Łanuszewska Joanna, Widłak Piotr
Department of Experimental and Clinical Radiobiology, Center of Oncology, Wybrzeze AK 15, Gliwice 44-100, Poland.
Cancer Lett. 2004 Mar 18;205(2):197-205. doi: 10.1016/j.canlet.2003.10.016.
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.
由Ku70和Ku86亚基组成的Ku异二聚体是DNA断裂的主要感受器。在来自不同人类细胞的提取物中检测到一种缺少C末端的Ku86截短形式，称为Ku86变体。我们在此报告，在人类淋巴细胞中，Ku86变体在体内并不存在，而是在细胞裂解时由一种类胰蛋白酶在体外产生。产生的Ku86变体仅以与Ku70形成的复合物形式存在，Ku70对DNA双链末端具有很强的亲和力。在不同的献血者中，Ku86变体的水平与辐射诱导的DNA断裂程度相关。
