Advertisement
Research Article Free access | 10.1172/JCI118562
Department of Medicine, Medical College of Georgia School of Medicine, Augusta, 30912-3100, USA.
Find articles by Suwa, A. in: JCI | PubMed | Google Scholar
Department of Medicine, Medical College of Georgia School of Medicine, Augusta, 30912-3100, USA.
Find articles by Hirakata, M. in: JCI | PubMed | Google Scholar
Department of Medicine, Medical College of Georgia School of Medicine, Augusta, 30912-3100, USA.
Find articles by Takeda, Y. in: JCI | PubMed | Google Scholar
Department of Medicine, Medical College of Georgia School of Medicine, Augusta, 30912-3100, USA.
Find articles by Okano, Y. in: JCI | PubMed | Google Scholar
Department of Medicine, Medical College of Georgia School of Medicine, Augusta, 30912-3100, USA.
Find articles by Mimori, T. in: JCI | PubMed | Google Scholar
Department of Medicine, Medical College of Georgia School of Medicine, Augusta, 30912-3100, USA.
Find articles by Inada, S. in: JCI | PubMed | Google Scholar
Department of Medicine, Medical College of Georgia School of Medicine, Augusta, 30912-3100, USA.
Find articles by Watanabe, F. in: JCI | PubMed | Google Scholar
Department of Medicine, Medical College of Georgia School of Medicine, Augusta, 30912-3100, USA.
Find articles by Teraoka, H. in: JCI | PubMed | Google Scholar
Department of Medicine, Medical College of Georgia School of Medicine, Augusta, 30912-3100, USA.
Find articles by Dynan, W. in: JCI | PubMed | Google Scholar
Department of Medicine, Medical College of Georgia School of Medicine, Augusta, 30912-3100, USA.
Find articles by Hardin, J. in: JCI | PubMed | Google Scholar
Published March 15, 1996 - More info
DNA-dependent protein kinase (DNA-PK) is an important nuclear enzyme which consists of a catalytic subunit known as DNA-PKcs and a regulatory component identified as the Ku autoantigen. In the present study, we surveyed 312 patients in a search for this specificity. 10 sera immunoprecipitated a large polypeptide which exactly comigrated with DNA-PKcs in SDS-PAGE. Immunoblot analysis demonstrated that this polypeptide was recognizable by a rabbit antiserum specific for DNA-PKcs. Although the patient sera did not bind to biochemically purified DNA-PKcs in immunoblots or ELISA, they were able to deplete DNA-PK catalytic activity from extracts of HeLa cells in a dose-dependent manner. We conclude that these antibodies should be useful probes for studies which aim to define the role of DNA-PK in cells. Since six sera simultaneously contained antibodies to the Ku protein, these studies suggest that relatively intact forms of DNA-PK complex act as autoantigenic particles in selected patients.