Figure 2.

The life cycle of SARS-CoV-2 and potential mechanisms of action of drugs. The virus lifecycle starts when the S protein binds to its cellular receptor angiotensin converting enzyme II (ACE2). Following a conformation change in the S protein, the viral envelope fuses with the cell membrane. After endocytosis, the RNA of SARS-CoV-2 is released to the cytoplasm. Genomic RNA, which is positive sense, is translated into the viral polyproteins pp1a and 1ab. The polymerase produces a series of subgenomic mRNAs and translates the relevant viral proteins. In the endoplasmic reticulum (ER) and Golgi, viral proteins and genome RNA are assembled into virions and transported via vesicles and released out of the cell. ERGIC (ER–Golgi intermediate compartment). Site of action for each therapeutic candidate is shown with red cross.