Dominant negative effect of the truncated p110 subunit of phosphatidylinositol-3 kinase

Abstract

Effects of p110, the catalytic subunit of PI-3 kinase, on induction of TPA response element-driven promoter by EGF was examined. The induction was enhanced by co-expression of the wild type of p110. The truncated p110 mutants containing the binding site for p85 but missing the catalytic activity repressed the induction. A mutant with no binding activity to p85 did not show this effect. These results suggest that PI-3 kinase is involved in signal transduction of EGF and that the truncated p110s capable of binding to p85 serves as a dominant negative reagent for PI-3 kinase.