Koga Asami, Ishibashi Toyotaka, Kimura Seisuke, Uchiyama Yukinobu, Sakaguchi Kengo
Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Yamazaki, Noda, Chiba, Japan.
Plant Mol Biol. 2006 May;61(1-2):227-40. doi: 10.1007/s11103-006-6408-z.
The human UV-damaged DNA binding protein (UV-DDB), a heterodimeric protein composed of 127 kDa (UV-DDB1) and 48 kDa (UV-DDB2) subunits, has been shown to be involved in DNA repair. To elucidate the in vivo function of plant UV-DDB2, we have analyzed T-DNA insertion mutants of the Arabidopsis thaliana UV-DDB2 subunit (atuv-ddb2 mutants) and AtUV-DDB2 RNAi silenced plants (atuv-ddb2 silenced plants). atuv-ddb2 mutants and atuv-ddb2 silenced plants were both viable, suggesting that AtUV-DDB2 is not essential for survival. Interestingly, both plant types showed a dwarf phenotype, implying impaired growth of the meristem. To the best of our knowledge, this is the first occasion that a dwarf phenotype has been found to be associated with a UV-DDB2 mutation in either plants or animals. The mutants also demonstrated increased sensitivity to UV irradiation, methyl methanesulfonate and hydrogen peroxide treatment, indicating that AtUV-DDB2 is also involved in DNA repair. Our results lead us to suggest that not only does AtUV-DDB2 function in DNA repair, it also has a direct or indirect influence on cell proliferation in the plant meristem.
人类紫外线损伤DNA结合蛋白（UV-DDB）是一种由127 kDa（UV-DDB1）和48 kDa（UV-DDB2）亚基组成的异源二聚体蛋白，已被证明参与DNA修复。为了阐明植物UV-DDB2的体内功能，我们分析了拟南芥UV-DDB2亚基的T-DNA插入突变体（atuv-ddb2突变体）和AtUV-DDB2 RNA干扰沉默植株（atuv-ddb2沉默植株）。atuv-ddb2突变体和atuv-ddb2沉默植株均能存活，这表明AtUV-DDB2对生存并非必不可少。有趣的是，这两种植株均表现出矮化表型，这意味着分生组织的生长受损。据我们所知，这是首次发现矮化表型与植物或动物中的UV-DDB2突变有关。这些突变体还表现出对紫外线照射、甲磺酸甲酯和过氧化氢处理的敏感性增加，表明AtUV-DDB2也参与DNA修复。我们的结果表明，AtUV-DDB2不仅在DNA修复中发挥作用，还对植物分生组织中的细胞增殖有直接或间接影响。
