title: The truncation of Ku86 in human lymphocytes.
abstract: The Ku heterodimer, which consists of Ku70 and Ku86 subunits, is a major sensor of DNA breaks. A truncated form of Ku86 lacking its C-terminus, termed Ku86 variant, has been detected in extracts from different human cells. Here we report that in human lymphocytes the Ku86 variant is not present in vivo but is generated in vitro upon cell lysis by a trypsin-like protease. The resulting Ku86 variant exists exclusively in complexes with Ku70, which possess strong affinity to DNA double strand termini. In different blood donors the levels of Ku86 variant correlated with the magnitude of radiation induced DNA breaks.
authors.affiliation: Department of Experimental and Clinical Radiobiology, Center of Oncology, Wybrzeze AK 15, Gliwice 44-100, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Łanuszewska
authors.forename: Piotr
authors.initials: P
authors.lastname: Widłak
mesh_terms: D000328:Adult; D034961:Antigens, Nuclear / Q000097:blood* / Q000737:chemistry / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D004249:DNA Damage; D004265:DNA Helicases; D004268:DNA-Binding Proteins / Q000097:blood* / Q000737:chemistry / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D006801:Humans; D000072200:Ku Autoantigen; D008214:Lymphocytes / Q000737:chemistry*
chemical_list: D034961:Antigens, Nuclear; D004268:DNA-Binding Proteins; D004247:DNA; D004265:DNA Helicases; C106893:XRCC5 protein, human; C000606509:Xrcc6 protein, human; D000072200:Ku Autoantigen