Movie S1.

Live imaging of early endosome budding in primary porcine RPE cultures by spinning disk microscopy. Cells expressing RFP-Rab5 (red; CellLightTM BacMam 2.0 Early Endosome-RFP, ThermoFisher, Waltham, MA) were labeled with CellMask Deep Red to delineate the plasma membrane (pseudo-colored green) and the formation of Rab5-positive early endosomes was monitored for 5 min.