Figure 2. FcRn transports IgG into the... | Rockefeller University Press

Figure 2.

$Figure 2. FcRn transports IgG into the common endosome. Compartments from 15–40 FcRn-EGFP polarized cells from 3D confocal images were analyzed for content of indicated markers as described in Fig. 1 and the Materials and methods section. Representative images are shown in panels a, c, and e. Panels b, d, and f show quantification of each analysis, with the number of objects studied indicated. Horizontal bars in the graphs indicate mean Mtarget protein. (a and b) Compartments masked for FcRn-EGFP or Tf-R show a fraction of endosomes containing both molecules. (c and d) Compartments masked for FcRn-EGFP show a fraction containing IgG internalized from both apical and basolateral membranes. Alexa Fluor 568–IgG and Alexa Fluor 647–IgG were applied to apical or basolateral membranes for 1 h, respectively. (e and f) Compartments masked for FcRn-EGFP show a fraction containing IgG internalized from the apical membrane and Tf internalized from the basolateral membrane. Alexa Fluor 568–IgG and Alexa Fluor 647–Tf were applied to apical or basolateral membranes for 1 h, respectively. In a, c, and e, the panels to the right show enlarged views of the boxed portions on the left. Circles highlight the same object in each panel. Bars, 10 µm.$

FcRn transports IgG into the common endosome. Compartments from 15–40 FcRn-EGFP polarized cells from 3D confocal images were analyzed for content of indicated markers as described in Fig. 1 and the Materials and methods section. Representative images are shown in panels a, c, and e. Panels b, d, and f show quantification of each analysis, with the number of objects studied indicated. Horizontal bars in the graphs indicate mean M_{target protein}. (a and b) Compartments masked for FcRn-EGFP or Tf-R show a fraction of endosomes containing both molecules. (c and d) Compartments masked for FcRn-EGFP show a fraction containing IgG internalized from both apical and basolateral membranes. Alexa Fluor 568–IgG and Alexa Fluor 647–IgG were applied to apical or basolateral membranes for 1 h, respectively. (e and f) Compartments masked for FcRn-EGFP show a fraction containing IgG internalized from the apical membrane and Tf internalized from the basolateral membrane. Alexa Fluor 568–IgG and Alexa Fluor 647–Tf were applied to apical or basolateral membranes for 1 h, respectively. In a, c, and e, the panels to the right show enlarged views of the boxed portions on the left. Circles highlight the same object in each panel. Bars, 10 µm.