Alteration of intracellular monovalent cation concentrations by a poliovirus mutant which encodes a defective 2A protease

Sindbis virus-induced inhibition of protein synthesis is partially reversed by medium containing an elevated potassium concentration

“…In contrast, medium containing a low concentration of Na t reduced [Na+]i in Sindbis virus-infected cells, but generally failed to restore host protein synthesis . In further contrast to our results in Sindbis virus-infected cells, high KC1 medium failed to restore host protein synthesis in either EMC virus-infected cells (Alonso & Carrasco, 1981) or wild-type poliovirusinfected cells (Castrillo et al, 1987;Garry, 1989a). Among other shutoff mechanisms, different lytic viruses appear to employ alternative strategies involving monovalent ions to terminate cellular protein synthesis.…”

“…Incubation of EMC virusinfected HeLa cells in medium containing a reduced concentration of NaC1 results in a reversal of the selective termination of host protein synthesis and an inhibition of the synthesis of EMC virus-specified proteins (Alonso & Carrasco, 1981). Shutoff by poliovirus is also reversed by low Na + medium early after infection (Castrillo et al, 1987;Garry, 1989a). Incubation in low NaC1 medium decreases intracellular concentrations of both Na + and K + .…”

Alteration of intracellular potassium and sodium concentrations correlates with induction of cytopathic effects by human immunodeficiency virus

“…For example, by day 5 postinfection, when differences in ion content were noted, cultures infected with the weakly pathogenic HIV SF2 and HIV UC1 had produced a level of viral proteins higher or nearly the same as that produced by the more cytopathic isolate SF13 (3.20, 1.93, and 1.91 ng per 10 6 cells, respectively). Similar changes in [K ϩ ] i and [Na ϩ ] i were induced by these HIV strains in studies that measured uptake of 22 Na ϩ or 86 Rb ϩ , a K ϩ tracer. Taken together, these data correlate changes in [K ϩ ] i and [Na ϩ ] i with virus strain cytopathic potential.…”

“…Alteration of intracellular ion concentrations may be important for triggering conformational changes in virion proteins during uncoating or penetration, for activation of viral transcriptases, or for virion assembly, budding, and maturation (10,45,56,60). Changes in intracellular ion concentrations caused by picornaviruses and alphaviruses also correlate with preferential translation of viral proteins (host cell shutoff) (2,11,22,23), and ion-driven osmotic cell swelling appears necessary for cell-cell fusion mediated by paramyxoviruses, myxoviruses, and herpesviruses (7,8,35,47). Osmotic cell swelling (balloon degeneration) induced by HIV and other fusogenic viruses could provide the primary force for membrane separation, destabilization, or the cytoskeletal disruption required for formation of multinucleated syncytial cells.…”

Picornavirus inhibitors

“…The major salient feature is that a viral gene product is required for the development of late modifications in membrane permeability. This modification starts in HeLa cells at about the third hour after infection with poliovirus (Nair et al, 1979;Lacal and Carrasco, 1982;Mufioz and Carrasco, 1983;Nair, 1984;L6pez-Rivas et al, 1987;Garry, 1989), or at the second hour p.i. in cells infected with SFV (Garry et al, 1979;Ulug et al, 1987).…”