檔案:SARS-CoV-2 cycle.png

English： Glycoprotein S, located in the virus envelope, interacts with the cellular receptor ACE2 and the virus enters the host cell by endocytosis. Once in the endosome, a lysosome-mediated pH drop occurs, promoting fusion of the endosome membrane with the virus envelope, releasing the nucleocapsid into the cytoplasm. Cellular proteases degrade the capsid and the virus genome is left free in the cytoplasm. Next, being a positive-sense RNA genome, the cellular machinery directly translates the polyproteins, which are then processed and the replication and transcription complex is formed. The complementary strand of negative-sense pre-genomic RNA is then synthesized and serves as a template to replicate the positive-sense viral genome. Furthermore, replication and transcription complex synthesized a number of smaller, positive-sense subgenomic RNAs, which are translated into viral proteins. This entire process occurs in the cytoplasm of the cell. The structural proteins are synthesized in the endoplasmic reticulum where assembly subsequently occurs. In fact, the virus envelope comes from the endoplasmic reticulum membrane. The viral particle travels to the surface, through the cellular vesicle transport system in which the Golgi apparatus intervenes. The viral particle leaves the cell by exocytosis. After a final phase of maturation, in which viral proteases are involved, all the components of the virus fit together, the particle is infectious and a new cell cycle may begin.

Reference: SARS and MERS: recent insights into emerging coronaviruses. de Wit E, van Doremalen N, Falzarano D, Munster VJ. Nat Rev Microbiol. 2016 Aug;14(8):523-34. doi: 10.1038/nrmicro.2016.81.

https://www.nature.com/articles/nrmicro.2016.81#MOESM6