Figure 4. Inhibition of PI4K blocks membrane fusion, PKC-ε concentration at cups, and slows target uptake.
(A) Wild type BMDM, treated with PIK93 or Wt, and PKC-ε-/- BMDM, were attached to IgG surfaces (20 min, 37°C) and capacitance quantified by whole cell patch-clamping. Data is reported as mean ± SEM, 15 cells/condition from two animals of each genotype. (B) BMDM expressing PKC-ε-GFP were treated with PIK93 and phagocytosis followed in real time (Movies 1 and 2). A selected frame from Movies 1 and 2 is shown with 4 targets identified (1-4) and tracked from attachment to phagosome closure; 0 defines the time of target binding. Bars = 2 μm. From the movies, PKC-ε concentration at cups (C) and the rate of internalization (D) were determined. Results are reported as mean ± SEM (n = 40-49 events compiled from 3 independent experiments). Significance was tested by ANOVA with Bonferroni's correction. *** p< 0.001 compared to No treatment