Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Sciences, Shanghai Medical College, Biosafety Level 3 Laboratory, Shanghai Institute of Infectious Disease and Biosecurity, Fudan University, Shanghai, China.
Center for Infectious Disease Research, School of Medicine, Tsinghua University, Beijing, China.
Nat Commun. 2021 Feb 11;12(1):961. doi: 10.1038/s41467-021-21213-4.
The global spread of SARS-CoV-2 is posing major public health challenges. One feature of SARS-CoV-2 spike protein is the insertion of multi-basic residues at the S1/S2 subunit cleavage site. Here, we find that the virus with intact spike (Sfull) preferentially enters cells via fusion at the plasma membrane, whereas a clone (Sdel) with deletion disrupting the multi-basic S1/S2 site utilizes an endosomal entry pathway. Using Sdel as model, we perform a genome-wide CRISPR screen and identify several endosomal entry-specific regulators. Experimental validation of hits from the CRISPR screen shows that host factors regulating the surface expression of angiotensin-converting enzyme 2 (ACE2) affect entry of Sfull virus. Animal-to-animal transmission with the Sdel virus is reduced compared to Sfull in the hamster model. These findings highlight the critical role of the S1/S2 boundary of SARS-CoV-2 spike protein in modulating virus entry and transmission and provide insights into entry of coronaviruses.
SARS-CoV-2 的全球传播带来了重大的公共卫生挑战。SARS-CoV-2 刺突蛋白的一个特征是在 S1/S2 亚基切割位点插入多个碱性残基。在这里，我们发现完整刺突（Sfull）的病毒优先通过细胞膜融合进入细胞，而缺失破坏多碱性 S1/S2 位点的克隆（Sdel）则利用内体进入途径。我们使用 Sdel 作为模型进行全基因组 CRISPR 筛选，并鉴定出几个内体进入特异性调节剂。CRISPR 筛选的命中的实验验证表明，调节血管紧张素转换酶 2（ACE2）表面表达的宿主因子会影响 Sfull 病毒的进入。与 Sfull 相比，Sdel 病毒在仓鼠模型中的动物间传播减少。这些发现强调了 SARS-CoV-2 刺突蛋白 S1/S2 边界在调节病毒进入和传播中的关键作用，并为冠状病毒的进入提供了新的见解。
