Fig. 4. Overexpression of SKD1(E235Q) specifically changes the distribution of endogenous SBP1. (A) HeLa cells transfected with GFP-SKD1(E235Q) were subjected to immunofluorescence analysis using anti-SBP1 antibody. GFP and Cy3 fluorescence signals obtained from GFP-SKD1(E235Q) and Cy3-conjugated secondary antibody were labeled with green and red pseudo color, respectively. The transfected cells are indicated by asterisks in the red color image. Notice, the transfected cells showed a redistribution of SBP1 to the aberrant membranous structures, E235Q compartments, while the non-transfected cells showed a cytoplasmic distribution of SBP1. (B) HeLa cells transfected with GFP-SKD1 were subjected to immunofluorescence analysis as described in A. (C) HeLa cells transfected with GFP-rab5bQL were subjected to immunofluorescence analyses with anti-SBP1. Upper panel, fluorescence micrographs of GFP-rab5bQL, indicating the enlarged endosomes. Lower panel, Cy3 fluorescence micrograph of SBP1, showing the cytoplasmic localization. Bars: 20 µm.