FIGURE 1.

Schematic presentation of early steps of SARS-CoV-2 life cycle. The virus enters the cells by interacting with its receptor ACE2 protein using the spike protein and priming by the cell surface protease TMPRSS2. This induces formation of a vesicle via clathrin-dynamin-mediated endocytosis. The internalized vesicle loses its clathrin coat and fuses with an endosome. As the endosome undergoes acidification, it activates host proteases that induce fusion of the virus particle with the endosomal membrane, releasing the viral genomic RNA into the cytosol. Since SARS-CoV-2 RNA is (+) sense, it can immediately undergo translation and further transcription to allow the remaining steps of virus life cycle to continue. The left panel illustrates the key explaining the different components of this pathway. See text for details.