions of these proteins would not only contribute to clarification of the signaling mechanisms but might also be used to improve crop yields. To obtain small molecules that interact with Arabidopsis ABA receptor PYR1, we screened 24 275 compounds from a chemical library at the RIKEN Natural Products Depository by using a chemical array platform. Subsequent SnRK2 and PP2C assays narrowed down the candidates to two molecules. One antagonized ABA in a competitive manner and inhibited the formation of the PYR1-ABA-PP2C ternary complex. These compounds might have potential as bioprobes to analyze ABA signaling.
脱落酸（ABA）信号传导参与植物的多个过程，如水胁迫控制和种子休眠。ABA信号传导的主要调节因子是PYR/PYL/RCAR家族受体蛋白、A类蛋白磷酸酶2C（PP2C）和SNF1相关蛋白激酶2（SnRK2）的III亚类。调节这些蛋白质功能的新型ABA激动剂和拮抗剂不仅有助于阐明信号传导机制，还可能用于提高作物产量。为了获得与拟南芥ABA受体PYR1相互作用的小分子，我们使用化学阵列平台从理化学研究所天然产物库的化学文库中筛选了24275种化合物。随后的SnRK2和PP2C分析将候选物缩小到两个分子。其中一个以竞争性方式拮抗ABA，并抑制PYR1-ABA-PP2C三元复合物的形成。这些化合物可能具有作为分析ABA信号传导的生物探针的潜力。
