朱健康连发2篇《Nature》文章 体外构建ABA信号通路

　　

生物通报道，美国加州大学河滨分校植物科学系，植物分子生物学中心，沙特阿拉伯

KingAbdullah大学植物应激与基因组研究中心，西班牙植物分子与细胞生物学研究所的科学家在Nature（11月

18日）在线版发表最新文章。

 

文章通讯作者是植物抗逆分子生物学领域领军人物朱健康教授，有趣的是，朱健康教授11月6日才与徐华强教

授在Nature在线版上发表ABA受体结构研究的重要文章，时隔12天后再度发表文章，进一步研究ABA信号通路。

相关报道请见生物通前期文章：徐华强 朱健康《Nature》ABA受体研究新进展

 

脱落酸（Abscisic acid, ABA）是植物中最为重要的激素之一，它与种子休眠、根系发育、叶子枯萎、抗旱反

应和其它的生理过程都有极为密切的关系。由于脱落酸能引发的下游反应过多，包括激酶、磷酸酶、G蛋白、

泛素通路中的蛋白等等都参与了ABA信号的调控。

 

在11月6日的Nature文章中，朱健康教授联合徐华强教授通过结构比较和生化分析，确认了PYL2–ABA–PP2C复合物的晶体结构，以及分析了该复合物对ABA信号通路的启动和关闭的分子结构机制。

 

在最新的Nature文章中，朱健康教授首次在体外通过重新构建PYL2–ABA–PP2C复合物，

建造了体外的ABA信号通路，研究结果表明，SnRK2激酶在ABA信号通路中具有重要的

调节作用。PYR/PYL受体蛋白能阻断SnRK2s与PP2Cs间的相互作用。

 

这些研究结果为ABA受体信号机制研究提供了新的视野。

 

朱健康简介

朱健康教授为植物抗逆分子生物学领域领军人物之一，他领导的实验室在植物抗旱、耐盐与耐低温方面的研究硕果累累，在国内外享有声誉。他的团队发现了组蛋白H2B去泛素化（deubiquitination）在表观遗传DNA甲基化和异染色质沉默方面的调控作用，在DNA甲基化修饰与泛素化之间建立了新联系，也为DNA甲基化修饰研究提出了新观点。目前主要开展小RNA (miRNA)转录机制和基因表现遗传调节方面的研究。已在Cell、Nature、Science、Gene & Development、Plant Cell、PNAS、Trends Plant Sci、EMBO J、Plant Physiology等国际著名学术刊物发表过论文190多篇。

 

朱健康教授现任美国加州大学河滨分校教授，整合基因研究所所长，《Plant Molecular Biology》副主编。曾任国际著名学术刊物《Plant Physiology》副主编。曾获得亚利桑那大学生命科学与农学院年度最佳研究员奖和美国植物生物学会颁发的Charles  Albert  Shull大奖。

（生物通 小茜）

生物通推荐原文检索

Letter

Nature advance online publication 18 November 2009 | doi:10.1038/nature08599; Received 16 September 2009; Accepted 26 October 2009; Published online 18 November 2009

 

In vitro reconstitution of an abscisic acid signalling pathway

Hiroaki Fujii1,2,5, Viswanathan Chinnusamy1,2,5, Americo Rodrigues3, Silvia Rubio3, Regina Antoni3, Sang-Youl Park1, Sean R. Cutler1, Jen Sheen4, Pedro L. Rodriguez3 & Jian-Kang Zhu1,2

 

Department of Botany and Plant Sciences, University of California at Riverside, Riverside, California 92521, USA

Center for Plant Stress Genomics and Technology, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia

Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-UPV, ES-46022 Valencia, Spain

Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts 02114, USA

These authors contributed equally to this work.

Correspondence to: Jian-Kang Zhu1,2 Correspondence and requests for materials should be addressed to J.-K.Z. (Email: [e-mail]).

【Abstract】

The phytohormone abscisic acid (ABA) regulates the expression of many genes in plants; it has critical functions in stress resistance and in growth and development1, 2, 3, 4, 5, 6, 7. Several proteins have been reported to function as ABA receptors8, 9, 10, 11, 12, 13, and many more are known to be involved in ABA signalling3, 4, 14. However, the identities of ABA receptors remain controversial and the mechanism of signalling from perception to downstream gene expression is unclear15, 16. Here we show that by combining the recently identified ABA receptor PYR1 with the type 2C protein phosphatase (PP2C) ABI1, the serine/threonine protein kinase SnRK2.6/OST1 and the transcription factor ABF2/AREB1, we can reconstitute ABA-triggered phosphorylation of the transcription factor in vitro. Introduction of these four components into plant protoplasts results in ABA-responsive gene expression. Protoplast and test-tube reconstitution assays were used to test the function of various members of the receptor, protein phosphatase and kinase families. Our results suggest that the default state of the SnRK2 kinases is an autophosphorylated, active state and that the SnRK2 kinases are kept inactive by the PP2Cs through physical interaction and dephosphorylation. We found that in the presence of ABA, the PYR/PYL (pyrabactin resistance 1/PYR1-like) receptor proteins can disrupt the interaction between the SnRK2s and PP2Cs, thus preventing the PP2C-mediated dephosphorylation of the SnRK2s and resulting in the activation of the SnRK2 kinases. Our results reveal new insights into ABA signalling mechanisms and define a minimal set of core components of a complete major ABA signalling pathway.