D614G Substitution of SARS-CoV-2 Spike Protein Increases Syncytium Formation and Virus Titer via Enhanced Furin-Mediated Spike Cleavage.
D614G Substitution of SARS-CoV-2 Spike Protein Increases Syncytium Formation and Virus Titer via Enhanced Furin-Mediated Spike Cleavage.
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DOI：
10.1128/mbio.00587-21
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发表时间：
2021-08-31
期刊：
影响因子：
6.4
通讯作者：
Yeh SH
中科院分区：
文献类型：
--
作者：
Cheng YW;Chao TL;Li CL;Wang SH;Kao HC;Tsai YM;Wang HY;Hsieh CL;Lin YY;Chen PJ;Chang SY;Yeh SH
自SARS冠状病毒2型（SARS-CoV-2）S蛋白D 614 G突变出现以来，变异株迅速扩大，成为全球最丰富的病毒株。因此，这种取代可以为病毒传播提供优势。为了探索其机制，我们分析了18个含有S蛋白的病毒分离株，其中G614或D 614（分别为S-G614和S-D 614）。空斑试验显示S-G614中的病毒滴度显著高于S-D 614分离株。我们进一步发现，在S-G614分离株中，S蛋白在弗林蛋白酶底物位点的裂解增加，这是促进合胞体形成的关键事件。D 614 G取代在S蛋白切割和合胞体形成中的增强已经在表达S蛋白的细胞中得到验证。弗林蛋白酶抑制剂处理和弗林蛋白酶切割位点的突变废除合胞体的影响，表明其依赖于弗林蛋白酶切割。我们的研究指出，D 614 G取代通过增强弗林蛋白酶介导的S裂解对合胞体形成的影响，这可能会增加含有S-G614的SARS-CoV-2菌株的传播性和感染性。
Since the D614G substitution in the spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged, the variant strain has undergone a rapid expansion to become the most abundant strain worldwide. Therefore, this substitution may provide an advantage for viral spreading. To explore the mechanism, we analyzed 18 viral isolates containing S proteins with either G614 or D614 (S-G614 and S-D614, respectively). The plaque assay showed a significantly higher virus titer in S-G614 than in S-D614 isolates. We further found increased cleavage of the S protein at the furin substrate site, a key event that promotes syncytium formation, in S-G614 isolates. The enhancement of the D614G substitution in the cleavage of the S protein and in syncytium formation has been validated in cells expressing S protein. The effect on the syncytium was abolished by furin inhibitor treatment and mutation of the furin cleavage site, suggesting its dependence on cleavage by furin. Our study pointed to the impact of the D614G substitution on syncytium formation through enhanced furin-mediated S cleavage, which might increase the transmissibility and infectivity of SARS-CoV-2 strains containing S-G614.