IDENTIFICATION OF A NOVEL HUMAN HOMOLOG OF THE DROSOPHILA DLG, P-DLG,SPECIFICALLY EXPRESSED IN THE GLAND TISSUES AND INTERACTING WITH P55

We have identified a novel human homolog of the Drosophila dlg tumor s uppressor gene, termed P-dlg, which has been mapped at chromosome 10q2 3, Unlike other human dlg homologs, P-dlg is expressed in placenta and various gland tissues but not in brain, The P-dlg protein is localize d at the plasma membrane and cytoplasm, and it is expressed in the gla nd epithelial cells in normal prostate tissue but not in prostate canc er cell lines, Furthermore, we identified interaction between P-dlg an d p55 palmitoylated membrane protein by yeast two-hybrid screening. Th ese findings suggest that P-dlg forms a complex with p55 at the plasma membrane and plays roles in maintaining the structure of epithelial c ells and transmitting extracellular signals to the membrane and cytosk eleton, which may negatively regulate cell proliferation. (C) 1998 Fed eration of European Biochemical Societies.