Fig. 7. FRK-1 mislocalizes to the nucleus in mutants defective in cell adhesion components. In wild-type embryos, FRK-1 localizes to the plasma membrane of all cells immediately before enclosure (A), and remains nuclear-excluded throughout elongation (e.g. 1.5-fold embryo; B). In a mutant lacking the HMP-2 ß-catenin, FRK-1 becomes mislocalized to the nucleus, as is particularly evident in the seam cells (D). FRK-1 is similarly mislocalized to nuclei in a mutant lacking the PAT-3 ß-integrin (F), albeit to a less pronounced extent. In both cases, FRK-1 is localized to the plasma membrane before enclosure (C,E), demonstrating that the shift in localization takes place after enclosure is completed. Arrowheads indicate seam cells (B) or seam cell nuclei (D,F). Co-immunoprecipitation demonstrates that HMP-2 and FRK-1 physically interact in vitro (G). The Western analysis shows a single band at 45 kD when probed with the anti-FRK-1 antibody and a band at approximately 75 kD (HMP-2) when probed with anti-FLAG.