Fig. 7.

Effect of LPS (A) and CK2 inhibitors (B) on biotin uptake by the human retinal pigment epithelial ARPE-19 cells. Postconfluency cells were incubated with LPS (50 μg/ml, 72 h) or with the CK2 inhibitors TBB and TBCA (30 µM; 1 h) followed by examination of biotin uptake (see Methods). C: effect of mutating the putative CK2 phosphorylation sites in the hSMVT protein on biotin uptake. Equal amounts of the wild-type and the mutated hSMVT constructs (3 µg/well, in 12-well culture plates) were transfected into ARPE-19 cells. Biotin uptake was then determined 48 h after transfection. Data are means ± SE from at least 3 independent experiments (*P < 0.01).