Fig. 4.

Dominant-negative (DN)- and wild-type (WT)-PKCδ increased Rab4 activity and PM NTCP. HuH-NTCP cells were transfected with empty vector (EV), DN-PKCδ, and WT-PKCδ, followed by treatment with or without 100 μM CPT-cAMP for 15 min. Rab4 activation was determined using a GTP overlay assay (B). NTCP translocation was measured by a biotinylation method (C). A: transfection was confirmed with PKCδ and HA antibodies. B: representative blot of Rab4-GTP and total Rab4 (top) and densitometric analysis (bottom). Rab4 activity (means ± SE, n = 3) was expressed as a ratio of Rab4-GTP to total Rab4. Data were analyzed by paired t-test. C: representative immunoblot of PM NTCP and E-cadherin (top) and densitometric analysis (bottom). Relative values of NTCP in the PM are expressed as means ± SE (n = 3). Data were analyzed by 1-way ANOVA. *Significantly different (P < 0.05) from respective control values in the absence of cAMP in cells transfected with EV.