The Small GTPase OsRac1 Forms Two Distinct Immune Receptor Complexes Containing the PRR OsCERK1 and the NLR Pit
The Small GTPase OsRac1 Forms Two Distinct Immune Receptor Complexes Containing the PRR OsCERK1 and the NLR Pit
复制标题
小 GTP 酶 OsRac1 形成两个不同的免疫受体复合物，其中包含 PRR OsCERK1 和 NLR 凹坑
DOI：
10.1093/pcp/pcab121
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发表时间：
2021-08-27
影响因子：
4.9
通讯作者：
Kawano, Yoji
中科院分区：
文献类型：
--
作者：
Akamatsu, Akira;Fujiwara, Masayuki;Kawano, Yoji
植物利用两种不同类型的免疫受体，即细胞表面模式识别受体（PRR）和细胞内核苷酸结合和富含亮氨酸的重复蛋白（NLR）来应对病原体入侵。两种免疫受体通常具有相似的下游成分和反应，但仍不清楚 PRR 和 NLR 是否组装成相同的蛋白质复合物或两个不同的受体复合物。我们之前发现，小 GTPase OsRac1 在 OsCERK1（真菌几丁质的 PRR）和 Pit（稻瘟菌的 NLR）的信号传导中发挥关键作用，并与这两种免疫受体直接或间接相关。在这项研究中，我们利用生化和生物成像方法，揭示了 OsRac1 与 OsCERK1 和 Pit 形成了两种不同的受体复合物。 OsCERK1 和 Pit 利用不同的运输系统来锚定质膜 (PM)，支持了这一结果。 OsCERK1 和 Pit 的激活导致 OsRac1 激活，同时 OsRac1 从小蛋白复合物部分转变为大蛋白复合物部分。我们还发现伴侣蛋白 Hsp90 有助于 Pit 向 PM 的正确运输以及 Pit 的免疫诱导。这些发现阐明了 PRR OsCERK1 和 NLR Pit 如何通过小型 GTPase OsRac1 协调水稻免疫。
Plants employ two different types of immune receptors, cell surface pattern recognition receptors (PRRs) and intracellular nucleotide-binding and leucine-rich repeat-containing proteins (NLRs), to cope with pathogen invasion. Both immune receptors often share similar downstream components and responses but it remains unknown whether a PRR and an NLR assemble into the same protein complex or two distinct receptor complexes. We have previously found that the small GTPase OsRac1 plays key roles in the signaling of OsCERK1, a PRR for fungal chitin, and of Pit, an NLR for rice blast fungus, and associates directly and indirectly with both of these immune receptors. In this study, using biochemical and bioimaging approaches, we revealed that OsRac1 formed two distinct receptor complexes with OsCERK1 and with Pit. Supporting this result, OsCERK1 and Pit utilized different transport systems for anchorage to the plasma membrane (PM). Activation of OsCERK1 and Pit led to OsRac1 activation and, concomitantly, OsRac1 shifted from a small to a large protein complex fraction. We also found that the chaperone Hsp90 contributed to the proper transport of Pit to the PM and the immune induction of Pit. These findings illuminate how the PRR OsCERK1 and the NLR Pit orchestrate rice immunity through the small GTPase OsRac1.