| Id |
Subject |
Object |
Predicate |
Lexical cue |
| T263 |
0-169 |
Sentence |
denotes |
Although not directly related to ACE2, the role of S “priming” by host cell proteases deserves particular attention in the context of SARS-CoV-2 virus entry and tropism. |
| T264 |
170-382 |
Sentence |
denotes |
Possibly, the most notable feature of SARS-CoV-2 genome, as compared to SARS-CoV and some related bat coronaviruses, is a four basic aminoacid insert (PRRA) at the S1/S2 junction (Figure 4B; Jaimes et al., 2020). |
| T265 |
383-538 |
Sentence |
denotes |
This site is potentially cleavable by the protease furin, a proprotein convertase widely recognized to activate the fusion machinery of viral glycoprotein. |
| T266 |
539-771 |
Sentence |
denotes |
Indeed, many authors showed that pseudoviruses bearing SARS-CoV-2 S were already “primed” (i.e., cleaved) at the S1/S2 boundary by furin upon assembly in the cell, at odds with pseudoviruses bearing SARS-CoV S (Shang et al., 2020a). |
| T267 |
772-1165 |
Sentence |
denotes |
SARS-COV-2 shows a large flexibility with regard to protease priming, which may independently occur by a) furin and furin-like proteases intracellularly, b) trypsin-like proteases such as TMPRSS2 that are present on the host cell membrane (particularly on airway epithelial cells), and 3) endosomal cathepsins activated by a drop in pH (e.g., cathepsin L) (Figure 7; Hoffmann et al., 2020a,b). |
| T268 |
1166-1317 |
Sentence |
denotes |
This flexibility could be the crucial factor that explain SARS-CoV-2 cell tropism and the peculiar features of COVID-19 symptoms (Jaimes et al., 2020). |
| T269 |
1318-1503 |
Sentence |
denotes |
Additionally, the kind of protease “priming” may determine whether the membrane fusion process occur directly at the plasma membrane or at endosomal level (Tang et al., 2020; Figure 7). |
