Rheostatic Control of ABA Signaling through HOS15-Mediated OST1 Degradation  

作　　者：Akhtar Ali Jae Kyoung Kim Masood Jan Haris Ali Khan Irfan Ullah Khan Mingzhe Shen Junghoon Park Chae Jin Lim Shah Hussain Dongwon Baek Kai Wang Woo Sik Chung Vicente Rubio Sang Yeol Lee Zhizhong Gong Woe Yeon Kim Ray ABressan Jose MPardo Dae-Jin Yun 

机构地区：[1]Department of Biomedical Science&Engineering,Konkuk University,Seoul 05029,South Korea [2]Department of Mathematical Sciences,Korea Advanced Institute of Science and Technology,Daejeon 34131,Korea [3]Division of Applied Life Science,Plant Molecular Biology and Biotechnology Research Center,Gyeongsang National University,Jinju 660-701,South Korea [4]State Key Laboratory of Plant Physiology and Biochemistry,College of Biological Sciences,China Agricultural University,Beijing 100193,China [5]Centro Nacional de Biotecnologia-CSIC Darwin,3.Campus de la UAM.Cantoblanco,28049 Madrid,Spain [6]Department of Horticulture and Landscape Architecture,Purdue University,625 Agriculture Mall Drive,West Lafayette,IN 47907-2010,USA [7]lnstituto de Bioquimica Vegetal y Fotosintesis,cicCartuja,CSIC-Universidad de Sevilla,AmericoVespucio 49,Sevilla 41092,Spain

出　　处：《Molecular Plant》2019年第11期1447-1462,共16页分子植物（英文版）

摘　　要：Dehydrating stresses trigger the accumulation of abscisic acid(ABA),a key plant stress-signaling hormone that activates Snf1-Related Kinases(SnRK2s)to mount adaptive responses.However,the regulatory circuits that terminate the SnRK2s signal relay after acclimation or post-stress conditions remain to be defined.Here,we show that the desensitization of the ABA signal is achieved by the regulation of OST1(SnRK2.6)protein stability via the E3-ubiquitin ligase HOS15.Upon ABA signal,HOS15-induced degradation of OST1 is inhibited and stabilized OST1 promotes the stress response.When the ABA signal terminates,protein phosphatases ABI1/2 promote rapid degradation of OST1 via HOS15.Notably,we found that even in the presence of ABA,OST1 levels are also depleted within hours of ABA signal onset.The unexpected dynamics of OST1 abundance are then resolved by systematic mathematical modeling,demonstrating a desensitizing feedback loop by which OST1-induced upregulation of ABI1/2 leads to the degradation of OST1.This model illustrates the complex rheostat dynamics underlying the ABA-induced stress response and desensitization.

关 键 词：ABA signaling drought stress HOS15 OST1 ABI1/2 protein degradation and stability 

分 类 号：Q94[生物学—植物学]