Association of plakoglobin with APC, a tumor suppressor gene product, and its regulation by tyrosine phosphorylation.
Plakoglobin is a cytoplasmic protein localized in both adherens junctions and desmosomes. Little is known about its function, but it may play a role in maintaining cell junction integrity. A partly homologous protein, beta catenin, is localized mainly in adherens junctions and plays a key role in cell adhesion by associating with cadherins, a family of Ca2+ dependent cell-to-cell adhesion molecules. Recently the product of APC, a tumor suppressor gene, was found to associate with beta catenin. In this study we demonstrated that plakoglobin also associates with APC and that tyrosine phosphorylated plakoglobin associates with cadherins but not with APC. These results suggest that plakoglobin could play a role in mediating the signals of APC by mutual interaction and that this may be regulated by tyrosine phosphorylation.
Shibata
T
T
Pathology Division, National Cancer Center Research Institute, Tokyo, Japan.
Gotoh
M
M
Ochiai
A
A
Hirohashi
S
S
D000230:Adenocarcinoma; D025601:Adenomatous Polyposis Coli Protein; D002294:Carcinoma, Squamous Cell; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002460:Cell Line; D002846:Chromatography, Affinity; D003598:Cytoskeletal Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D051180:Desmoplakins; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D017491:Genes, APC; D006801:Humans; D015151:Immunoblotting; D011485:Protein Binding; D013274:Stomach Neoplasms; D014407:Tumor Cells, Cultured; D014846:Vulvar Neoplasms; D051185:gamma Catenin
D025601:Adenomatous Polyposis Coli Protein; D015815:Cell Adhesion Molecules; D003598:Cytoskeletal Proteins; D051180:Desmoplakins; D051185:gamma Catenin