[Signal transduction of PI3-kinase].

Phosphatidylinositol (PI)-3 kinase is an enzyme that phosphorylates D3 position of PI and its derivatives. It is activated immediately after growth factor or differentiation factor stimulation, suggesting that PI-3 kinase is involved in signal transduction of the stimulations. PI-3 kinase appears to play important roles in various points including signaling to the nucleus, vesicle transport, and rearrangement of cytoskeleton since many cell responses which requires these events were affected by inhibition or activation of PI-3 kinase. There are many mechanisms of activation of PI-3 kinase including binding to phosphotyrosine containing proteins or binding to Ras. Each mechanism can target PI-3 kinase to the right place to induce the right cell responses.