Classical and alternative receptors for SARS-CoV-2 therapeutic strategy

Understanding the molecules that are essential for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) entry can provide insights into viral infection and dissemination. Recently, it has been identified from several studies that angiotensin-converting enzyme 2 receptor and transmembrane serine protease 2 are the main entry molecules for the SARS-CoV-2, which produced the pandemic of Covid-19. However, additional evidence showed several other viral receptors and cellular proteases that are also important in facilitating viral entry and transmission in the target cells. In this review, we summarized the types of SARS-CoV-2 entry molecules and discussed their crucial roles for virus binding, protein priming and fusion to the cellular membrane important for SARS-CoV-2 infection.