21 Specificity of Coronavirus/Receptor Interactions

Abstract

CORONAVIRUS
Coronavirus Glycoproteins That Bind to Cell Membranes
Coronaviruses are large, enveloped, plus-strand RNA viruses that cause epidemic diseases of man and domestic animals (Wege et al. 1982; Spaan et al. 1988; Holmes 1989; Lai 1990; Moestl 1990). Coronaviruses generally have limited host ranges and infect only a limited number of tissues. One factor that determines the host range is that the viral attachment glycoproteins may recognize species-specific determinants on the receptor glycoproteins. Recently, receptors for four coronaviruses have been identified (Table 1) (Dveksler et al. 1991Dveksler et al. 1993b; Williams et al. 1991; Delmas et al. 1992; Schultze and Herrler 1992; Yeager et al. 1992; Yokomori and Lai 1992a,b; Nedellec et al. 1994). These receptors include glycoproteins in the immunoglobulin superfamily (MHVR, Bgp), metalloproteases (pAPN and hAPN), and a carbohydrate moiety (9-O-acetylated neuraminic acid). The diversity of receptors and their interactions with different virus strains provide fascinating insight into the importance of virus receptors in virus pathogenesis.

Two coronavirus envelope glycoproteins have the capacity to bind to receptors on cell membranes (Fig. 1) (Holmes 1989). All coronaviruses encode a 180–200-kD glycoprotein, S, which forms the large, petal-shaped spikes that make up the characteristic corona around the virion. In addition to S, the group of coronaviruses serologically related to mouse hepatitis virus (MHV) (Hogue et al. 1984) encodes a glycoprotein, HE, that has hemagglutinating and esterase activities. The characteristics of these two viral envelope glycoproteins, their mutations and the variable levels of their expression, are important determinants of coronavirus species specificity...