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Regulators of PP2C Phosphatase Activity Function as Abscisic Acid Sensors

SciencePublished 30 April 2009
Yue Ma, Izabela Szostkiewicz, Arthur Korte, Danièle Moes, Yi Yang, Alexander Christmann
Citations2,476
SJR quartileQ1
SJR score10.42
SNIP6.62

TL;DR

This study identifies interactors of ABI1 and ABI2 which are named regulatory components of ABA receptor (RCARs) in Arabidopsis and suggests that the ABA receptors may be a class of closely related complexes, which may explain previous difficulties in establishing its identity.

Abstract

The plant hormone abscisic acid (ABA) acts as a developmental signal and as an integrator of environmental cues such as drought and cold. Key players in ABA signal transduction include the type 2C protein phosphatases (PP2Cs) ABI1 and ABI2, which act by negatively regulating ABA responses. In this study, we identify interactors of ABI1 and ABI2 which we have named regulatory components of ABA receptor (RCARs). In Arabidopsis, RCARs belong to a family with 14 members that share structural similarity with class 10 pathogen-related proteins. RCAR1 was shown to bind ABA, to mediate ABA-dependent inactivation of ABI1 or ABI2 in vitro, and to antagonize PP2C action in planta. Other RCARs also mediated ABA-dependent regulation of ABI1 and ABI2, consistent with a combinatorial assembly of receptor complexes.

Keywords

Agricultural and Biological Sciences