Arabidopsis Lectin Receptor Kinase P2K2 Is a Second Plant Receptor for Extracellular ATP and Contributes to Innate Immunity1[OPEN]
Arabidopsis Lectin Receptor Kinase P2K2 Is a Second Plant Receptor for Extracellular ATP and Contributes to Innate Immunity1[OPEN]
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DOI：
10.1104/pp.19.01265
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发表时间：
2020-07-01
期刊：
影响因子：
7.4
通讯作者：
Stacey, Gary
中科院分区：
文献类型：
--
作者：
An Quoc Pham;Cho, Sung-Hwan;Stacey, Gary
在动物中，细胞外ATP是被质膜定位的P2型嘌呤能受体识别的充分研究的信号分子。然而，相比之下，对植物中嘌呤能信号的了解要少得多。P2受体在包括免疫系统调节在内的多种动物生物学过程中发挥关键作用。第一个植物嘌呤能受体，拟南芥（拟南芥）P2 K1（L型凝集素受体激酶-I.9），被证明有助于植物防御细菌，卵菌和真菌病原体。在这里，我们证明了第二个嘌呤能受体，P2 K2的分离，通过互补的一个pneumopsisp 2k 1突变体。P2 K2（LecRK-I.5）与P2 K1具有74%的氨基酸相似性。P2 K2胞外凝集素结构域以比P2 K1更高的亲和力与ATP结合（解离常数[K-d] = 44.47 +/- 15.73 nm）。有趣的是，p2 k2和p2 k1 p2 k2突变体植物表现出对病原体假单胞菌的敏感性增加，双突变体表现出更强的表型。在体外和在植物中的研究表明，P2 K2和P2 K1相互作用，并在细胞外ATP处理交叉磷酸化。因此，与动物一样，植物也具有多种嘌呤受体，其中一种能与ATP高亲和力结合的受体激酶在植物免疫过程中起着部分冗余的作用。
In animals, extracellular ATP is a well-studied signaling molecule that is recognized by plasma membrane-localized P2-type purinergic receptors. However, in contrast, much less is known about purinergic signaling in plants. P2 receptors play critical roles in a variety of animal biological processes, including immune system regulation. The first plant purinergic receptor, Arabidopsis (Arabidopsis thaliana) P2K1 (L-type lectin receptor kinase-I.9), was shown to contribute to plant defense against bacterial, oomycete, and fungal pathogens. Here, we demonstrate the isolation of a second purinergic receptor, P2K2, by complementation of an Arabidopsisp2k1mutant. P2K2 (LecRK-I.5) has 74% amino acid similarity to P2K1. The P2K2 extracellular lectin domain binds to ATP with higher affinity than P2K1 (dissociation constant [K-d] = 44.47 +/- 15.73 nm). Interestingly,p2k2andp2k1 p2k2mutant plants showed increased susceptibility to the pathogenPseudomonas syringae,with the double mutant showing a stronger phenotype. In vitro and in planta studies demonstrate that P2K2 and P2K1 interact and cross-phosphorylate upon extracellular ATP treatment. Thus, similar to animals, plants possess multiple purinergic receptors.A receptor kinase that can bind to ATP with high affinity plays a partially redundant role during plant immunity.