Guo Zhi-Hong, Qin Xin-Yu, Guo Hong-Fang, Zheng Chuan, Zhang Zong-Ying, Chen Qian, Wang Xian-Bing, Han Cheng-Gui, Wang Ying
Ministry of Agriculture and Rural Affairs Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China.
State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing, China.
Cell Rep. 2025 Apr 22;44(4):115449. doi: 10.1016/j.celrep.2025.115449. Epub 2025 Mar 18.
The ubiquitin-26S proteasome system (UPS) is a conserved protein degradation process involved in plant growth and immunity. However, whether some UPS E3 ligases directly target plant viruses in the endoplasmic reticulum (ER) remains less understood. Here, we identify an E3 ubiquitin ligase Hmg-CoA reductase degradation 1 of Nicotiana benthamiana (NbHRD1) interacting with the triple gene block (TGB) movement proteins of beet necrotic yellow vein virus (BNYVV) in the ER. The TGB proteins are ubiquitinated by NbHRD1 and then degraded by the UPS. Consequently, overexpression of NbHRD1a significantly inhibits BNYVV infection, whereas silencing of NbHRD1 promotes BNYVV infection in N. benthamiana. Moreover, NbHRD1a mainly impairs BNYVV cell-to-cell movement, rather than virus replication. Interestingly, NbHRD1 also targets the TGB proteins of potato virus X for ubiquitination and virus inhibition. Collectively, our results demonstrate that NbHRD1 is an important antiviral component targeting plant viruses with TGB movement proteins.
泛素-26S蛋白酶体系统（UPS）是一种保守的蛋白质降解过程，参与植物生长和免疫。然而，一些UPS E3连接酶是否在内质网（ER）中直接靶向植物病毒仍不太清楚。在这里，我们鉴定了一种E3泛素连接酶，即本氏烟草（Nicotiana benthamiana）的Hmg-CoA还原酶降解1（NbHRD1），它在内质网中与甜菜坏死黄脉病毒（BNYVV）的三基因块（TGB）移动蛋白相互作用。TGB蛋白被NbHRD1泛素化，然后被UPS降解。因此，NbHRD1a的过表达显著抑制BNYVV感染，而NbHRD1的沉默则促进本氏烟草中BNYVV的感染。此外，NbHRD1a主要损害BNYVV的细胞间移动，而不是病毒复制。有趣的是，NbHRD1也靶向马铃薯X病毒的TGB蛋白进行泛素化和病毒抑制。总的来说，我们的结果表明，NbHRD1是一种重要的抗病毒成分，靶向具有TGB移动蛋白的植物病毒。
