The role of monovalent cation transport in Sindbis virus maturation and release.
Alterations in intracellular monovalent cation concentrations in Sindbis virus-infected avian cells result, in part, from a reduction in Na+/K+ ATPase (Na+ pump) activity. Inhibition of Na+ pump activity was shown previously to temporally correlate with the appearance of viral envelope proteins on the cell surface and the release of virus particles. Cells infected with envelope-defective temperature-sensitive mutants exhibited reduced Na+ pump activity at the nonpermissive temperature, where viral particles are not released. By contrast, Na+ pump activity was not inhibited in Sindbis virus-infected cells treated with tunicamycin or with antiviral serum, which block virus maturation and release. Diuretic-sensitive transport of 86Rb+, aK+ tracer, was stimulated in cells which express virus envelope proteins, but fail to release virus particles. In these cells, the furosemide-sensitive 86Rb+ influx exhibited an increase in Vmax and was responsive to changes in the extracellular concentration of NaCl. Furosemide inhibited the rapid release of virus from low salt-inhibited cells after shift to isotonic conditions. Alterations in ion transport during alphavirus infection may, therefore, facilitate the efficient release of progeny virus particles.
Ulug
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Department of Microbiology, University of Texas, Austin 78712-1095.
Garry
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Bose
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D001692:Biological Transport; D002034:Bumetanide / Q000494:pharmacology; D002414:Cations, Monovalent / Q000502:physiology*; D002462:Cell Membrane / Q000502:physiology; D005665:Furosemide / Q000494:pharmacology; D009154:Mutation; D010042:Ouabain / Q000494:pharmacology; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D012845:Sindbis Virus / Q000502:physiology*; D000254:Sodium-Potassium-Exchanging ATPase / Q000502:physiology; D014415:Tunicamycin / Q000494:pharmacology; D014759:Viral Envelope Proteins / Q000502:physiology*; D014779:Virus Replication
D002414:Cations, Monovalent; D014759:Viral Envelope Proteins; D002034:Bumetanide; D014415:Tunicamycin; D010042:Ouabain; D005665:Furosemide; D000254:Sodium-Potassium-Exchanging ATPase