Fig. 11. PI4Kß distribution in UTP-stimulated PC12 cells. The cells grown on petri dishes were incubated for 3 minutes at 37°C in KBR in the absence (CON) or presence of 300 µM UTP (UTP) or in KBR minus Ca²⁺ supplemented with 2 mM EGTA and UTP (UTP-Ca⁺⁺OUT). The cells were homogenized and cytosolic (C) and membrane (M) fractions were obtained. Equal volumes of the various fractions were analyzed by western blotting using anti-PI4Kß. (A) Immunoblots showing the distribution of PI4Kß in the membranes and cytosol of control and stimulated cells in the presence or absence of Ca²⁺. (B) The amounts of PI4Kß in the membrane fractions were analyzed by immunoblotting and the signals for PI4Kß were normalized to those of synaptophysin present in the same blots. The results are expressed as a percentage of the control and represent the mean±s.e.m. (n=14, ^*P<0.005 compared with control).