Parvovirus interference with intracellular signalling: mechanism of PKCeta activation in MVM-infected A9 fibroblasts.
Autonomous parvoviruses are strongly dependent on the phosphorylation of the major non-structural protein NS1 by members of the protein kinase C (PKC) family. Besides being accompanied with changes in the overall phosphorylation pattern of NS1 and acquiring new modifications at consensus PKC sites, ongoing minute virus of mice (MVM) infections lead to the appearance of new phosphorylated cellular protein species. This prompted us to investigate whether MVM actively interferes with phosphoinositol-dependent kinase (PDK)/PKC signalling. The activity, subcellular localization and phosphorylation status of the protein kinases PDK1, PKCeta and PKClambda were measured in A9 cells in the presence or absence of MVM infection. Parvovirus infection was found to result in activation of both PDK1 and PKCeta, as evidenced by changes in their subcellular distribution and overall (auto)phosphorylation. We show evidence that activation of PKCeta by PDK1 is driven by atypical PKClambda. By modifying the hydrophobic motif of PKCeta, PKClambda appeared to control docking and consecutive phosphorylation of PKCeta's activation-loop by PDK1, a process that was inhibited in vivo in the presence of a dominant-negative PKClambda mutant.
Program 'Infection and Cancer', Abteilung F010 and Institut National de la Santé et de la Recherche Médicale U701, Deutsches Krebsforschungszentrum, Heidelberg, Germany.
Sylvie
S
Lachmann
Severine
S
Bär
Jean
J
Rommelaere
Jürg P F
JP
Nüesch
D000818:Animals; D002460:Cell Line; D002467:Cell Nucleus / Q000737:chemistry; D003593:Cytoplasm / Q000737:chemistry; D005347:Fibroblasts / Q000821:virology*; D007527:Isoenzymes / Q000378:metabolism; D051379:Mice; D008856:Microscopy, Fluorescence; D008915:Minute Virus of Mice / Q000502:physiology*; D010766:Phosphorylation; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D000081382:Pyruvate Dehydrogenase Acetyl-Transferring Kinase; D000099293:Protein Kinase C-lambda
D007527:Isoenzymes; D011493:Protein Kinase C; D017346:Protein Serine-Threonine Kinases; D000081382:Pyruvate Dehydrogenase Acetyl-Transferring Kinase; D000099293:Protein Kinase C-lambda; C000631433:Pdk1 protein, mouse; C081975:protein kinase C eta