Fig. 2.

Proposed model for the inhibitory role of integrin in SARS-CoV-2 and SARS-CoV.

In uninfected condition, integrin could associate with ACE2 through KGD motif. Upon SARS-CoV-2 or SARS-CoV infection, integrin could interact with ACE2 (through KGD) and S protein (through RGD/KGD) individually, which will mask the interface between S protein and ACE2. Thus, ACE2 could not recognize S protein, leading to a suppressed viral entry. When ACE2 associates with S protein, a robust virus entry will occur.