Fig. 2.
PI-3K is constitutively activated in B-CLL cells.
PI-3K activity was measured by incubation of anti-p85 antisera with PI and P32-γg-ATP. P32-labeled enzymatic products of PI-3K were resolved by TLC using a silica gel, as described in “Materials and methods,” and visualized by autoradiography. Total cell lysate (200 μg) of freshly isolated B-CLL cells was used for immunoprecipitation. Lanes 1 to 7 show constitutive PI-3K activity of 7 different CLL samples. IL-3–stimulated (2 ng/mL) Ba/F3 cells were used for positive control (pc). Kinase reaction could be inhibited sufficiently by adding 300 nM wortmannin (Wn) to the reaction (lanes 8 and 10).
