Flavinkins (@Flavinkins)

https://archive.vn/pj7MZ Again, if “O-linked glycosylation” is such an important feature of in-vivo adaptation and “immune selection”, why it is abolished alongside P681 in all of the current most transmissible VOCs (Alph, Delta, Omicron) of SARS-CoV-2, which also happens to feature the strongest immune evasion amongst all the current variants of SARS-CoV-2? https://gab.com/Flavinkins/posts/108777215248937177 https://archive.vn/qXMsd https://archive.vn/Nfu5p https://archive.is/6qUW3 https://archive.vn/CFNcS https://archive.vn/az10E https://journals.asm.org/doi/10.1128/mBio.01930-20 In fact, the exact opposite of purifying immune selection exists for P681–the PRRARS sequence and the underlying CTCCTCGGCGGGCACGTAG sequence (yes. The first C in the CTCCTCGGCGGGCACGTAG sequence is important for binding of ZAP on the positive strand) is one of the the most immunogenic sequence in the SARS-CoV-2 genome. https://gab.com/Flavinkins/posts/109093899892435225 https://www.biorxiv.org/content/10.1101/2020.11.16.384594v1.full https://gab.com/Flavinkins/posts/108699507011264068 https://gab.com/Flavinkins/posts/108734935678495831 https://gab.com/Flavinkins/posts/109018016524597940 https://gab.com/Flavinkins/posts/109106790806751902 https://gab.com/Flavinkins/posts/108943039799474712 https://gab.com/Flavinkins/posts/109160332614014817 https://gab.com/Flavinkins/posts/108779333080481680 When glycosylated (as in VERO E6 or CaLu-3 cells, but especially in VERO E6 cells), the S is less cleaved (compared to in HEK293T cells where no glycosylation of the S1-S2 happens). A less cleaved S is favored by cell cultures. That is why it gets P681, and why P681 is favored above R681 or H681 in these cells. Passage ARRAR or RRRARR in VERO/HAE or CaLu-3, and it turns into PRRAR.