Interaction of Ras with phosphoinositide 3-kinase gamma.
Phosphoinositide 3-kinase gamma (PI3Kgamma) can be activated in vitro by both alpha and betagamma subunits of heterotrimeric G-proteins and does not interact with p85, the regulatory subunit of PI3Kalpha. Here we demonstrate the binding of Ras to PI3Kgamma in vitro. An N-terminal region of PI3Kgamma was identified as a binding site for Ras. After co-expression with PI3Kgamma in COS-7 cells, Ras induced only a modest increase in PI3K activity compared with the stimulation of PI3Kalpha by Ras in the same cells.
Rubio
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I
Max-Planck Research Unit of Molecular Cell Biology, Drackendorfer Strasse 1, D 07747 Jena, Federal Republic of Germany.
Rodriguez-Viciana
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P
Downward
J
J
Wetzker
R
R
D000818:Animals; D001665:Binding Sites; D019556:COS Cells; D004789:Enzyme Activation; D019869:Phosphatidylinositol 3-Kinases; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism*; D015398:Signal Transduction; D018411:Spodoptera; D018631:ras Proteins / Q000378:metabolism*
D019869:Phosphatidylinositol 3-Kinases; D017853:Phosphotransferases (Alcohol Group Acceptor); D018631:ras Proteins