Absence of DNA ligase IV protein in XR-1 cells: evidence for stabilization by XRCC4
Absence of DNA ligase IV protein in XR-1 cells: evidence for stabilization by XRCC4
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DOI：
10.1016/s0921-8777(98)00063-9
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发表时间：
1999-01-26
期刊：
影响因子：
--
通讯作者：
Stamato, TD
中科院分区：
文献类型：
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作者：
Bryans, M;Valenzano, MC;Stamato, TD
XR-1是一种双链断裂修复和V(D)J重组缺陷的CHO突变细胞系。这些缺陷是由于编码38kda核磷酸化蛋白的XRCC4基因的缺失。最近的研究表明，XRCC4在体外与DNA连接酶IV相互作用并增强其活性。在本研究中，我们研究了XRCC4缺失对XR-1细胞中DNA连接酶IV水平的影响。Western blot分析表明，在这些细胞中几乎检测不到DNA连接酶IV蛋白的水平，然而，将XRCC4 cDNA引入XR-1导致该蛋白恢复到野生型水平。此外，DNA连接酶TV mRNA的分析显示，XR-1和XRCC4转染的XR-1中的DNA连接酶TV mRNA水平相当，这表明DNA连接酶IV水平的改变不是由于基因表达的变化。这些数据有力地表明，XRCC4的一个重要功能是稳定DNA连接酶IV蛋白。(C) 1999 Elsevier Science B.V.版权所有
XR-1 is a CHO mutant cell line defective in double strand break repair and V(D)J recombination. These defects are due to a deletion of the XRCC4 gene which encodes a 38-kDa nuclear phosphoprotein. Recent studies have shown that XRCC4 interacts with and enhances the activity of DNA ligase IV in vitro. In this study we investigate the effect of the absence of XRCC4 on the level of DNA ligase IV in XR-1 cells. Western blot analysis indicates that levels of DNA ligase IV protein are almost undetectable in these cells, however, introduction of the XRCC4 cDNA into XR-1 resulted in a return to wild type levels of the protein. Furthermore, analysis of DNA Ligase TV mRNA showed equivalent levels in both XR-1 and XRCC4 transfected XR-1 indicating that the altered level of DNA ligase IV is not due to a change in the expression of the gene. These data strongly suggest that an important function of XRCC4 is to stabilize the DNA ligase IV protein. (C) 1999 Elsevier Science B.V. All rights reserved.