The tumor suppressor protein APC colocalizes with beta-catenin in the colon epithelial cells.
The APC gene is mutated in familial adenomatous polyposis and sporadic colorectal tumors. The product of this gene is a 300 kDa cytoplasmic protein associated with catenin. In the present study, we examined the subcellular localization of the APC protein and beta-catenin in the mouse colon by double-labeling immunocytochemistry. While the APC protein was localized in the lateral and apical cytoplasm and in microvilli of the epithelial cells, beta-catenin was present exclusively in the lateral cytoplasm. Double-labeling-immunoelectron microscopy demonstrated precise colocalization of the APC protein and beta-catenin along the lateral plasma membrane. These results suggest that the APC protein functions in cooperation with beta-catenin in the lateral cytoplasm but has other functions independent of beta-catenin in the apical cytoplasm and in microvilli.
Senda
T
T
Department of Anatomy I, Nagoya University School of Medicine, Japan.
Miyashiro
I
I
Matsumine
A
A
Baeg
G H
GH
Monden
T
T
Kobayashil
S
S
Monden
M
M
Toyoshima
K
K
Akiyama
T
T
D025601:Adenomatous Polyposis Coli Protein / Q000032:analysis*; D000818:Animals; D015820:Cadherins / Q000032:analysis; D003106:Colon / Q000166:cytology*; D003593:Cytoplasm / Q000648:ultrastructure; D003598:Cytoskeletal Proteins / Q000032:analysis*; D004847:Epithelial Cells; D004848:Epithelium / Q000648:ultrastructure; D017491:Genes, APC; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000166:cytology* / Q000648:ultrastructure; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D016253:Microscopy, Immunoelectron; D008871:Microvilli / Q000648:ultrastructure; D015534:Trans-Activators; D051176:beta Catenin
D025601:Adenomatous Polyposis Coli Protein; C495267:CTNNB1 protein, mouse; D015820:Cadherins; D003598:Cytoskeletal Proteins; D015534:Trans-Activators; C000613192:adenomatous polyposis coli protein, mouse; D051176:beta Catenin