Modification of phospholipase C and phospholipase A2 activities during poliovirus infection.
The infection of HeLa cells by poliovirus leads to profound alterations in the activities of both phospholipase C and the A23187-stimulated phospholipase A2. As early as the third hour after poliovirus infection, the activity of phospholipase C is enhanced, as measured by the increase in inositol triphosphate (IP3) in the cells. By the fifth hour post-infection there is a 5-fold increase in IP3 in the infected cells. Therefore, the synthesis of the bulk of poliovirus proteins and poliovirus genomes takes place in cells containing a high and sustained increase in IP3. This augmentation in IP3 is dependent on the multiplicity of infection used. Poliovirus gene expression is required to induce the increase in phospholipase C activity, since the presence of cycloheximide or guanidine blocked it. In contrast to the activation of phospholipase C induced by poliovirus, there is a drastic blockade of the A23187-induced phospholipase A2 activity, measured as the release of [3H]arachidonic acid to the medium. This action on phospholipase A2 is dependent on poliovirus gene expression because it was prevented by cycloheximide or 3-methylquercetin. To our knowledge this is the first report analyzing these two activities in animal virus-infected cells. The findings described may help to explain the profound modifications of both membrane permeability and lipid metabolism undergone by poliovirus-infected cells.
Guinea
R
R
Centro de Biología Molecular (Consejo Superior de Investigaciones Cientificas-Universidad Autonoma de Madrid), Spain.
López-Rivas
A
A
Carrasco
L
L
D000998:Antiviral Agents / Q000494:pharmacology; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism; D000001:Calcimycin / Q000494:pharmacology; D002472:Cell Transformation, Viral; D003513:Cycloheximide / Q000494:pharmacology; D044948:Flavonols; D006367:HeLa Cells / Q000187:drug effects / Q000201:enzymology; D006801:Humans; D006921:Hygromycin B / Q000494:pharmacology; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D007295:Inositol Phosphates / Q000302:isolation & purification / Q000378:metabolism; D007700:Kinetics; D010740:Phospholipases / Q000378:metabolism*; D010741:Phospholipases A / Q000378:metabolism*; D054467:Phospholipases A2; D017955:Poliovirus / Q000235:genetics*; D011794:Quercetin / Q000031:analogs & derivatives / Q000494:pharmacology; D010738:Type C Phospholipases / Q000378:metabolism*
D000998:Antiviral Agents; D001095:Arachidonic Acids; D044948:Flavonols; D007295:Inositol Phosphates; C047368:3-methylquercetin; D016718:Arachidonic Acid; D000001:Calcimycin; D006921:Hygromycin B; D015544:Inositol 1,4,5-Trisphosphate; D003513:Cycloheximide; D011794:Quercetin; D010740:Phospholipases; D010741:Phospholipases A; D054467:Phospholipases A2; D010738:Type C Phospholipases