Phosphatidylinositol-3 kinase is activated in v-src, v-yes, and v-fps transformed chicken embryo fibroblasts.
PI-3 kinase activity has been shown to associate with p60v-src. We found that immunoprecipitates of p60v-src exhibit an activity that catalyzes the formation of PI-3-P, PI-3,4-P2 and PIP3 from PI, PI-4-P, and PI-4,5-P2, respectively. Transformation of chicken embryo fibroblasts (CEF) by p60v-src of Rous sarcoma virus (RSV) caused elevation of PI-3-P, PI-3,4-P2, and PIP3, suggesting that the PI-3 kinase may be activated in these cells. Similar elevations were seen in cells transformed with the v-yes or v-fps oncogenes, but not with v-ros or v-ras. We have established also a system that allows the binding of PI-3 kinase to purified p60v-src in vitro, reproducing the binding seen in vivo. This assay indicated that more PI-3 kinase activity binds to purified p60v-src in cell lysates from CEF transformed with v-yes or v-fps, suggesting that some modification or over-expression of PI-3 kinase takes place in these cells.
Fukui
Y
Y
Rockefeller University, New York 10021.
Saltiel
A R
AR
Hanafusa
H
H
D019870:1-Phosphatidylinositol 4-Kinase; D000818:Animals; D001358:Avian Sarcoma Viruses; D002472:Cell Transformation, Viral; D002642:Chick Embryo; D004789:Enzyme Activation; D005347:Fibroblasts / Q000201:enzymology / Q000382:microbiology; D016391:Genes, src / Q000235:genetics*; D009857:Oncogenes / Q000235:genetics*; D010770:Phosphotransferases / Q000378:metabolism*; D011233:Precipitin Tests
D010770:Phosphotransferases; D019870:1-Phosphatidylinositol 4-Kinase