Functional Divergence of Two Secreted Immune Proteases of Tomato
Functional Divergence of Two Secreted Immune Proteases of Tomato
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DOI：
10.1016/j.cub.2015.07.030
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发表时间：
2015-08-31
期刊：
影响因子：
9.2
通讯作者：
van der Hoorn, Renier A. L.
中科院分区：
文献类型：
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作者：
Ilyas, Muhammad;Hoerger, Anja C.;van der Hoorn, Renier A. L.
Rcr 3和Pip 1是番茄分泌的类木瓜蛋白酶。这两种蛋白酶都被来自真菌病原体叶枝孢菌的Avr 2抑制，但只有Rcr 3作为番茄Cf-2免疫受体识别Avr 2的共受体[1-4]。在这里，我们表明，Pip 1耗尽番茄植物是超敏感的真菌，细菌和卵菌植物病原体，表明Pip 1是一个重要的广泛的免疫蛋白酶。相比之下，在不存在Cf-2的情况下，Rcr 3缺失不影响真菌和细菌感染水平，但仅导致对卵菌病原体致病疫霉的易感性增加。Rcr 3和Pip 1存在于3600万年前进化的基因位点上。这些蛋白质的不同之处在于底物结合沟外的表面暴露残基，Pip 1的丰度是Rcr 3的5至10倍。我们提出了一个模型，其中Rcr 3和Pip 1分歧的基因复制功能，可能驱动的军备竞赛与病原体衍生的抑制剂或协同进化与Cf-2免疫受体检测抑制剂的Rcr 3，但不是Pip 1。
Rcr3 and Pip1 are paralogous secreted papain-like proteases of tomato. Both proteases are inhibited by Avr2 from the fungal pathogen Cladosporium fulvum, but only Rcr3 acts as a co-receptor for Avr2 recognition by the tomato Cf-2 immune receptor [1-4]. Here, we show that Pip1-depleted tomato plants are hyper-susceptible to fungal, bacterial, and oomycete plant pathogens, demonstrating that Pip1 is an important broad-range immune protease. By contrast, in the absence of Cf-2, Rcr3 depletion does not affect fungal and bacterial infection levels but causes increased susceptibility only to the oomycete pathogen Phytophthora infestans. Rcr3 and Pip1 reside on a genetic locus that evolved over 36 million years ago. These proteins differ in surface-exposed residues outside the substrate-binding groove, and Pip1 is 5- to 10-fold more abundant than Rcr3. We propose a model in which Rcr3 and Pip1 diverged functionally upon gene duplication, possibly driven by an arms race with pathogen-derived inhibitors or by coevolution with the Cf-2 immune receptor detecting inhibitors of Rcr3, but not of Pip1.