p14–MP1-carrying late endosomes target FAs. (A) IF of p14–MP1-carrying endosomes colocalizing with FAs in cells coexpressing GFP-MP1 (green) and mCherry-Paxillin (red; see white arrowheads). (B) NIH3T3 cell coexpressing GFP-MP1 (green) and mCherry-Paxillin (red). White arrows: FAs repetitively targeted by p14–MP1-carrying endosomes. See Video 4. (C) TIRF microscopy. Overlay of MP1-GFP Z-projection (green) and FAs (mCherry-Paxillin is shown in red). White arrowheads on selected time-lapse images point to individual MP1 endosomes (green) that target FAs (red). See Video 5. (D) Colocalization of MP1 with Rab7 and Transferrin. Top: images from time-lapse series of HeLa cell coexpressing GFP-MP1 (green) and mCherry-Rab7 (red). GFP-MP1 colocalizes with mCherry-Rab7 in cell center and cell periphery. Deconvolved image from the time-lapse shows colocalization of MP1 (green) and Rab7 (red) on ring-like structures of endosomes. Bottom: uptake of Transferrin (red) in HeLa cell expressing GFP-MP1 (green). (E) Quantification of the colocalization (mean ± SEM) between Rab7 and MP1 versus Transferrin and MP1. Insets in A and D are taken from white boxes in main panels.