Park Sang-Youl, Fung Pauline, Nishimura Noriyuki, Jensen Davin R, Fujii Hiroaki, Zhao Yang, Lumba Shelley, Santiago Julia, Rodrigues Americo, Chow Tsz-Fung F, Alfred Simon E, Bonetta Dario, Finkelstein Ruth, Provart Nicholas J, Desveaux Darrell, Rodriguez Pedro L, McCourt Peter, Zhu Jian-Kang, Schroeder Julian I, Volkman Brian F, Cutler Sean R
Department of Botany and Plant Sciences, University of California at Riverside, Riverside, CA 92521, USA.
Science. 2009 May 22;324(5930):1068-71. doi: 10.1126/science.1173041. Epub 2009 Apr 30.
Type 2C protein phosphatases (PP2Cs) are vitally involved in abscisic acid (ABA) signaling. Here, we show that a synthetic growth inhibitor called pyrabactin functions as a selective ABA agonist. Pyrabactin acts through PYRABACTIN RESISTANCE 1 (PYR1), the founding member of a family of START proteins called PYR/PYLs, which are necessary for both pyrabactin and ABA signaling in vivo. We show that ABA binds to PYR1, which in turn binds to and inhibits PP2Cs. We conclude that PYR/PYLs are ABA receptors functioning at the apex of a negative regulatory pathway that controls ABA signaling by inhibiting PP2Cs. Our results illustrate the power of the chemical genetic approach for sidestepping genetic redundancy.
2C型蛋白磷酸酶（PP2Cs）在脱落酸（ABA）信号传导中起着至关重要的作用。在此，我们表明一种名为吡拉布汀的合成生长抑制剂可作为选择性ABA激动剂发挥作用。吡拉布汀通过PYRABACTIN RESISTANCE 1（PYR1）起作用，PYR1是START蛋白家族中一个名为PYR/PYLs家族的创始成员，在体内对于吡拉布汀和ABA信号传导都是必需的。我们表明ABA与PYR1结合，而PYR1又结合并抑制PP2Cs。我们得出结论，PYR/PYLs是ABA受体，在通过抑制PP2Cs来控制ABA信号传导的负调控途径的顶端发挥作用。我们的结果说明了化学遗传学方法在规避遗传冗余方面的强大作用。
