The kinase LYK5 is a major chitin receptor in Arabidopsis and forms a chitin-induced complex with related kinase CERK1.
The kinase LYK5 is a major chitin receptor in Arabidopsis and forms a chitin-induced complex with related kinase CERK1.
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激酶LYK5是拟南芥中的主要几丁质受体，并形成了与相关激酶CERK1的几丁质诱导的复合物。
DOI：
10.7554/elife.03766
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发表时间：
2014-10-23
期刊：
影响因子：
7.7
通讯作者：
Stacey G
中科院分区：
文献类型：
--
作者：
Cao Y;Liang Y;Tanaka K;Nguyen CT;Jedrzejczak RP;Joachimiak A;Stacey G
几丁质是一种真菌微生物相关的分子模式，在拟南芥中识别的溶素基序受体激酶（LYK），AtCERK 1。先前的研究表明AtCERK 1是主要的几丁质受体，通过同源二聚化和磷酸化介导几丁质诱导的信号传导。然而，报道的AtCERK 1的几丁质结合亲和力是相当低的，这表明可能存在另一种具有高几丁质结合亲和力的受体。在这里，我们建议，AtLYK 5是在拟南芥的主要几丁质受体。AtLYK 5的突变导致几丁质反应的显著降低。然而，AtLYK 5与AtLYK 4共享重叠功能，因此，Atlyk 4/Atlyk 5 -2双突变体显示完全丧失几丁质反应。AtLYK 5以几丁质依赖的方式与AtCERK 1相互作用。几丁质与AtLYK 5的结合对于几丁质诱导的AtCERK 1磷酸化是必不可少的。AtLYK 5与甲壳素的结合亲和力比AtCERK 1高得多。这些数据表明，AtLYK 5是几丁质的主要受体，与AtCERK 1形成几丁质诱导复合物以诱导植物免疫。DOI：http://dx.doi.org/10.7554/eLife.03766.001入侵真菌是影响全球作物生产的许多植物疾病的罪魁祸首。植物必须能够识别这些真菌，并激活正确的防御策略，如果他们要保护自己。甲壳素是一种聚合物，存在于所有真菌的细胞壁中，但不存在于植物中，所以如果植物检测到甲壳素，它就知道附近可能有潜在的有害真菌。几丁质的检测以及由此产生的植物防御的激活需要一种名为CERK 1的受体蛋白。在水稻中，CERK 1需要与另一种名为CEBiP的受体蛋白相互作用，该蛋白与甲壳素结合。然而，在植物研究中被广泛研究的拟南芥中，CERK 1可以自行与几丁质结合，尽管这种相互作用非常弱，因此有人提出可能涉及第二种蛋白质。Cao等人现在发现一种叫做LYK 5的受体蛋白，它与CERK 1非常相似，在A. thaliana.它也可以与CERK 1结合，但只有当几丁质存在时，并且是激活基本植物防御所必需的。实验表明，LYK 5代表CERK 1检测甲壳素，其方式与CEBiP在水稻中的作用方式类似。这项研究的下一步是弄清楚CERK 1和LYK 5是如何激活植物防御的。DOI：http://dx.doi.org/10.7554/eLife.03766.002网站
Chitin is a fungal microbe-associated molecular pattern recognized in Arabidopsis by a lysin motif receptor kinase (LYK), AtCERK1. Previous research suggested that AtCERK1 is the major chitin receptor and mediates chitin-induced signaling through homodimerization and phosphorylation. However, the reported chitin binding affinity of AtCERK1 is quite low, suggesting another receptor with high chitin binding affinity might be present. Here, we propose that AtLYK5 is the primary chitin receptor in Arabidopsis. Mutations in AtLYK5 resulted in a significant reduction in chitin response. However, AtLYK5 shares overlapping function with AtLYK4 and, therefore, Atlyk4/Atlyk5-2 double mutants show a complete loss of chitin response. AtLYK5 interacts with AtCERK1 in a chitin-dependent manner. Chitin binding to AtLYK5 is indispensable for chitin-induced AtCERK1 phosphorylation. AtLYK5 binds chitin at a much higher affinity than AtCERK1. The data suggest that AtLYK5 is the primary receptor for chitin, forming a chitin inducible complex with AtCERK1 to induce plant immunity. DOI: http://dx.doi.org/10.7554/eLife.03766.001 Invading fungi are responsible for many of the plant diseases that affect global crop production. Plants have to be able to identify these fungi, and activate the right defense strategies if they are to protect themselves. Chitin is a polymer that is found in the cell walls of all fungi, but not in plants, so if the plant detects chitin, it knows that a potentially harmful fungus may be nearby. The detection of chitin, and the resulting activation of a plant's defenses, requires a receptor protein called CERK1. In rice, CERK1 needs to interact with another receptor protein called CEBiP, which binds to chitin. However, in Arabidopsis thaliana—which is widely studied in plant research—CERK1 can bind to chitin on its own, although this interaction is very weak, so it has been suggested that a second protein may be involved. Cao et al. have now found that a receptor protein called LYK5, which is very similar to CERK1, is much better at attaching to chitin in A. thaliana. It can also bind to CERK1, but only when chitin is present, and is required for activation of basic plant defenses. The experiments suggest that LYK5 detects chitin on behalf of CERK1, in a similar way to how CEBiP works in rice. The next step in this research is to work out how CERK1 and LYK5 are able to activate plant defenses. DOI: http://dx.doi.org/10.7554/eLife.03766.002