Fig. 2

p.L13_L15del variant does not affect E-cadherin trafficking or degradation. a CDH1 and 18S mRNA levels were analyzed by real-time PCR in CHO cells transfected with vectors encoding the E-cadherin mutant L13_L15del, the wild-type protein, and the empty vector (Mock condition). 18S was used as endogenous control. b Total levels of E-cadherin were analyzed in Mock, wild-type and L13_L15del mutant cells upon treatment with 2% DMSO and 10 μM MG132. α-Tubulin was used as a loading control. c Band intensity average + SE is presented. d Flow cytometry was used to assess surface E-cadherin in cells untreated and treated with DMSO or with the proteasome inhibitor MG132. e Graph representing the percentage of cells positive for E-cadherin. f For each sample, median fluorescence intensity + SE was determined and normalized for untreated wild-type cells. * represents p ≤ 0.05, ** p ≤ 0.01, *** p ≤ 0.001 and **** p ≤ 0.0001. g Scheme illustrating the interaction of a chemical chaperone with a newly synthesized polypeptide at the lumen of the endoplasmic reticulum. The chemical chaperone assists the folding of the protein and evades its quality control and degradation. At the cytoplasm, MG132 blocks the proteolytic activity of the 26S proteasome complex, resulting in accumulation of immature and unfolded proteins