Expression of αE-catenin-EPLIN fusion prohibits pAJ formation. (A) Immunoprecipitation assays to detect coprecipitation of E-cadherin and αE(1–508) or αE(1–508)EPLIN. Lysates were collected from DLD1cells transfected with these constructs. E-cadherin immunoprecipitates contain not only endogenous αE-catenin but also these artificial proteins. Molecular masses are given in kilodaltons. Ecad, E-cadherin; αE, endogenous αE-catenin. The arrows indicate the αE(1–508)EPLIN band. (B) A representative colony of αE(1–508)EPLIN-transfected DLD1 cells. This colony does not have pAJs, as marked with asterisks. Arrowheads point to an lAJ. (C and D) Time-lapse images of E-cadherin–mKOR and αE(1–508)EPLIN-EGFP doubly transfected into DLD1 cells. A starting image is shown in C (boxed region). E-cadherin colocalizes with the fusion protein on ZA rings, but not at pAJs. pAJs were initially detected, but then gradually lost, because of their flow into the ZA ring. Time points are given in hours, minutes, and seconds. See also Video 10. Bars, 10 µm.