Deletion of <i>flotillin 1</i> causes a small reduction in APP endocytosis in mouse embryonic fibroblasts.

<p>All cells are primary MEFs <b>A</b>. Cells expressing GFP-APPswe were labelled on ice, or at 37°C with Alexa555 conjugated anti-GFP antibodies and subsequently analysed by flow cytometry. The right hand panel overlays signals from 4°C and 37°C. The difference between the signals is due to endocytosis of the antibody at 37°C. <b>B</b>. Colocalisation of GFP-APPswe with internalised anti-GFP(Alexa555) antibodies following 30 minute incubation at 37°C <b>C</b>. Primary MEFs from <i>flotillin 1-/-</i> mice or congenic controls, expressing GFP-APPswe, were labelled for 30 min at 37°C with Alexa555 anti-GFP antibodies as in A. In order account for variable expression levels, APP uptake was calculated as the ratio of median Alexa555 fluorescence (anti-GFP) over median GFP fluorescence, after gating for GFP-positive cells as shown by the black line overlaid in A. This ratio was normalised so that the mean of the control values equalled 1, to allow comparison of different experiments. Data from 5 separate flow cytometry experiments are shown. Bars are SEM.