Mechanistic Analysis of AKT1 Regulation by the CBL-CIPK-PP2CA Interactions

作     者：Wen-Zhi Lan Sung-Chul Lee Yu-Fen Che Yuan-Qing Jiang Sheng Luan 

作者机构：Department of Plant and Microbial Biology University of California Berkeley CA 94720 USA School of Biological Sciences (BK21 program) Chung-Ang University Seoul.156-756 Korea College of Food Science and Nutritional Engineering China Agricultural University Beijing 100083 China DBST-WCU Program Chonnam National University-Gwangju 500-757 Korea 

出 版 物：《Molecular Plant》 (分子植物（英文版）)

年 卷 期：2011年第4卷第3期

页      面：527-536页

核心收录：

学科分类：0710[理学-生物学] 12[管理学] 071010[理学-生物化学与分子生物学] 1201[管理学-管理科学与工程(可授管理学、工学学位)] 081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 0901[农学-作物学] 0902[农学-园艺学] 081201[工学-计算机系统结构] 0812[工学-计算机科学与技术（可授工学、理学学位）] 

基　　金：This work is supported by the National Science Foundation (to SL) the WCU program National Research Foundation Korea 

主　　题：Abscisic acid Arabidopsis environmental stress K+ uptake. 

摘      要：Arabidopsis K＋ transporter I （AKT1） participates in K＋ uptake in roots, especially under Iow-K conditions. We recently identified a Ca2＋ signaling pathway consisting of multiple calcineurin B-like calcium sensors （CBLs） and multiple target kinases （CBL-interacting protein kinases or CIPKs） that phosphorylate and activate AKT1, whereas a specific PP2C-type phosphatase inactivates CIPK-dependent AKT1 activity. In this study, we analyzed the interactions between PP2Cs and the CBL-CIPK pathway and found previously unsuspected mechanisms underlying the CBL-CIPK-PP2C signaling processes. The interaction between the CIPKs and PP2Cs involves the kinase domain of the CIPK component, in addition to the protein phosphatase interacting motif （PPI） in the regulatory domain. Furthermore, specific CBLs physically interact with and inactivate PP2C phosphatases to recover the CIPK-dependent AKT1 channel activity. These findings provide fur- ther insights into the signaling network consisting of CBL-CIPK-PP2C interactions in the activation of the AKT1 channel.