Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada.
Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada.
J Biol Chem. 2021 Jan-Jun;296:100306. doi: 10.1016/j.jbc.2021.100306. Epub 2021 Jan 19.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of COVID-19, so understanding its biology and infection mechanisms is critical to facing this major medical challenge. SARS-CoV-2 is known to use its spike glycoprotein to interact with the cell surface as a first step in the infection process. As for other coronaviruses, it is likely that SARS-CoV-2 next undergoes endocytosis, but whether or not this is required for infectivity and the precise endocytic mechanism used are unknown. Using purified spike glycoprotein and lentivirus pseudotyped with spike glycoprotein, a common model of SARS-CoV-2 infectivity, we now demonstrate that after engagement with the plasma membrane, SARS-CoV-2 undergoes rapid, clathrin-mediated endocytosis. This suggests that transfer of viral RNA to the cell cytosol occurs from the lumen of the endosomal system. Importantly, we further demonstrate that knockdown of clathrin heavy chain, which blocks clathrin-mediated endocytosis, reduces viral infectivity. These discoveries reveal that SARS-CoV-2 uses clathrin-mediated endocytosis to gain access into cells and suggests that this process is a key aspect of virus infectivity.
严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）是 COVID-19 的病原体，因此了解其生物学和感染机制对于应对这一重大医学挑战至关重要。SARS-CoV-2 已知其利用刺突糖蛋白与细胞表面相互作用作为感染过程的第一步。对于其他冠状病毒，SARS-CoV-2 很可能接下来经历内吞作用，但内吞作用是否是感染所必需的，以及所使用的确切内吞作用机制尚不清楚。使用纯化的刺突糖蛋白和带有刺突糖蛋白的慢病毒假型，我们现在证明 SARS-CoV-2 在与质膜结合后会迅速发生网格蛋白介导的内吞作用。这表明病毒 RNA 从内体系统的腔内向细胞质转移。重要的是，我们进一步证明，阻断网格蛋白介导的内吞作用的网格蛋白重链的敲低会降低病毒感染性。这些发现表明 SARS-CoV-2 使用网格蛋白介导的内吞作用进入细胞，并表明该过程是病毒感染性的关键方面。
