Fig. 3. Native LN5-rich ECM induces E-cadherin targeting to the lateral membrane. Caco-2 cells were plated at 20,000 cells/cm² on glass or on native LN5-rich-ECM deposited by HT29-MTX cells, and RNA and proteins were prepared for further analysis. (A) RNase Protection Assay of apoA-IV and E-cadherin mRNA, using ß actin mRNA as a control. The ratio of apoA-IV or E-cadherin to ß actin mRNA on LN5-rich ECM was compared to that measured in Caco-2 cells grown on glass and expressed as a percentage. Note that ECM increases apoA-IV but not E-cadherin mRNA levels. (B) Western blot analysis of the total amount of E-cadherin and ß-catenin. Note that the total amount of either E-cadherin or ß-catenin proteins does not vary. (C) Western blot analysis of E-cadherin after immunoprecipipation of biotinylated membrane-associated proteins. Total E-cadherin (a,c) and biotinylated E-cadherin (b,d) amounts of E-cadherin in cells grown on plastic without ECM (a,b) or LN5-rich ECM (c,d). Note the increase in E-cadherin localized at the cell surface in cultures grown on ECM. The data are means ±s.e.m. of three independent cultures performed in triplicate. ^* differs from the control at P<0.05.