Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, Tianjin, 300071, China.
Precision Medicine Center, Tianjin Medical University General Hospital, Tianjin, 300052, China.
Virol J. 2024 Sep 13;21(1):216. doi: 10.1186/s12985-024-02489-6.
Enterovirus A71 (EV-A71), as a neurotropic virus, mainly affects infants and young children under the age of 5. EV-A71 infection causes hand-foot-mouth disease and herpetic angina, and even life-threatening neurological complications. However, the molecular mechanism by which EV-A71 induces nervous system damage remains elusive. The viral protease 3C plays an important role during EV-A71 infection and is also a key intersection of virus-host interactions. Previously, we used yeast two-hybrid to screen out the host protein Double-stranded RNA-binding protein Staufen homolog 2 (Stau2), an important member involved in neuronal mRNA transport, potentially interacts with 3C.
We used coimmunoprecipitation (Co-IP) and immunofluorescence assay (IFA) to confirm that EV-A71 3C interacts with Stau2. By constructing the mutant of Stau2, we found the specific site where the 3C protease cleaves Stau2. Detection of VP1 protein using Western blotting characterized EV-A71 viral replication, and overexpression or knockdown of Stau2 exhibited effects on EV-A71 replication. The effect of different cleavage products on EV-A71 replication was demonstrated by constructing Stau2 truncates.
In this study, we found that EV-A71 3C interacts with Stau2. Stau2 is cleaved by 3C at the Q507-G508 site. Overexpression of Stau2 promotes EV-A71 VP1 protein expression, whereas depletion of Stau2 by small interfering RNA inhibits EV-A71 replication. Stau2 is essential for EV-A71 replication, and the product of Stau2 cleavage by 3C, 508-570 aa, has activity that promotes EV-A71 replication. In addition, we found that mouse Stau2 is also cleaved by EV-A71 3C at the same site.
Our research provides an example for EV-A71-host interaction, enriching key targets of host factors that contribute to viral replication.
肠道病毒 A71（EV-A71）作为一种嗜神经病毒，主要感染 5 岁以下婴幼儿。EV-A71 感染引起手足口病和疱疹性咽峡炎，甚至危及生命的神经系统并发症。然而，EV-A71 诱导神经系统损伤的分子机制仍不清楚。病毒蛋白酶 3C 在 EV-A71 感染过程中起着重要作用，也是病毒-宿主相互作用的关键交汇点。之前，我们使用酵母双杂交筛选出宿主蛋白双链 RNA 结合蛋白 Staufen 同源物 2（Stau2），这是一种参与神经元 mRNA 运输的重要成员，可能与 3C 相互作用。
我们使用免疫共沉淀（Co-IP）和免疫荧光检测（IFA）来确认 EV-A71 3C 与 Stau2 相互作用。通过构建 Stau2 的突变体，我们找到了 3C 蛋白酶切割 Stau2 的特定位点。通过 Western blot 检测 VP1 蛋白来描述 EV-A71 病毒复制，过表达或敲低 Stau2 对 EV-A71 复制产生影响。通过构建 Stau2 截短体来证明不同切割产物对 EV-A71 复制的影响。
本研究发现 EV-A71 3C 与 Stau2 相互作用。Stau2 在 Q507-G508 位点被 3C 切割。Stau2 的过表达促进 EV-A71 VP1 蛋白的表达，而通过小干扰 RNA 敲低 Stau2 则抑制 EV-A71 复制。Stau2 是 EV-A71 复制所必需的，3C 切割 Stau2 的产物，508-570aa，具有促进 EV-A71 复制的活性。此外，我们发现小鼠 Stau2 也在同一位置被 EV-A71 3C 切割。
本研究为 EV-A71-宿主相互作用提供了一个范例，丰富了宿主因子促进病毒复制的关键靶标。
