Fig. 4.

E-cadherin expression level affects monomer dynamics. (A,B) Estimation of junctional integrity and cell adhesion strength using TEER (A) and Dispase (B) assays. N=3 for each; error bars represent s.e.m. (C) Schematic diagram of different types of cell junctions assayed by FRAP, showing junctions between Ecad-GFP Hi cells (Hi), between Ecad-GFP Lo cells (Lo), between Ecad-GFP Hi cells and the parental cell line (P) expressing endogenous E-cadherin, and between Ecad-GFP Hi cells and L cells (Ø) expressing no E-cadherin. (D) F_i of Ecad-GFP is the same in Ecad-GFP Hi and Ecad-GFP Lo cells (blue and green circles respectively), however T_1/2 is shorter for Ecad-GFP Lo cells. The level of Ecad-GFP expression in the neighboring cell of a junction also affects E-cadherin dynamics. When FRAP is measured between cells expressing high levels of Ecad-GFP and no Ecad-GFP (black circles) both T_1/2 and F_i are significantly reduced. F_i and T_1/2 are further decreased in the absence of trans-dimer formation (red circle). Value for Ecad-GFP is included from Fig. 2C for comparison; see supplementary material Table S2 for list of all FRAP values. Error bars represent s.e.m.