Open AccessNuclear and cytoplasmic localizations of the adenomatous polyposis coli protein
Author(s) -
Kristi L. Neufeld,
R. White
Publication year - 1997
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.94.7.3034
Subject(s) - adenomatous polyposis coli , cytoplasm , nucleolus , biology , nuclear protein , microbiology and biotechnology , cell fractionation , cell nucleus , colocalization , immunofluorescence , immunoelectron microscopy , gene , biochemistry , colorectal cancer , cancer , genetics , immunohistochemistry , immunology , membrane , transcription factor , antibody
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.