title: Nuclear and cytoplasmic localizations of the adenomatous polyposis coli protein.
abstract: Mutation of the adenomatous polyposis coli (APC) gene is an early step in the initiation of colon cancer. Because the distribution pattern of a protein within the cell can provide important clues as to function, we have used a combination of immunofluorescence microscopy and biochemical fractionation to determine the location of APC protein in epithelial cells. Immunofluorescence microscopy placed full-length APC protein in both the nucleus and the cytoplasm. The nuclear APC protein was concentrated in discrete subnuclear regions, including nucleoli, whereas the cytoplasmic APC protein concentrated at the leading edge of migrating cells. Colocalization of APC protein with rRNA confirmed a nucleolar localization. These immunocytochemical findings have been supported by cell fractionation, which demonstrated that full-length APC protein was located in both the membrane/cytoskeletal and the nuclear fractions.
authors.affiliation: Huntsman Cancer Institute, University of Utah, Salt Lake City 84112, USA.
authors.forename: K L
authors.initials: KL
authors.lastname: Neufeld
authors.forename: R L
authors.initials: RL
authors.lastname: White
mesh_terms: D025601:Adenomatous Polyposis Coli Protein; D001692:Biological Transport; D002461:Cell Line, Transformed; D002467:Cell Nucleus / Q000378:metabolism*; D003110:Colonic Neoplasms / Q000378:metabolism / Q000473:pathology; D003593:Cytoplasm / Q000378:metabolism*; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D004848:Epithelium / Q000378:metabolism; D017491:Genes, APC; D008856:Microscopy, Fluorescence; D014407:Tumor Cells, Cultured
chemical_list: D025601:Adenomatous Polyposis Coli Protein; D003598:Cytoskeletal Proteins