Expression of an ATP binding mutant of PKC-delta inhibits Sis-induced transformation of NIH3T3 cells

Oncogene. 1996 Aug 15;13(4):731-7.


In an effort to determine the role of protein kinase C-delta (PKC-delta) in cellular transformation mediated by the sis proto-oncogene, we cotransfected expression vectors containing cDNAs that encode for c-sis with an ATP binding mutant of PKC-delta (PKC-delta K376R) or wild type PKC-delta (PKC-delta WT) into NIH3T3 cells. Our results showed that expression of PKC-delta K376R severely impaired Sis-induced focus formation, whereas cotransfection of PKC-delta WT cDNA had no effect on Sis-mediated transformation. Consistent with this result, PKC-delta K376R expression also inhibited PDGF-BB-mediated anchorage-independent colony formation. While cotransfection of a vector containing a dominant negative mutant of ras (N17 ras) cDNA potently inhibited Sis-induced transformation, the expression of PKC-delta K376R did not block transformation mediated by v-H-Ras or v-Raf. In addition, PDGF-BB-induced Raf and mitogen-activated protein kinase activation, which are known to be downstream molecules in the Ras cascade, were not affected by the expression of PKC-delta K376R, indicating that PKC-delta and Ras are segregated in mediating Sis-induced transformation. Interestingly, expression of PKC-delta K376R strongly reduced TPA responsive element (TRE) transactivation induced by PDGF stimulation, suggesting that activation of TRE-containing genes, which may be involved in Sis-mediated transformation, are negatively regulated by expression of PKC-delta K376R.

MeSH terms

  • 3T3 Cells
  • Adenosine Triphosphate / metabolism*
  • Animals
  • Base Sequence
  • Cell Transformation, Neoplastic / genetics
  • DNA Primers
  • Enzyme Induction
  • Isoenzymes / antagonists & inhibitors
  • Isoenzymes / genetics
  • Isoenzymes / metabolism*
  • Luciferases / biosynthesis
  • Mice
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • Phosphorylation
  • Platelet-Derived Growth Factor / metabolism*
  • Protein Binding
  • Protein Kinase C / antagonists & inhibitors
  • Protein Kinase C / genetics
  • Protein Kinase C / metabolism*
  • Protein Kinase C-delta
  • Proto-Oncogene Proteins / metabolism*
  • Proto-Oncogene Proteins c-sis
  • Receptor, Platelet-Derived Growth Factor beta
  • Receptors, Platelet-Derived Growth Factor / metabolism
  • ras Proteins / metabolism


  • DNA Primers
  • Isoenzymes
  • Platelet-Derived Growth Factor
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-sis
  • Adenosine Triphosphate
  • Luciferases
  • Prkcd protein, mouse
  • Receptor, Platelet-Derived Growth Factor beta
  • Receptors, Platelet-Derived Growth Factor
  • Protein Kinase C
  • Protein Kinase C-delta
  • ras Proteins