2009年7月23日，我所张跃林实验室在Cell Host & Microbe杂志上发表题为“Regulation of Cell Death and Innate Immunity by Two Receptor-like Kinases in Arabidopsis”的文章。该文章报道了受体类蛋白激酶BIR1对分别依赖于PAD4和SOBIR1的两条植物先天性免疫反应信号通路的负调控机制。
受体类蛋白激酶BAK1在调控植物发育和先天性免疫反应中发挥了重要的作用。运用反向遗传学技术，我们分离到一株T-DNA插入突变体bir1-1，表现出植株矮小、苗期死亡的表型。BIR1的突变导致植物先天性免疫反应的激活。BIR1与BAK1在细胞膜上形成蛋白复合物。双突变体bak1bkk1的表型与bir1-1极为相似。PAD4和EDS1的突变可以部分抑制bir1-1的表型，而EDS5、SID2和NDR1对bir1-1的表型也有一定的调控作用。为了进一步分析bir1-1激活的信号通路，用EMS对bir1-1进行遗传诱变，我们克隆了bir1-1的一个抑制突变体（sobir1-1）。SOBIR1 对bir1-1的表型是必需的，SOBIR1和PAD4的同时突变可以完全抑制bir1-1的表型。SOBIR1编码一个受体类蛋白激酶。过量表达SOBIR1会导致植物自发性的细胞死亡，对病原菌的抗性大大增强。说明SOBIR1正调控植物的抗病反应。这些研究结果表明BIR1在依赖于SOBIR1和PAD4的两条信号通路中发挥了负调控作用。（生物谷Bioon.com）
生物谷推荐原始出处：
Cell Host & Microbe, Volume 6, Issue 1, 34-44, 23 July 2009 doi:10.1016/j.chom.2009.05.019
Regulation of Cell Death and Innate Immunity by Two Receptor-like Kinases in Arabidopsis
Minghui Gao1,2,Xia Wang2,Dongmei Wang3,4,Fang Xu2,Xiaojun Ding2,Zhibin Zhang2,Dongling Bi2,Yu Ti Cheng3,She Chen2,Xin Li3andYuelin Zhang2,,
1 College of Biological Sciences, China Agricultural University, Beijing 100094, China
2 National Institute of Biological Sciences, Zhongguancun Life Science Park, Beijing 102206, China
3 Michael Smith Laboratories, University of British Columbia, Vancouver V6T 1Z4, Canada
Upon recognition of bacterial flagellin, the plant receptor FLS2 heterodimerizes with brassinosteroid insensitive 1-associated receptor kinase 1 (BAK1) and activates plant defense responses. Because constitutive activation of defense responses is detrimental, plant resistance signaling pathways must benegatively controlled, although the mechanisms involved are unclear. We identified Arabidopsis BIR1 as a BAK1-interacting receptor-like kinase. Knocking out BIR1 leads to extensive cell death, activation of constitutive defense responses, and impairment in the activation of MPK4, a negative regulator of plant resistance (R) protein signaling, by flagellin. sobir1-1, a mutant obtained in a screen for suppressors of the bir1-1 phenotype, rescued cell death observed in bir1-1. SOBIR1 encodes another receptor-like kinase whose overexpression activates cell death and defense responses. Our data suggest that BIR1 negatively regulates multiple plant resistance signaling pathways, one of which is the SOBIR1-dependent pathway identified here.
