Activated type I phosphatidylinositol kinase is associated with the epidermal growth factor (EGF) receptor following EGF stimulation

Jeffrey D. Bjorge, Tung On Chan, Michael Antczak, Hsing Jien Kung, Donald J. Fujita

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We have shown that a type I phosphatidylinositol (PI) kinase activity is associated with the epidermal growth factor (EGF) receptor in a mouse fibroblast cell line expressing human EGF receptors (NRHER5) and that this activity increases dramatically upon treatment of cells with physiologically relevant concentrations of EGF. EGF stimulated a time-dependent increase in EGF receptor-associated PI kinase activity measured in EGF receptor immunoprecipitates. Activation was detected 15 min after the addition of EGF, and it peaked between 1 and 2 hr. Activation of PI kinase was detected with EGF concentrations as low as 10 pM and maximal stimulation occurred at ≈1 nM. Analysis of deacylated PI phosphate products, and inhibition of the PI kinase activity by nonionic detergent, indicated that the PI kinase described here was type I or PI 3′ kinase. These results demonstrate the regulation of a type I PI kinase by EGF and suggest a potential role in the EGF receptor signal transduction pathway. (.

Original languageEnglish
Pages (from-to)3816-3820
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number10
Publication statusPublished - Jan 1 1990
Externally publishedYes



  • Signal transduction
  • Tyrosine kinase

ASJC Scopus subject areas

  • General

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