Specific recognition of two MAX effectors by integrated HMA domains in plant immune receptors involves distinct binding surfaces.
Specific recognition of two MAX effectors by integrated HMA domains in plant immune receptors involves distinct binding surfaces.
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植物免疫受体中整合的 HMA 结构域对两个 MAX 效应子的特异性识别涉及不同的结合表面。
DOI：
10.1073/pnas.1810705115
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发表时间：
2018-11-06
影响因子：
11.1
通讯作者：
Kroj T
中科院分区：
文献类型：
--
作者：
Guo L;Cesari S;de Guillen K;Chalvon V;Mammri L;Ma M;Meusnier I;Bonnot F;Padilla A;Peng YL;Liu J;Kroj T
在这项研究中，我们深入了解了植物核苷酸结合域和富含亮氨酸的重复蛋白（NLR）的效应器识别机制，NLR是一类普遍存在的免疫受体，在作物保护中发挥着核心作用。通过对真菌效应子和水稻 NLR 的集成诱饵结构域 (ID) 之间的复合物进行结构和功能分析，我们证明了 ID 在效应子识别中的重要性，并为未来 NLR 工程扩展其识别特异性提供了关键知识。此外，我们提出，作为关于真菌效应子多样性的假设，在结构保守的效应子家族中，宿主靶蛋白结合的分子机制是保守的，但宿主靶蛋白本身不是保守的。来自稻瘟病菌米霉的结构保守但序列无关的 MAX（稻瘟病菌无毒力和 ToxB 样）效应子 AVR1-CO39 和 AVR-PikD 分别被水稻核苷酸结合域和富含亮氨酸重复蛋白 (NLR) RGA5 和 Pikp-1 识别。在这两种情况下，这都涉及效应器与 NLR 中重金属相关 (HMA) 集成域 (ID) 的直接相互作用。在这里，我们解析了单独携带 HMA ID (RGA5_S) 的 RGA5 C 端片段以及与 AVR1-CO39 形成的复合物的晶体结构，并将其与 Pikp1HMA/AVR-PikD 复合物的结构进行比较。在这两种复合物中，HMA ID/MAX 效应子相互作用涉及来自每个伙伴的 β-折叠的反平行排列。然而，效应器结合发生在 Pikp1HMA 和 RGA5HMA 的不同表面，表明这些相互作用是通过这两个 MAX 效应器与相同类型的植物靶蛋白的收敛而独立进化的。有趣的是，RGA5HMA 中的效应器结合表面与介导 RGA5HMA 自相互作用的表面重叠。 AVR1-CO39 HMA 结合界面的突变在体外和体内扰乱 RGA5HMA 结合，并影响含有 Pi-CO39 的水稻品种中米霉的识别。我们的研究提供了对 NLR 效应器识别机制的详细见解，这对于 NLR 的未来工程扩展其识别特异性具有重大意义。此外，我们提出，作为理解效应器多样性的假设，在结构保守的 MAX 效应器中，宿主靶蛋白结合的分子机制是保守的，而不是宿主靶蛋白本身。
In this study, we provide insight into the mechanism of effector recognition by plant nucleotide-binding domain and leucine-rich repeat proteins (NLRs), a ubiquitous class of immune receptors that plays a central role in crop protection. By structural and functional analysis of a complex between a fungal effector and an integrated decoy domain (ID) from a rice NLR, we demonstrate the importance of IDs in effector recognition and generate crucial knowledge for future engineering of NLRs to expand their recognition specificities. In addition, we propose, as a hypothesis regarding the diversity of fungal effectors, that in structurally conserved effector families, the molecular mechanisms of host target protein-binding are conserved but not the host target proteins themselves. The structurally conserved but sequence-unrelated MAX (Magnaporthe oryzae avirulence and ToxB-like) effectors AVR1-CO39 and AVR-PikD from the blast fungus M. oryzae are recognized by the rice nucleotide-binding domain and leucine-rich repeat proteins (NLRs) RGA5 and Pikp-1, respectively. This involves, in both cases, direct interaction of the effector with a heavy metal-associated (HMA) integrated domain (ID) in the NLR. Here, we solved the crystal structures of a C-terminal fragment of RGA5 carrying the HMA ID (RGA5_S), alone, and in complex with AVR1-CO39 and compared it to the structure of the Pikp1HMA/AVR-PikD complex. In both complexes, HMA ID/MAX effector interactions involve antiparallel alignment of β-sheets from each partner. However, effector-binding occurs at different surfaces in Pikp1HMA and RGA5HMA, indicating that these interactions evolved independently by convergence of these two MAX effectors to the same type of plant target proteins. Interestingly, the effector-binding surface in RGA5HMA overlaps with the surface that mediates RGA5HMA self-interaction. Mutations in the HMA-binding interface of AVR1-CO39 perturb RGA5HMA-binding, in vitro and in vivo, and affect the recognition of M. oryzae in a rice cultivar containing Pi-CO39. Our study provides detailed insight into the mechanisms of effector recognition by NLRs, which has substantial implications for future engineering of NLRs to expand their recognition specificities. In addition, we propose, as a hypothesis for the understanding of effector diversity, that in the structurally conserved MAX effectors the molecular mechanism of host target protein-binding is conserved rather than the host target proteins themselves.
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影响因子：
11.6
作者：
van der Hoorn, Renier A. L.;Kamoun, Sophien
通讯作者：
Kamoun, Sophien
影响因子：
7.7
作者：
Maqbool A;Saitoh H;Franceschetti M;Stevenson CE;Uemura A;Kanzaki H;Kamoun S;Terauchi R;Banfield MJ
通讯作者：
Banfield MJ
影响因子：
5.4
作者：
Sarris PF;Cevik V;Dagdas G;Jones JD;Krasileva KV
通讯作者：
Krasileva KV
影响因子：
6.7
作者：
de Guillen K;Ortiz-Vallejo D;Gracy J;Fournier E;Kroj T;Padilla A
通讯作者：
Padilla A
影响因子：
3.4
作者：
Tehseen, Muhammad;Cairns, Narelle;Cobbett, Christopher S.
通讯作者：
Cobbett, Christopher S.