Wang Pei, Tian Buyun, Xiao Ke, Ji Wei, Li Zonghong
The First Affiliated Hospital of Guangzhou Medical University, Guangzhou National Laboratory Clinical Base, Guangzhou Medical University, Guangzhou, 510120, China; Guangzhou National Laboratory, Guangzhou, 510005, China.
National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
Virol Sin. 2025 Apr;40(2):225-235. doi: 10.1016/j.virs.2025.03.010. Epub 2025 Mar 28.
The evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in mutations not only in the spike protein, aiding immune evasion, but also in the NSP3/4/6 proteins, crucial for regulating double-membrane vesicle (DMV) formation. However, the functional consequences of these NSP3/4/6 mutations remain poorly understood. In this study, a systematic analysis was conducted to investigate the evolutionary patterns of NSP3/4/6 mutations and their impact on DMV formation. The findings revealed that the NSP4 T492I mutation, a prevalent mutation found in all Delta and Omicron sub-lineages, notably enhances DMV formation. Mechanistically, the NSP4 T492I mutation enhances its homodimerization, leading to an increase in the size of puncta induced by NSP3/4, and also augments endoplasmic reticulum (ER) membrane curvature, resulting in a higher DMV density per fluorescent puncta. This study underscores the significance of the NSP4 T492I mutation in modulating DMV formation, with potential implications for the transmission dynamics of SARS-CoV-2. It contributes valuable insights into how these mutations impact viral replication and pathogenesis.
严重急性呼吸综合征冠状病毒2（SARS-CoV-2）的进化不仅导致刺突蛋白发生突变，有助于免疫逃逸，还导致非结构蛋白3/4/6（NSP3/4/6）发生突变，而这些蛋白对调节双膜囊泡（DMV）的形成至关重要。然而，这些NSP3/4/6突变的功能后果仍知之甚少。在本研究中，我们进行了系统分析，以研究NSP3/4/6突变的进化模式及其对DMV形成的影响。研究结果表明，NSP4 T492I突变是在所有德尔塔和奥密克戎亚谱系中发现的一种普遍突变，它显著增强了DMV的形成。从机制上讲，NSP4 T492I突变增强了其同二聚化，导致由NSP3/4诱导的斑点大小增加，同时也增加了内质网（ER）膜曲率，导致每个荧光斑点的DMV密度更高。本研究强调了NSP4 T492I突变在调节DMV形成中的重要性，这可能对SARS-CoV-2的传播动力学产生影响。它为这些突变如何影响病毒复制和发病机制提供了有价值的见解。
