Journal Article

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

Fujii, Hiroaki, Alfred, Simon E, Rodrigues, Americo, Jensen, Davin R, Volkman, Brian F, Fung, Pauline, Zhu, Jian-Kang, Lumba, Shelley, Bonetta, Dario, Cutler, Sean R, Santiago, Julia, Desveaux, Darrell, Schroeder, Julian I, Park, Sang-Youl, Provart, Nicholas J, Chow, Tsz-fung F, Rodriguez, Pedro L, Zhao, Yang, McCourt, Peter, Finkelstein, Ruth, Nishimura, Noriyuki

2009

Overview

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.

• Publisher: American Association for the Advancement of Science,The American Association for the Advancement of Science
• Subject: abscisic acid / Abscisic Acid - agonists / Abscisic Acid - metabolism / Agonists / Arabidopsis - enzymology / Arabidopsis - genetics / Arabidopsis - growth & development / Arabidopsis - metabolism / Arabidopsis Proteins - antagonists & inhibitors / Arabidopsis Proteins - genetics / Arabidopsis Proteins - metabolism / Binding sites / Biological and medical sciences / Cell physiology / Cellular biology / Fundamental and applied biological sciences. Psychology / Genes, Plant / Genomes / Germination - drug effects / Ligands / Membrane Transport Proteins - genetics / Membrane Transport Proteins - metabolism / Molecular and cellular biology / Molecular genetics / Mutation / Naphthalenes - chemistry / Naphthalenes - metabolism / Naphthalenes - pharmacology / Phenotypes / Phosphatases / Phosphoprotein Phosphatases - antagonists & inhibitors / Phosphoprotein Phosphatases - metabolism / Plant biology / Plant cells / Protein Binding / Proteins / Receptors / Recombinant Fusion Proteins - metabolism / Seeds - growth & development / Seeds - metabolism / Signal Transduction / Sulfonamides - chemistry / Sulfonamides - metabolism / Sulfonamides - pharmacology / Two hybrid system techniques / Yeasts