A viral effector blocks the turnover of a plant NLR receptor to trigger a robust immune response

作者：Chunli Wang, Min Zhu, Hao Hong, Jia Li, Chongkun Zuo, Yu Zhang, Yajie Shi, Suyu Liu, Haohua Yu, Yuling Yan, Jing Chen, Lingna Shangguan, Aiping Zhi, Rongzhen Chen, Karen Thulasi Devendrakumar, Xiaorong Tao · 发表于：The EMBO Journal · 年份：2024 · DOI：10.1038/s44318-024-00174-6 · 被引用次数：11 · 研究领域：Plant Virus Research Studies、Plant-Microbe Interactions and Immunity、Transgenic Plants and Applications

Plant intracellular nucleotide-binding and leucine-rich repeat immune receptors (NLRs) play a key role in activating a strong pathogen defense response. Plant NLR proteins are tightly regulated and accumulate at very low levels in the absence of pathogen effectors. However, little is known about how this low level of NLR proteins is able to induce robust immune responses upon recognition of pathogen effectors. Here, we report that, in the absence of effector, the inactive form of the tomato NLR Sw-5b is targeted for ubiquitination by the E3 ligase SBP1. Interaction of SBP1 with Sw-5b via only its N-terminal domain leads to slow turnover. In contrast, in its auto-active state, Sw-5b is rapidly turned over as SBP1 is upregulated and interacts with both its N-terminal and NB-LRR domains. During infection with the tomato spotted wilt virus, the viral effector NSm interacts with Sw-5b and disrupts the interaction of Sw-5b with SBP1, thereby stabilizing the active Sw-5b and allowing it to induce a robust immune response.