FIGURE 8:

PI4KIIα targeting to neuronal processes is impaired in BLOC-1–deficient neurons. Primary cultured forebrain neurons from control (Dtnbp1^+/+) (A, B) or dysbindin-BLOC-1–deficient sandy mice (Dtnbp1^sdy/sdy (C, D) either not transfected (E) or transfected with EGFP-PI4KIIα (A, C) or EGFP-PI4KIIαL60-61A (B, D) were cultured for 7DIV. Cells were stained for VAMP2 (red) and PI4KIIα for untransfected cells or VAMP2 and EGFP (green) for transfected cells. Fixed cells were imaged by confocal fluorescence microscopy. Fluorescent pixels present in cell body and processes were quantified for VAMP2 (E1, F1, G1), endogenous PI4KIIα (E), and transfected PI4KIIα (F, G) cells. Closed circles depict PI4KIIα or EGFP fluorescent pixels from wild-type neurons, whereas open circles depict pixels from dysbindin-BLOC-1–null sandy neurons. Closed triangles depict VAMP2 fluorescent pixels from wild-type neurons, whereas open triangles depict pixels from dysbindin-BLOC-1–null sandy neurons. Each point represents an individual neuron. Twenty neurons per condition were obtained from three independent experiments. Scale bars, 50 μm.