Fig. 7
Freeze-fracture morphology of mCldn15 S67 and E157 mutants. a Cartoon representations of the Cis-1 interface in mCldn15 WT and mutants: S67A, E157A, E157S, and S67E/E157S. Residues at positions 67, 79, and 157 are color-coded green for serine, blue for arginine, red for glutamic acid, and gray for alanine. Freeze-fracture TEM of HEK293T expressing mCldn15 WT, S67A, E157A, E157S, and S67E/E157S showing the strand morphology. The P-face partitioning is distinctly altered in the S67A, E157A, and E157S. Size bar = 200 nm. b Quantification of P-face intramembrane strand persistence length (n = 50 segments) and number of strand interruptions per µm c (n = 10 strands) in WT mCldn15, S67A, E157A, E157S, and S67E/E157S shown as box plots: whiskers = 5th–95th percentile;+ = mean value; dots = outlier points, **** = p < 0.0001, ns = not significant
