Localization of Fanconi anemia C protein to the cytoplasm of mammalian cells.
Features of chromosomal aberrations, hypersensitivity to DNA crosslinking agents, and predisposition to malignancy have suggested a fundamental anomaly of DNA repair in Fanconi anemia. The function of the recently isolated FACC (Fanconi anemia group C complementing) gene for a subset of this disorder is not yet known. The notion that FACC plays a direct role in DNA repair would predict that the polypeptide should reside in the nucleus. In this study, a polyclonal antiserum raised against FACC was used to determine the subcellular location of the polypeptide. Immunofluorescence and subcellular fractionation studies of human cell lines as well as COS-7 cells transiently expressing human FACC showed that the protein was localized primarily to the cytoplasm under steady-state conditions, transit through the cell cycle, and exposure to crosslinking or cytotoxic agents. However, placement of a nuclear localization signal from the simian virus 40 large tumor antigen at the amino terminus of FACC directed the hybrid protein to the nuclei of transfected COS-7 cells. These observations suggest an indirect role for FACC in regulating DNA repair in this group of Fanconi anemia.
Youssoufian
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Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115.
D000818:Animals; D001483:Base Sequence; D018797:Cell Cycle Proteins; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D002522:Chlorocebus aethiops; D003593:Cytoplasm / Q000378:metabolism; D017931:DNA Primers; D004260:DNA Repair; D004268:DNA-Binding Proteins; D004591:Electrophoresis, Polyacrylamide Gel; D005199:Fanconi Anemia / Q000235:genetics* / Q000378:metabolism; D052218:Fanconi Anemia Complementation Group C Protein; D051856:Fanconi Anemia Complementation Group Proteins; D006801:Humans; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D016133:Polymerase Chain Reaction; D014176:Protein Biosynthesis; D011506:Proteins / Q000032:analysis / Q000235:genetics; D014162:Transfection; D014407:Tumor Cells, Cultured
D018797:Cell Cycle Proteins; D017931:DNA Primers; D004268:DNA-Binding Proteins; C497651:FANCC protein, human; D052218:Fanconi Anemia Complementation Group C Protein; D051856:Fanconi Anemia Complementation Group Proteins; D009687:Nuclear Proteins; D011506:Proteins