Viruses use peptide expressed on cellular membrane as “receptors” to enter host cells and then downregulate the expression of these peptides. SARS-CoV-1,2 and ACE2.

Recently Discovered Human Coronaviruses - an article by Wevers and van der Hoek.

Physiological Literacy:
Brigitte A. Wevers, Lia van der Hoek, two researchers from the Netherlands, did a good job in describing how common coronaviruses penetrate host cells and some possible mechanisms of their pathological action.