Fig. 2

Mt3 deletion disrupts clathrin-dependent CtxB endocytosis in astrocytes. a-c Confocal fluorescence micrographs of WT (Mt3 ^+/+) and Mt3 ^−/− astrocytes treated with 20 nM FITC-CtxB for 30 min at 37 °C and of Mt3 ^−/− astrocytes treated with 20 nM FITC-CtxB for 30 min at 37 °C in the presence of 10 μg/ml of the N-terminal Mt3 peptide (C). Fixed cells were immunostained for the Golgi marker GM130 (red) or with GFAP (purple) to stain the astrocytes. In contrast to WT cells, Mt3 ^−/− cells showed disruption of the Golgi localization of CtxB (green), which exhibited a dispersed distribution 30 min after uptake, but this effect was partially reversed by the Mt3 peptide treatment (10 μg/ml). Scale bar, 20 μm