Cellular entry of the SARS coronavirus

Enveloped viruses have evolved membrane glycoproteins (GPs) that mediate entry into host cells. These proteins are important targets for antiviral therapies and vaccines. Several efforts to understand and combat infection by severe acute respiratory syndrome coronavirus (SARS-CoV) have therefore focused on the viral GP, known as spike (S). In a short period of time, important aspects of SARS-CoV S-protein function were unraveled. The identification of angiotensin-converting enzyme 2 (ACE2) as a receptor for SARS-CoV provided an insight into viral tropism and pathogenesis, whereas mapping of functional domains in the S-protein enabled inhibitors to be generated. Vaccines designed on the basis of SARS-CoV S-protein were shown to be effective in animals and consequently are attractive candidates for vaccine trials in humans. Here, we discuss how SARS-CoV S facilitates viral entry into target cells and illustrate current approaches that are used to inhibit this process.