Figure 3.

Effect of inhibition of MRCKα kinase activity on ABCB4 protein expression. (A) HEK-293 cells stably expressing ABCB4 were either transfected with the empty vector-Flag (ctrl vector) or Flag-tagged MRCKα-kinase-dead (MRCKα-KD-Flag) or treated with 10 mM of chelerythrine chloride for 2 h. Cells were then lysed and analyzed by immunoblotting using anti-MRCKα, anti-ABCB4, and anti-a-tubulin antibodies. (B) Amounts of ABCB4 were quantified from immunoblots by densitometry. ABCB4 levels were expressed as a percentage of total expression in HEK-293 cells transfected with ctrl vector. Means (±SEM) of at least eight independent experiments are shown. *** p < 0.001; ** p < 0.01. (C) Primary human hepatocytes were treated with 20 mM of chelerythrine chloride for the indicated time points. Cells were then lysed and analyzed by immunoblotting using anti-ABCB4 and anti-a-tubulin antibodies. Presented data were cropped from the full immunoblots shown in Supplementary Figure S3. (D) Amounts of ABCB4 were quantified from immunoblots by densitometry. ABCB4 levels were expressed as a percentage of total expression of untreated (Time 0 min) hepatocytes. Means (±SD) of at least three independent experiments are shown. *** p < 0.001; ** p < 0.01; * p < 0.05.