LYK4 is a component of a tripartite chitin receptor complex in Arabidopsis thaliana
LYK4 is a component of a tripartite chitin receptor complex in Arabidopsis thaliana
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LYK4 是拟南芥三联几丁质受体复合物的一个组成部分
DOI：
10.1093/jxb/erz313
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发表时间：
2019-10-01
影响因子：
6.9
通讯作者：
Staehelin, Christian
中科院分区：
文献类型：
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作者：
Xue, De-Xing;Li, Chun-Lian;Staehelin, Christian
拟南芥的LysM受体样激酶（LYKs）（即LYK1、LYK4和LYK5）在几丁质感知和对病原真菌的免疫中起重要作用。几丁质诱导的LYK1和LYK5异二聚化已经有报道，但LYK4的蛋白相互作用伙伴尚未确定。在本研究中，我们通过分析突变体证实了LYK4在几丁质感知中的作用，并发现LYK4的外结构域在体外与LYK5的外结构域同源二聚并相互作用。原生质体中表达蛋白的下拉实验表明，LYK4-LYK4和LY4-LYK5在植物中相互作用。当原生质体用壳七糖或几丁质处理时，免疫沉淀了一种蛋白质复合物，该蛋白复合物似乎由LYK1， LYK4和LYK5组成。在lyk突变体植物中表达的蛋白质的类似实验表明，激发子处理诱导了LYK1和LYK5之间的物理相互作用，而不是LYK1和LYK4之间的相互作用。双分子荧光互补实验证实了这些发现。总的来说，我们的数据表明，LYK4作为lyk5相关的共受体或支架蛋白，在拟南芥中增强几丁质诱导的信号传导。
LysM receptor-like kinases (LYKs) of Arabidopsis thaliana (namely LYK1, LYK4 and LYK5) play a major role in chitin perception and immunity against pathogenic fungi. Chitin-induced heterodimerization of LYK1 and LYK5 has been previously reported, but protein interaction partners of LYK4 have not yet been identified. In this study, by analysing mutants we confirmed a role of LYK4 in chitin perception, and found that the ectodomain of LYK4 homodimerizes and also interacts with the ectodomain of LYK5 in vitro. Pull-down experiments with proteins expressed in protoplasts indicated LYK4-LYK4 and LY4-LYK5 interactions in planta. When protoplasts were treated with chitoheptaose or chitin, a protein complex was immunoprecipitated that appeared to be composed of LYK1, LYK4, and LYK5. Similar experiments with proteins expressed in lyk mutant plants suggested that elicitor treatment induced a physical interaction between LYK1 and LYK5 but not between LYK1 and LYK4. Bimolecular fluorescence complementation experiments substantiated these findings. Overall, our data suggest that LYK4 functions as a LYK5-associated co-receptor or scaffold protein that enhances chitin-induced signaling in Arabidopsis.