The role of proteases in the invasion of SARS-CoV-۲ virus into human host cells

The new coronavirus, which originally broke out in Wuhan, China, in December ۲۰۱۹, increase quicklyaround the world, causing a pandemic all over the world. The virus uses its spike protein to enter thehuman host cells. Protein S binds to the angiotensin-converting enzyme II (ACE۲) receptor and entersthe host cell. For the more successful binding, several proteases facilitate and optimize this binding, themost important of which are transmembrane protease serine ۲ (TMPRSS۲), furin, and cathepsin Lproteases. After binding of protein S to the ACE۲ receptor, cleavage of protein S is required formembrane fusion by protein S, which causes viral entry into host cells. This proteolytic activity may becathepsin L-dependent and occurs with changes in pH in cell endosomes, or it may occur through serineproteases activity at the surface of the host cell membrane or within vesicles. Finally, the cell becomesinfected with the virus. Several studies have tried to reduce the rate of viral infection by using inhibitorsof these proteases.

Keywords:

SARS-CoV-۲ , TMPRSS۲ , Furin , Cathepsin L , COVID-۱۹