Figure 4.

Analysis of furin activation site in other coronaviruses. A. Schematic of SARS-CoV-2 S protein and the alignment of SARS-CoV-2, RaTG13, and PCoV-GD/GX at S1/S2 and S2′ sites. B–D. Infectivity of mutated RaTG13 (B), PCoV-GD (C), and PCoV-GX (D) pseudoviruses in 293T-ACE2, 293T-ACE2-furin, and 293T-ACE2-TMPRSS2 cells. RLU signals were normalized to 293T-ACE2 control cells. +F indicates that PRRA was inserted into the viruses at the S1/S2 site. The statistical tests were comparisons of each pseudotyped mutated virus group with pseudotyped WT virus group.