Figure 4 - full size

Figure 4.
Par-3 enriches PTEN at the junctional membranes via its PDZ3 domain. A, overexpressed Par-3 was specifically enriched at the junctional membrane in polarized epithelial cells, and PTEN was partially colocalized with Par-3 (white arrows). In this experiment, MDCK II cells were transiently co-transfected with GFP-Par-3 and Myc-PTEN. B, C-terminal tail deletion mutant of PTEN failed to colocalize with Par-3 at the junctional membrane regions (arrowhead). C, the DED3A mutant of PTEN also failed to colocalize with Par-3 at the membrane junctions (arrowhead). Instead, the PTEN mutant is diffused in the cytoplasm. D, PDZ2 lipid binding-deficient mutant of Par-3 (K3E) is diffused in cytoplasm (25). Co-expressed PTEN is also absent at the junctional membranes. E, the oligomerization-deficient mutant of Par-3 (ΔNTD) (21) is diffused in MDCK cells. Co-expressed PTEN is also missing from the junctional membranes. Note that the Par-3 mutants in D and E retain the PTEN binding capacities. Scale bar, 10 μm. WT, wild type.