6 Receptors for Picornaviruses

Abstract

Infection of specific host cells by picornaviruses is initiated by the attachment of virions to host cells (for reviews, see Crowell and Landau 1983; Colonno 1987, 1992; Crowell 1987; Flore et al. 1990; Lentz 1990; Stanway 1990; Koike et al. 1992b; Racaniello 1992). This event is usually a specific one, in that susceptible cells possess membrane-associated molecules, called receptors (R), which virions recognize in a specific way. The receptors generally are plasma membrane glycoproteins, which are embedded in the membrane lipid bilayer of the cell by the transmembrane region of the molecule, with the amino-terminal amino acid chain extending away from the cell and the carboxy-terminal region extending into the cytoplasm. It is presumed that picornaviruses have evolved differentiated regions in their symmetrical capsid structure, referred to as virion attachment sites (VAS), which recognize specific features of selected cellular membrane proteins for binding. The receptors for virus attachment also serve the cell for other functions, which are just becoming known for some picornaviruses (Greve at al. 1989; Staunton et al. 1989; Tomassini et al. 1989b; Bergelson et al. 1992, 1994; Huber 1994).

Interest in the early events of infection of cells by picornaviruses was ushered in by the early studies of poliovirus attachment to mammalian cells (McLaren et al. 1959; Holland 1961). These studies revealed the importance of the presence of specific cellular receptors to initiate infection. Only primate cells possessed specific receptors and were permissive to poliovirus infection, whereas nonprimate cells were devoid of specific receptors for polioviruses and,...