Table 2

Inhibition of PI4K activity in subcellular fractions of SH-SY5Y cells by WT, LY-294002, PAO, or the monoclonal antibody 4C5G

PI4K activity
P1V1S2
% of control
Cells pretreated with inhibitor
 10 μM WT96  ± 1362  ± 6*29  ± 5*
 100 μM LY-294002118  ± 7102  ± 396  ± 6
 20 μM PAO103  ± 874  ± 7*72  ± 8*
Inhibitor added directly to subcellular fraction
 10 μM WT85  ± 248  ± 5*2  ± 1*
 100 μM LY-29400292  ± 371  ± 2*66  ± 3*
 20 μM PAO93  ± 593  ± 3100  ± 5
 200 μM PAO95  ± 272  ± 3*51  ± 4*
 4C5G (50 μg/ml)54  ± 7*66  ± 3*85  ± 6

Cells were pretreated with WT, LY-294002, or PAO for 15 min at the concentrations indicated and washed once; then, subcellular fractions were isolated as described in the text. PI4K activity in the fractions was determined. In addition, cells were first fractionated, and then subcellular fractions were incubated in the presence of WT, LY-294002, PAO, or 4C5G at the concentrations indicated. Values are expressed as PI4K activity (percentage of control). Results shown are the mean ± standard error of three or four separate experiments for each inhibitor. The specific activities of PI4K in P1, V1, and S2 fractions obtained from control cells were 238 ± 26, 605 ± 49, and 98 ± 13 pmol/min/mg of protein, respectively (n = 11–13). Approximately 35%, 48%, and 17% of PI4K activity recovered was located in P1, V1, and S2 fractions, respectively.

  • * p < .05, different from control.