Rabip4’ and AP-3 cooperate in lysosome positioning.
HEK293T cells were depleted of rabip4s or AP-3 and then labeled for immunofluorescence with mouse antibodies against CD63 and TfR (green) or with rabbit antisera specific for cathepsin D and Ti-VAMP (red) (A). HEK293T cells were processed as above and co-labeled with anti-cathepsin D (red) and anti-tubulin (green) antibodies or with anti-cathepsin D antibody (red) and Alexa-488-conjugated phalloidin for actin staining. Nuclei were stained with DAPI. (B). Images represent projections of confocal Z-stacks. Scale bar, 10 µm. Depletion of rabip4s and AP-3 selectively redistributed the lysosomal markers CD63, Cathepsin D, and Ti-VAMP to cellular protrusions (arrows).