Akutsu Noriyuki, Iijima Kenta, Hinata Takeo, Tauchi Hiroshi
Department of Environmental Sciences, Faculty of Science, Ibaraki University, Bunkyo 2-1-1, Mito, Ibaraki 310-8512, Japan.
Biochem Biophys Res Commun. 2007 Feb 9;353(2):394-8. doi: 10.1016/j.bbrc.2006.12.030. Epub 2006 Dec 13.
The Nbs1 gene is known to code for a protein involved in the hereditary cancer-prone disease, Nijmegen breakage syndrome. This gene is conserved in animals and fungi, but no plant homolog is known. The work reported here describes a homolog of Nbs1 isolated from higher plants. The Nbs1 proteins from both Arabidopsis thaliana and Oryza sativa are smaller in size than animal or yeast Nbs1, but both contain the conserved Nbs1 domains such as the FHA/BRCT domain, the Mre11-binding domain, and the Atm-interacting domain in orientations similar to what is seen in animal Nbs1. The OsNbs1 protein interacted not only with plant Mre11, but also with animal Mre11. In plants, OsNbs1 mRNA expression was found to be higher in the shoot apex and young flower, and AtNbs1 expression increased when plants were exposed to 100 Gy of X-rays. These results suggest that plant Nbs1 could participate in a Rad50/Mre11/Nbs1 complex, and could be essential for the regulation of DNA recombination and DNA damage responses.
已知Nbs1基因编码一种与遗传性易患癌疾病尼曼-匹克氏症候群相关的蛋白质。该基因在动物和真菌中保守，但尚无已知的植物同源物。本文报道的研究描述了从高等植物中分离出的Nbs1同源物。拟南芥和水稻的Nbs1蛋白在大小上比动物或酵母的Nbs1小，但两者都含有保守的Nbs1结构域，如FHA/BRCT结构域、Mre11结合结构域和与Atm相互作用的结构域，其方向与动物Nbs1中的相似。OsNbs1蛋白不仅与植物Mre11相互作用，还与动物Mre11相互作用。在植物中，发现OsNbs1 mRNA在茎尖和幼花中表达较高，当植物暴露于100 Gy的X射线时，AtNbs1表达增加。这些结果表明，植物Nbs1可能参与Rad50/Mre11/Nbs1复合体，并且可能对DNA重组和DNA损伤反应的调节至关重要。
