Overexpression of CD2AP alters the intracellular localization of APP.
a, effect of CD2AP on the intracellular distribution of APP. Myc-APP was transfected into HEK293 cells in the absence (left, −) or presence (right, +) of CD2AP and was observed after staining with anti-Myc antibody. A higher magnification view of the white box is shown on the right. The nucleus (N) is indicated by dotted lines. Bars represent 20 and 5 μm for low and high magnification, respectively. b, effect of CD2AP overexpression on the endosomal localization of APP. Myc-APP was cotransfected into HEK293 cells with EGFP-Rab4, -Rab5, -Rab7, -Rab8 or -Rab11, markers for fast recycling endosomes, early endosomes, late endosomes, Golgi-derived secretory vesicles, or recycling endosomes, in the absence (left, −) or presence (right, +) of CD2AP. Rabs were visualized by EGFP fluorescence and APP was immunostained with anti-Myc antibody. APP is shown in the 1st column, Rabs in the 2nd column, and merge in the 3rd column. The right panels are a higher magnification view of the white box in the merges. Bar for the left three panels, 20 μm; right panels, 5 μm. c, percentage of APP colocalized with each Rab. Data are expressed as the mean ± S.E. (n = 10 for each Rab). d, relative level of APP colocalization with each Rab in the presence (+) and absence (−) of CD2AP (mean ± S.E. n = 10 for Rab4, Rab5, Rab8, and Rab11, and n = 20 for Rab7. ns, not significant. *, p < 0.05, Student's t test).