Abscisic Acid Inhibits Type 2C Protein Phosphatases via the PYR/PYL Family of START Proteins

作者：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^*

来源：Science, 2009, 324(5930): 1068-1071.

DOI：10.1126/science.1173041

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.

• 出版日期2009-5-22