Localization of Sac2 on endosomes. (A and B) GFP- or mCherry (mCh)-Sac2 is present on Rab5-positive endosomes, as shown by colocalization with endogenous Rab5 immunoreactivity (A) or with GFP-Rab5 (B). (C and D) GFP-Sac2 also colocalizes with the majority of APPL1 (RFP-APPL1)-positive endosomes (C), but does not colocalize with a lysosomal marker protein, RFP-LAMP1 (D). In A, B, and C, examples of colocalizations are indicated by arrows. Images were taken by spinning-disc confocal microscopy. Bars, 5 µm.