Proteolytic Activation of SARS-CoV‑2 Spike the S1/S2 Boundary: Potential Role of Proteases beyond Furin

This is the authors' abstract. We don't add key points for this paper.

The acute respiratory syndrome coronavirus 2 (SARS-CoV-2) its spike (S) protein to mediate viral entry into host cells. of the S protein at the S1/S2 and/or S2′ site(s) is with viral entry, which can occur at either the cell plasma (early pathway) or the endosomal membrane (late pathway), on the cell type. Previous studies show that SARS-CoV-2 a unique insert at the S1/S2 site that can be cleaved by furin, appears to expand viral tropism to cells with suitable protease receptor expression. Here, we utilize viral pseudoparticles and inhibitors to study the impact of the S1/S2 cleavage on infectivity. results demonstrate that S1/S2 cleavage is essential for early entry into Calu-3 cells, a model lung epithelial cell line, not for late pathway entry into Vero E6 cells, a model cell line. S1/S2 cleavage was found to be processed by other proteases beyond. Using bioinformatic tools, we also analyze the presence of furin S1/S2 site in related CoVs and offer thoughts on the origin the insertion of the furin-like cleavage site in SARS-CoV-2.