RT Journal Article
SR Electronic
T1 Abscisic Acid Inhibits Type 2C Protein Phosphatases via the PYR/PYL Family of START Proteins
JF Science
JO Science
FD American Association for the Advancement of Science
SP 1068
OP 1071
DO 10.1126/science.1173041
VO 324
IS 5930
A1 Park, Sang-Youl
A1 Fung, Pauline
A1 Nishimura, Noriyuki
A1 Jensen, Davin R.
A1 Fujii, Hiroaki
A1 Zhao, Yang
A1 Lumba, Shelley
A1 Santiago, Julia
A1 Rodrigues, Americo
A1 Chow, Tsz-fung F.
A1 Alfred, Simon E.
A1 Bonetta, Dario
A1 Finkelstein, Ruth
A1 Provart, Nicholas J.
A1 Desveaux, Darrell
A1 Rodriguez, Pedro L.
A1 McCourt, Peter
A1 Zhu, Jian-Kang
A1 Schroeder, Julian I.
A1 Volkman, Brian F.
A1 Cutler, Sean R.
YR 2009
UL http://science.sciencemag.org/content/324/5930/1068.abstract
AB 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.