Figure 3.

Identification of colocalized α3β1, E-cadherin, and TGF-βR1 on cell surfaces of α3 wt and H245A mutant cells. Cells serum starved overnight were exposed to 300 µM MDC to inhibit clathrin-mediated endocytosis for 30 min and TGF-β1 for 4 h. E-cadherin and α3β1 were clustered with fluorescent secondary antibodies on live cells, and the cells were fixed and stained for TGF-βR1 (TRI). Representative confocal images with individual color and the merged images of α3 wt and H245A mutant cells are shown. Quantitative analysis of E-cadherin–α3β1–TGF-βR1 coclusters comparing multiple fields on each of six separate clusters for each cell type indicated significantly (P < 0.001) more colocalization on α3 wt cells (see Identification of a tripartite complex…. for details). This experiment has been performed three times with similar results. Bar, 2 µm.