Plant intracellular innate immune receptor Resistance to Pseudomonas syringae pv. maculicola 1 (RPM1) is activated at, and functions on, the plasma membrane
Plant intracellular innate immune receptor Resistance to Pseudomonas syringae pv. maculicola 1 (RPM1) is activated at, and functions on, the plasma membrane
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DOI：
10.1073/pnas.1104410108
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发表时间：
2011-05-03
影响因子：
11.1
通讯作者：
Dangl, Jeffery L.
中科院分区：
文献类型：
--
作者：
Gao, Zhiyong;Chung, Eui-Hwan;Dangl, Jeffery L.
植物利用细胞内先天免疫受体识别病原体并启动抗病性。这些核苷酸结合的富含亮氨酸的重复序列（NB-LRR）蛋白被递送到宿主细胞中以抑制宿主防御反应的病原体效应蛋白激活。目前对NB-LRR激活的位点和机制知之甚少，但一些NB-LRR蛋白可以在植物细胞核内发挥作用。我们证明，RPM 1被激活的质膜上，不重新定位到细胞核。一个自身活性的RPM 1（D505 V）等位基因，概括了正常RPM 1激活的关键特征，也驻留在质膜上。没有检测到激活的RPM 1重新定位到细胞核。阻碍RPM 1-Myc的潜在核进入并不影响其效应子触发的超敏反应（HR）细胞死亡或其抗病功能，进一步表明核转位不是RPM 1功能所必需的。用双酰化N-末端表位标签拴系在质膜上的RPM 1保留了介导HR的能力，这与在质膜上激活的RPM 1功能一致。因此，植物NB-LRR蛋白可以在细胞中的不同位置发挥作用。
Plants deploy intracellular innate immune receptors to recognize pathogens and initiate disease resistance. These nucleotide-binding, leucine-rich repeat (NB-LRR) proteins are activated by pathogen effector proteins that are delivered into the host cell to suppress host defense responses. Little is known about the sites and mechanisms of NB-LRR activation, but some NB-LRR proteins can function inside the plant nucleus. We demonstrate that RPM1 is activated on the plasma membrane and does not relocalize to the nucleus. An autoactive RPM1(D505V) allele that recapitulates key features of normal RPM1 activation also resides on the plasma membrane. There is no detectable relocalization of activated RPM1 to the nucleus. Hindering potential nuclear entry of RPM1-Myc did not affect either its effector-triggered hypersensitive-response (HR) cell death or its disease resistance functions, further suggesting that nuclear translocation is not required for RPM1 function. RPM1 tethered onto the plasma membrane with a dual acylated N-terminal epitope tag retained the ability to mediate HR, consistent with this RPM1 function being activated on the plasma membrane. Plant NB-LRR proteins can thus function at various locations in the cell.