Alteration of intracellular monovalent cation concentrations by a poliovirus mutant which encodes a defective 2A protease.
Poliovirus mutant 2A-1, which encodes a defective protease 2A, fails to inhibit translation of capped mRNAs selectively. Despite the failure of 2A-1 to inactivate cap-dependent translation, a reduction in the overall rate of protein synthesis, both virus and cell-specified, does occur after 2A-1 infection. This global reduction in protein synthesis is temporally correlated with an increase in [Na+]i and a decrease in [K+]i. The extensive global shutoff of protein synthesis is not observed in 2A-1 infected cells incubated in low NaCl medium or medium containing an elevated concentration of KCl which compensate for the virally-induced alterations in intracellular monovalent cation concentrations. Furthermore, 2A-1-specified protein synthesis is only partly resistant to hypertonic NaCl media which increase [Na+]i, in contrast to protein synthesis specified by wild-type poliovirus. These results suggest that shutoff of host and viral protein synthesis during infection by poliovirus mutant 2A-1 is a consequence of the virus-induced changes in intracellular monovalent cation concentrations.
Garry
R F
RF
Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA 70112.
D009154:Mutation; D010447:Peptide Hydrolases / Q000235:genetics*; D017955:Poliovirus / Q000378:metabolism*; D011188:Potassium / Q000032:analysis*; D014176:Protein Biosynthesis; D012964:Sodium / Q000032:analysis*; D012965:Sodium Chloride / Q000494:pharmacology; D014764:Viral Proteins / Q000096:biosynthesis
D014764:Viral Proteins; D012965:Sodium Chloride; D012964:Sodium; D010447:Peptide Hydrolases; D011188:Potassium