Fig. 3.

The chemical chaperone 4-PBA restores membrane localization and rescues cholesterol efflux function of ABCA1 mutants. Transfected HEK293 cells were treated with 10 mM 4-PBA for 24 h. A: Confocal microscopy of cells expressing ABCA1-GFP (green) counterstained with AlexaFluor594 WGA membrane stain (red); regions of yellow indicate colocalization of ABCA1-GFP with membrane. Scale bars represent 10 μm and arrows indicate areas of substantial intracellular GFP signal. B: Cholesterol efflux from ABCA1-GFP transfected cells to 10 μg/ml apoA-I. C: Western blot and (D) quantification of foldchange in ABCA1-GFP protein level with 4-PBA treatment. Data represent mean + SEM of two experiments performed in quadruplicate for efflux and duplicate for Western blot protein quantification. *p < 0.05, **p < 0.01, ***p < 0.001 compared with untreated wild-type value (symbols directly above error bars) and for treated versus untreated values of the same genotype (symbols above lines). For (D), the comparison was to all other values, as assessed by ANOVA.