Fig. 2.

A cartoon depicting the attack of a target cell by COVID-19, and the inhibitory actions of chloroquine on it. The endocytosed virus travels from early endosomes to late endosomes-lysosomes, where the acidic environment activates their hydrolytic enzymes the uncoat the virus, liberating its genomic RNA into the cytoplasm. In the endoplasmic reticulum of the host cell (ER) the open reading frames (ORFs) of the genome are translated into pp1a and pp1ab proteins, which are cleaved by proteases of the host cell to 16 non structural proteins (nsps). They form the replicase/transcriptase complex that will produce the new viral RNA genome, which is translated into the four structural proteins E, M, N, and S to reconstitute a new viral particle. After suitable modification and quality control of the structural proteins in the ER and Golgi complex, the new virus travels to the surface of the host cell to be escreted. The text contains additional details.