Increased telomere length and hypersensitivity to DNA damaging agents in an Arabidopsis KU70 mutant
Increased telomere length and hypersensitivity to DNA damaging agents in an Arabidopsis KU70 mutant
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DOI：
10.1093/nar/gkf445
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发表时间：
2002-08-01
影响因子：
14.9
通讯作者：
Hooykaas, P
中科院分区：
文献类型：
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作者：
Bundock, P;van Attikum, H;Hooykaas, P
我们已经从拟南芥中鉴定出一个假定的KU70基因同源物（AtKU70）。为了研究其在植物中的功能，我们分离了一个含有插入AtKU70的T-DNA的拟南芥系。这种插入的纯合子植株看起来正常并且是可育的。在其他生物体中，KU70基因已被证明在电离辐射（IR）和模拟辐射的化学物质（如甲基甲烷磺酸盐（MMS））引起的DNA损伤的修复中发挥作用。我们发现AtKU70（-/-）植物对IR和MMS敏感，因此AtKU70基因在植物和其他生物的DNA修复中起着类似的作用。KU70基因也在维持端粒长度方面发挥作用。缺乏Ku70的酵母和哺乳动物细胞端粒缩短。当我们研究AtKU70（-/-）植物的端粒时，我们意外地发现它们比野生型植物的端粒（2-4 kb）长得多（大约30 kb）。我们提出了几种假说来解释AtKU70（-/-）植物端粒的延长。
We have identified a putative homologue of the KU70 gene (AtKU70) from Arabidopsis thaliana. In order to study its function in plants we have isolated an A.thaliana line that contains a T-DNA inserted into AtKU70. Plants homozygous for this insertion appear normal and are fertile. In other organisms the KU70 gene has been shown to play a role in the repair of DNA damage induced by ionising radiation (IR) and by radiomimetic chemicals such as methylmethane sulfonate (MMS). We show that AtKU70(-/-) plants are hypersensitive to IR and MMS, and thus the AtKU70 gene plays a similar role in DNA repair in plants as in other organisms. The KU70 gene also plays a role in maintaining telomere length. Yeast and mammalian cells deficient for Ku70 have shortened telomeres. When we studied the telomeres in the AtKU70(-/-) plants we found unexpectedly that they were significantly longer (>30 kb) than was found in wild-type plants (2-4 kb). We propose several hypotheses to explain this telomere lengthening in the AtKU70(-/-) plants.