>>14102781to elaborate a little more:
Sars-CoV-2's spike protein attaches to a cell wall by binding with ACE2. (ACE2 is protein that lives on/in your cell membranes, and is involved with blood pressure regulation, i digress). At this point, furin attaches to the cleavage site, and by cleaving the spike protein, also manages to "open up" the cell at that point, releasing the Sars-CoV-2 rna into your cell. From there it goes on to get translated like any other mRNA in your cell and the viral particles start self-assembly.
interestingly, most other sars viruses use ACE2 as an antry point, they use other "cleaving" proteins, and at a different point, the use of furin, as well as it's specific FCS-marker, seems unique.
Bioinformatics is a *huge* field, and there is lots of data. I've seen some things saying that no other sars viruses use FCS sequences. i have seen a few papers claiming they have found occurances. I dunno. i'm just explaining what i do know.
