Fig. 6.

Live-cell imaging of GFP-NaPiIIa and mRFP-Shank2-containing endosomes. A: live-cell confocal imaging of GFP-NaPiIIa (green) and mRFP-Shank2 (red) in OK cells shows that in low-Pi media both proteins are concentrated within the apical domain with very little of either protein in the subapical domain. Upon shifting cells into high-Pi media, both proteins migrate into the subapical domain. High-Pi images were taken after 60 min in high-Pi media. Merged images of both channels show a high degree of colocalization of both proteins within the apical and subapical domains. Bar = 5 μm. B: merged images of GFP-NaPiIIa (green) and mRFP-Shank2E (red) captured at sequential 20-s time intervals. Arrowheads highlight the sequential migration of a dual-labeled endosome after 0, 20, and 40 s. Bar = 5 μm.