Immunoreactivity of the amino-terminal portion of the amyloid-beta precursor protein in the nucleolus.
The functioning and metabolic pathway of the amyloid β-precursor protein (APP) have not been fully elucidated. To fill this research gap, this study immunocytochemically investigated the intracellular localization of APP in the neuroblastoma cell line SK-N-SH and in normal primary cells. Using antibodies against the amino-terminal portion of the APP molecule, immunoreactivity was detected not only in the cytoplasm but also in the nucleus and nucleolus. Further analysis revealed the co-localization of amino acids 44-63 of the APP molecule with fibrillarin, a nucleolus marker. These findings indicate that a fraction of APP, including its amino-terminal portion, may be localized in the nucleus as well as in the nucleolus, suggesting an important role of APP in RNA metabolism and other intra-nucleolus functions.
Research and Development Administration Department, Toagosei Co., Ltd., 1-14-1, Nishisinbashi, Minato-ku, Tokyo 105-8419, Japan. masaji_okamoto@mail.toagosei.co.jp
Masaji
M
Okamoto
D016564:Amyloid beta-Protein Precursor / Q000378:metabolism*; D001921:Brain / Q000378:metabolism; D045744:Cell Line, Tumor; D002466:Cell Nucleolus / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D006801:Humans; D007668:Kidney / Q000378:metabolism; D008856:Microscopy, Fluorescence; D009447:Neuroblastoma; D009928:Organ Specificity; D061251:Primary Cell Culture
D016564:Amyloid beta-Protein Precursor; D002868:Chromosomal Proteins, Non-Histone; C047458:fibrillarin