Fig. 1.

SARS-CoV-2 spike (S) protein binds the cell surface receptor ACE2 on host cells. Viral genome is delivered into the host cytosol by 1) directly fusing with the plasma membrane after being cleaved and activated by the serine protease TMPRSS2 or 2) using the host cell’s endocytic machinery in which the endocytosed virions are subjected to an activation step in the endosome. The viral genome also functions as the messenger RNA, which is translated into proteins, such as 3CLPro, papain-like cysteine protease (PLpro), and RdRp, by host cell machineries. The SARS-CoV-2 genome also encodes the structural proteins (S), envelope (E), membrane (M), and nucleocapsid (N). RdRP is essential for viral replication and therefore is an attractive target for anti–SARS-CoV-2 drugs. Drugs that are currently in clinical trials are shown here in red, along with their targets of viral life cycle or viral-host interactions. Figure created in BioRender.