The Raf-like MAPKKK INTEGRIN-LINKED KINASE 5 regulates purinergic receptor-mediated innate immunity in Arabidopsis
The Raf-like MAPKKK INTEGRIN-LINKED KINASE 5 regulates purinergic receptor-mediated innate immunity in Arabidopsis
复制标题
Raf样MAPKKK整合素连接蛋白5调节拟南芥中嘌呤能受体介导的先天免疫
DOI：
10.1093/plcell/koad029
复制
发表时间：
2023-02-10
期刊：
影响因子：
11.6
通讯作者：
Stacey, Gary
中科院分区：
文献类型：
--
作者：
Kim, Daewon;Chen, Dongqin;Stacey, Gary
ILK 5的磷酸化激活嘌呤信号通路，导致MKK 5和MPK 3/6的磷酸化，从而诱导植物的天然免疫应答。丝裂原活化蛋白激酶（Mitogen-activated protein，MAP）信号级联在真核生物防御多种病原体中发挥重要作用。细胞外ATP（eATP）受体P2 K1的激活触发MAP激酶3和6（MPK 3/6）磷酸化，这导致植物防御反应的提高。然而，P2 K1激活MAPK级联的机制尚不清楚。在这项研究中，我们表明，在拟南芥中，P2 K1磷酸化的Raf-like MAP激酶（MAPKKK）整合素连接激酶5（ILK 5）丝氨酸192在eATP的存在下。P2 K1和ILK 5之间的相互作用在体外和在植物中均得到证实，并且它们的相互作用通过ATP处理而增强。与P2 K1表达类似，ILK 5表达水平通过用ATP、flg 22、假单胞菌属植物致病变种处理而高度诱导。番茄DC 3000和各种非生物胁迫。ILK 5与MAP激酶MKK 5相互作用并使其磷酸化。此外，在ilk 5突变体植物中，相对于野生型（WT），ATP处理后MPK 3/6的磷酸化显著降低。ilk 5突变体植物相对于WT植物显示出对烟草疫霉病原体感染的更高易感性。仅表达突变体ILK 5（S192 A）蛋白的植物，具有降低的激酶活性，在加入ATP后不激活MAPK级联。这些结果表明，P2 K1的eATP激活导致Raf-like MAPKKK ILK 5的转磷酸化，其随后触发MAPK级联反应，最终激活与升高的先天免疫应答相关的MPK 3/6。
Activation of the purinergic signaling pathway by phosphorylation of ILK5 leads to phosphorylation of MKK5 and MPK3/6, resulting in the induction of the plant innate immune response.Mitogen-activated protein (MAP) kinase signaling cascades play important roles in eukaryotic defense against various pathogens. Activation of the extracellular ATP (eATP) receptor P2K1 triggers MAP kinase 3 and 6 (MPK3/6) phosphorylation, which leads to an elevated plant defense response. However, the mechanism by which P2K1 activates the MAPK cascade is unclear. In this study, we show that in Arabidopsis thaliana, P2K1 phosphorylates the Raf-like MAP kinase kinase kinase (MAPKKK) INTEGRIN-LINKED KINASE 5 (ILK5) on serine 192 in the presence of eATP. The interaction between P2K1 and ILK5 was confirmed both in vitro and in planta and their interaction was enhanced by ATP treatment. Similar to P2K1 expression, ILK5 expression levels were highly induced by treatment with ATP, flg22, Pseudomonas syringae pv. tomato DC3000, and various abiotic stresses. ILK5 interacts with and phosphorylates the MAP kinase MKK5. Moreover, phosphorylation of MPK3/6 was significantly reduced upon ATP treatment in ilk5 mutant plants, relative to wild-type (WT). The ilk5 mutant plants showed higher susceptibility to P. syringae pathogen infection relative to WT plants. Plants expressing only the mutant ILK5(S192A) protein, with decreased kinase activity, did not activate the MAPK cascade upon ATP addition. These results suggest that eATP activation of P2K1 results in transphosphorylation of the Raf-like MAPKKK ILK5, which subsequently triggers the MAPK cascade, culminating in activation of MPK3/6 associated with an elevated innate immune response.