Institut de Biologie des Plantes, CNRS UMR8618, Bâtiment 630, Université Paris Sud 11, 91405 Orsay Cedex, France.
DNA Repair (Amst). 2010 May 4;9(5):567-78. doi: 10.1016/j.dnarep.2010.02.009. Epub 2010 Mar 12.
The SOS screen, as originally described by Perkins et al. (1999) [7], was setup with the aim of identifying Arabidopsis functions that might potentially be involved in the DNA metabolism. Such functions, when expressed in bacteria, are prone to disturb replication and thus trigger the SOS response. Consistently, expression of AtRAD51 and AtDMC1 induced the SOS response in bacteria, even affecting E. coli viability. 100 SOS-inducing cDNAs were isolated from a cDNA library constructed from an Arabidopsis cell suspension that was found to highly express meiotic genes. A large proportion of these SOS(+) candidates are clearly related to the DNA metabolism, others could be involved in the RNA metabolism, while the remaining cDNAs encode either totally unknown proteins or proteins that were considered as irrelevant. Seven SOS(+) candidate genes are induced following gamma irradiation. The in planta function of several of the SOS-inducing clones was investigated using T-DNA insertional mutants or RNA interference. Only one SOS(+) candidate, among those examined, exhibited a defined phenotype: silenced plants for DUT1 were sensitive to 5-fluoro-uracil (5FU), as is the case of the leaky dut-1 mutant in E. coli that are affected in dUTPase activity. dUTPase is essential to prevent uracil incorporation in the course of DNA replication.
最初由 Perkins 等人描述的 SOS 筛选（1999 年）[7]，旨在鉴定可能参与 DNA 代谢的拟南芥功能。当这些功能在细菌中表达时，它们容易扰乱复制，从而引发 SOS 反应。一致地，AtRAD51 和 AtDMC1 的表达在细菌中诱导了 SOS 反应，甚至影响了大肠杆菌的活力。从拟南芥细胞悬浮液构建的 cDNA 文库中分离出 100 个诱导 SOS 的 cDNA，该细胞悬浮液高度表达减数分裂基因。这些 SOS(+)候选物中的很大一部分显然与 DNA 代谢有关，其他候选物可能参与 RNA 代谢，而其余的 cDNA 编码完全未知的蛋白质或被认为不相关的蛋白质。七种 SOS(+)候选基因在γ射线照射后被诱导。使用 T-DNA 插入突变体或 RNA 干扰研究了几个诱导 SOS 的克隆在植物体内的功能。在所检查的 SOS(+)候选物中，只有一个表现出明确的表型：沉默 DUT1 的植物对 5-氟尿嘧啶（5FU）敏感，正如在大肠杆菌中漏型 dut-1 突变体的情况一样，它们在 dUTP 酶活性中受到影响。dUTP 酶对于防止尿嘧啶在 DNA 复制过程中掺入是必不可少的。
